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Old 11-15-2017, 07:27 AM   #11
Celsdogg
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Quote:
Originally Posted by 325ftmfw View Post
if you're only boosting it lightly on a street car I wouldn't worry too much.
put some ARP studs in if you can. Years ago we used to boost the
20v silvertops to 10psi and they run a 10.5 comp on a standard gasket and bolts.

at least being cat free it can shed the heat a bit easier. Not like it will be on full boost constantly.


4AGE?!?!
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Old 11-22-2017, 10:31 PM   #12
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Just an idea. Since you already know exactly what your swept volume is, bottom out a piston and fill the cylinder with that amount of liquid (I was thinking maybe seafoam), have a clear tube that shoves into the spark plug threads and seals, make sure both valves are closed and measure how much fluid it takes to fill it up to the threads. Swept volume:combustion chamber volume
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Old 12-11-2017, 01:14 AM   #13
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4AGE?!?!
yep
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Old 12-11-2017, 01:34 PM   #14
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you just need to know your measurements and you can do compression ratio.

but the fluid way is generally the best way to get your volumes to get compression ratio.

but you know the cylinder bore and the stroke so you just head chamber volume and you got it to figure it out.

pie x radius squared is your area. that times the stroke plus the chamber volume gives you the full displacement of that cylinder. get your stroke and do the math to figure out how much to subtract from the full displacement and then you just have to divide the numbers. will come out with x.xxx so it would be x.xxx:1

if I was at home, I could write out the formula for you because I have it written on an empty page in my aviation mechanic handbook because that is part of the formula to figure out horsepower for an engine
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Old 12-12-2017, 08:55 PM   #15
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the math is not the problem, knowing which of the 3 variants of the M20B25 i have is the problem.
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Old Yesterday, 07:50 AM   #16
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ahhhh, ok. I misread
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