pump gas

whats the highest compression you can run with pump gas? might be starting a 3rd gen project

[The Fixer]

Iron-head LT1s had 10:1, and aluminum head LT1s had 10.5:1, but it's a good chamber design and fuel-injected, with a knock sensor to retard timing if it does start knocking. Really, it depends on a lot of variables (like quench, chamber design) but generally you can go that high on the street safely with 93 octane, a knock sensor, and a good tune. It can be done with a carb too, but will definitely take some experimenting and plenty of tuning.

what about 12:1?

[The Fixer]

I wouldn't recommend it, unless you really knew what you were doing and could check the plugs constantly. Maybe you could get away with it on the street if you babied it, kept the timing retarded, and threw in octane boost or a few gallons of race gas.

[JSPERFORMANCE]

If the car is light enough and you have good aluminum heads...

[Batman]

I wouldn't go more then 10.5 on a 3rd Gen computer

computer? why do you speak of such a thing? its gettin carbed im not dealin with electrical gremlins anymore. http://www.jegs.com/webapp/wcs/store...85971_-1_10763 is what i was lookin at.

[radialtireking]

Every combo is going to be differant. Cyl. head design and cam profile play a big part in it. Weight of the car, gearing, stall speed also play a role. Another key to running high compression on pump gas is keeping coolant temp down. The closer you get to the limit the better you need to be at tuning. Correct fuel and timing curves are a must. The above numbers of 10-1 with iron heads and 10.5-1 with aluminum are a good safe number to go by. What are your intentions with the car? A point of compression may not gain enough power to warrent the potential tuning problem or the need for better fuel. Will this engine be N/A or planning on a power adder? I think knowing the goals of the car will help lead you in the direction you need to go.

[Tru2Chevy]

That's an iron head 12:1 circle track motor you listed there.....I agree with radialtireking, we need to know a bit more about what you are planning.

- Justin

i want it to be streetable and i would be satisfied with 11s at the track even 11.9XX and and streetable to me is having functional turn signals and headlights and not stalling when i come to a red light lol. might do nitrous. im not looking to build a motor from scratch im looking for something crate and not too expensive.

[JSPERFORMANCE]

Stay away from crate enigines. You will have better luck with a engine custom built for your application...

[Batman]

Originally Posted by radialtireking

Every combo is going to be differant. Cyl. head design and cam profile play a big part in it. Weight of the car, gearing, stall speed also play a role. Another key to running high compression on pump gas is keeping coolant temp down. The closer you get to the limit the better you need to be at tuning. Correct fuel and timing curves are a must. The above numbers of 10-1 with iron heads and 10.5-1 with aluminum are a good safe number to go by. What are your intentions with the car? A point of compression may not gain enough power to warrent the potential tuning problem or the need for better fuel. Will this engine be N/A or planning on a power adder? I think knowing the goals of the car will help lead you in the direction you need to go.

Listen to this guy...you'd think he drives an 8 second street car or something....

Originally Posted by JSPERFORMANCE

Stay away from crate enigines. You will have better luck with a engine custom built for your application...

that usually requires more money. unless you know of a place i could have something decent built for around 4-5k

[Tru2Chevy]

If you wanna go with a crate motor, look into GM's Fastburn 385 or the ZZ 383/425

- Justin

[BonzoHansen]

I have good good things about that ZZ383. If my motor popped tomorrow, I'd be hardpressed not to go get one.

thanx justin i appreciate that im gonna look into the 383 if i can get the Roller. its race ready from what im told and just needs a motor and tranny dropped in

[radialtireking]

Originally Posted by Tru2Chevy

If you wanna go with a crate motor, look into GM's Fastburn 385 or the ZZ 383/425

- Justin

Good choices for your goal. 425 horsepower is enough to get a properly set up car into the 11's.They should also give the streetability you are looking for.

[98tadriver]

Originally Posted by 86Formula

computer? why do you speak of such a thing? its gettin carbed im not dealin with electrical gremlins anymore. http://www.jegs.com/webapp/wcs/store...85971_-1_10763 is what i was lookin at.

LOL @ electrical gremlins!