Old Corvette Engine

[Oldsmobile Doctor]

Working on an old Corvette engine in an older truck that has the ram-horn exhaust manifolds. It keeps burning the valve cover gaskets over the two center exhaust ports. I have tried the Felpro reinforced blue silicone with ultra blue sealer. I have used the Felpro thick cork with hi temp orange sealer. I just put the Felpro thick cork with the fast dry hard set permatex. My question is what did GM use and or does anyone have any ideas?

Thanks in advance
Chris Garnett

[MrPbody]

Chris,

Try richening the mixture and/or increasing initial ignition timing. The exhaust shouldn't be that hot. Do the anifolds "sweep" towards the rear where they "dump"? If so, those are "truck" manifolds. Not uncommon in the mid-to-late '60s and '70s.

Jim

[Oldsmobile Doctor]

Straight down in the middle, The truck idles for real long periods running the PTO for a pump for lawn chemicals. The guy who owns the truck takes care of the carb settings and is particular. The engine has hi compression pistons and can't set the timing too much advanced. I guess if he wants to keep paying me to change gaskets so be it.

[MrPbody]

If it's supposed to have "hi octane" gas, and it's not getting it, and timing is being retarded to "compenstate", it will only get worse, until the rings simply give up. Even if the "pinging" can't be heard, it's STILL detonating.

I would tell him to richen it up a LOT, at least at idle, so he doesn't continue to "burn it up". Being "particular" is no guarentee he's doing it correctly.

The straight "dump" indicates passenger car exhaust. NOTE: ALL Chevys of the early '60s used "Rams Horns" exhaust, not just Corvette. So is it like a 340-"bigger" HP 327?

FWIW

Jim