Looking for some advice. I've a BDS 6-71 350 SBC, 2 x 600 Eldebrocks, Eagle crank, Blower pistons, Crane custom roller cam and rockers. Whats the best static ignition timing set-up to start up with (16-22 BTDC ) or less. I'tll be running on pump gas. Also need to know best size Primary's, needels, jets etc for the Elderbrock carbs. Ian.
check out http://www.blowerdriveservice.com/ that have a great FAQ section and tech section. Blowers love ignition advance. Especially initial advanced. For most blower applications, the initial timing should be set at 16-24 degrees initial advance with a total of 32-36 degrees advance, in all by 2500-2800 RPM. More advance can be run if there is not a detonation problem. Some vacuum advance systems will have as much as 45-50 degrees total advance under part throttle, cruise conditions.
I run my dist. locked out @ 36 deg. For the safety of the motor, you can over fatten the carbs & then jet them down till the plugs read right. You've gotta read them correctly though. (full throttle run & shut it down w/ no idling.) 1 to 2 heat ranges colder than the stock plug is a fine place to start. If you run straight pipes or loud exhaust, it can be impossible to hear detonation. Be alert to the "feeling" of the engines nosing over, or detonating. Start w/ small levels of boost, say 5 lbs. or so. Then tune up from there.
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