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-   -   12:1 on pump gas (https://www.racingjunk.com/forums/showthread.php?t=31375)

giblet182 12-11-2011 09:30 AM

12:1 on pump gas
 
Does anyone run their small block chevy with aluminium heads and 12:1 compression on pump gas without problems?

hotrod1994 12-11-2011 12:54 PM

12:1 is really pushing it if you run 12:1 and have to run a low degree of timing to stop it from pinging you just lost way more power than you you get from the compression compared to 10:1 @36 degrees you could do it but there be no benefit because of the timing 11:1 is about the max and thats pushing it

DRTRCR22 12-11-2011 08:29 PM

NO WAY...! That would be insane... I have seen more destroyed engines than you can count by doing this! And DO NOT juice up pump gas with off the shelf octane additives... it is way to risky. Broken top ring lands, holes in tops of pistons, valve damage, etc.

Going fast with gobs of power is not cheap, so don't screw around with your high dollar engine by taking chances ... I know by experience, both myself and by friends who thought they could save a buck.

At bare minimum you can try 100LL Av-Gas at about 5.00 a gallon, but you really need to use VP110 or 113 or higher at about 9.00 a gallon.
If you are drag racing you will only use a little fuel each time out anyway. A full night of dirt track racing of 30 laps I burn about 8 gallons but that is much easier to swallow than building another $10K+ motor.
If you are talking about a lot of street use, it is time to think hard about dropping a lower compression engine in your ride...

Or, you could convert to methanol or ethanol, if you don't mind all the side effects...

outlaw256 12-12-2011 03:46 AM

NO WAY!!!! back in the day when gas WAS gas yes. but with this shi-- they call gas today no. i cant even run any of my old cars on it. i build and drive old cars and this gas just dont cut it. i got a 62 galaxie with a stock 352i call put regular gas in it and it will evaparate out of the bowl in about 45 min. and you want to run gas on 12.5 engine. i spend a small fortune on good fuel and i got to travel to get it.

BEAST477 12-12-2011 02:46 PM


Originally Posted by mrbigtrucks
12:1 is really pushing it if you run 12:1 and have to run a low degree of timing to stop it from pinging you just lost way more power than you you get from the compression compared to 10:1 @36 degrees you could do it but there be no benefit because of the timing 11:1 is about the max and thats pushing it

Is this from past experience or is this what someone told you :?:

Your post sounds awful familiar. :? Just sayin'

Tod74 12-20-2011 05:05 PM

No.

coolracing 12-20-2011 07:24 PM

Well survey says NO! and I agree


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