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Old 07-29-2020, 03:28 AM   #61
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Join Date: Jul 2019
Location: Southern Oregon
Posts: 520
Default Re: Let's build a drag race 8BA engine

One more time

I didn't read the whole 2nd page! I now know that it 11 lb per CI, right?

First a FH will put out more HP per CI, the smaller it's displacement. The ports are the limiting factor, they are only 1.312, in diameter. You can increase the size a with a high level, grinding effort but the middle area is the most difficult and much harder to make consistent. Bigger intake valves won't do much w/o opening that port.

It was mentioned to use 239 CI and 2629 lb so I have a suggestion. I'm building a 21 stud at 3.142 (.080 over) and I'm going to have a 59A crank offset ground to 3.85 stroke, equaling 239 CI. The stoke isn't so much for CI but, much more to increase the CR, using my Victor compressed thickness of .060.

I goes like this:

1/2 stroke = 1.925

Rod = 7.00

CH of piston = 1.53

Block 10.437

Head gasket = .060
0.042 piston to head clearance with FT pistons and heads.

You can juggle the dimensions any way you want, such as different head gasket thickness, stroke lengths and CH's But, what ever you do, get that piston as high as you can w/o getting under .036 clearance.
'35 Ford Model 51
'48 Ford F3

Last edited by frnkeore; 07-29-2020 at 12:44 PM.
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