you stated you adjusted the valves! and only the exhausts are leaking, try backing off the exhaust valves a little. to give them a little more clearance and they might seat better! The intake valves run cooler and the exhaust valve stems expand a little with the combustion temps and might be rising just a hair off the seats! Do the exhaust valves have rotators installed ? Is it a solid cam or hyd.? What did you set the valve clearances at? Is this a Chevy, Volvo, Ford, ETC? Reverse rotation? What r.p.m. did your old engine turn at 30?
Last edited by painted jester; 01-27-2013 at 02:55 PM.