Whats the deck on a 455'' , uncut, big dish pistons. ???? I have plugged all kinds of numbers in my program got all kinds of different answers,lol. Just can't remember the deck, and piston dish. I can measure them, and will tommorrow afternoon if needed. Just thought I would try here in case someone knew off the top of their head. Putting together a bracket bomb motor,lol. Deck = ??? The piston has to be .050'' in doesnt it ? Chamber = 58cc Felpro = .038'' Dish = 23/6cc ???? 3.900 stroke and a standard 4.313 bore. I am thinking around 9 to 1. Am I close ? Any help appreciated.
I haven't seen a head chamber volume that small on stock heads. I used .025" deck to piston top when I computed my compression. I cc'ed 2 sets of heads and 2 sets of pistons during this process. 1972 Stock 455 Heads = 73cc 1975 Stock 455 Heads = 77cc 1972 Stock 455 Piston = 1975 Stock 455 Piston = 27cc I will have to go back through some threads to see what I got on the 72 Pistons, I think it was 33cc, but need to check. These 75 pistons, which I installed, are a bit of a puzzle. The motor was virgin when I disassembled it. But the compression did not compute to the 7.9 : 1 CR advertised in that year. Figured Buick was emptying parts bins ans slipped a set of 70 pistons in this motor. Using 27cc pistons, 73cc heads, FelPro Head gasket computed @ .040 compressed and .025" deck clearance, I computed my compression the following way: divided stactic volume into displaced volume + static volume = 9.07 : 1 CR Displaced volume = 933.27cc Static Volume = 115.55cc Plugging your #s in nets 9.89 : 1 CR w/ 26cc slug and 10.15 : 1 CR w/ 23cc slug. Forgetting to add static to displaced before dividing gives a false low figure.
I think Daves heads are milled thats why he is using 58CC on his head measurements. Dave, you almost need a Texas oil rig to set up the Dial indicator to figure how far those things are in the hole. My guess is right at about .050 +/-.
Just did a similiar stock 73 low compression motor total combustion volume was 131 cc my felpro's were .045 thick computed compression was 8.07 with pistons .050 in the hole.Cut the heads .060 and got heads to 61cc and on top of the same short block compression was a tad under 8.7 to 1.
