Well, this thread turned out great. I will state my opinion form experience only. 1. Holley was in the rebuilt carburetor business several years ago. They had a building in Springfield TN where a close friend of mine was in charge of the rebuilding business. 2. I ran a 455 800 Q-Jet on a stock 350 that we built in the mid 90's as a school project drag vehicle and we tried several different carburetors, and it went fastest with the 800. 3. The next engine we had in the car was a 455 Stage 1, 9 to 1 compression ratio engine with a street cam and wildcat intake. We tried several carburetors and spacers and combinations of both and all kinds of jetting. It went the fastest and quickest with a 1050 Dominator in back to back testing. People thought I was crazy to run such a big carburetor on such a mild Buick engine. It started and idled great and had excellent throttle response and went faster, so why not use it. Working closely with a noted modifier, we managed to get a modified 4150 (1000 cfm)to run close but never better, and this carburetor would have cost twice as much if we had to buy it. I'm putting together a mild 350 right now and I'm going to try a modified 4150 (950 cfm) and just see how it does, will also try a 750 and 800 Q-Jet and a 750 and 800 Edelbrock. Just an old man fooling around. Jim N.
Rob Margels 551 hp Buick 350 used a 1000 cfm carb, and this 449 hp loved the 850 demon. http://www.v8buick.com/showthread.php?t=106735&highlight=350
I'm going to dissagree with these statements - A pro-strock engine exceeds 115% v.e., and i'm gunna say cup cars and F1 cars also beat this number. Carbs are mainly flowed dry, so the rated cfm does not include fuel delivery. So although an engine may "theoretically" only need a rated cfm, it doesn't acount for fuel flow. Dual plane intakes also require bigger carbs than an identical engine with a single plane intake due to the seperation of each set of runners from the total airflow of the carb. THe required size of a carb for an engine should be by manifold vacuum at WOT. I can't tell you the numbers, but i know that low numbers work best, but make tuning harder, and therfor more skill.
Browse though this thread, http://www.v8buick.com/showthread.php?t=171806&highlight=50CFM I got yelled at allot write or wrong for suggesting that another 50CFM wouldn't make that big a difference on a 350. As stock they come with a 750..........
hey Sean, do you remember the jet sizes for primary and secondary for 800 on a stockist/mild 350? This will give me a good idea on what to start with on my 800 eddy avs
The carb you have is a whole different design, you would be best off using a wideband 02 sensor and reading the spark plugs to tune the carb.
