PDA

View Full Version : Engine meltdown disaster


Valentine One Radar Detector

DonTom
08-11-2007, 05:47 AM
Here, I am going to explain all the problems, from the very beginning we had with the RV, in the order they came, during our trip half way across the country.

Before we got out of Reno, the oil pressure gauge stopped working. I figured that was not worth worrying about for now. The gauge was acting like the wire came loose from the sensor.

When in Yellowstone, we stopped at a store at a place that was level and I decided to check the tranny fluid. It was a quart low, so I added a quart. As I was filling it, a cup or so of it dripped to the ground just as if there is a hole in the tranny filler tube. I know that this could be the case, because I once had a small hole in a tranny dipstick tube in another GM van which leaked the tranny fluid right on the the drive belts from such a small hole. I have no clue how or why this hole develops. Anyway, the RV only drips the tranny fluid as I fill it, not when I drive it, It didn't lose a drop of tranny fluid after I added the quart in Yellowstone.

Besides it eating a quart of engine oil per day at high sustained speeds, these were the only problems on the way to Dodge. All very minor problems.

Then, about five miles west of Dodge, the very start of the return trip, while Tom was driving, the engine died. About as far from home as possible! I checked what I could and noticed the fuel pump had no voltage from the ECM, fuel pump relay not keyed by the ECM. I wiggled a few wires and heard the fuel pump come on and drove another 20 minutes and the engine died again. After this happening three of four times after many hours, I changed the ECM (I carry a lot of spare parts). By now, it is later and a little cooler and the RV ran perfect for many more hours until we stopped for the night.

The next day, with the ECM changed, the RV ran fine until about 1600 hrs, when it was again over 100 F outside. Then the engine died again and I changed the ECM to the first one and went on for about a half an hour and the engine died again. By this time, I figured out that the ECM was getting too warm and that was really causing the problem. The ECM is mounted in front of the right door inside the cab right next to a vent hat I can open and close. But it gets too warm there for the ECM with the vent open or closed. It was just a coincidence that the fuel pump came on as I wiggled some wires the first time.

Tom (who knows nothing about electronics ) came up with an idea that I would not have thought of. He said remove the 12 VDC van that we keep on for the doggies when we park in the heat and use it to help cool the area where the ECM is. That worked to keep the ECM cooler so it would no longer fail.

BTW, during all this, I was wondering if technophobic Eric is correct, Carbs have no ECM to overheat!

BTW, I think I heard somewhere that there is a much more expensive ECM that can take a lot more heat and can even be mounted in the engine compartment. Seems that's what I am going to need to fix this problem of the ECM failing at very high temps. The only cooler place I could move it to would be to block the A/C.

Tom's fan trick worked for the rest of the trip and no more ECM failures.

Now, the BIG problem:

About six miles east of Wendover, NV (on the state line between Utah and NV on I-80), while Tom was driving (late night), it SEEMED like we had a blow out on one of our new tires. The vehicle shook all over the lane. We were doing about 70 MPH, slightly downhill, when this happened at around 0100 hrs on Friday. When we got out and checked the tires, all looked fine. I knew this was bad news!

We tried to start the engine. The engine is FROZEN. Only straining the starter by trying to start. We used a cellphone and called AAA to be towed to Wendover, NV. We're there by 0300 hrs or so. We find all the hotels in Wendover are booked because of races in the Bonneville slat flats. We stayed in the lot overnight (that we were towed to) and slept in the RV overnight. This was next to Brad's Automotive Repair in Wendover. Seemed we had a lot of problems. In Wendover, there was no kennels for the doggies. No way we could think of to get home. We're stuck 420 miles from home.

In the end, the next day, we made contact with the same tow truck driver and I made a deal with him. He would tow me 100 miles free on my AAA Plus card. And to be towed the other 320 miles to Reno, I pay him a thousand dollars. He drops off the RV at Bob's Auto and Truck repair in Reno (the same place the engine was replaced last time) and from there, drove us home.

Now, I have some questions.

What's the most likely problem with the engine (I have a guess, but I want to hear the guess from others, before I give my guess)?

If it needs a new engine do I junk this RV with the new $1,300 A/C and new thousand dollars worth of less than one week old new tires tires?

One thing I have decided on is that I will NOT have another 400 CID small block rebuilt engine. Most of the miles this blown engine has on it is from this trip. This 400 CID rebuilt crapped out in about 8,000 miles. Barely broken in!

-Don-

Eric
08-11-2007, 08:35 AM
Hey Don,

First - very sorry to hear your trip went sour this way. I won't say a thing about the ECM, either (will save that for later!)

Based on what you wrote - and the fact that you have a 400 V-8 - here is what I would guess happened:

The high heat/load led to a head gasket failure (common with these siamesed-bore 400s), coolant got into the engine and it experienced hydraulic lock in one or more cylinders.

You also mentioned the oil gauge reading erratically - so it's also a good guess that this "new" engine" had a defective oil pump - or that it simply used enough oil (a quart per day struck me as way excessive, incidentally) so that it ran low enough to cause you serious trouble.

Let us know what it turns out to be... .

And as far as the replacement issue:

I agree with you on NOT using another 400. I know some people have used these engines without problems, but there's a reason why GM discontinued this particular small block after just a few short years of production.

I would, if I were in your place, find a low-miles GM Vortec (5.4) V-8 or similar from a junkyard and remove all the EFI crap and swap on a conventional dual-plane four-barrel intake and HEI ignition. These are very strong/durable engines and when converted to a carb, simple as hell, too.

GM also sells "Targetmaster" 350s (brand new) over the counter for about $1,500 (with a warranty) last time I checked. This is a complete long-block engine. Just add inatke/ignition and accessories....

mrblanche
08-11-2007, 11:22 AM
It wasn't hydraulic lock, at least not initially, since it happened at speed. But a blown head gasket is not an impossibility. If so, it squirted enough water into one or two cylinders to kill them, then locked it after it stopped. But my guess would be a broken rod or rod end. It broke, stuffing the piston to the top of the bore until they stopped, causing the crank to be severely unbalanced. After they stopped, the piston fell back down, and the rod blocked the crank from turning any more.

The first and easiest fix would be to buy a good new crate 350 and put everything from the 400 on it. I think everything fits, but I'll see a 400 expert this afternoon. As Eric says, the engine would cost you less than $2000, and the labor would come close to that, maybe less. You wouldn't lose much power, and you'd gain a lot of dependability. My advice would be to go for a 350 designated for truck use; the main difference would be four-bolt mains, rather than 2. Again, I think all the electronics, exhaust, etc. would bolt right up.

And believe me, for less than $5,000, you won't get another RV worth having.

Eric
08-11-2007, 01:04 PM
It wasn't hydraulic lock, at least not initially, since it happened at speed. But a blown head gasket is not an impossibility. If so, it squirted enough water into one or two cylinders to kill them, then locked it after it stopped. But my guess would be a broken rod or rod end. It broke, stuffing the piston to the top of the bore until they stopped, causing the crank to be severely unbalanced. After they stopped, the piston fell back down, and the rod blocked the crank from turning any more.

The first and easiest fix would be to buy a good new crate 350 and put everything from the 400 on it. I think everything fits, but I'll see a 400 expert this afternoon. As Eric says, the engine would cost you less than $2000, and the labor would come close to that, maybe less. You wouldn't lose much power, and you'd gain a lot of dependability. My advice would be to go for a 350 designated for truck use; the main difference would be four-bolt mains, rather than 2. Again, I think all the electronics, exhaust, etc. would bolt right up.

And believe me, for less than $5,000, you won't get another RV worth having.


Amen to all of that; and esp. what Mike says about the four-bolt "truck" blocks. Another option to consider is a big block (396/402/454). These engines will cost you more than a small block, but you'll get the horsepower and toughness you need....

mrblanche
08-11-2007, 01:22 PM
I believe Don said he didn't have room for a big-block already. And they are significantly more expensive.

Eric
08-11-2007, 02:39 PM
I believe Don said he didn't have room for a big-block already. And they are significantly more expensive.


I wonder whether it's a question of swapping motor mounts (easy to do, as you know) or having to cut/beat the firewall, etc. to make it fit (too much hassle)...?

I agree the big blocks are more expensive; then again, how much has Don already spent on the blown small block?

I don't know RVs well - but I'm assuming Don's weighs at least twice what a typical ful-size SUV weighs. Asking a small block to lug that kindof a load around seems like it's asking a lot!

DonTom
08-11-2007, 03:28 PM
"But my guess would be a broken rod or rod end."

That's my guess too, mainly because when this happened, the engine unbalance felt just like a blown out tire. I have had this happen before in the same vehicle. Also, it seems to me that rods usually break when driving down hill as was the case then.

I am sure that the oil pressure gauge problem is unrelated to anything serious. I know how these gauges act when they are disconnected from the sensor and that's how this one is acting. It's not acting like low oil pressure. In fact, it reads way too high, not low, which is what happens when the wire is removed from the oil pressure sensor.

No room for a big block (the small block barely fits as it is, making it very difficult to get the spark plugs out, etc.). Also, the exhaust system would have to be changed and my EFI won't fit.

I agree with the new 350. I will not put in a rebuilt or another 400 CID. I do believe everything will fit, but I should get a new chip for the ECM, but I assume the prom chip for a 400 will work in a 350, just won't be perfect. I can find a way to deal with the ECM heat problem. If I have to go back to a carb, I will also junk the vehicle (hear that, Eric!).

BTW, when a rod breaks, does it always mean a new engine is needed? And are rods less likely to break in a 350 than in a 400 CID?

BTW, it was after midnight, downhill and fairly cool when this happened. Does NOT seem to be related to an overheating problem and the coolant temp gauge was only a third up.

One thing nice about all this is that the more serious problems were on the way home so it didn't spoil most of the trip. OTOH, our trip to China was cheaper!

I should know for sure what's wrong with the engine by Monday or Tuesday. A small chance even for today (Saturday). They normally are not open on Saturdays, but this week is an exception.

BTW, Tom and I decided to never take a vacation in August again, Too many things going on, such as Sturgis, the races in Wendnover and even "Hot August Nights" here in Reno, causing crowds just about everywhere. Here in Reno, "Hot August Nights" is when Reno fills up with people showing off their very old classic cars.

http://renotahoe.about.com/cs/artsentertainment/a/HotAugustNights.htm

-Don-

DonTom
08-11-2007, 03:44 PM
"but I'm assuming Don's weighs at least twice what a typical ful-size SUV weighs."

I have weight my RV at a truck stop. It's total weight is about 11,100 lbs, with all tanks about half full.

Rear axle weight is 7,520 lbs.

Front axle weight is 3,580 lbs.

BTW, in SD, even my RV has to go to the truck weight stations. At least true on I-90 and we did such. The sign says "all vehicles over 6,000 lbs MUST stop at weight station".

In all other states I have been to, it says all commercial trucks or whatever.

-Don-

MikeHalloran
08-11-2007, 04:04 PM
Yeah, go with the new 5.7 truck block, and break it in gently ... at least 600 miles before you even get on a freeway.

DonTom
08-11-2007, 04:10 PM
"or that it simply used enough oil (a quart per day struck me as way excessive, incidentally) so that it ran low enough to cause you serious trouble."

I forgot to mention something about this. Right after the engine broke down, I did check the oil and it showed no oil on the dipstick. I then added oil just to see how low it really was. Two quarts filled it up to a little above the "full" line, showing tha I was less than two quarts low from "full", or less than one quart below the "min" line. This means three quarts in the engine. That's not low enough to cause any problem, is it? Besides, I assume the break down made the oil level look lower on the dipstick somehow, because it has never used up that much oil even after almost 20 hours of high speed driving.

BTW, the day before we did not have to add any oil, it only went down a drop. We were driving a little slower that day as there were no more 75 MPH speed limits. There were only two days we did not have to add oil, the day when we went 45 MPH all day (not a drop of oil used) and the day before the engine blew up (just used up a cup of oil or so). The high speeds (4,000 RPM's at about 80 MPH for more than 12 hours per day) all day was eating up the oil. However, I agree that a quart per day still seems excessive even at those speeds.

-Don-

mrblanche
08-11-2007, 05:10 PM
Using a quart of oil per 500 miles is within the "normal" range, especially in as heavy a vehicle as that. Just for curiosity...how was the water level after this incident?

I've checked with my hot-rod friends, and so far they've said that the 350 might have a little less torque, but you can get a version that would actually have more. Also, be sure to get an engine with the harmonic balancer, flex plate, and starter, since those items are different in most cases (the 400 is externally balanced, and the 350 is internally balanced). Also be sure that you get the water pump with the same direction of rotation as the current pump. That means if you have serpentine belt (not likely), be sure you get the same kind of setup.

It's possible you didn't beat the living daylights out of the engine with a broken rod, but I wouldn't bet that way.

misterdecibel
08-11-2007, 05:52 PM
I agree with the assessment of a thrown rod, or other major bottom-end engine failure. Maybe a turned bearing.

As for why it went at a time when it wasn't hot or heavily stressed, well engine damage is cumulative.

If the engine only had 8000 miles on it, wasn't there any sort of warranty from whoever built it?

DonTom
08-11-2007, 06:48 PM
"Using a quart of oil per 500 miles is within the "normal" range, especially in as heavy a vehicle as that. Just for curiosity...how was the water level after this incident?"

We were doing well more than 500 miles per day at around 80 MPH, which is a lot of RPM's in this thing (4,000). I wasn't sure if that was normal or not, but I thought there was a chance that it might be when it ate up no oil at all driving at 45 mph all day through the parks.

"As for why it went at a time when it wasn't hot or heavily stressed, well engine damage is cumulative."

I have experienced three broken rods, always in a RV or large van. In every case, it was when it was cool and going down hill. My theory is that going down hill is pushing more outward on the rods and after climbing many hills the rods break as the attempt to stretch out while going down hill.
Think about the piston as it's pushing the rod down. Then it's hard to break. But going down hill, the rod is pushing our from the piston, which is when it's most likely to break. However, it's probably made weak by going up hill, but won't break until going down.

The question I have is a rod more likely to break in a thin wall 400 than in a thicker wall 350? I can understand the head gasket problem, but does the thickness of the cylinder walls have an effect on the rods breaking? I wouldn't think so. I tend to believe that the rebuilt engine didn't have new rods and that perhaps that was the problem more than it being a 400 small block. If I am wrong, I hope somebody here will correct me.

If I cannot get a decent and NEW engine put in this thing, it will be junked with the thousand bucks worth of new tires & etc.

I lean toward junking it and buying a much newer RV with a better, larger engine. I might even consider a diesel, the only problem is I don't know a thing about diesel engines, not even the basics as I never owned one. But I guess I can start learning about them.

"If the engine only had 8000 miles on it, wasn't there any sort of warranty from whoever built it?"


They only give short warranties on truck/RV engines. Usually a few months or a few thousand miles, whichever comes first. I am a little over on both. I hear I cannot even get any warranty if I don't put back in the same engine the vehicle came with. However, that's out of the question, I would rather take my chances without a warranty than putting in another rebuilt 400 CID.

-Don-

DonTom
08-12-2007, 03:11 AM
Today, I heard from Bob at Bob's Auto & truck repair. He said he could see damage near the oil pan, so a rod must be jammed up. Well, later, but after Bob left, I went down there to see for myself. The only damage I saw under the RV was a dent in the TH400 TRANNY oil pan. But that was there before the engine blew out. This makes me think Bob didn't take a very good look. I stayed under the RV for several minutes with a flashlight, I did not see any damage anywhere that wasn't there before the start of this last trip and the engine oil pan looked fine to me.

The tranny oil pan looks like it got damaged by a large rock or something. It does not leak, so I don't worry about it. Besides, that happened so many years ago I forgot about what even caused it.

Perhaps Bob noticed something I didn't, but I kinda doubt it. Or perhaps he knows what to look for that I don't. But the entire engine oil pan looked as good as new to me.

But at this point, I have made a decision anyway, to junk the RV, regardless. I figure it will be at least a year or two before we go on another RV trip to anywhere. We will buy another much newer RV then, before we want to go on the next trip.

Today, we started to remove stuff from the RV, such as the backup camera, GPS antenna, power inverter, DC converter and such stuff that I would normally keep in the RV if I were going to just have it repaired. Of course, it's still not too late for me to change my mind, but the more we thought about it, it's a good time to junk the thing and buy a much more expensive RV later, before the next trip we take, which may not be for quite a while anyway.

But we quite firmly decided to junk this thing, with the new $1,300.00 A/C and thousand bucks worth of one week old tires.

At least the break downs all happened on the way home, so our trip wasn't spoiled by any of this. We saw all the places we wanted to see from here to half way across the country.

We will be looking for deals for decent RV a bit later. But I would like to get some advice on a good engine to look for. And should I be looking for a diesel?

-Don-

Eric
08-12-2007, 09:13 AM
"We were doing well more than 500 miles per day at around 80 MPH, which is a lot of RPM's in this thing (4,000). I wasn't sure if that was normal or not, but I thought there was a chance that it might be when it ate up no oil at all driving at 45 mph all day through the parks."

Now I know why the engine failed. Running that 400 at a steady 4,000 RPM for extended periods likely stressed it beyond endurance. The redline of this engine is probably only slightly higher than 4,000 RPM. Ideally, you want "cruise" RPM to be closer to 2,200-2,500 RPM. The stock rods were not designed for the kind of abuse you subjected them to!

PS - If you want to save your warranty coverage (if any) do not tell them about running that puppy at 4,000 rpm for hours on end!

mrblanche
08-12-2007, 11:48 AM
Yeah, that was exactly my thought when I saw it!

A diesel engine would be great, but you need to be prepared for some of the oddities, including problems with letting it sit. But you'll get a lot more easy work out of it than any gas engine.

However...it seems to me that the for the price of an RV, you could stay in a pretty nice motel every night.

I wish I was closer...I'd take it off your hands!

In fact, you could probably e-bay it for the price of your A/C and tires.

DonTom
08-12-2007, 01:36 PM
"Ideally, you want "cruise" RPM to be closer to 2,200-2,500 RPM."

That would be very slow in this RV. It's geared very low. If 80 MPH is @ 4K RPM, then 2,200 RPM would be 44 MPH, which would be rather slow where the speed limit is 75 MPH.

But we also climbed several mountains in Colorado to above 11,000 feet, which was not easy on that engine.

I am not sure, but I think the red line is about 5,000 RPM.

-Don-

DonTom
08-12-2007, 01:45 PM
"Just for curiosity...how was the water level after this incident?"

I think I forgot to answer that. I did check, there was no change. It used no coolant during this trip, not even after the meltdown. It does have a coolant recovery tank.

There's no evidence of coolant getting into the engine.
-Don-

DonTom
08-12-2007, 02:03 PM
"Yeah, that was exactly my thought when I saw it!"

What are you referring to?

"but you need to be prepared for some of the oddities, including problems with letting it sit. "

What happens to diesels when they are left sitting? And would it help much by simply starting the engine once in a while?

"However...it seems to me that the for the price of an RV, you could stay in a pretty nice motel every night."

Hotels are often a hassle to find when traveling with a couple of doggies, but if not too hot, they could be left in the car. We sometimes stay in the RV over night far from any hotels. The RV is NOT to save money, but for the convenience. It's much like bringing a home with the refrigerator, stove, bathroom all that can be used at any time. Also, we often drive until very late hours, when motels that are NOT full, turn on their "no vacancy" signs because they don't want to be bothered. We often stay the night at rest stops right on the freeways.

-Don-

Eric
08-12-2007, 03:56 PM
"Ideally, you want "cruise" RPM to be closer to 2,200-2,500 RPM."

That would be very slow in this RV. It's geared very low. If 80 MPH is @ 4K RPM, then 2,200 RPM would be 44 MPH, which would be rather slow where the speed limit is 75 MPH.

But we also climbed several mountains in Colorado to above 11,000 feet, which was not easy on that engine.

I am not sure, but I think the red line is about 5,000 RPM.

-Don-




I understand - slow sucks - but 4,000 rpm continuously was (and is) excessive strain. It's actually impressive it held together as long as it did...

I forget whether the RV had an overdrive transmission; sounds like it did not.

mrblanche
08-12-2007, 06:41 PM
That RV was severely in need of an overdrive, truck-grade automatic transmission.

Diesel suppliers have a high turnover, so the fuel sold on any given day is usually formulated for the current weather. Diesel sold at 32 degrees is not the same as diesel sold at 100 degrees. Usually that's not a problem, but it's important to know it.

Also, diesel is prone to algae formation if it sits at high temps and humidity for a period of time. This can be fought with additives, and I've never had the problem.

If you buy a diesel RV, don't buy one from 2007 up. To many emissions controls.

chiph
08-12-2007, 07:33 PM
The tranny oil pan looks like it got damaged by a large rock or something. It does not leak, so I don't worry about it. Besides, that happened so many years ago I forgot about what even caused it.



If the damage to the oil pan had been caused by a thrown rod, the dent would have been an "outie" not an "innie"

It still may have thrown a rod (just not damaged the oil pan). Or spun a bearing, or broken the crankshaft, or any number of expensive items.

The eBay option is a good one. Someone who has a spare 4-bolt main 350ci motor is probably out there looking for something to put it in.

Chip H.

DonTom
08-12-2007, 08:59 PM
"but 4,000 rpm continuously was (and is) excessive strain. It's actually impressive it held together as long as it did..."

If that's the case, they designed a RV that should not ever be driven on today's freeways. And if it did have an overdrive, that would probably strain the engine even more. They geared it low for a reason and I doubt the reason is that GM wanted it to blow out on the freeway.

But I just remembered something. In 1979, the national speed limit was 55 MPH. So perhaps the RV was designed for 55 MPH.

"I forget whether the RV had an overdrive transmission; sounds like it did not. "

The TH400 does not have an OD.

My next RV will have a more reliable engine, perhaps a large diesel in a small RV (25 feet long or so). But I won't even be looking for a while.

-Don-

DonTom
08-12-2007, 09:06 PM
"The eBay option is a good one. "

Could be, but I would rather just junk it and get it over with.

-Don-

mrblanche
08-12-2007, 09:23 PM
"The eBay option is a good one. "

Could be, but I would rather just junk it and get it over with.

-Don-


In the real estate business, we called that a "don't wanter." The biggest bargain you can ever get.

My boss called it "Getting up from the game and leaving your money on the table."

chiph
08-12-2007, 09:27 PM
"The eBay option is a good one. "

Could be, but I would rather just junk it and get it over with.

-Don-


List it, and give it a couple of weeks to sell. You'll still have the option to junk it afterwards, and you might actually find a buyer.

Chip H.

DonTom
08-12-2007, 09:31 PM
I would like to know opinions here on the type of engine I should be looking for in my next RV. I want something large and reliable, even if it sucks gas (or diesel).

And I will make sure that it does have an OD tranny. I think all the newer ones do anyway, and larger RV get better MPG than my old smaller one. I hear they are a bit lighter too, yet can carry more weight.

-Don-

DonTom
08-13-2007, 01:07 AM
Mike,

The tow truck that towed my RV was a diesel. It was so quiet that I thought it was a gasoline engine, so I asked. I expect tow trucks to be diesel, as all I have been towed with so far have been. It was a year old, had more than 100,000 miles on it and had no problem towing my 11,100 lbs RV up several hills (drive line disconnected, of course) . I asked what type of engine it has and it was a name I never heard before, so I assume it's a company that only makes diesels.

But I don't know a thing about diesels and this one had a minor problem where, usually after a stop, he had to get out and lift the hood and pump some thingie a few times so it would run correctly. I asked him what it was about, and I didn't understand his answer and just let the subject drop. Do you have any idea what that thingie could have been?

-Don-

DonTom
08-13-2007, 01:43 AM
"My boss called it "Getting up from the game and leaving your money on the table."

Yep, but I don't care. I don't like to bother to sell vehicles, I just drive them until they are junk.

I think from now on, if a vehicle is more than ten years old, I will junk it at the first major problem.

I have made this mistake before. More so on this RV than any other vehicle. I feel sorry for the poor sucker that ends up with it!

I have decided that the money it will take to fix this thing could be better spent on a newer RV that has a better and more powerful engine, OD, and all the safety features (my 1979 doesn't even have a shoulder strap for the seatbelt). And our next RV will be a small class A, not a Class C. A class C is really a one ton van, junk added to make it a RV. A Class A is designed to be a RV from the ground up. A class B is a van conversion. My 1979 RV was a Class C, one ton van, where the weight was above the GVWR the day it was sold (no longer legal to do such).

Or, as some say, in a Class A, none of it is made in Detroit. In a Class B, all of it is made in Detroit. In a Class C, half of it is made in Detroit.

When we do buy another RV, we will spend some bucks from the start, but it most likely will NOT be a new one. I would only consider a new one if we were to live in it full time and then it would be much larger too. But we plan on always owning these two houses, so there's no need for a large new RV.

Anyway, no hurry as it will be a while before we desire to go on another RV trip.

-Don- (Reno)

mrblanche
08-13-2007, 08:37 AM
What make of vehicle was the tow truck? He may have used the term Powerstroke?

DonTom
08-13-2007, 08:41 AM
"What make of vehicle was the tow truck? "

I don't know. I never looked at it that close.

"He may have used the term Powerstroke?"

That could have been it, but I am not sure.

-Don-

mrblanche
08-13-2007, 08:58 AM
"Powerstroke" is the Ford engine, which is actually made by International Harvester.

"Duramax" is the the GM brand, made by AM General, I believe.

Dodges use a Cummins engine.

DonTom
08-13-2007, 03:26 PM
" "Duramax" is the the GM brand, made by AM General, I believe."

That was it! It was a Duramax. I never heard the name before. It seemed very quiet for a diesel. He said it was less than a year old and had more than 100,000 miles on it.

Have any idea what hat thingie was he had to pump? It had something to do with the fuel. He said it was a minor problem that he never go around to fixing.

I just talked to Bob at Bob's Auto & Truck Repair. I told him he could keep the RV and they will, as long as I can get him the title. I told him it's at the other house, but I will either mail it to him or bring it here the next time I come to this house in Reno.

-Don-

mrblanche
08-13-2007, 05:31 PM
I'm guessing it's a priming pump, and it means he has some sort of a leak in the plumbing somewhere, maybe a checkvalve letting fuel flow back to the tank.

DonTom
08-14-2007, 04:56 AM
"Ideally, you want "cruise" RPM to be closer to 2,200-2,500 RPM."

Do you believe we should cruise in all engines at less than 50% of red line, or is the 400 CID a special l case?

BTW, I have blown three rods in three different engines. Now, two times in the RV.

Things in common:

1. All three engines were GM small blocks (two 400 CIDS in the RV and one 305 CID in a 3/4 ton 1984 van conversion).

2. In every case, a rod broke while going down hill, after climbing up a lot of hills.

3. All three engines were rebuilds.

BTW, the 1984 Van ran at very LOW RPM's. It had the same TH400 tranny as the RV, but the rear axle or whatever was geared a lot higher and less than 2,000 RPM's would be freeway speeds.

I have to wonder if the high RPM's had little or nothing to do with my rod breaking on this trip.

And while I realize the 400 CID is unreliable, isn't it because of blown head gaskets only? I have not had a blown head gasket in ANY vehicle I have driven.

Is there any reason for me to believe that a rod would be less likely to break in a 350 than in a 400?

BTW, do large block engines use different rods?

Are rods less likely to break in large block gasoline engines and diesel engines?

-Don-

Eric
08-14-2007, 07:10 AM
"Do you believe we should cruise in all engines at less than 50% of red line, or is the 400 CID a special l case?"

For an old-design V-8 like the Chevy 400 (with a long stroke and not an especially tough bottom end or rods and prone to overheating), steady-state operation at 4,000 is abusive; I installed an OD transmission in my Trans-Am to keep the revs down in my 455 for just this reason. A 327 or 350 (shorter stroke relative to bore) would handle high RPM loads better, but even that engine would likely have an abbreviated life if operated continuously at 4,000 RPM.

"Is there any reason for me to believe that a rod would be less likely to break in a 350 than in a 400?"

Not all rods (or bottom ends) are created equal. Some "rebuilds" use junk rods that are marginal at best. The 350 is aninherently better (stronger by design) engine than the 400, but a 350 with "junk" rods won't stand up to HD service much better than a 400 with "junk" rods. If you look through the spec. sheets for 350s used in HD/high-performance/truck applications, you'll discover they typically feature things like four-bolt mains and forged rods, etc. For a standard passenger car, these extras are not usually needed. But for HD service, they are a necessity - if you don't want to replace the engine every 8,000 miles!

"BTW, do large block engines use different rods?"

Different engines use different rods; displacement is a function of stroke and bore, etc. Materials-wise, high-perf. engines (or engines designed to handle HD service) typically have higher-strength (forged vs. cast, etc.) rods than standard-duty rods.

"Are rods less likely to break in large block gasoline engines and diesel engines?"

Many engines have "weak points" - long-stroke engines (like my 455) tend to be more susceptible to rod/bottom end issues if they are operated at excessively high RPM due to the loads experienced. My 455 has stock rods and the block is a standard (non SD/HO) block, so only two-bolt mains. Which is why I do not rev it past 5,400 RPM - and only briefly, as under hard acceleration. Steady-state cruise RPM (thanks to the OD) is under 2,500 RPM.

MikeHalloran
08-14-2007, 08:19 PM
1. All three engines were GM small blocks (two 400 CIDS in the RV and one 305 CID in a 3/4 ton 1984 van conversion).
2. In every case, a rod broke while going down hill, after climbing up a lot of hills.
3. All three engines were rebuilds.


Those rods may have gone up a lot of hills before you got them.

Rods and cranks have a finite life, limited by metal fatigue. There is no way to visually or instrumentally assess the life left in them. Reputable rebuilders discard rods and cranks with detectable cracks, which are clearly in the process of failing. On the rest, they bascially gamble. . Racers discard them after a predetermined number of cycles at a given stress level. Nobody keeps history for individual rods and cranks, so you don't know if your cores wound up in the rebuild pile after 5 pct, or 95 pct, of their life was consumed.

The typical fatigue life curve for steel is hyperbolic. At some low stress level, a steel part will last indefinitely. At a much higher stress level, the life is drastically shortened. In between, you can think of the usable life as being roughly proportional to the product of load and speed and time, e.g. horsepower-hours.

Regardless of the rpm your engines were turning, they were all running at a high _power_ level in order to drag an RV around at speed. The problem is, they may have _already_ dragged around someone else's RV until something else failed, that left them uncracked, but near the end of their life anyway.

In a beater car, where expectations and power levels are low, rebuilds make sense. In an RV, you are much better off with a new engine.

DonTom
08-14-2007, 09:58 PM
"In an RV, you are much better off with a new engine."

And other than with the 400, wouldn't a larger engine be more reliable?

IAC, my next RV will be a small class A with a rather large engine, OT tranny, perhaps a diesel. I won't be looking for a couple of years as we won't desire another RV trip until then anyway. Just as with cars, RV's keep on getting better and better in countless ways, even if technophobic Eric doesn't agree.

-Don-

MikeHalloran
08-15-2007, 01:08 AM
And other than with the 400, wouldn't a larger engine be more reliable?


Yes.

mrblanche
08-15-2007, 07:44 AM
And other than with the 400, wouldn't a larger engine be more reliable?


Yes.



However, a larger engine usually likes a lower RPM range, so putting a big block in and running it at 4,000 rpms all day would kill it as quickly as a small block, and maybe quicker.

The stroker 383, designed for trucks, would be a good choice, along with a truck-grade overdrive transmission and a higher rear-end ratio.

DonTom
08-15-2007, 08:29 AM
"and running it at 4,000 rpms all day would kill it as quickly as a small block, and maybe quicker."

IYO, what would be a safe RPM range to run all day on that 400 in an 11,100 LB RV? And with an OD tranny, would it even go 75- 80 MPH without lugging the engine?

-Don-

DonTom
08-15-2007, 08:33 AM
"In an RV, you are much better off with a new engine."

I know, but I couldn't then get a new 400 and all the new 350's were for light duty.

-Don-

Eric
08-15-2007, 09:01 AM
[quote=DonTom ]
"and running it at 4,000 rpms all day would kill it as quickly as a small block, and maybe quicker."

IYO, what would be a safe RPM range to run all day on that 400 in an 11,100 LB RV? And with an OD tranny, would it even go 75- 80 MPH without lugging the engine?

-Don-



/quote]

Assuming adequate power for the weight of the vehicle, with proper gearing and an OD transmission you should not be seeing more than 3,000 RPM at 75-80 mph. Ideally, under 3,000 and closer to 2,500 RPM at steady-state cruise.

DonTom
08-15-2007, 03:29 PM
"Assuming adequate power for the weight of the vehicle, with proper gearing and an OD transmission you should not be seeing more than 3,000 RPM at 75-80 mph. Ideally, under 3,000 and closer to 2,500 RPM at steady-state cruise."

But that's a lot to assume. I am not so sure if the 400 would have enough power to even get up to 75 MPH below 3,000 RPM's.

I had a rod break in a 3/4 ton van, which had a 305 and ran at very low RPM's. It was rather gutless, but it ran fine on level ground.

I have to wonder if rods break more often in GM small blocks than in any other engine, regardless of RPM's.

But we were tough on that RV engine during that last trip, driving more than 75 MPH for most of the day. But I didn't think 4,000 RPM's was too much. It felt fine at those RPM's until the meltdown.

-Don-

Eric
08-15-2007, 03:45 PM
"But I didn't think 4,000 RPM's was too much. It felt fine at those RPM's until the meltdown."

Continuous operation of any non-HD (heavy duty) or high-performance GM small block from that era ('70s) at 4,000 RPM is almost begging for major problems and an early demise. The stock blocks during that era were not the best; the rods were mediocre. Most of those engines (and rods) had redlines just over 5,000 RPM (if that), so you can imagine the loads you were placing on the internals. Only a few engines of the period (Pontiac SD-455, Chevy L-82 350, etc.) were built to handle higher RPM and sustained high speeds/loads. These engines had tougher blocks (better material; reinforced areas, etc.) as well as HD rods designed to handle abuse.

Newer Chevy V-8s (Vortec and LT-1/LS series) are probably much tougher.

But even so, I personally would not run one at 4,000 continuously and expect it to live long.

With a modern OD transmission, though, this ought not to be an issue. I drive new vehicles of all kinds and none of the V-8 powered ones has a cruise (70-75 MPH) RPM much over 2,500 RPM (if that; usually, it's lower).

Even my Trans-Am (a heavy car with an aggressive 3.90 rear axle) lopes along at just over 2,000 RPM in OD at 70 mph...

DonTom
08-15-2007, 06:14 PM
"I drive new vehicles of all kinds and none of the V-8 powered ones has a cruise (70-75 MPH) RPM much over 2,500 RPM (if that; usually, it's lower)."

Even those that weight in at above 11,000 lbs? BTW, I hear the newer RVs are lighter at the same size. I think there might be more to it than just the high RPM's, since I had a rod break in my 1984 Chevy 3/4 ton van too, which ran at very low RPM's.

But I guess it's no longer an issue, as I will most likely never have a GM engine from that era again--at least not in a RV.

We usually get a lot of miles out of of our vehicles, such as tha Oldsmobile V-6 that almost made it to 400,000 miles before the first engine problem. That's the only engine I have driven long enough to experience low oil pressure (at around 385.000 miles). That's when we junked it. We have had the worse luck with the GM V-8 small blocks. Those are the only engines we've blown rods in.

-Don-

misterdecibel
08-15-2007, 07:14 PM
Gotta say, doing 80 MPH all day in an RV was begging for trouble. Especially in the summer.

DonTom
08-16-2007, 12:20 AM
"Gotta say, doing 80 MPH all day in an RV was begging for trouble. Especially in the summer."

Well, I should have realized we were overdoing it when it was eating a quart per day above 75 MPH, but almost no oil when we had to go lower speeds. No doubt we were very tough on the engine during that trip. We climbed many mountains to above 11,000 feet. I didn't know that there were so many freeways and highways in Colorado that went to that elevation -- no matter which way you cross the state. We also didn't know so many states had a 75 MPH interstate freeway speed limit, even the Eastern part of this state (NV).

And it was over 100F for most of that trip, 107 in Dodge, KS was the high. But the coolant temperature never got more than half way up the scale. There was no sign of overheating at anytime during the trip ( other than the ECM problem I mentioned in the fist message in this thread, which is in the cab). It has a very large radiator.

-Don-

DonTom
08-16-2007, 12:23 AM
"Gotta say, doing 80 MPH all day in an RV was begging for trouble. Especially in the summer."

I forgot to mention that we had a couple of larger, newer RV pass us, one that was towing a car, when we were doing above 75 MPH.

-Don-

Eric
08-16-2007, 08:16 AM
"Even those that weight in at above 11,000 lbs? "


Well, not quite that heavy - but close to it. For example, I recently had a huge GMC Sierra 2500 Quad Cab 4x4 truck; had to weigh at least 6,000 pounds,if not more. And like most any modern vehicle with an OD transmission, at 70-75 its engine was turning not much faster than a fast idle.

mrblanche
08-16-2007, 10:47 AM
I have towed my T to our national meet the last 3 years. In my Ford F150 (4.6 litre, towing package), I cruise on the highway at somewhere around 2,000 (that's at a legal speed). On a hill, first the converter clutch unlocks (+200 rpm), then it downshifts to third, then on a hard pull, even down to 2nd. That's 4500 rpm at 60 mph! It sounds bad, but it doesn't seem to do any damage.

So, Don ran his RV at what was essentilly a low gear in most modern vehicles.

DonTom
08-16-2007, 04:00 PM
"So, Don ran his RV at what was essentilly a low gear in most modern vehicles."

I assumed it was geared so low because of its weight. But it might also be because of the 55 MPH speed limit when that thing was built. So we were going all day and half the night at 20 MPH faster than it was designed for. The speedometer pins at 80 MPH, but I checked the true speed on my GPS. We were averaging close to 80, which is the speed of most of the other traffic where the speed limit is 75 MPH. The higher speed limits is what blew out my engine! We never would have went that fast if the speed limit was still 55 MPH! Does this mean we can blame Gail for raising the speed limits? ;D

-Don-

misterdecibel
08-16-2007, 09:26 PM
So did I understand correctly that you just gave the hulk to your mechanic?

Will a proper post-mortem be done, or is there even any point in tearing down a seized engine that will just be replaced by another whole engine anyway?

DonTom
08-16-2007, 10:11 PM
"So did I understand correctly that you just gave the hulk to your mechanic?"

Yep.

"Will a proper post-mortem be done, or is there even any point in tearing down a seized engine that will just be replaced by another whole engine anyway?"

I have no idea what he will do with it. He does sell used vehicles too, so he might fix it up for the next poor sucker.

In the next two years or so, we will be deciding what type of RV to buy. Only things for sure at this point is that it will be a Class A, less than 25 feet long, and later than year 2000.

Is that smog junk they put in diesels after 2007 sort of like what they did with the early 1980 vehicles? IOW, they just added the junk on vehicles that really were not designed for it, and caused more problems than anything else. My 1984 GM van 3/4 ton van had so many hoses that it was difficult to find the engine under them!

-Don-

MikeHalloran
08-16-2007, 11:01 PM
The Diesel emissions junk is in about the same state that gasoline emission control was in, in about 1972.

No, make that worse; you have to add urea regularly.

And no, you can't just piss in the urea tank ... but you'll want to.

misterdecibel
08-17-2007, 03:38 AM
What does "Class A" mean?

DonTom
08-17-2007, 06:53 AM
"What does "Class A" mean?"

See message 28 in this thread.

-Don-

DonTom
08-17-2007, 07:01 AM
Does Diesel fuel go bad faster or slower than gasoline? Is it still usable after a year just as gasoline usually is <even if Eric doesn't agree, because he's never used one year old gasoline countless times as I have>?

-Don-

mrblanche
08-17-2007, 02:50 PM
The Diesel emissions junk is in about the same state that gasoline emission control was in, in about 1972.

No, make that worse; you have to add urea regularly.

And no, you can't just piss in the urea tank ... but you'll want to.




Not yet, you don't. Maybe in 2010; the jury is still out.

Don't get anything after 2006. The new engines DO have self-regenerating particulate traps and converters.

MikeHalloran
08-17-2007, 08:22 PM
Don't get anything after 2006. The new engines DO have self-regenerating particulate traps and converters.

Agreed about 2006.

I've installed self- regenerating particulate traps and converters in generators for big yachts (engines about the same size as in your truck).

They were not required at the time; the owners (people of whom you've heard) wanted to be perceived as environmentally responsible, and spent amazing amounts of money in that pursuit.

In the constant high load service typical of a big yacht's genset, the converters should have worked great, and were so advertised ... but didn't come with a performance guarantee. The traps clogged, repeatedly, and had to be manually cleaned, repeatedly. When the crews threatened to mutiny, they were cleaned thoroughly and deposited at the bottom of an anonymous body of water. They should make nice fish habitat.

The people who sold the converters were very smart, and very knowledgeable about catalysis; demonstrably less so about engineering, and Diesels. With money, technical help, and especially pressure and production volume, from the car/truck Diesel guys, they may eventually get it right, but I don't expect it to happen soon.

mrblanche
08-17-2007, 08:59 PM
The people who sold the converters were very smart, and very knowledgeable about catalysis; demonstrably less so about engineering, and Diesels. With money, technical help, and especially pressure and production volume, from the car/truck Diesel guys, they may eventually get it right, but I don't expect it to happen soon.




They are on the road now, and seem to be doing fine. I test drove a new Volvo with the system, and it regenerated frequently and imperceptibly. Of course, after a certain amount of time, they do have to be removed and cleaned by another method. The talk is of making it a regular maintainance item, with the trap removed and replaced with a unit that has already been cleaned to minimize downtime.

MikeHalloran
08-17-2007, 10:09 PM
Yeah, and the off-line cleaning will gradually become less effective and have to be done at progressively decreasing intervals, until it gets to the point where you change out the cat and drive out of the shop and it needs it again and... that's pretty much what happened on the yachts.

Until the online regeneration actually works, without offline cleaning, they're doomed.

DonTom
08-19-2007, 01:08 AM
Many vehicles, especially motorcycles, have engines that can run well above 10,000 RPM's. While I can understand that a high RPM engine has to be designed differently for several reasons, I don't understand why a rod is likely to break in any engine at 4,000 RPM's when there are so many vehicles that can operate at above 10,000 RPM's. Do they go out of their way to use cheap metals in low RPM engines or what? Why can't they use rods and pistons that can handle a lot more speed in slower revving engines? After owning three engines where rods have broken, I would think this is one area that could easily be improved.

When the rod broke in my 1984 3/4 ton van conversion (which ran at very low RPM's) , while going downhill (west) on highway 80 near Cofax, CA, the tow truck driver mentioned he has seen a lot of rods break in that area and all have been while downhill (just as with my three broken rods in two different GM vehicles). His theory is that after climbing up a lot of hills it makes the rods weaker for when going down. That seemed to be the case when all three of my rods broke. We climbed up a lot of hills in Colorado the day the rod broke in extreme west Utah (six miles east of the NV state line).

While the steady 4,000 RPM's may have contributed to the rod breaking in my RV, I still wonder if it had more to do with the several 11,000 foot peaks we had to go over that day.

-Don-

MikeHalloran
08-19-2007, 01:35 AM
They don't use Unobtainium for rods, because it expensive, and because you can't get it.

Seriously, every part of every car and every truck is made of materials that are good enough to get it through the warranty period, and a bit beyond, for the vast majority of possible driving cycles.

... as the rods in all of your rebuilds almost certainly did, once.

DonTom
08-19-2007, 05:42 AM
"every part of every car and every truck is made of materials that are good enough to get it through the warranty period, and a bit beyond, for the vast majority of possible driving cycles."

I usually get several hundred thousand miles out of all my vehicles except for GM vans, such as my one ton van Class C RV and 3/4 ton Class B (Van Conversion RV). The only two vehicles where I have blown rods.

I just wonder if rods are any better in the newer GM engines.

-Don-

Eric
08-19-2007, 08:47 AM
"Many vehicles, especially motorcycles, have engines that can run well above 10,000 RPM's. While I can understand that a high RPM engine has to be designed differently for several reasons, I don't understand why a rod is likely to break in any engine at 4,000 RPM's when there are so many vehicles that can operate at above 10,000 RPM's. Do they go out of their way to use cheap metals in low RPM engines or what? Why can't they use rods and pistons that can handle a lot more speed in slower revving engines? After owning three engines where rods have broken, I would think this is one area that could easily be improved. "

A DOHC 1,000 cc sport bike engine and a 400 cubic inch pushrod V-8 are two wildly different designs - and use wildly different materials. Rods and so on used in a sport bike engine are, first of all, made of exotic/high-strength material compared with the stamped steel type usually found in a low-po engine such as your dead 400.

Also, the sport bike engine is typically a short stroke design - and of course, there's much less mass in the reciprocating assembly.

VIrtually no large displacement passenger car engines can rev beyond 7,000 RPM, incidentally. Most V-8s "redline" in the 6,000 RPM range or lower. Some bike engines, on the other hand, run to 14,000-15,000 RPM....

Eric
08-19-2007, 08:53 AM
"I just wonder if rods are any better in the newer GM engines."

The answer there is a definitive "yes."

Why?

The new V-8 architecture derives from the Corvette's V-8, which is already, by design, an engine built for high-horsepower/high load use; two, the operating range of GM's new V-8s is broader. Redlines are now well above 5,000 RPM (some will tickle 6,000 before hitting the rev limiter) vs. closer to 5,000-5,200 RPM for the "old" small blocks. (Standard-duty/mass produced ones, anyhow. There were a few high-performance versions built that had higher redlines - and better internals - such as the old L82 350, for example. But most of GM's V-8s from the mid-late '70s through the early '90s were not built to handle sustained high RPM duty.)

Also, keep in mind that your 400 (like my Pontiac 455, incidentally) was by design a low RPM engine - even in its day. It was much more vulnerable to bottom end problems if you ran it at high RPM than a 350 or 327, all else being equal.

And for such an engine, RPM above 4,500 is "high" - and should only be done briefly, as when under full throttle acceleration. Continuous operation at 4,000 RPM therefore was "on the edge" - and led to the meltdown disaster!

mrblanche
08-19-2007, 09:40 AM
A DOHC 1,000 cc sport bike engine and a 400 cubic inch pushrod V-8 are two wildly different designs - and use wildly different materials. Rods and so on used in a sport bike engine are, first of all, made of exotic/high-strength material compared with the stamped steel type usually found in a low-po engine such as your dead 400.




I think the rods in most Chevy engines are made of powdered metal, not stamped steed.

Eric
08-19-2007, 09:42 AM
A DOHC 1,000 cc sport bike engine and a 400 cubic inch pushrod V-8 are two wildly different designs - and use wildly different materials. Rods and so on used in a sport bike engine are, first of all, made of exotic/high-strength material compared with the stamped steel type usually found in a low-po engine such as your dead 400.




I think the rods in most Chevy engines are made of powdered metal, not stamped steed.


Should have said "cast" rods, etc.

I think the current rods in LS series V-8s are all forged; the pistons are (last time I checked) "hypereutectic" high silicone content, etc.

mrblanche
08-19-2007, 09:47 AM
Should have said "cast" rods, etc.

I think the current rods in LS series V-8s are all forged; the pistons are (last time I checked) "hypereutectic" high silicone content, etc.


Stamped steel would be better, but I don't think rods are mainly steel, anyway. And I'd bet the pistons in his 400 were hypereutectic, just as the pistons in my rebuilt 350 are. In fact, I don't think you can buy anything less.

misterdecibel
08-19-2007, 03:50 PM
It's not just the 4000 RPM that did you in. It's 4000 RPM all day, carrying a heavy load, with lots of wind resistance. That's asking a lot of an engine.

DonTom
08-19-2007, 04:40 PM
"Rods and so on used in a sport bike engine are, first of all, made of exotic/high-strength material compared with the stamped steel type usually found in a low-po engine such as your dead 400."

It seems to me that the rods are the biggest weak point in the older GM small block engines. Couldn't they have improved this by simply using the using the "exotic/high-strength material" that's used in the sport bikes?

I understand that push rod engines run slower, but that doesn't explain why the rods have to be made from cheap material that's likely to break at 20% below red line.

-Don-

DonTom
08-19-2007, 04:48 PM
"It's not just the 4000 RPM that did you in. It's 4000 RPM all day, carrying a heavy load, with lots of wind resistance. That's asking a lot of an engine."

I think the 11,000 foot high mountains of Colorado had a lot to do with it too, but not much could be done about that.

-Don-

Eric
08-19-2007, 06:41 PM
GM used rods made to endure given loads/speeds, etc. in thatengine. Better quality/high strength rods would have made the engine tougher, perhaps - but also more expensive to build, etc.

I think I mentioned, though, that the siamese bore Chevy 400 smallblock V-8 is inherently a low-speed engine not designed for high rpm use - let alone extended high rpm use. It was never offered in high-performance/HD form as a stock production engine. It was used mainly as a high torque/low-speed engine in large, heavy vehicles during the '70s... like big old Impalas, etc.

You can build an engine to handle almostanything, of course, but why start out with an engine that's not well-suited for a given type of use? A 327 or 350, for example, can handle high rpm better than the 400 - all else being equal.

It's a similar story, incidentally, with Pontiac V-8s. For example, the 400 Pontiac (a totally different engine than the 400 Chevy) has a relatively short stroke so is more tolerant of high RPMs than the 455 - which has a long stroke.

The Pontiac V-8 family has two branches - sort of like the Chevy small and big block V-8s - only with Pontiac engines, there is no difference in the physical size of the block and a "small" 326 looks just like a "big " 455 on the outside. Many parts - including cylinder heads and intakes - interchange between the "small" and "big" Pontiac V-8s.

In contrast, a smallblock Chevy is an entirely different engine from a big block Chevy; bigger in physical exterior dimensions and no parts interchange.

But your 400 Chevy would look smaller than a "big" block 396 ....

DonTom
08-19-2007, 07:29 PM
"A 327 or 350, for example, can handle high rpm better than the 400 - all else being equal."

Why would a rod be less likely to break in a 327 or 350? Did they use rods made from a stronger material than in a 400?

And what about the 305? I had a rod break in that 1984 3/4 ton van conversion which was famous for its very low RPM's. Many said it ran too low in RPM's to be able to tow much of anything.

In that van, IIRC, 2,000 RPM's would be about 70 MPH. Ran about half the speed of my Class C RV, but it still blew a rod.
-Don-

DonTom
08-20-2007, 12:21 AM
I am back at my sinecure in San Francisco and I was just chatting with a day shift radio technician who seems quite knowledgeable about the 400 CID small block. He said besides the problems the new ones had (such as head gasket problems from the cylinders being too close together), the rebuilds had many more problems, one being that the 400 CID cranks have not been made for many years so they have to keep on using old ones and these often fail.

He also said the red line on a 400 CID is 5,300 RPM and it should be able to run all day at 4,000 RPM's without any problem, if it had new parts to begin with. He thinks my break down was only because it was a rebuild.

He also said that a quart per day of oil at 4,000 RPM's all day would be about normal on these.

-Don-

mrblanche
08-20-2007, 02:51 AM
A 400 can be made into a high-performance engine. We have several club members with them, including Tim "The Toolman" Taylor (not the famous one) who just built a new engine after some 200,000 miles on his old one, much of it at 80+ mph, and some of it at 140 mph.

You can use a 350 block with a 400 crank to make the 383, which is a really popular hot rod engine.

When you start talking engine performance versus longevity, you are always talking trade-offs. You can get beautiful H-beam aluminum rods...but they don't last very long. They're great for drag racing, but they eventually stretch.

If you had told us at the outset that your RV ran 4,000 rpm at 80 mph, I trust we all would have advised either a change in gearing or a change in driving habits. It was a prescription for disaster.

DonTom
08-20-2007, 06:28 AM
"You can use a 350 block with a 400 crank to make the 383, which is a really popular hot rod engine."

Where do you find a decent 400 crank?

"If you had told us at the outset that your RV ran 4,000 rpm at 80 mph, I trust we all would have advised either a change in gearing or a change in driving habits. It was a prescription for disaster."

I wonder if it would even do 80 if it were geared much higher. In a 400, what RPM range has the max power? I tend to think to move a 11,100 LB RV, it has to be geared low.

-Don-

Eric
08-20-2007, 08:13 AM
"He also said the red line on a 400 CID is 5,300 RPM and it should be able to run all day at 4,000 RPM's without any problem, if it had new parts to begin with. He thinks my break down was only because it was a rebuild."

I think that is pushing it; even with new parts. I would never subject an engine to continuous operation within 1,000 RPM of its redline and not expect either a catastrophic failure (as happened to you) or massively accelerated wear and tear. That's just abusive, plain and simple. I would not run my Kaw sport bike at 10,000 RPM, either (about 1,000 RPM shy of its redline) despite it having "unobtanium" rods and so n...

Eric
08-20-2007, 08:18 AM
" In a 400, what RPM range has the max power?"

That would be determined by things such as the camshaft profile, compression ratio - and so on. A cam change can radically alter an engine's power curve/peak output, etc. This is why one picks the cam profile and so on to meet the intended use the engine will be put to. Thiscan be even more important than the engine type/size, etc.

For RV duty, I'd say you don't need high rpm power as much as you do low-end torque - so the engien should be "cammed" to deliver high torque off-idle and throughout the mid-range.

But for an 11,000 pound rig, I'm thinking a diesel might be the best possible way to go.... you can get one tht develops 500-600-plus lbs.-ft. of torque at 1,500-2,200 RPM or so. And that is what you want to get a lump like that moving!

DonTom
08-20-2007, 09:21 AM
" I would never subject an engine to continuous operation within 1,000 RPM of its redline "

But 4,000 RPM's is 1,300 below redline on a 400CID. That's about 25 % below.

"That's just abusive, plain and simple. I would not run my Kaw sport bike at 10,000 RPM, either (about 1,000 RPM shy of its redline) despite it having "unobtanium" rods and so n..."

But that 10K RPM is less than 10% below red line.

"But for an 11,000 pound rig, I'm thinking a diesel might be the best possible way to go.... you can get one tht develops 500-600-plus lbs.-ft. of torque at 1,500-2,200 RPM or so. And that is what you want to get a lump like that moving!"

Yep, no doubt a diesel would be best. However, Tom & I were just looking at the prices of used Diesel RV's on E-Bay. For the price difference, one can buy four or five large gasoline engines ( installed) and have enough left over to pay for the poorer MPG of gasoline engines!

-Don-

mrblanche
08-20-2007, 10:46 AM
Yep, no doubt a diesel would be best. However, Tom & I were just looking at the prices of used Diesel RV's on E-Bay. For the price difference, one can buy four or five large gasoline engines ( installed) and have enough left over to pay for the poorer MPG of gasoline engines!

-Don-[/size]


Really? What was the quote on replacing the 400 with a new 400 (or, as my friends in the business recommended, a truck-rated 383), installed? Keep in mind the engine itself is $4500. Labor would be another $2000 or so, I'd guess.

http://paceperformance.com/images/products/manufacturer/GM/images/12497317.jpg

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=18295

And the RV's with diesels tend to start out with higher quality overall.

And, keep in mind that if you use it enough (I think 15 days per year, but see your tax man) the interest can be deducted as a second home.

Eric
08-20-2007, 10:48 AM
"But 4,000 RPM's is 1,300 below redline on a 400CID. That's about 25 % below."

Not much of a distinction there!

The problem is not running it to 4,000 (or even 5,000)... it's keeping it at the high end of the RPM scale, as you did. That is at best "severe" service; arguably abuse.

"Yep, no doubt a diesel would be best. However, Tom & I were just looking at the prices of used Diesel RV's on E-Bay. For the price difference, one can buy four or five large gasoline engines ( installed) and have enough left over to pay for the poorer MPG of gasoline engines!"

Yeah, but is the hassle and uncertain reliability worth the savings? On a long road trip, far from home and in unfamiliar surroundings, I'd want to have confidence in my vehicle - and that it will get me there and back without grenading!

mrblanche
08-20-2007, 11:01 AM
Where do you find a decent 400 crank?

I wonder if it would even do 80 if it were geared much higher. In a 400, what RPM range has the max power? I tend to think to move a 11,100 LB RV, it has to be geared low.

-Don-
[/size]


The cranks are available new and higher quality than OEM from a number of sources. Below is a link to one of the best sources for high-quality connecting rods. If you go down to the bottom, you'll find OEM replacements that are forged from steel, CNC machined, shot peened, and guaranteed for extended use at 9,000 rpm. Only $1800 per set of 8.

http://www.campbellenterprises.com/manley_sbc_steel_rods.htm

misterdecibel
08-20-2007, 01:35 PM
Really? What was the quote on replacing the 400 with a new 400 (or, as my friends in the business recommended, a truck-rated 383), installed? Keep in mind the engine itself is $4500. Labor would be another $2000 or so, I'd guess.



383? A Chrysler engine in a Chevy truck? Heaven forfend!

Eric
08-20-2007, 01:57 PM
Really? What was the quote on replacing the 400 with a new 400 (or, as my friends in the business recommended, a truck-rated 383), installed? Keep in mind the engine itself is $4500. Labor would be another $2000 or so, I'd guess.



383? A Chrysler engine in a Chevy truck? Heaven forfend!


Same displacement - different engines!

Just like Don's 400 and the 400 Pontiac are two entirely different mills....

mrblanche
08-20-2007, 02:24 PM
383? A Chrysler engine in a Chevy truck? Heaven forfend!


Read more closely. I clearly said to use a 400 Chevy crank in a 350 Chevy engine to make a 383.

misterdecibel
08-20-2007, 03:27 PM
383? A Chrysler engine in a Chevy truck? Heaven forfend!


Read more closely. I clearly said to use a 400 Chevy crank in a 350 Chevy engine to make a 383.


Oh. Well the factory never released one with that displacement.

DonTom
08-20-2007, 06:10 PM
"Keep in mind the engine itself is $4500. Labor would be another $2000 or so, I'd guess. "

I last labor quote I got for changing an engine (in Wendover, NV) was $1,500. And the engine would be a bit cheaper too, because I've been told you cannot buy a new 400 and I would have to use a rebuild. And the new 350's are not made for the load of a RV.

But I have heard from others (who are NOT in the business) that there are other places where it is possible to buy a new 350 that is made for the heavy duty use, such as in a RV.

IAC, from what you guys are telling me, I would not only have to change the engine, but find a way to have it geared higher. That's another reason to junk it.

-Don-

DonTom
08-20-2007, 06:36 PM
"it's keeping it at the high end of the RPM scale, as you did. That is at best "severe" service; arguably abuse. "

My understanding that in a 11,000 lb RV, it's considered severe service regardless of RPM's. Wouldn't you expect a heavy vehicle to be geared a lot lower than a light one? Often, places that normally give a one year (and so many miles) warranty on engines, reduce the warranty by 75% in the more heavy vehicles, such as RV's. Mid range might be lugging the engine in this thing, which also wouldn't be a good idea. It's not a car, where one would expect to be running much lower RPM's. But my guess is that this RV is a bit too low geared as you say, at least for 80 MPH, because it was built during the time of the 55 MPH national speed limit. The speedometer pins right at 80 MPH!

I agree with what you say about the diesels, but since the newer gasoline engines are much more reliable (and often have an O/D tranny) than a 400 small block, is it that much of an issue?

I think I heard somewhere (I think the RV Forum) that GM now makes a 500 CID gasoline engine that's designed for RV use, but not available here in CA because it won't meet the smog requirements. But that's not a problem because of my house in NV. And wasn't the ten cylinder Ford engine also designed for RV use, or do they use it in other vehicles too?

But IAC, I would think the newer gasoline engines would be MUCH more reliable than my 400 CID, as well as have an OD. Nevertheless, I will be looking at diesels as well, if I can find a used one below a hundred grand! And that's a lot of bread for something that might only get used once a year or so!

-Don-

Eric
08-20-2007, 08:29 PM
Well, a couple of points...

First, the overdrive's in the transmission and independent of the engine. Most all (probably every) modern vehicle has an OD transmission; and it's easy to retrofit one to an older vehicle that didn't have one originally (like my Trans-Am, for example).

As far as the 500 CID engine; dunno - but GM does offer an extensive array of engines in a variety of displacements/power levels and so on; see the Goodwrench catalog (or check www.summitracing.com or JEGS, etc.)

As far as diesel vs. gas: I personally would prefer the diesel in an application such as yours, even if it cost significantly more - because I'd rather spend money once than several times and hate hassles if I can avoid them. As Mike noted, good rebuilds/new gas engines aren't cheap, either!

Plus, the diesel will last longer - and probably add to the resale value, too.

DonTom
08-20-2007, 09:02 PM
"Most all (probably every) modern vehicle has an OD transmission; and it's easy to retrofit one to an older vehicle that didn't have one originally (like my Trans-Am, for example)."

You mean I could simply bolt on a tranny with an overdrive in place of the TH400? And I think in some vehicles they bypass the automatic tranny when the RPM's get so high, which is much like an OD. I think our Sebring does that. Has a three gear tranny and when the RPM's get so high, the tranny just locks up as if it is simply a shaft to connect the engine to the front wheels (FWD).

"and probably add to the resale value, too."

As you should know by now, I do NOT care about resale value of anything. Not even my two homes. I almost never resell anything and Tom is the same way.

People in the RV forum say that these days, most likely, there will be a tranny failure long before the first engine problem, even with gasoline engines.

-Don-

MikeHalloran
08-20-2007, 09:10 PM
Oh. Well the factory never released one with that displacement.

Strictly speaking, true.

However, the LT1 as used in the Camaro SS was stroked to 383, not in the GM engine factory so far as I know, but sold by Chevy dealers, with a warranty.

mrblanche
08-20-2007, 09:26 PM
A big-block truck engine, used in an RV, would be a much better bet than any small-block. But it's still going to be a gas hog, and it's never going to have the torque of a diesel.

DonTom
08-20-2007, 09:28 PM
And, keep in mind that if you use it enough (I think 15 days per year, but see your tax man) the interest can be deducted as a second home.

Well, since I already have a second home . . .

But it doesn't matter for a couple of reasons. Our NV home is paid for free and clear which means I can get another loan on a third home and deduct the interest. The law is that you can only take loans out on two homes to deduct interest so that would be no problem to call the RV my second home (for tax purposes) even if it's my third home.

Also, I have a large HELOC (Home line of credit) on this SSF home and can easily write a check right now for a couple of hundred thousand, if I really want to (and I just might want to when I see some of the diesel RV's!). So it will be a tax deduction regardless of anything, when it comes to the interest, even if it's a car or something else.

For a while, we were considering buying a third home in Las Vegas, but we decided it's too much trouble to own three. The main reason I don't want to spend a lot of money on a RV is because I know it will get very little use and will just sit there most of the time, just as did my last one. But when it gets used, it will really get used, as we put on a lot of miles each day during most of our RV trips.

-Don-

DonTom
08-20-2007, 09:34 PM
"A big-block truck engine, used in an RV, would be a much better bet than any small-block. But it's still going to be a gas hog, and it's never going to have the torque of a diesel."

I certainly prefer a diesel, but that doesn't mean I won't consider a large gasoline hog engine if it's known to be reliable.

BTW, do you know anything about the ten cylinder Ford gasoline engine that's in a lot of RV's these days? Do they use it in anything other than RV's?

-Don-

mrblanche
08-20-2007, 10:56 PM
They used it in large pickups (F-250's and F-350's?) but I was under the impression production had stopped.

MikeHalloran
08-20-2007, 11:31 PM
The V10 was also the big engine in the Excursion, which was of course a tarted up and overpriced F250.

It was part of the 'modular' engine line, so the per- cylinder parts interchange with smaller engines.

I thought they tooled it up so that they could make any variation up to a V12 without major setup changes, so they could profitably make small batches of V10s as long as there's a demand.

D_E_Davis
08-21-2007, 12:52 AM
First, the overdrive's in the transmission and independent of the engine. Most all (probably every) modern vehicle has an OD transmission...

I think you need to lose the term "overdrive" (or OD), as that hasn't been germane for quite a few years now. Many transmissions nowdays don't have a 1:1 ratio, so what do you calculate "overdrive" from?

Now, the 1940 Lincoln could be bought with an overdrive unit in the differential, and my 48 Hudson had one aft of the tranny, but now days...

DonTom
08-21-2007, 01:24 AM
"but I was under the impression production had stopped."

Slow sales? or was there other reasons. Is it a reliable engine? About the only thing I heard about it is that it sucks gasoline, not much better than my old RV.

-Don-

MikeHalloran
08-21-2007, 01:38 AM
It's a big engine, in all possible ways.

If a Chevy 400 was a tight fit, you'd never squeeze a Ford V10 in the same hole.

I measured less than 9 mpg in an Excursion over a weekend ... but that included a lot of 80mph cruising and a lot of idling to keep it warm in subzero weather. I'd guess it would break 10 mpg if driven gently.

DonTom
08-21-2007, 01:51 AM
"If a Chevy 400 was a tight fit, you'd never squeeze a Ford V10 in the same hole."

I was thinking more in line of a new RV with the V-10, the old RV is history as far as I am concerned. I should have junked the thing years ago!

I have a lot of time to figure out what my next RV will be, but I want to explore all the possibilities. The only thing for sure is I want a small Class A (less than about 26 feet long) with a rather large engine and an OD tranny. I am willing to spend more on a diesel, but how much more is not yet decided.

-Don-

misterdecibel
08-21-2007, 01:58 AM
For a while, we were considering buying a third home in Las Vegas, but we decided it's too much trouble to own three. The main reason I don't want to spend a lot of money on a RV is because I know it will get very little use and will just sit there most of the time, just as did my last one. But when it gets used, it will really get used, as we put on a lot of miles each day during most of our RV trips.


Have you considered renting an RV, just when you need it?

DonTom
08-21-2007, 02:39 AM
"Have you considered renting an RV, just when you need it?"

That's way too logical for us. We would rather own than rent--anything.

-Don-

misterdecibel
08-21-2007, 04:38 AM
"Have you considered renting an RV, just when you need it?"

That's way too logical for us. We would rather own than rent--anything.

-Don-


Even if it's ruined by sitting fallow for years-long intervals?

DonTom
08-21-2007, 06:17 AM
"Even if it's ruined by sitting fallow for years-long intervals?"

Yep. That's never stopped me from owning any vehicle yet. But we try to drive them just enough to prevent that. BTW, can somebody here tell me if diesel fuel goes bad faster or slower than gasoline? I try to go through a tank per year in all my ( many) vehicles, but my BMW motorcycle and Volvo (inboard Volvo in-line 4 engine) boat has not been started for years now, which means some work before I do, such as cleaning out the gas tank and carbs.

I still register and have them insured, because I figure some day soon I might decide to work on them. But I have been saying that for years.

-Don-

mrblanche
08-21-2007, 06:55 AM
Diesel has a problem with algae growing in it, among other things, but there are treatments for it. It's more of a problem in hot humid climates, where the diesel picks up more water.

Diesel is formulated for the temperature at the time it's made, so you wouldn't want to use diesel you bought in July in January. In fact, the engine might not start.

But by and large, the large the diesel engine, the more durable it is. The infamous GM diesel engine back in the early 80's was a conversion from the small-block 350, and it wasn't particularly durable, although later models were much improved. An actual Cat, Cummins, or International Harvester engine can be very good.

If you get a large enough RV to use a Cummins M11 or a Cat C12, you will have no trouble climbing mountains at the speed limit, and get 12 mpg or more doing it. I had a truck with an M11 and moved 80,000 lbs down the road right smartly.

DonTom
08-21-2007, 07:20 AM
"Diesel has a problem with algae growing in it, among other things, but there are treatments for it. It's more of a problem in hot humid climates, where the diesel picks up more water."

Does diesel pick up water more so than the alcohol they add to gasoline? I guess additives are more important to the diesel. But at least the RV will be kept at our Reno home, which is in the rather dry desert.

"Diesel is formulated for the temperature at the time it's made, so you wouldn't want to use diesel you bought in July in January. In fact, the engine might not start."

I saw your message that explained that before, but this time you explained it a bit better. I recall what you said about the temperature, but I thought you said before it's normally not a problem, but this time you said the engine might not start. As you know, weather can change quite a bit in some times during the year where it's possible to go from below sea level in the desert to 11,000 feet in the same day. Is it possible to have the wrong diesel for the same day ( when putting on a lot of miles) to the point that you stop and cannot restart the engine?

Are newer diesels less sensitive to having diesel for the wrong season? And how many times do they change the formula for the weather during the year?

"If you get a large enough RV to use a Cummins M11 or a Cat C12, you will have no trouble climbing mountains at the speed limit, and get 12 mpg or more doing it."

I am hoping to find a large engine in a small RV, less than 25 feet long.

-Don-

Eric
08-21-2007, 08:28 AM
First, the overdrive's in the transmission and independent of the engine. Most all (probably every) modern vehicle has an OD transmission...

I think you need to lose the term "overdrive" (or OD), as that hasn't been germane for quite a few years now. Many transmissions nowdays don't have a 1:1 ratio, so what do you calculate "overdrive" from?

Now, the 1940 Lincoln could be bought with an overdrive unit in the differential, and my 48 Hudson had one aft of the tranny, but now days...




Well, it's the standard usage, so I use it!

My 2004R transmission has something like a .67 ratio in "fourth" - which would be a true overdrive, wouldn't it?

Eric
08-21-2007, 08:33 AM
"You mean I could simply bolt on a tranny with an overdrive in place of the TH400? "

Yes. It's very easy. With many GM engines, it is a direct "bolt-in." With some, you might need an adapter plate. But other than that (and maybe a different slip yoke, driveshaft and fiddling with the mounting points a bit) it's an afternoon's job.

My Trans-Am, for example, was designed to use the THM400/THM350 automatic. But it was very easy to bolt in the 2004R four-speed overdrive automatic. These transmissions were used OEM behind the Buick 3.8 V-6 (among others) in the 1980s and the Buick and Pontiac (and Olds) engines have a common bellhousing pattern. All I had to do was move the transmission crossmember back about two inches (and provide a "hot" wire for the 2004R's lock-up converter).

mrblanche
08-21-2007, 08:45 AM
Well, it's the standard usage, so I use it!

My 2004R transmission has something like a .67 ratio in "fourth" - which would be a true overdrive, wouldn't it?


And you are correct. The 200-4R has a 3rd gear ratio of 1:1, so 4th is an overdrive of .67:1. The 700R4 has a third-gear ratio of 1:1, and a 4th of .7:1, so it is an overdrive. And the shifter on most of these has a way of selecting the 3rd gear as the driving gear.

mrblanche
08-21-2007, 09:07 AM
"Diesel has a problem with algae growing in it, among other things, but there are treatments for it. It's more of a problem in hot humid climates, where the diesel picks up more water."

Does diesel pick up water more so than the alcohol they add to gasoline? I guess additives are more important to the diesel. But at least the RV will be kept at our Reno home, which is in the rather dry desert.

I saw your message that explained that before, but this time you explained it a bit better. I recall what you said about the temperature, but I thought you said before it's normally not a problem, but this time you said the engine might not start. As you know, weather can change quite a bit in some times during the year where it's possible to go from below sea level in the desert to 11,000 feet in the same day. Is it possible to have the wrong diesel for the same day ( when putting on a lot of miles) to the point that you stop and cannot restart the engine?

Are newer diesels less sensitive to having diesel for the wrong season? And how many times do they change the formula for the weather during the year?I am hoping to find a large engine in a small RV, less than 25 feet long.

-Don-




OK, just a few points.

Alcohol in gasoline absorbs water, but that's no big deal. It's in solution, and it burns just fine. In fact, one way to keep your gas tank from collecting water (and freezing in the winter) is to put in an alcohol solution, which absorbs the gas and is then burned. The alcohol/water argument is largely a red herring by those who oppose ethanol.

There are additives in diesel already, but you can buy others that will fight the algae and will remove water. The algae actually forms in the water/diesel interface, living in the water but eating the diesel.

Keep in mind that truck stops sell fuel that may be used for the next 1500 miles. So, a truck stop in Fairfield, CA (yes, there is one; nasty little place, spent a month there one week) has to sell fuel that will be able to go from the 70's there to freezing and below across Donner, out through Utah, and into Wyoming, where the temp might be -20. So, while fuel formulations change, they change more by season than by day. If you buy fuel in a blizzard, you may find that it runs a little "hot" when you get to Texas, because it has more anti-gelling additives, and probably a certain amount of diesel #1 (the fuel sold in most places is diesel #2) to improve cold-weather ability.

When we have a really cold spell, it's not unusual to see trucks at a truck stop that have quit running. I was once laid over in the Chicago area. I put the winterfront on the truck, pointed it out of the wind, and idled it up as high as it would go all night. It got down to -17 overnight, and about half the trucks in the parking lot had quit running overnight. Most diesel trucks have fuel heaters, either electric or part of the engine coolant system. My truck doesn't, but it's heated by the engine, since this particular engine bypasses about 10 gallons of fuel for every gallon it burns.

On the other hand, if you bought diesel in Houston in July, drove the vehicle to Wyoming, and then tried to start it in January at 10 degrees, the odds are good it won't start, since the diesel will have turned to jello. Gelling is the biggest concern. Cold weather fuel will always work in hot weather, although it won't have the power hot-weather fuel will.

When buying diesel, you should always buy it at a station with a heavy turnover. Go to the TA or the Petro in Sparks. I don't know a good station in the Bay area, but that's not where you'd be keeping it, right?

As to an RV, I'd find a high-quality unit with a diesel pusher. That shortens the driveline and keeps the noise away from the driving area. Get one with an Onan generator that pulls fuel from the diesel tanks. And personally, I have an aversion to slide-outs; they increase weight and complexity and likelihood of air and water leaks.

DonTom
08-21-2007, 10:06 AM
Yes, the RV will be kept at the Reno home on the side of the house where we have a lot of room, unlike our home in South SF.

It seems diesel has more problems than does gasoline, in a rig that isn't driven often.

I think the Diesel Pusher RV's are all very large rigs and usually cost about as much as a house, if not more.

Not having sideouts is not a big deal to us, but it sure is a big selling point these days. But I think that's mainly for full-timers, as they want all the room they can get. We don't need a lot of room.

Is that truck stop in Fairfield near the truck scales? Those scales case a lot of traffic problems there in Fairfield and they have even been thinking about moving it to a location that won't screw up the traffic as much on I-80. There's no easy way for cars to bypass that area.

"When buying diesel, you should always buy it at a station with a heavy turnover. "

That's true with gasoline too, but probably not nearly as important as with Diesel. But I don't think that's ever a problem at the cheaper stations. IMO, cheaper stations may have the freshest gasoline for the reason of high turnover and I assume it will be the same with the diesel.

"Cold weather fuel will always work in hot weather, although it won't have the power hot-weather fuel will."

I assume that means it's best to store a diesel engine with cold weather fuel as at least it will be more likely start and run, even if not as well as it should until the first fill up.

-Don-

mrblanche
08-21-2007, 10:18 AM
Diesel engines have their faults. But a true truck engine (like the M11 I mentioned) has a long life, especially in the relatively easy job of pulling an RV. Even a large RV is not much more than 1/2 the weight of a truck, or about the weight of my truck, trailer, and load of a couple thousand pounds.

A little knowledge of how a diesel works can pay big dividends.

The truck stop I mentioned is, indeed, right there by the scales.

DonTom
08-21-2007, 07:39 PM
"The truck stop I mentioned is, indeed, right there by the scales."

Not any more. It was torn down about a year ago. IIRC, I was on or very near Suisun Valley Road.

-Don-

chiph
08-21-2007, 10:30 PM
Or sometimes more than a house:

http://www.prevost-stuff.com/coaches/index.htm

They have a new 2006 Prevost 45ft Country Coach for $1.3m
(ouch)

Even the ones that are 16 years old aren't what you'd call cheap. $175k for this 40 footer:
http://www.prevost-stuff.com/1991_prevost__pacific_h340calcoach.htm

Chip H.

DonTom
08-22-2007, 12:20 AM
I just found out why diesel RV's or so much more expensive. It's not only the engine that's different, but the frame is MUCH stronger when diesel engines are used and the vehicle can carry a lot more weight than a gasoline engine RV, when of the same size. GVWR is a lot higher in RV's of the same size when diesel engines are used.

-Don-

mrblanche
08-22-2007, 12:29 PM
I just found out why diesel RV's or so much more expensive. It's not only the engine that's different, but the frame is MUCH stronger when diesel engines are used and the vehicle can carry a lot more weight than a gasoline engine RV, when of the same size. GVWR is a lot higher in RV's of the same size when diesel engines are used.

-Don-




Probably the bargain in the bunch right now is the conversion to RV of the Dodge Sprinter van, which is actually a Mercedes van from Europe.

The best bargain in a serious RV is a diesel pusher using an actual truck engine. Those engines are much stouter than the smaller light-truck versions, easily capable of a million miles without a major overhaul, and with filters and other systems capable of handling the daily vagaries than can kill much smaller engines.

chiph
08-22-2007, 12:36 PM
The one I linked to had a 8V92 Detroit motor and Allison automatic.

Good motor? Or so-so?

Chip H.

misterdecibel
08-22-2007, 12:48 PM
I just found out why diesel RV's or so much more expensive. It's not only the engine that's different, but the frame is MUCH stronger when diesel engines are used and the vehicle can carry a lot more weight than a gasoline engine RV, when of the same size. GVWR is a lot higher in RV's of the same size when diesel engines are used.

-Don-




Probably the bargain in the bunch right now is the conversion to RV of the Dodge Sprinter van, which is actually a Mercedes van from Europe.




Isn't the Sprinter a 2.5 liter 5 cylinder turbo diesel? I was under the impression that its range of usefulness is pretty much limited to in-down delivery.

mrblanche
08-22-2007, 01:25 PM
Isn't the Sprinter a 2.5 liter 5 cylinder turbo diesel? I was under the impression that its range of usefulness is pretty much limited to in-down delivery.


I think you're right, currently.

http://www.dodgeforum.com/m_439352/tm.htm

DonTom
08-23-2007, 11:01 PM
"Isn't the Sprinter a 2.5 liter 5 cylinder turbo diesel? "

Looked rather impressive, until I saw they wanted more than 100K for what looks like a van conversion.

"I was under the impression that its range of usefulness is pretty much limited to in-down delivery."

Why? Because of the small engine size?

-Don-

misterdecibel
08-24-2007, 01:54 AM
"Isn't the Sprinter a 2.5 liter 5 cylinder turbo diesel? "

Looked rather impressive, until I saw they wanted more than 100K for what looks like a van conversion.

"I was under the impression that its range of usefulness is pretty much limited to in-down delivery."

Why? Because of the small engine size?

-Don-



I'm sure that not all the Sprinter conversions are that expensive. But is it a Mercedes-Benz...

Small engine size is not necessarily a deterrent, if the vehicle is small and light too. But if it weighs as much as any other van, then one would think that if a 6.5 liter V8 can be run to death in an RV, a 2.5 liter engine might be even more overworked...

DonTom
08-24-2007, 02:19 AM
"Small engine size is not necessarily a deterrent, if the vehicle is small and light too."

What I am hoping to find is a large powerful (even if fuel sucking) engine in a rather small size RV, about 25 feet or a bit less. I don't care too much about the MPG but I want the thing to move up the hills without too much effort.

BTW, today I signed off the pink slip on the RV and delivered it in person. I now officially no longer own that thing. Bob said he will most likely crush it at the place next door to him, after removing the thousand dollars worth of new tires and getting the hundred and fifty bucks worth of fresh gasoline out of it. Looks like all the MPFI stuff will be crushed too, as few are looking for such stuff these days. He doesn't think he will find any of the parts to be useful, in that old thing.

I think I forgot to mention that the meltdown happened perhaps 20 miles after it was filled top 55 gallons. Seems that thing was trying to rip me off in every way possible!

-Don- (Reno)