Compression question.

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Dec 2, 2009 | 07:28 PM

GatorFan08

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From: Winter Haven, FL

Compression question.

Im buying a 454 with 13:1 compression, and was wondering If could drive it on 93?? Its going in my weekend warrior, anyways the only reason I asked is because my buddy's 383 has 12:1 and runs 93 with NO PROBLEMS.

Dec 2, 2009 | 09:10 PM

ZONES89RS

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Wel, if it has aluminum heads and you run the timing WAY back, yep.

Dec 2, 2009 | 10:58 PM

mrdragster1970

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From: Illinois, RT 66 dragway area

..

I wouldn't say no problems, but as mentioned.
If you choke it way down and don't hammer it, who knows??

..

Dec 3, 2009 | 05:57 AM

cambirdracing

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From: League City Texas

I had a Pontiac that I tried to do that with. it got to where I could change the head gaskets in any parking lot in less than a hour.

Dec 3, 2009 | 07:08 AM

pancherj

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There is a good real lead fuel additive out there called Kemco. I plan on using it in my 489 with 12:1 compression and iron heads. The guys over on Chevelles.net rave about the stuff. I haven't checked into the price yet...

Dec 3, 2009 | 09:29 AM

mrdragster1970

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From: Illinois, RT 66 dragway area

.

If you have a real fuel system on there, it might be cheaper to just use E-85 if available.

.

Dec 8, 2009 | 03:29 PM

1 FMF

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From: CT

it would depend on cylinder pressures, but those are variable and dependent on other variables.
you can use the dynamic compression ratio, which depends on camshaft profile, to get a better feel but it won't guarantee that a certain octane fuel would not detonate under various conditions.

http://www.kennedysdynotune.com/Dyna...ion%20Tech.htm
http://www.empirenet.com/pkelley2/DynamicCR.html
http://www.hotrod.com/pitstop/hrdp_0...ion/index.html

Last edited by 1 FMF; Dec 8, 2009 at 03:34 PM.

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Dec 12, 2009 | 12:31 PM

tom falco

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Its all in the DCR. If the valves stay open longer the mechanical compression ratio means nothing. Check the DCR and that will tell the story. I run 12.5 -1 with no problem in my Chivelle. Big block