Exhaust leak between intake and exhaust manifolds. (1 Viewer)

[AJFJ40]

I have a 1970 F engine that was leaking exhaust where the exhaust and intake manifolds bolt together. I took the manifolds off, cleaned up the mating surfaces, put in a new gasket and put in back together. Well the thing still leaks-now what? I did notice that the mating surface on the exhaust was slightly uneven but it seemed like the new gasket was tight. Any suggestions would be appreciated.

 

[bandy rooster]

i have heard in some application people double up the gaskets, you could get the manifold milled but that would be pricey, and i would also use a hi-temp gasket sealer... like an rtv type solution

 

[Poser]

You could try to double-up the gaskets, with some high-temp RTV...but I would not expect that to last too long either....as there is a lot of heat/stress on the joint where the intake and exhaust bolt together under the carb....


You may find another intake and exhaust in good shape someplace and could install that...or you could install headers like a lot of folks do,(myslef included) when this and a big crack was the issue back in 1988...


I tried the multiple gasket route, and the machining the surfaces true again...to no avail.


Good luck!


-Steve

 

[rgentry]

Is it still leaking in the same place? Did you put the intake and exhaust on the head "loose" and then tighten the nuts that connect the manifolds to the head and the bolts that squeze the two manifolds together at the same time? On the early manifolds, the two of the bolts go through the exhaust (cast iron) manifold and thread into the soft aluminum intake manifold. The screws strip in the intake sometimes and don't provide the necessary clamping force to stop it from leaking.

A question for you "double up the gasket" guys. Are you talking about doubling up the manifold gasket or doubling up the gasket that goes between the two manifolds?

 

[AJFJ40]

The two bolts into the aluminum were striped, but I had that repaired at a machine shop. I bolted the two pieces together and put in as a complete unit.

 

[bandy rooster]

hey didn't notice you lived in PA, where at? i'm getting rid of my F engine and have headers on mine if you still have the problem i'll let ya have them for a cheap price. where are you located? if your close enough i'll swing by and stare at your cruiser

 

[AJFJ40]

I'm outside of Altoona a few miles. My cruiser is nothing you will want to stare at for long. But I'm trying to slowly make it functional on a minimal budget. I would be interested in your header if I can't get this thing figured out. I am going to look into the high temp RTV and give that a try unless someone comes up with something better. What do you want for the header? I should probably consider it in case the repair doesn't last long.

 

[bandy rooster]

50.00 i only live a short distance from you, i could even give you the down tubes and exhaust i have for it , its a 6 into one and sounds good, you can have it as soon as you want it. nothing rustic either