badta115

i was wondering if it is other the next money to up the compression to 13.5-1 or just stay around 12-1? My motor is aready in the shop get a new crank the motor is all forged with stock p&p heads cam is a custom grind with .575 lift. I was going to use race fuel and mix it was 93 to come out a li more then 100 oct. I would go e85 but we dont not have any good e85 around here

Kevin Blown 95 TA

Race car or what? What are you doing with it? and you really need to figure out what that buys you and if it is needed for the cam and valve timing. Mixing special fuel is a real pain, especially with crap mileage, so unless it is a track only car, I'd give that some hard thought.

badta115

weekend driver at the most Would there be a big power differance i plan on sparying too if that matter ths much if u need to know more about the car i can tell u about everything it is getting a hole new drivetrain right now just can make my mind up about this and need some help and opions

kgkern01

iTrader: (10)

I've been running E85 for 7 years, I'm at 13.4:1 compression, not daily driven but is driven in nice weather a lot, no issues, great throttle response. Would've went higher but was trying to stay away from going domed pistons. In hindsight, I probably should've went with very small domes and gone 14+

96capricemgr

iTrader: (1)

There is a lot more to cams than peak lift BUT that said .575 is pretty mild by today's standards, you can get a shelf Comp grind with more lift than that.

I would put a flat top piston in it with .035 quench and live with whatever compression that nets you. In modern chambers domes hurt flame travel.

You can get into the 12 range on pump gas depending on the cam.

DUDCOUPE

Thats alot of compression for a weekend warrior

Ed Wright

iTrader: (1)

Cam lift means pretty much nothing when you are talking about compression ratio or tuning. Higher compression makes more difference in torque than anything. Makes more difference with long duration cams than short.

moehorsepower

iTrader: (3)

Yup, you know every time I ask a customer what are the cam specs, they always say X lift, I care more of duration than lift..

Ed Wright

iTrader: (1)

I finally added a cam lift blank on my order forms to prevent phone calls telling me there was not a place to write down their cam lift. I don't really care, it has nothing to do with my part. They can always tell me how much lift they have, damn near never tell me what I do need to know: duration @.050" and lobe centers. LOL

moehorsepower

iTrader: (3)

Duration? LSA? uh I dunno.....LOL...

96capricemgr

iTrader: (1)

OK so I got distracted by stuff at home and completely failed to make my point.

My point was I think there are MUCH better places for this guy to be chasing power than racegas compression levels.

I mentioned the lift simply because that is not much lift compared to what most of the quick street/strip LT1s are running so it suggests the cam is not particularly aggressive and I feel he could probably gain a lot more optimizing other things than he is going to get with jacking the compression to a point where fuel costs double and is harder to get ahold of.