Exhaust Sealing??

[OLDMANSOLDSBOAT]

:confused: Hey guys I'm new to the board... I need some help with the exhust logs. My problem is they won't seal. We are running a 455 w/ alumminum heads and through transom exhaust. What gasket should I be using? and are there any tricks to make this happen. :hammer2:

[sdpm]

First make sure they are flat with a straight edge. If they are o.k. scuff them up a little with some coarse sand paper. Then clean with lac. thinner. Don't use any gaskets! Put a bead of Permatex Ultra Black #598B on the manifold side and a thin layer on the clean side of the head! Studs work a little better than bolts! Install manifolds and don't over tighten. Let dry. Start engine and let it warm up then let it cool all the way down and then retighten again not to tight. Make sure timing is correct and engine is not running too lean. This should work for you. Good luck. Neil ;)

[FLOJO]

Take Them To A Engine Rebuilding Place And Have Them Re Surfaced. I Did That To My Logs I Think The Guy Charged Me 30.00. He Just Had A Large Flat Belt Sander.

[riverbound]

My buddy had this same problem with his, he took them to a machine shop and had them straightened out. He also runs to sets of gaskets and that black sealant.

[mgar_red]

Been there, done that. I tried the no gasket, high heat silicone method after hand planing my logs to what I thought was flat across, using a straight edge. Finally went to a former t/f drag racer's machine shop and had them milled true for $25/ea. Run one set of Mr Gasket Ultra Seal w/o silicone and they seal just fine.

[Ken F]

Not sure if they make them for an Olds or not, but Earls Performance Products makes some great header gaskets which sure stopped mine from leaking on the old boat. They are re-useable too...they claim 8-10 uses.
Ken F

[notfastenuf]

Has anyone split the flange between each exhaust port on their logs? I saw this done on an old set of logs and was told it help to seal them up I don’t know if this will help or not.