'51 Buick Manifold gaskets

[Kestrel]

While I wait for the penetrant on my heat riser  to do its job, I have a gasket question. I learned here that these engines had no exhaust gaskets when made and only thin metal ones on the intake ports. I bought a full engine gasket kit a while back  (Fusick Automotive) and it has  3 gasket sections that cover all intake and exhaust ports. They look like traditional manifold gaskets. Are these an " upgrade" over factory and okay to install  ? I don't want to introduce anything the engine was not designed to have. I definitely had exhaust leaks so this might be a good remedy. Thanks all !!

 

3 new gaskets in kit

 

What came out on removal

 

[Aaron65]

The best way is to mount the manifold like the factory did.  I've cut the modern gaskets up to just use the intake portions and used the graphite mix recommended in the shop manual on the exhaust.  The exhaust surface of my heads is not good enough, however, to continue to do this, so I've switched to Remflex gaskets.  They are expensive, but they've lasted through two driving seasons, and I never got more than one season out of any other type of gasket.  

 

https://catalog.remflex.com/BUICK_Header_Exhaust_Manifold_Gasket_p/13-007.htm

 

I wouldn't even bother using the ones you have; they will almost certainly start leaking sooner or later, probably sooner.  One note with the Remflex gaskets: the heat riser gasket did not fit; it wasn't even close, but you can use any gasket there.  I always coat both sides with High Temp RTV (not the Remflex gaskets, but the regular ones for the heat riser).

 

To sum up: factory method is best, Remflex is next (IMO).  

Edited January 11, 2019 by Aaron65 (see edit history)

[Kestrel]

 After putting a straight edge across the ports, it was warped pretty bad on one end. Since both manifolds were still bolted together (with frozen bolts)  I decided to leave it that way and take the whole assembly to a machine shop to have it milled true. That way I have a better chance of permanent seal and can decide what gasket method to go with. Why separate them if not needed ?

 

That's a terrific option with Remflex. Thanks for the link. My head mating surface didn't look too good so I'll probably go with their gaskets.

 

Meanwhile, after 2 hours with a propane torch, Kroil penetrant, and a hammer drill (set on just the hammer mode) targeting both shaft ends,  I got that stubborn riser shaft loose. Oiled it with ATF  and machine oil, rotated it  about a 100 times by hand. It easily fully opens and closes now. Plus the old coil rusty thermostat actually works. I applied and removed heat with the torch causing the coil spring to expand and contact turning the the shaft and flapper valve with it,  operating as designed.

 

I just can't believe it.

 

I must confess however, I had direction and emotional support from an experienced fellow restorer I was able to snagg on his way back home from work