Is anyone running locked out timing on a 350? engine is a 10.5:1 355, hydraulic roller cam 230/237 110lsa, stock heads with TA oversized valves, SP3 intake, UR5 plug. car weighs im guessing somewhere around 4200 pounds, where should I set total timing?
well it had a 3000 stall in it when I blew up the th350 with a 3.73 gear. But im putting a th400 in it with a 3500 stall.
actually runs great on the street with 91 octane. the only real issue im fighting is the msd atomic efi and going with a carb. so im planing on running a digital 6 plus box with a carb. currently running 32* with the atomic. was just curious to see if people thought I should take some timing out of it.
32* is a good starting point, but no one will be able to tell you what timing it will ultimately like.. The track will tell you that. You are after maximum trap speed. Run it at 32, and note the trap speed. Bump the timing to 34* and make another run. If the trap speed increases, try 36. Back it down when the trap speed stays the same or decreases. I run locked out timing on my 470. I get the best and most stable idle with constant timing.
sounds like a nice fun engine to have. on mine I used a gm hei w/o the vac adv hooked up. think I set total timing at 34* for the supercharger. have no issues at all. I use ngk ur6's in it. 9.2@145 and looking for more.
It doesnt seem to like the either the cam or intake. it always runs way to rich and is super sensitive to timing changes. and the IAC doesnt work a well IMO I find it easier to cold start a carb'd engine.
Sounds like a fun ride! I would really like a supercharger one of these days. Im shooting for 12.50's NA and 11.20's with a 150 shot. I was planning on racing it some last year but it flattened a cam and broke the stock rockers so I put a hyd roller in and bought roller rockers. now its time for a th400 lol.
you do have a good base to start with. if you're racing, you need to launch about 3500. at 4k the engine changes attitude. you will need major chassis mods to keep it in control so you can have lower et's. said this many times...www.classracer.com these guys do it week to week and know the ins and outs of chassis control. s/chargers are fun and easy.
chassis mods so far are coilovers up front, and UMI double ajustable rear control arms with roto joints, and a I did put a Chevelle 8.2 in car but to make it similar to the buick I had it narrowed an inch and 9in ends welded on.
