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RICHARD TILL · 03-03-2016

About 30 years ago i installed a .578/.578 solid lifter cam with the same pistons and rectangular port closed chamber heads. 2.190/1.880 valves. Heads were shaved .030 . The valves hit the pistons. No money for new pistons so i took a die grinder and afro-engineered the valve reliefs. It looked awful. Was in a jet boat and would turn 5500 rpm`s @ wot. Ran it one summer and replaced with forged TRW`s. Dome height was about .250 . BYEBYEU gave good advise on a cam. @ .050 duration a .230 cam will just begin to lope. @ .240 it`ll be more than just a lope with an increased idle speed and decreased vacuum. If you don`t have enough intake manifold vacuum, it wont close the power valve. Then it`ll be rich at idle and the exhaust will burn your eyes. Replace those pistons and use Melling M77 oil pump. Fro-Pro gaskets. Some of those heads had exhaust valve rotators and aluminum spring retainers. Both belong in file thirteen. Good insurance is to upgrade the 3/8 rod bolts. Lets build a monster that will survive.

03-03-2016	#19
RICHARD TILL Join Date: Aug 2005 Location: Iuka, Mississippi 38852 Posts: 756	Re: The Time is Now...... About 30 years ago i installed a .578/.578 solid lifter cam with the same pistons and rectangular port closed chamber heads. 2.190/1.880 valves. Heads were shaved .030 . The valves hit the pistons. No money for new pistons so i took a die grinder and afro-engineered the valve reliefs. It looked awful. Was in a jet boat and would turn 5500 rpm`s @ wot. Ran it one summer and replaced with forged TRW`s. Dome height was about .250 . BYEBYEU gave good advise on a cam. @ .050 duration a .230 cam will just begin to lope. @ .240 it`ll be more than just a lope with an increased idle speed and decreased vacuum. If you don`t have enough intake manifold vacuum, it wont close the power valve. Then it`ll be rich at idle and the exhaust will burn your eyes. Replace those pistons and use Melling M77 oil pump. Fro-Pro gaskets. Some of those heads had exhaust valve rotators and aluminum spring retainers. Both belong in file thirteen. Good insurance is to upgrade the 3/8 rod bolts. Lets build a monster that will survive.