jeepguy1948
Well-known member
Paul Shin recommends a sealant between the exhaust/intake manifold gasket (only the engine block side of the gasket). There are soooo many high temperature sealant’s available that I don’t have a clue which one to use.
Manifold Sealant
- Thread starter jeepguy1948
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Gary WA
Well-known member
Permatex Ultra Copper i just use small amount on exhaust ones.
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Jim Brierley
Well-known member
Or no sealant at all!
Y-Blockhead
Well-known member
Synchro909
Well-known member
For years I have used a wipe of High Temp RTV silicone on the block side of the gasket. It works well so I'll keep on doing it.
As for being fussy about the two manifolds forming a flat face to go against the block, on a RHD car too much machining means you lose the clutch. That means it i better to keep it to as smaller minimum as possible, even if it means using a sealer.
As for being fussy about the two manifolds forming a flat face to go against the block, on a RHD car too much machining means you lose the clutch. That means it i better to keep it to as smaller minimum as possible, even if it means using a sealer.
Gary WA
Well-known member
seems like excessive torque number? Had model a's for 60 years never torqued! Where did this number come from??
You need to be careful you don't overtorque or you run the risk of breaking the ears off the manifold(s). If that happens, you're screwed.
I torque to 25 ft-lbs not so much because I want torque, but because I want even pressure across the gaskets. I use the two-piece copper clad, late '31 style.
Synchro, I will freely admit to being ignorant of how things mount up on a RHD car, but how does decking the intake/exhaust manifolds a few thousandths of an inch (tenths of a millimeter) interfere with the clutch? Not questioning your statement, just trying to learn.
I torque to 25 ft-lbs not so much because I want torque, but because I want even pressure across the gaskets. I use the two-piece copper clad, late '31 style.
Synchro, I will freely admit to being ignorant of how things mount up on a RHD car, but how does decking the intake/exhaust manifolds a few thousandths of an inch (tenths of a millimeter) interfere with the clutch? Not questioning your statement, just trying to learn.
nkaminar
Well-known member
You can torque to 55 foot-pounds. Check the torque after the first heat and 100 miles and 500 miles, and each year thereafter. Correct gasket, proper surfaces, and proper torque will get you further than the gasket sealer. The paper gaskets will burn out after a few hundred miles. Although there is no harm in using the gasket sealer.
Synchro909
Well-known member
A few thousandths of an inch won't matter but when it has been done a few times or there is a big difference to correct, it can become problematic. Try putting your fingers between the exhaust/muffler pipe flange and the block. There is not much room there. That is where the clutch pedal arm goes. Even taking more metal off the bottom edge of the manifolds by poor machining makes a difference in closing up that small gap. If there is not enough room, the pedal can't be pushed down far enough to disengage the clutch because it hits the flange. IMO, not one of Henry's better design features on the Model A and he should have known better - after all, he sold lots of RHD Model Ts.
The vendors now offer exhaust clamps with bolts only - not nuts and bolts as Henry did it. I have been converting my clamps like that for many years and I bet the idea was originally from a RHD owner. It eliminates the need for a nut, thus making the orientation of the clamp less critical.
German guy
Senior Member
Permatex Copper spray sealant on both sides of the gasket! Spray it on rather generously and allow it to sit (I hang mine from a string to get at both sides) for a few minutes before mounting it so that it does not drip onto the engine (it is a pain to scrape off once it dries).
jeepguy1948
Well-known member
The reason that I’m asking is that Paul Shinn uses a sealant on the block side of the gasket. I’m not saying that Paul knows everything there is to know about a Model A but I sure as heck respect his opinion. Paul torques to 45-50# as well.
FWIW this is an RHD car.
FWIW this is an RHD car.
Bob Bidonde
Well-known member
I agree with "no sealant." I also say that the steel clad manifold gaskets are the most durable for Model A's that get used regularly.
Big hammer
Well-known member
That’s the way I do it !
I’ve wondered why the connection between the two manifolds, the carburetor inlet air is preheated by the exhaust pipe !? No need to add more heat into the engine , better gas economy??
Y-Blockhead
Well-known member
To improve fuel vaporization. Even V-8s have an exhaust cross over in the intake manifold to heat the gas.
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old ugly
Well-known member
i wouldn't believe everything you hear and see on the YouTube or from Paul Shin.
if the block to manifold mating surfaces are good it don't need sealer.
i have never used sealer on the Model A manifold, even when using any of the different available types of gasket materials. no issues.
i do like the gland rings when the block and manifold will accommodate them.
if the block to manifold mating surfaces are good it don't need sealer.
i have never used sealer on the Model A manifold, even when using any of the different available types of gasket materials. no issues.
i do like the gland rings when the block and manifold will accommodate them.
Mike1291
Senior Member
How about for the engine blocks that are not so good? Mine has some pitting, especially around #4 where it has an exhaust leak. Tried filling with high heat epoxy, using copper sealant, and the copper gaskets but no luck. I can try being more aggressive with the epoxy but not sure if I'm just going to make things worse by doing so.