Joseph Bisinger
New Member
I have a 1965 383 stock dished piston and summit k6400 camshaft with 452 cylinder heads with edlebroke preformer intake manifold. What would be my compression ratio and would it be a dog or not.
383 compression ratio
- Thread starter Joseph Bisinger
- Start date
IF the engine started life as a 2bbl, then the rated compression ratio was 9.2 to 1. IF it started life as a 4bbl, then the compression ration would be 10.0 to 1. All with 73.5cc cyl head combustion chamber volumes.
Using .040" compressed thickness head gaskets and the larger 79.5cc combustion chambers on the earlier motor's factory pistons would drop the CR about 1 notch. To 8.2 and 9.0, respectrively, with factory pistons.
Next question is what pistons are actually in the motor? By observation, unless "pains" are taken to maintain the factory compression height (distance from the piston pin centerline and the top of the piston), they something more generic can result. Which means one piston fits a lot of different compression ratios, usually lower than what the factory used back then. So, conceptually, you could end up with a "high 7s" compression ratio with the larger chamber heads you mention.
Next question is about the cam specs? Duration at .050" valve lift and total valve lift, for example? Intake and exhaust system on the car now? Carb size?
Unfortunately, not a easy answer to your question.
As to the "dog" part, that depends upon your expectations and ultimate use. Just doing a "plug 'n play" installation, the "dog factor" might be a bit high, I suspect. With competent tuning and adjustments (carb jetting and distributor timing), the DF might be decreased a bit, I suspect.
Just some thoughts,
CBODY67
Using .040" compressed thickness head gaskets and the larger 79.5cc combustion chambers on the earlier motor's factory pistons would drop the CR about 1 notch. To 8.2 and 9.0, respectrively, with factory pistons.
Next question is what pistons are actually in the motor? By observation, unless "pains" are taken to maintain the factory compression height (distance from the piston pin centerline and the top of the piston), they something more generic can result. Which means one piston fits a lot of different compression ratios, usually lower than what the factory used back then. So, conceptually, you could end up with a "high 7s" compression ratio with the larger chamber heads you mention.
Next question is about the cam specs? Duration at .050" valve lift and total valve lift, for example? Intake and exhaust system on the car now? Carb size?
Unfortunately, not a easy answer to your question.
As to the "dog" part, that depends upon your expectations and ultimate use. Just doing a "plug 'n play" installation, the "dog factor" might be a bit high, I suspect. With competent tuning and adjustments (carb jetting and distributor timing), the DF might be decreased a bit, I suspect.
Just some thoughts,
CBODY67
cbarge
World Famous Barge in a Budget
The lifters in that kit will not fit 1965 block.
The duration and lift are fine and should work with the 452 heads.
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