No exhaust manifold gasket???

[mg911guy]

I am working on my fathers' 65 Cutlass with the 330 v-8. We have pulled the exhaust manifolds and found NO gaskets on either side. What do need to do when reinstalling? We have ordered a felpro set already. Should we use the felpro or not? Will it cause problems if we do use a gasket? Please help. We are waiting until someone can clear this up for us. Thanks In Advance. Mark mg911guy@yahoo.com

[rocketraider]

The factory didn't use gaskets, opting instead for a tight machine fit with graphite grease to seal things. If the manifold and head sealing surfaces aren't pitted or warped, you can probably seal them up again the same way. However, using service gaskets is no biggie. Install the metal side towards the manifold and torque the bolts to 25 ft/lb working from center bolt outward. Run the engine awhile and retorque while hot.

[imported_JPIndusi]

This approach was used on old Buick straight eight engines during the 40's and early 50's. Because the exhaust manifold was fairly long and one piece on the "small" Special and Super 263 cubic inch engine there was a concern that the manifolds would crack as the engine went from dead cold to fully hot. This occurs because the manifold is relatively light compared to the cylinder head which is also filled with coolant. As the engine is started the manifold gets hot very quickly, much quicker than the cylinder head. Given that long straight eight configuration, the exhaust manifold wants to stretch out and get slightly longer but the cylinder head being more massive is not expanding at the same rate. The older system of using gaskets would restrict the exhaust manifold movement resulting in cracks, especially if the head bolts were too tight.
So at some point Buick discarded the gaskets, and used flat compression washers around the intake manifold ports. For the exhaust they used a "special" compound at the factory but for replacement in the field they recommend a mixture of motor oil and powdered graphite. This system evidently sealed quite well and allowed the manifoild to slide a little.
Joe, BCA 33493

[imported_Sgt Art]

Seems to be the norm. I haven't seen exhaust manifold gaskets on any Olds engines, nor have I seen them on 6.2L GM diesel, a 1972, Ford 460 (Lincoln Mk IV) any Chevy even though a lot of gasket kits come with them.

I think you're right about the expansion causing cracks. I had to replace the right side exhaust manifold on the 72, Ford 460 (a common problem from what I've read on other boards). The replacement manifold had what I would describe as strengthening and heat radiating ribs cast on it.