I hear a lot of different things on how much compression I can run with pump gas on a buick 350. I've heard 9.25 up to 10.25:1. So how high can I go. I would like to hear from the buick gurus.
i run 11-1 in my 455 but that is with aluminum heads you can get away with about 0.5 more compression with the aluminum , so id say you should be ok with about 10 to 10.5 ...mike
YOu cam get away with 11.0 comp with a big enough cam. Its all about cylinder pressure and how hard you plan on running it with pump gas. How big of a cam do you plan on running? Theres a little more to it but you have to give more details and what you plan to do with the car.
Well I plan to kill late model trans ams and camaros, so it won't be easy. I need enough compression to get the job done, but not so much compression that I will need race gas.
Trans Am's and Camaro's huh? Well you better come packin' since LS1's and 6's are a strong package. It is not uncommon to run up against a solid 12 sec ride on the street. And 11's and better if they have a supercharger or turbo. How serious of a buildup do you want to do. Pump gas is an easy issue to deal with, but what are you looking at for driveability and mods to the engine? 10-10.5 is what you should set it up for but it will take alot more than compression to get you the numbers your looking for. Buicks are generally no lightweights.
One thing you must do is reduce the weight of your car. Now you could bump compression beyond 10.5 and run race gas. Orrrrrr, you could reduce compression to 8.5 or so and hit it with a big shot of nitrous oxide. BTW, did I mention you need to make your car lighter? Seriously, the F bodies can really bring it. Just today I saw some LS1s in a magazine using 105 octane race gas/high compression with the 347ci engine running 10.5s or better. Most of them had 408ci engines with 105 octane race gas and were running very low 10s or high 9s! What was more scary is they were all street driven. That means one of us could run into them.
Your absolutely right those cars are not easy to beat, but I think that those ARE THE CARS TO BEAT. I'm going to see if It can be accomplished with the 350, and still keep it steetable and reliable if not I may just have to move on to the 455 (BUT HAS A VERY VERY VERY LAST RESORT)
I think what your gonna need here is money...lots of it. You want high performance and streetability, which don't usually go together. I'm not saying it cannot be done, but it is going to take a lot of work (and money). Heads, Ignition, Cam, Suspension, (with a lot of power you need something to hold those tires to the ground), etc. Remember even with a 376 hp and 510 ft lb torqin' 455 stage 1 engine, the GS 455 was only able to hit 13s, which was about as fast as most super cars were able to do in the quarter mile. But I do say good luck on your endevor, if ya go through with it, give a TA or Z-28 a black eye for the Tri Shield. Patrick
I'm sure you've read the 350 build up Jim B. did. That was a pump gas motor that was fairly cheep to build. I would stay with a hydraulic cam with 5 additional degrees on the exhaust, 10.0 comp, and install a nitrous kit. the nitrous will keep the gearing from having to be to high. The 3.73 you have would work fine as to 4.10's which would work better for a motor only car. If your serious about making good power with that 350, it will be getting those heads to flow. You can go to a bigger cam, add more nitrous, more gear, but nothing will work better than good flowing heads which should be the base of your combination.
