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CR on lq9 ?

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Old 12-31-2008, 12:32 AM
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Default CR on lq9 ?
does anyone know what the cr is on a totally stock lq9 with stock 241 heads on it?
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Old 12-31-2008, 03:06 AM
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Old 12-31-2008, 02:33 PM
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10.70 lower then i thought
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Old 12-31-2008, 03:48 PM
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Originally Posted by 405HP_Z06
Not to steal this thread. Since you have a nice calculator.. How about a
LQ4 with 59cc heads. Think the dish in a LQ4 piston is -6cc. Stock gasket.

Thanks
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Old 12-31-2008, 03:55 PM
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How about an LQ9 with stock gasket and 243 heads?
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Old 12-31-2008, 04:19 PM
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here is everyone a calculator..

http://web.tampabay.rr.com/1bking/ch....htm#calc_comp
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Old 12-31-2008, 05:28 PM
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Originally Posted by WYATT318MOPAR
This calculator, like most, doesn't account for piston top OD and ring depth. It also makes an assumption on head gasket bore diameter that's incorrect. Close but no cigar.
Last edited by 405HP_Z06; 12-31-2008 at 07:34 PM.
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Old 12-31-2008, 05:42 PM
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Originally Posted by 405HP_Z06
This calculator, like most, doesn't account for piston top OD and ring depth. Close but no cigar.

So where is your calculator
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Old 12-31-2008, 05:43 PM
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Originally Posted by STOCK12SECZ
Not to steal this thread. Since you have a nice calculator.. How about a
LQ4 with 59cc heads. Think the dish in a LQ4 piston is -6cc. Stock gasket.

Thanks
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Old 12-31-2008, 05:44 PM
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Originally Posted by GMCtrk
How about an LQ9 with stock gasket and 243 heads?
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Old 12-31-2008, 05:46 PM
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Originally Posted by zx9rgreen
So where is your calculator
On my computer, you can purchase the program from Performance Trends. It's called Compression Ratio Calculator.
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Old 12-31-2008, 06:31 PM
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now the question is that bump in cr worth more then like 5 horsepower
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Old 12-31-2008, 06:46 PM
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I got 10.9:1 for the LQ9 guy on the free calculator, but i guess that little bit can make the difference on a built race motor.
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Old 12-31-2008, 07:36 PM
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Originally Posted by djsanchez2
I got 10.9:1 for the LQ9 guy on the free calculator, but i guess that little bit can make the difference on a built race motor.
If accuracy isn't a concern than why even calculate it? There is only one correct way to calculate compression ratio and as long as the parameters are correct one can't argue with the math.
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Old 12-31-2008, 08:29 PM
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Originally Posted by 405HP_Z06
Much appreciated!
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Old 12-31-2008, 11:08 PM
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Originally Posted by pewter02z28gs
now the question is that bump in cr worth more then like 5 horsepower
If your going to swap heads, at least use some 243's.
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Old 12-31-2008, 11:19 PM
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so it looks like I'll be sitting at right at 11:1. That should give me a nice gain coming from 10.1:1
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Old 12-31-2008, 11:30 PM
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Stock 241's on a LQ9 is going to suck ballz..
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Old 01-01-2009, 12:03 AM
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Originally Posted by the_merv
Stock 241's on a LQ9 is going to suck ballz..
Yep.

I'm personally debating picking up some 241s dirt cheap and having them ported. 11:1 may be too much compression for me. The 67cc 241s would be more friendly
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Old 01-01-2009, 12:19 AM
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Go with L92's..
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