I've been trying to see what compression I will get if I put P73 A0 (US ITR) pistons in my B17A.

I used this compression calculator http://www.ff-squad.com/technet/cr-calculator.htm and got 10.042:1.

Then I tried this one http://www.c-speedracing.com/h...c.php and got 10.224:1.

Now which is correct????? I think the 1st one is probably correct because I know a B17A is supposed to have 9.7:1 compression stock and it says 9.679:1, but the c-speed one says 9.54:1 stock. Can someone tell me what the compression will really be with the P73 A0 pistons in a B17A?

 

come on now.. somebody has to know.

 

come on.. somebody help me with this

 

My experience with comp calculators are that they give you quick ballpark answers.They make a few assumptions that can be critical if added up.They assume that the head has never been surfaced or had a valve job.To know the true compression ratio you need to measure the parts your going to use.I measure the deck height,measure the dome or dish,measure the head volume.Then breakout the $2 calculator and I have the real number.The numbers you have would tell me that if I wanted a 10.2 to 10.5 I would have a shot doing it.
Glenn

 

thanks man.. finally some help. but considering everything is stock and none of the parts have been modified, which would be more accurate?

well at least i know now that it's safe to say my compression will be somewhere between 10.0:1 and 10.3:1, either of which is ok for what i'm trying to achieve.

 

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