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Kwozzie1
04-03-2007, 01:44 AM
A friend of mine recently had to replace spark plugs on his transverse engined V6 Mitsubishi Magna

There are two types of plugs on this car..... Regular for the front, but platinum tipped for the rear.....
Reason...the intake manifold has to be removed to replace them.

DonTom
04-03-2007, 02:11 AM
".the intake manifold has to be removed to replace them."

That's not uncommon for cars these days.

"Regular for the front, but platinum tipped for the rear..... Reason...the intake manifold has to be removed to replace them."

Why not use the platinum in the rear too?

-Don-

Kwozzie1
04-03-2007, 02:34 AM
".the intake manifold has to be removed to replace them."

That's not uncommon for cars these days.

"Regular for the front, but platinum tipped for the rear..... Reason...the intake manifold has to be removed to replace them."

Why not use the platinum in the rear too?

-Don-



Ummm...think you mean front. ;)
Not sure of the logic, but cost of the plugs would be the reason I guess.

Jim Rose
04-03-2007, 08:21 AM
>>A friend of mine recently had to replace spark plugs on his transverse engined V6 Mitsubishi Magna

There are two types of plugs on this car..... Regular for the front, but platinum tipped for the rear.....
Reason...the intake manifold has to be removed to replace them. <<

Perhaps so, but sometimes it's because of the ignition system. The distributorless ignition systems are much like a magneto when they fire. One cylinder has a positive pulse and the next a negative. The negative fireing cylinders will erode the spark plug material 4 times faster than the positive fireing cylinders because of the heat transfer of electrode material. When the spark jumps from the center electrode to the ground, (negative fireing) that plug will erode faster, and I'll bet that's the reason for the platinum plugs. Ford uses 2 types of platinum plugs in DIS ignition engines for that reason.
What does the owner's manual say about plug replacement? All at the same time or front at shorter intervals than rear. Most engines nowadays are of the 100000 mile plug life variery.

Eric
04-03-2007, 09:17 AM
A friend of mine recently had to replace spark plugs on his transverse engined V6 Mitsubishi Magna

There are two types of plugs on this car..... Regular for the front, but platinum tipped for the rear.....
Reason...the intake manifold has to be removed to replace them.


One more reson to hate new cars... gawd!

Dave Brand
04-03-2007, 10:40 AM
Ford uses 2 types of platinum plugs in DIS ignition engines for that reason.


My Alfa uses two totally different types of plug, four of them 14mm, the other four 10mm. There are four coils, each firing two plugs in two different cylinders simultaneously.

Jim Rose
04-03-2007, 02:27 PM
>>My Alfa uses two totally different types of plug, four of them 14mm, the other four 10mm. There are four coils, each firing two plugs in two different cylinders simultaneously. <<

Those Italians are at it again-- ran out of parts and used whatever was handy!

DonTom
04-03-2007, 04:17 PM
but cost of the plugs would be the reason I guess.

Seems like a rather silly reason to me, considering the better spark plugs often last near the entire life of the car. It still makes more sense to replace them all at once, IMO.

My Sebring (2.5L) is also like that where the upper intake manifold has to be removed to get to the rear plugs. But the plugs last twice as long as a timing belt change, where it's also required to remove the upper intake manifold. I change all the plugs when I do a timing belt change (60K) , which is more often than required for the changing of the plugs.

-Don-

ChevyMan
04-04-2007, 04:10 AM
Ah reminiscing of the days back in the '50's with my in-line 6 1953 Chevrolet 210 sedan where changing of the plugs can be done by a blind man literally.

DonTom
04-04-2007, 06:34 AM
"Ah reminiscing of the days back in the '50's with my in-line 6 1953 Chevrolet 210 sedan where changing of the plugs can be done by a blind man literally."

But then it was every 3,000 miles instead of every 110,000 miles. You spent more time replacing plugs then than you do now.

-Don-

Dave Brand
04-04-2007, 07:35 AM
Those Italians are at it again-- ran out of parts and used whatever was handy!


...or maybe, with two plugs per cylinder, just ensuring that the plugs are not mixed up!

Eric
04-04-2007, 07:58 AM
"Ah reminiscing of the days back in the '50's with my in-line 6 1953 Chevrolet 210 sedan where changing of the plugs can be done by a blind man literally."

But then it was every 3,000 miles instead of every 110,000 miles. You spent more time replacing plugs then than you do now.

-Don-


True - but it was easy, cheap - and kind of fun.

All that's gone now. I miss it, myself.

Jim Rose
04-04-2007, 09:12 AM
>>or maybe, with two plugs per cylinder, just ensuring that the plugs are not mixed up! <<

On an Alfa, I'll stand my ground! ;D

mrblanche
04-04-2007, 10:45 AM
But then it was every 3,000 miles instead of every 110,000 miles. You spent more time replacing plugs then than you do now.

-Don-[/color]


I had a 1974 Yamaha RD350 that fouled the plugs on a 150 mile basis. Extended electrodes helped, but checking the carbs and setting them to the correct setting, rather than the rich-from-the-factory setting, made a world of difference, too.

DonTom
04-04-2007, 05:59 PM
"All that's gone now. I miss it, myself."

But now that you spend less time changing plugs, you can spend even more time talking about it. ;D

"Time is at once the most valuable and the most perishable of all our possessions."
--John Randolph

-Don Quoteman

Kwozzie1
04-04-2007, 07:31 PM
"Ah reminiscing of the days back in the '50's with my in-line 6 1953 Chevrolet 210 sedan where changing of the plugs can be done by a blind man literally."

But then it was every 3,000 miles instead of every 110,000 miles. You spent more time replacing plugs then than you do now.

-Don-


True - but it was easy, cheap - and kind of fun.

All that's gone now. I miss it, myself.


Me too! my Fiat 500 was the one I had to be careful with.....I once stripped one of the thread of the two cylinders when using an airpump. Had to have an insert fitted and rethreaded.

My J1 Bedford also was hard on plugs, and they used to oil up a bit too. I always seemed to knock skin off my hands.

Eric
04-05-2007, 06:50 AM
"All that's gone now. I miss it, myself."

But now that you spend less time changing plugs, you can spend even more time talking about it. ;D

"Time is at once the most valuable and the most perishable of all our possessions."
--John Randolph

-Don Quoteman


There are pros and cons, of course. No question most anything new is superior, in terms of reliabiity and so on. But we've lost some of the mechanical intimacy that used to come from getting close to a machine through frequent raising of the hood, etc.

DonTom
04-05-2007, 10:50 AM
"But we've lost some of the mechanical intimacy that used to come from getting close to a machine through frequent raising of the hood, etc. "

I get under the hoods just a much as ever, but mainly for reasons that never used to exist, such as a check engine light. While the cars are more reliable, there is a lot more junk in them, especially smog junk and that must all be working perfectly here in CA where they have tough smog checks.

-Don-