Originally Posted by hotrodharley
I BOUGHT A NEW SET OF DIAMOND FLAT TOP PISTONS FOR MY 540BBC BLOWER ENGINE I'M BUILDING.AFTER BUYING I DECIDED TO GO ALKY ON ENGINE.NOW I'M BEING TOLD I SHOULD HAVE AT LEAST A 11-1 COMP...PISTON INFORMATION IS 4;50 BORE--COMP HEIGHT IS 1.520--EFFECTIVE VOLUME= -3.0CC
I HAVE A TALL DECK[NEW DART BLOCK.NO MACHINE WORK DONE YET ON IT.]..4.25 STROKE CRANK..6.353 RODS..BRODIX HEADS WITH 119CC CAMBERS RIGHT NOW[I'M GOING TO HAVE CBOGGS DO THE PORTING AND FLOWING ON THEM]
MY QUEST IS CAN I GET THE COMP I NEED WITH THESE PISTONS AND IF SO HOW DO I GO ABOUT IT?
OR SHOULD I SELL AND BUY DIFFERENT PISTONS?
Might be a better move to sell those and get another set. i did the calculis and you have 9.04 with those pistons and 119cc heads, useing .062 gaskets. I don't know how much you can mill the heads to get 11 to 1 ratio. Yrs. ago i was running 13 to 1 with a 1471 littlefield @ 30% overdrive.
Alcohol likes lot's of compression to preform at it's best, but be sure to get blower pistons/dropped ring land.
JMO
Zip.