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I bought a 455 apart it came with silverlight pistons 14cc shallow dish not sure if I can use them motor is going into a 69 cutlass street car and a acasional trip to the track I wanna get a good cam for combo with the procomp heads were bought bare car has 3.73 gears th400 3000 stall would like to run hi 11s if possible will the cast pistons work ok or do I need to get forged
Obviously, forged would be better. Cast pistons don’t like detonation, be conservative on the timing, and generous on the fuel octane. I ran a 69 455 stock bottom end for years, and I beat on it pretty hard. I also had a cast piston 66 425, it was worn out and smoked when I bought it. I swapped it into a 78 Grand Prix, it ran well until a piston shattered.
if it going to be a street car with occasional track time, assuming the machine work is good it will probably last a long time. How many millions of engines did GM build with cast pistons?
11 seconds? I am no expert but to run mid 11s your going to need 450+ hp that’s going to put a bit of a strain on the motor and reciprocating assemblies I would seriously consider going forged
Your compression ratio will only be about 9.25:1 with those pistons, a regular head gasket and a set of out of the box Procomps. That will limit you’re cam choices, which will hinder your ability to make it into the 11’s.
I’d change the rods and pistons if you’re really set on going that quick.
Surface heads to 77cc and piston is .005 in the hole piston has a 14cc dish do you w
Originally Posted by cutlassefi
Your compression ratio will only be about 9.25:1 with those pistons, a regular head gasket and a set of out of the box Procomps. That will limit you’re cam choices, which will hinder your ability to make it into the 11’s.
I’d change the rods and pistons if you’re really set on going that quick.
the heads will be surface to 77cc and piston is. 005 in the hole with a 14cc dish but do you think the piston will be a problem we build circle track motors with cast pistons for street stock cars with 0 issues just asking for advice not real formilier with the oldsmobile engines
Last edited by Gene kerr; February 13th, 2020 at 06:07 AM.
Reason: Typed message in the title spot
the heads will be surface to 77cc and piston is. 005 in the hole with a 14cc dish but do you think the piston will be a problem. we build circle track motors with cast pistons for street stock cars with 0 issues just asking for advice, not real familiar with the Oldsmobile engines
Then someone decked the hell out of the block. That piston is only 1.72 high, add half of the stroke and all of the rod length and you get 10.580. Std deck height on a 455 is about 10.630.
I wouldn't use a cast piston if I'm trying to go 11's. Sorry.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Cast pistons were used in NHRA stock for years with 455 Oldsmobiles and ran 11s with stock production heads, so it can be done. But, in the present we have much better, lighter pistons, stronger pistons. Spend your money on good pistons, I ran 11s in less than ideal conditions in the eighties with stock pistons, filled heat cross over, welded exhaust divider, .474 lift hyd Lunati cam, zero bearing problems. STD bore, STD crank, I did have Mondello restrictors in there, stock oil pump, Toro pan, C4B intake 850 Holley. 1970 Toro engine core, very cost effective! Example of an Olds NHRA stocker.
Last edited by VORTECPRO; February 13th, 2020 at 07:21 AM.
February 12th, 2020, 08:34 PM
