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-   -   496 bbc compression on pump gas (https://www.racingjunk.com/forums/showthread.php?t=31000)

hotrod1994 09-22-2011 09:45 AM

496 bbc compression on pump gas
 
im looking to build a 496 bbc for my camaro and want to run pump gas what do you guys think about 11:1 on pump gas

block will get zero decked and i will use a 15-25 thousandths thick head gasket to achieve a good and low quench height
it will be ran with aluminum heads also


what do you guys think

bbchevy 09-22-2011 10:59 AM

?
 
Thats NOT a Problem,but dont think you can Run 87 Octane and 38* of Timing!!
93 0r 94 Octane and keep the Total Timing in Check,and Let HER Eat!!
Later
G 8)

cncmotorsports 09-23-2011 06:08 AM

11.0:1 On pump Gas (91 92 93 or 94? E85 definitely will), If you put the right cam in it. Look at it this way. Let's say you build it with 11.0:1 and it pings, so you drop the timing back to 30 degrees to get rid of the ping. You lost way more than you would gain if you would have lowered the compression ratio to 10.0:1 and ran 36 degrees timing.

Or you just end up having to mix race fuel to cover it up. I'm not saying it is not possible, just giving you some worst case scenarios that many people run into.

Good luck with your build.

weingartnerce 09-27-2011 07:45 PM

I had 11.2 in my EMC motor all dyno pulls on 91 octane no pinging even down low I think it depends on your other parts selection and the rate that the timming comes in.

desoto30 11-10-2011 11:28 PM

my concern would be the 0.015'' min piston-head clearance

oldandtired 11-11-2011 11:33 AM


Originally Posted by desoto30
my concern would be the 0.015'' min piston-head clearance

x2
Minimum of .035-.040 with steel rods. Aluminum rods need even more.

Also need to check valve to piston.


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