Exhaust Gasket question

[sprice]

I was checking the exhaust gasket against the heads and exhaust manifold and am finding the matching is off slightly, or can be considerably off depending on where the gasket ends up when fastened. Its a Fel-Pro gasket from an overhaul gasket set for a 440. When I apply the gasket and center the front bolt hole, the rear bolt hole and port is out as in the photo. Has anyone experienced this and do the exhaust gasket holes have to be so large? So much play in there.

I could cut and trim the gasket however with so much play in the bolt hole, its still a nit and miss. Thanks,

 

[Big_John]

Best thing to do is to do just like the factory did... and that is not using an exhaust manifold gasket.

 

[Davea Lux]

Unless you are running headers, throw the gaskets in you parts box. If you use them they will just blow out. Factory manifolds were a precision fit that required no gasket.

Dave

 

[Big_John]

throw the gaskets in the trash

Fixed it.

 

[Davea Lux]

Fixed it.

Probably a good choice since the Fel-Pro gaskets do not work worth **** with headers. Been there done that. Could also put them on Facebook "Rare Mopar 440 exhaust manifold gaskets" $50.

Dave

 

[CBODY67]

The indicated style of exhaust manifold gasket is in almost every engine overhaul gasket set, whether they were needed or not. Of course, everybody thinks they need to use them, even if the OEM didn't use them.

Agreed, Chrysler didn't use any gaskets there. IF you feel the need to put a gasket there, get the "black" header gaskets. They have a higher-heat material plus internal wire reinforcements (think re-bar in concrete). The normal "white" header gaskets, should the manifold/header get loose, will quickly blow out. The "black" ones can be retorqued and last. They are more expensive. But you should be fine going "bare", there.

CBODY67

 

[cbarge]

In the past, I went commando and went without exhaust manifold gaskets.
I did however got the logs planed to avoid any leaks.
But on the BoaB with its HP manifolds, I used the gaskets with the heat-shield designed into them.
They do work,no leaks and no signs of any baked valve covers and gaskets.
Richard Ehrenberg sell these and are top notch quality and do match up with the bolt holes and ports.

 

[Big_John]

In the past, I went commando and went without exhaust manifold gaskets.
I did however got the logs planed to avoid any leaks.
But on the BoaB with its HP manifolds, I used the gaskets with the heat-shield designed into them.
They do work,no leaks and no signs of any baked valve covers and gaskets.
Richard Ehrenberg sell these and are top notch quality and do match up with the bolt holes and ports.
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View attachment 232436

Those gaskets were on my 300, installed by the previous owner. He was singing their praises to me when I bought the car. They blew out on the Pennsylvania Turnpike on a Carlisle trip.

He also installed them on a car he bought from me.... I advised against them, but again, he sung the praises and said they were the best thing since sliced bread. They blew out even sooner than I predicted.

 

[Davea Lux]

Those gaskets were on my 300, installed by the previous owner. He was singing their praises to me when I bought the car. They blew out on the Pennsylvania Turnpike on a Carlisle trip.

He also installed them on a car he bought from me.... I advised against them, but again, he sung the praises and said they were the best thing since sliced bread. They blew out even sooner than I predicted.

Years ago, for the race only applications, there was a very thick stainless gasket that was solid metal embossed on one side and machined on the other that was used for the nitrous engines. They were the only gasket i ever saw that would not eventually blow out on mopar exhaust. The header flange or the head would burn out before the gasket. Think they were made by "Mr Gasket" but I am not sure. Have not seen them in 30 years.

Dave

 

[70bigblockdodge]

Little bit of ultra high temp rtv around each port (very thin), no gasket.
Use the gaskets with headers, metal embossed against header flange with ultra high temp rtv and cardboard against head, with headers stop overtightening.