I have d3ve heads and I am wanting to get to 12:1 compression. My block is bored 60 over and I have the TRW domed pistons. How much do I have to get to 12:1. Mill the heads, but how much? Anyone know. Thanks

 

well first thing we need to know is how many CC the dome is? second how close to the deck the piston is (not the dome but the flat part of the piston) without those 2 figures there is no way to calculate what is needed.

 

I will have to check on those things. Thanks

 

I think the dome on the forged TRW/Speedpro 460 pistons is in the neighborhood of 12(ish) CC's. Because of deck height changes over the years, the year your 460 block was made is also a factor when figuring the static compression ratio.

 

what size is the chamber on d3ve heads? Is it 92 cc?

 

94.7 to 97.7 according to my 1980 shop manual. I measured mine and found the largest to be 99 due to corrosion (this engine sat around unused quite a while). I used my die grinder to even them up to 99.
KB 137 pistons have now given me about 9.5:1 CR

 

Ok using some assumptions here, 12cc dome, nominal 95cc heads, and the pistons at zero deck you have approx 11.33:1. To get to 12:1 you would need to get your chambers down to 89cc (if the other figures are correct lke zero deck and 12cc dome) it takes approx .006 per CC on these heads so you would need to take off .036. I would just go with .035 and you are going to be in the ballpark.

 

If your shooting for the 12:1 neighborhood, a combo using a TRW flat top, zero deck height, and the early, smaller combustion chamber head (C8,C9,Dove) would give you a lighter piston/better flame travel combo without the dome.