Quote:
Originally Posted by BYEBYE2U
Tom
You have the right idea about bumping comp. but unless you mill the "215"s ALOT you will not see a point
Use a set of TRW/Speed Pro H693CP with a .230 dome that will give you 10-1 with your 781 heads
Look for a slightly bigger cam in duration around 225-235 degrees of duration on the intake @.050
Do not exceed 240 duration with power brakes !
Definitely bump spring pressure up at least by 20+ lbs
Mill block n heads flat n drive over to Astoria NY n we will assemble engine
Got Fel-Pro gaskets n oil pump waiting for you
Congrats on retirement
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Thanks, and will keep you in mind for the engine assembly......
Quote:
Originally Posted by RICHARD TILL
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.
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Questions for the two of you.......
1- I checked out the pistons from Summit and they are reasonable.
Since I already own the roller cam that I mentioned above, can I still use those "215" heads with the new pistons and that cam without any complications?
2- Can I use that roller cam with the stock pistons and one of the "781" head sets that I have without any complications?
3- Will the roller cam that I have create a vacuum problem, and if so, will an additional vacuum tank correct that problem?
4- I may be doing away with my vacuum headlights and go electric, since I have all the parts to do so. If that be the case, will the vacuum from the factory reservoir be sufficient enough for the motor to perform properly?
Again, thanks for any opinions and advice......
