.080 pistons for 1969 383???

[CLEAN B]

I am rebiolding a 100% original numbers matching superbee. It is bored .060 over, and has been sitting for 20 years. It needs to be either bored to .080, or sleeved. I would rather bore it out, but where will I find .080 oversize pistons and rings?

I also need front (buckets) and rear seats as well as windshield. ANy ideas where I can find these?

I appreciate the help.
CLEAN B
doug@productbuilders.com
530.682.7524

[dave571]

Do you think it will clean up at .070"?

If it would, a 440 std piston is .070" bigger than 383 std.

"Too tall" you may say? No, a smog 440 piston is quite short. A set for a std bore 78 or so, and they will give you a 9. something :1, 396" mopar.

Sonic checking the block might be a good idea first.

[toad490]

What about knurling your pistons? I've heard it mentioned in cases like yours but I don't know much about it. Just a thought.

[Stoga]

Originally Posted by toad490

What about knurling your pistons? I've heard it mentioned in cases like yours but I don't know much about it. Just a thought.

Knurling never seems to last long, that is pretty much pre-WW2 technology anyway.
I'd might do it on an old lawn mower or tractor motor, but not on a car engine, cept maybe something pre-1940s that I wouldnt be driving alot.
Also, I agree on the sonic checking, best to be sure if you got good metal to work before you put your cash down.

[perfmachst]

hello, could bore it another .030, this would make it 4.340, same as a 400 mopar. 4.34-4.250 =.090 total oversize. you already at .060. just food for thought.

[mr_340]

I think I would use the late model 440 pistons as previously mentioned. The later 440 pistons have about the same compression height as the early 383 pistons. You would end up with 10+:1 compression ratio. The standard bore 440 should be enough for a cleanup unless you have a nicked cylinder wall or some deep gouges.



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[DartGT66]

Really not on the subject, but a typical BB open chamber head has 88-90cc chamber voulme. They have about .020" thick stell shim head gaskets from the factory. This means, that with a zero deck piston there is about 93-95cc chambers above the pistons. This means, that with the pistons in the zero deck you typically have about 9.5:1 CR, not 10+:1. Since the chambers hang over the bores at some points, the .020" clearance you get with the steel shims is pretty small and may cause problems, so in practice you will propably need even more clearance and as a result the CR will be even lower.