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Do the math, first !!
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Discussion Starter #1 (Edited)
can anyone tell for sure the exact and total cc of the valve pockets for the SE 103 forged flat top piston, so i can calculate CR thanks
 

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HATER OF THE GRAVEL!!!!!!
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5,761 Posts
Using Big boyz compression calculator, ASSUMING 85cc head chambers and the stock piston with 1.5cc for the valve reliefs and a stock Harley headgasket (0.045) and adding in Cleveland's 800 foot elevation and assuming your deck height is 0.034 on both cylinders.

You should have a static compression of 9.28:1 and adding in the SE-255 can strait up you should be right at 9.0:1.

IF you used the Cometic headgasket (0.030) with the same above you will have a static of 9.53:1 and a adjusted running with the SE-255 of 9.24:1.

The only way to really know is to blueprint the top end, this will require the heads to be removed to measure everything on both cylinders.
 

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Do the math, first !!
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389 Posts
Discussion Starter #4
OK thanks, my understanding was, the forged were larger than the cast. is that correct ? also than, would the forged be closer to 2.0 and the cast be closer to 1.5 ??? i want to make sure i got my facts straight .
 

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Do the math, first !!
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