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Compression Ratio
#1
If a stock Cleveland with closed heads ('71) had a compression ratio of 10.8 to 1, what would the ratio be if the cylinders were bored to .030?

mike

[Image: 1_11_11_13_11_50_27.png]
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#2
How's your math skills. http://www.csgnetwork.com/compcalc.html. You'll like this. did it manually once.

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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#3
markmel;37936 Wrote:How's your math skills. http://www.csgnetwork.com/compcalc.html. You'll like this. did it manually once.

Have to get my slide rule.

mike

[Image: 1_11_11_13_11_50_27.png]
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#4
Nah! Just good measurements.
Pulled out what I wrote on a piece of paper when I did it on my 454 .030 over

57.55+.216+.275+.795+5.98 64.18
________________________= _____ = 8.92:1 w/ flat top 2 valve relief
.216+.275+.795+5.98 7.266

So we had to greatly improve on the last rebuild! Tongue
DAHH! forgot to give you the formula.

Cylinder volume+clearance volume+piston volume+head gasket volume+chamber volume
________________________________________________________________
Clearance volume+piston volume+head gasket volume+chamber volume

Sorry

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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#5
markmel;37939 Wrote:Nah! Just good measurements.
Pulled out what I wrote on a pice of paper when I did it on my 454 .030 over

57.55+.216+.275+.795+5.98 64.18
________________________= _____ = 8.92:1 w/ flat top 2 valve relief
.216+.275+.795+5.98 7.266

So we had to greatly improve on the last rebuild! Tongue
DAHH! forgot to give you the formula.

Cylinder volume+cleaance volume+piston volume+head gasket volume+chamber volume
________________________________________________________________
Clearance volume+piston volume+head gasket volume+chamber volume

Sorry

Addition involved also? Have to get my abacus.
Neither slide rule nor abacus use batteries.

mike

[Image: 1_11_11_13_11_50_27.png]
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#6
It's not that bad. But good to know when:
"We have great plans for the future" during your rebuild!

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
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#7
goodnigh;37926 Wrote:If a stock Cleveland with closed heads ('71) had a compression ratio of 10.8 to 1, what would the ratio be if the cylinders were bored to .030?

mike
It should increase about .1 assuming the new piston is exactly the same except for the + .030 diameter. You may want to look into what the original compression was in 71 for M code. It seems I remember reading something about stated and actual CR being different, actual being lower almost a full point. http://www.network54.com/Forum/119419/th...shaft+Data
This link for general calculations, others slightly more accurate but require data you may not have. .http://www.wallaceracing.com/cr_test2.php
Chuck
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#8
Possibly you can find something here that may be easier.
http://www.wallaceracing.com/Calculators.htm
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