Hi guys,
I would like to change the exhaust manifold gasket because sometimes it smells a lot gazes into the car while driving.
What reference would you recommend for a 383 engine with HP manifold?
Thanks!
I used SCE gaskets.
A little high temp silicone.
Leak free now over 2 years.
Do not use Fel Pro. :thumbdown:
https://www.summitracing.com/parts/sce-4064
Also check out the heat riser, on the exhaust manifold. They will leak exhaust . I sure would like to visit Normandy A lot of history there.
I don't use gaskets between the manifold and the head. I think that is one reason why some manifolds crack.
When they were built Mopar didn't use gaskets, as long as the manifolds are flat they don't leak.... Heat risers can have issues & the manifold to head pipe flange is known to leak.... Usually the head pipe gasket fails because the pipe flange warps....
Thanks for the information!
I think it won't be a easy fix for me... :bricks:
Look for black soot as a clue to where it is leaking. I have even stuck my hand near everything (carefully of course) to feel for air blowing too.
Yes sheldon, i took some picture but for the moment didn t see anything wrong.
I will try engine on!
By looking the picture 1 and 4 i m guessing if it isn't black soot on the orange of the block? :thinking:
Well your team won today. Congrats. :slapme5:
I have to disagree that exhaust manifolds don't need gaskets.
But it depends on the type of gasket material used.
The SCE are a compressible Copper gasket with ridges to add extra sealing.
The benefit is they don't break down and burn out like old style designed manifold gaskets do.
To me that equates to being a cushion, reducing vibrations that would be the reasons for manifolds tending to crack.
Manifolds are alloyed I believe with Silicone from what I remember.
OEM 40 year old manifolds cracking? I can see that.
Now? Not as likely. Technology has improved.
The factory never used gaskets. Both surfaces were machined flat and they sealed just fine. Manifolds can be resurfaced if they aren't flat but it's cheaper to just put a gasket in there. On my small block, I just put a thin layer of high temp silicone on the matting surfaces with no gaskets.
Use a mechanics stethoscope to find your exhaust leak. I heard an exhaust leak and thought I had a cracked manifold. I used a stethoscope and found the problem in 30 seconds. The heat riser shaft was leaking.
:iagree:
I never use gaskets with the factory iron manifolds , if you want to create a leak use a gasket !
Like Burdar I often put a thin layer of high heat / copper silicone though
Thanks for the answers guys!
Welle i have to uninstall them to see how they look i guess!
Sorry but what do you call the heat riser shaft?
Is it what is visible on the picture ? Manifold on the passznger side
The passengers side manifold has a shaft with a flapper valve on it down where the exhaust pipe attaches. This flapper is closed when the engine is cold which forces exhaust gasses through the bottom of the intake and over to the drivers side. This aids in engine warm up. Over the years, the shaft can wear and cause an exhaust leak.
Husk: You see where that pin is coming out the side of the manifold? Near that is a shaft that runs across the manifold and it has a flapper valve inside. Quite often the shaft wears there and exhaust gas leaks out around it. There should be soot there if it is leaking.
Thanks guys!
Now it s clear!
How do you fix it if the leak comes from there?
There should be a shaft that goes across the opening in the manifold that will rotate or used to but it may have already been removed , the pin visable is where the spring pulls against to keep the valve closed when cold
Thanks Chryco!