how high of comression can be ran on pump gas

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11-06-2008, 05:08 PM

wmcfa

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how high of comression can be ran on pump gas

i am building a 347 engine and have the trex cam. The trex cam loves compression according to thunder racing. what is the safest compression i can run with that cam and spray on a good tune on pump gas? 11:1, 11:5?

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11-06-2008, 05:15 PM

Sales4@Texas-Speed

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We usually cut the line at 11.5:1. I do know some people have been able to go higher but since we are out here in West Texas and 93 octane is pretty hard to come by we just stick to the 11.5:1 rule.

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11-06-2008, 05:20 PM

wmcfa

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Quote:

Originally Posted by JohnJanz@Texas-Speed

We usually cut the line at 11.5:1. I do know some people have been able to go higher but since we are out here in West Texas and 93 octane is pretty hard to come by we just stick to the 11.5:1 rule.

is that o.k with nitrous?

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11-06-2008, 05:43 PM

AKAFRED

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my old motor ended up 12.5:1 (wrong pistons) and it ran fine on ultra 94 octane.. if your limited to 92 i would probably keep it to 11.5:1

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11-06-2008, 05:51 PM

bad6as

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we have 93 over here in md. 12.1 sound good for me

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11-06-2008, 06:10 PM

2001 Pewter WS6

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I run 12.1:1 on Sunoco 93 with no issues. I previously ran 12.5:1 with no problems either.

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11-06-2008, 06:25 PM

KMS.1320

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Running 12.5 with the next heads/cam combo

Yes, "pump" gas

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11-06-2008, 06:30 PM

gectek

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pump gas is a VERY relative term, esp with the new blends being used as substitutes for the real thing in most gas pumps. basically it is all in the tuning/timing/setup. some engines like more cr, some dont.