Exhaust manifold gasket 65 390

[Bob611]

On my 65, I had a cracked manifold on fight side that I had replaced with new one from Birds Nest. From beginning would not stay sealed. Used stock gasket at first which started to leak within a week. Then used a thick one and that was good for about two months, but now you can hear a leak again. My question is, has anyone experienced this and found a successful solution. I'm thinking of going back to stock gasket and using some type of high temp sealant. All and any advice would be appreciated. Also if anyone knows of a good mechanic in the DFW area of Texas, a lot of places don't want to work on the old cars.

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[inspector]

Possibly your manifold is warped. You may have to take it to a machine shop and get it shaved down.

 

[Bob611]

Before installation I did check for straightness, unless it warped since, worth checking. Thanks for the reply.

 

[sre]

On my 65, I had a cracked manifold on fight side that I had replaced with new one from Birds Nest. From beginning would not stay sealed. Used stock gasket at first which started to leak within a week. Then used a thick one and that was good for about two months, but now you can hear a leak again. My question is, has anyone experienced this and found a successful solution. I'm thinking of going back to stock gasket and using some type of high temp sealant. All and any advice would be appreciated. Also if anyone knows of a good mechanic in the DFW area of Texas, a lot of places don't want to work on the old cars.

For what it's worth . Many years ago I had a problem with an exhaust gasket. I took my exhaust manifolds to a machine shop and had them milled. I've done this with probably 12-15 engines, I DO NOT use any gaskets and haven't in at least 25 years. Yes it cost more money but I have no leaks.

 

[Buck]

I have had the same problem on 2 of the three TBirds I have owned. One had a cracked exhaust manifold which I replaced with used one that was warped (like most of them). I had it machined and then for insurance I replaced the gasket with one of the very thick ones. I torqued to specs and then re-torqued after use. That was about 25 years ago. I gave that car to my daughter who drives it to this day. It has not leaked since. I also have a 65 that had a leaking exhaust. The car had several issues when I bought it so I had a mechanic go through several items including the exhaust leak. I told him about the very thick exhaust gaskets but he didn't listen to me and tried a standard gasket and then two gaskets on top of each other which also didn't work. I was not happy! When I got the car home I replaced the exhaust gasket with a thick one and followed the same torque regimen and it has not leaked yet which is going on 10 years. You need to find the special gasket from one of the TBird parts suppliers. I think I used Pat Wilson's for this part.

 

[Bob611]

Thanks, SRE and Buck. That does make sense about having it milled. It isn't a factory part so who know's what their tolerances are in the manufacturing. I will see about having it machined. Appreciate the advice.

 

[74 Harley]

On any FE engine, the exhaust face of the head warps also. If you're going to the trouble of matching the manifold you need to machine the head also. The best gaskets I have used are the copper o-ringed ones.

 

[Bob611]

Head was machined due to broken studs with cracked manifold, just not the manifold. Thanks 74 Harley

 

[Critterpainer]

You might give REMFLEX gaskets a try.

 

[dishmaker]

On my 65, I had a cracked manifold on fight side that I had replaced with new one from Birds Nest. From beginning would not stay sealed. Used stock gasket at first which started to leak within a week. Then used a thick one and that was good for about two months, but now you can hear a leak again. My question is, has anyone experienced this and found a successful solution. I'm thinking of going back to stock gasket and using some type of high temp sealant. All and any advice would be appreciated. Also if anyone knows of a good mechanic in the DFW area of Texas, a lot of places don't want to work on the old cars.

put no gasket there machine flat head and manifold

 

[Thunderbird1963]

the fe motor is a machine fit and yes you can have the manifold and head shaved for trueness. But who wants to yank the motor apart to machine the exhaust side ? If you
Are lucky enough not to have any broken
Bolts you can buy some special gaskets
From a tbird vendor like Wilson’s. They are not cheap but they will work. Regular gaskets like gel pro will burn out in 2 or 3 months.

 

[Bob611]

So not I ordered the correct gaskets with just bolts holes at the 12 & 6 O'clock positions. Now just to gather up the strength to do it myself.
Thanks for the input. Appreciate it!