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New exhaust manifolds

briang0

Regular Contributor
I am in the process of putting

I am in the process of putting new exhaust manifolds on my cs280 "Chevy 409". The old manifolds were camel hump style the new ones are generic log style. The engine is at a slight angle higher in the front lower at the fly wheel approximately 1.5 to 2" difference. The old manifolds the raw water in went in the front or the "high" side. The risers did not have a separate fill it just fill up the manifold and out the riser. The new manifolds give me an option to feed the raw water into the low side and then to the risers I have to run a hose to feed the new risers unlike the old. Which will mean feeding the manifold on the low side cloest to the riser and then running a hose to the riser from the high side approximatly 2'.I remember reading that this is better way it helps reduce air pockets. The old ones didn't seem to have a problem worked for years. The question is do I leave well enough alone or change it to the "right" way?
 
The water should enter the man

The water should enter the manifold at the low side for the reasons you stated. Stu
 
Be sure your risers are high e

Be sure your risers are high enough or water may get in. You can buy (usually) spacers of various heights to raise the riser higher. These can be stacked as well.

Jeff
 
Thanks for the help. I know n

Thanks for the help. I know now what I need to do. The fittings are in and this weekend I plan to install. Hopefully I'll turn her over and things will be good.
 
One more thing. Osco says no

One more thing. Osco says no teflon or pipe goop on the threads of the fittings because it could cause the manifolds to crack when they expand. How about it what is the general consensis on this. goop or tape or dry ?
 
"I put tape on mine, hard to b

"I put tape on mine, hard to believe teflon tape would cause a manifold to crack, that worries me about the quality of the manifold unless I am missing something."
 
I;m opposed to silicone or oth

I;m opposed to silicone or other stuff that can plug the tiny water outlet holes.

Jeff
 
"You'll never get them sea

"You'll never get them sealed without something. That's cast iron, not titanium, it's very porous."
 
"Serious, Senior Richardo, I h

"Serious, Senior Richardo, I haven't had a problem using just good gaskets and tightening them correctly.

Jeff"
 
I ended up putting never-sez o

I ended up putting never-sez on the fittings. I am not planning on putting anything on the paper gasket between the riser and lower piece or on the gasket between the log and the head. So far I haven't fully asssembled every thing due to a lot of rain this weekend. Hopefully I'll get to it in the next two nights.
 
"Jeff,, I don't believe B

"Jeff,, I don't believe Brian was referring to the gasket surfaces, just the threaded fittings, as was I."
 
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