Has anyone here used the stainless exhaust manifold bolt on stock manifoldso No: I was wondering how the do with the heat and expansion on the stock cast iron manifolds. Also, do they stay in, or not. Are they always vibrating looseo No: Thanks, Dan:3gears:
I have not put in a set, but I stopped by TA Friday and bought some. Dave told me they are made to Grade 8 strength.
They will loosen up due to the way they react differently than the manifolds going through the heating/cooling cycles.
Grade 8 strength? Doesn't sound right to me. If I remember, I'll look it up tomorrow. There are a lot of grades of stainless, but still generally weak.uzzled:
I have used the Stainless bolts on stock exhaust with great success. I have early stuff so they have stainless lockers that prevent the bolts from backing out.
Once I used 304 stainless studs in mine for attaching the pipe flanges to the manifolds and when I tried taking them out 1 year later they were siezed in quite badly. I used brass this time.:bglasses:
Re: Grade 8 strength? Stainless steel fasteners can be made to EVEN STRONGER than grade 8 strength. Check out ARP's product line.
The Vega actually used an aluminum block with cast iron head. The problem was with the steel cylinder liners used in the aluminum block and the radiator Chevy chose to use in these cars. The radiator could barely keep the stock engine cool as it was rough 16" tall and no more than about 20" wide. Charles
Since you guys are discussing Vegas--got to get this correct--Vegas didn't use steel cylinder liners--that was their downfall---GM thought they had a great new invention in treating the aluminum cylinder walls with some chemical process that would eliminate the need for steel liners--great idea in theory--but not in actual use. Apparently the process used to apply the chemical did not result in a thorough or complete application of the process, thus leaving "bare" untreated areas on the walls. Now we have the complete history of the Vega Cylinder Wall. Patton
FYI I've been using stainless bolts for the cast iron manifolds now for 4 years with not backing out or problems removing. The ticket is to use anti-seize on the threads due to the two different metals used heat and moister can seize one very rapidly. No real need to use grade 8 harden bolts on the exhaust, no big torque used there. corrosion is your enemy. fernando
