(Title should be type of exhaust manifold GASKET

I have looking into exhaust manifold gaskets and there appear to be three main options for my car.

1. $9 fel pro standard (part # BMS90078)
2. $25 fel pro - high performance (part #1439)
3. $35 copper

I want the best appropriate for my car. #2 seems to be thicker and has anti-coating. I don't anyone who tried these though. Some people say copper didn't seal well for them. Worried that #1 won't last long, but heard good reviews.

 

For stock manifolds and iron heads, use 4) none $0. For headers, I'd go with copper.

 

That might be tough if the manifold isn't true after 50 years. I take it that is why people use gaskets?

 

I think people use gaskets because they are used to working on Chevys. In 40 years I've never needed a gasket on a stock Olds manifold (except on my 85 and 86 307s, which came with them for the tubular manifolds). By the way, if the manifold isn't true, a gasket may not seal anyway.

 

Holy Cow I agree if surfaces have been surfaced on option 4. Joe i am using copper with my 468 ebrock heads and ARH 2" headers in my 1970 442 street/race car. Good advice Joe.

 

How come Chevy's need gaskets and Olds don't? If not supposed to use gaskets for Olds, why can I buy one?

I have an exhaust manifold leak but maybe it is not a gasket leak. The manifold maybe needs to be smoothed then?

Do mechanics just install metal on metal or do they use any type of paste?

 

You'll have to ask Chevrolet why they do what they do. I do know that you won't find exhaust manifold gaskets in the Oldsmobile factory parts book, nor will you see them called for in the factory Chassis Service Manual. Aftermarket companies sell anything they think they can make money on, whether needed or not (witness the "spiral" throttle body spacers that promise incredible mileage improvements). Most "mechanics"at fail to read the factory service manuals and do whatever they want (witness how most machine shops incorrectly set up Olds valves when they do the heads).

One more time: the FACTORY says no gasket is needed, nor did they use one. If it lets you sleep better, feel free to spend your money and use gaskets.

 

Thank you! I don't want to buy a gasket! I just have to sound like I know what I am talking about when I approach my mechanic.

 

The last few Olds top end engine gasket kits I bought came with them. If you feel you need to put a gasket on them, go for it. It won't hurt anything.

 

My factory manifold has some pitting on it leaving the surface a little rough. Would this be good application for the gasket or still no?

 

I talked to the mechanic. Says that most old cars he works with has leaks /imperfect block so the gasket is a safer bet, but if the both surfaces are true, metal on metal is better.

Thanks gents- learn so much here!

 

Yes if you are not going to have them resurfaced.JMO

 

My Caddy’s engines didn’t use gaskets either.

 

While I agree with Joe, if you have to use gaskets, and they just won't seal, I've had good luck with the multi-layered aluminum gaskets. Summit sells them, I believe Mr. Gasket is the maker. I have a '68 Toronado that has had the manifolds decked a few times. The aluminum gaskets were the only thing I could get to seal up permanently. Noisy exhaust manifolds are a common problem on both Toronados, and later, the GMC motorhomes that the powertrains went into. My car would blow out the Fel-pro gaskets in a matter of weeks.

 

SCE copper gaskets with freshly milled manifolds.


No issues in 10 years of driving.

 

It's worth pointing out that -- manifolds or headers, gaskets or not -- nothing will stay sealed if you don't do something to keep the five bolts from backing out. The factory used sheet-metal thingies on which you fold over some tabs to keep the bolts from rotating. I've had good luck using simple lock washers with grade 8 bolts.


Also, make sure you don't overtighten the center bolt, especially if you're using gaskets. Since it's not in line with the others, it can tilt the manifold and cause less gasket compression along the bottom. (Of course, it should go without saying that you should never over tighten a bolt and in fact should torque them to spec. But it's a little hard to get a torque wrench in there, especially with headers.)