Exhaust manifold torque

[fsj1978]

I've looked up the torque specs for exhaust manifold to head in my service manual and it shows 25ft/lbs. That has to be for the older engines that use all six 3/8" bolts. Torque for a 5/16 is 15ft/lbs, and my heads use 5/16 (late model?) bolts (studs now) for the outer ports. I'm using Remflex gaskets that squish a *lot*. So far I've torqued all 6 bolts to 15ft/lbs.

The siemiesed(sp) center ports are much bigger, thus the 3/8 but I'm kind of wondering with as much squish as the gasket has, if it's wise to have uneven stress on the manifold? Or even, would 25ft/lbs be too much for the Ramflex gasket?

So what say ye, ol' great FSJ collective?

Chris

[candymancan]

Im not sure on the torque sorry . but i do know with gaskets you need to re torque again and again and again to keep the gaskets sealed when you drive it.. Otherwise they can spring leaks and burn the gasket out easily.

tbh i dunno why they needed gaskets when chryslers magnum blocks dont use gaskets its just metal on metal and ive never had exhaust leaks on my 5.9l... but this wagoneer has probly 2 or 3 of em..

[FSJunkie]

Would be helpful to know if this was a six cylinder or a V8.

Remflex specifies 20 foot-lbs regardless. I have Remflex gaskets installed on both an AMC six and an AMC V8. Both are torqued to 20 foot-lbs and required periodic retorquing for the first few thousand miles.

I have no idea what you're talking about with 5/16" bolts. I have never heard of any AMC engine using exhaust manifold bolts that small, but I agree that 20 foot-lbs is a lot for a 5/16" bolt to handle. I'd much rather have them be 3/8" and torqued to 20 foot-lbs.

[fulsizjeep]

Good luck getting a torque wrench lined up to get a good read on the wrench if it is the needle style. The AMC V8s did change exhaust bolt size around 1980. When I put the 76 401 in my 88, I found this out the hard way and had to ream the manifold center holes for 3/8" bolts. That was a pita.

[fsj1978]

Thanks for the replies, guys, it's appreciated.

[fsj1978]

I just got a reply from Remflex who said to look at the back of the package (who looks there? or reads instructions?!) And they have the information on their website as well if you've already tossed the packaging. 20ft/lbs is what they recommend but they don't show AMC after 1976.