Poorsche

We pulled one engine this afternoon and mechanic reports all exhaust manifold bolt heads are badly rusted and need replaced on both engines. The bolts are just at three (3) years old.

I asked about replacing with stainless bolts and mechanic felt that was bad choice--said stainles was too btille and couldn't be torqued properly without breaking bolts...

Is 3 years reasonable life expectancy for these bolts? Is stainless a solution or problem?

While I've got engines out I want to fix everything possible for longest term fix in salt-water enviors..

Thanks-

Poorsche

formula31

well, I dont use any 300 series stainless bolts that have to handle any torque or load, but, exhaust manifolds are not torqued enough to cause a problem with stainless. Ive used them for years. Use neversieze if going into aluminum heads.

Danny_Ocean

Just discussed this very same issue in detail. Feel free to read my recent post:

http://www.offshoreonly.com/forums/s...threadid=75258

ARP makes hardened S/S bolts. Find another mechanic.

D. Ocean
Pompano Beach, FLA

Dixie Doug

Merc HP exhaust uses S/S bolts.If you use steel,try to put some kind of sealer on the outside.And you could make sure you wash the salt off those rear bolts.

deboatmon

I have found it useful in many applications to install a couple of studs in each head for the exhaust manifolds. Maybe one each end or so. This allows the gasket to be kept in place easily during installation.