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Post by monkihead on Apr 27, 2011 12:15:49 GMT -5
For peeps that don't have a computer controlled distributor, keep reading. There are 2 ways to set timing. Base timing and full-advance timing.
1. base timing It is the most commonly used and works best for most street vehicles. Provides easy starting, comfortable throttle transitions and decent power.
2. full advance timing Mainly used on street vehicles with aggressive cams, major after market parts(ie intake, heads). Starting may become difficult and max power is closer to target hp.
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Post by monkihead on Apr 27, 2011 12:20:43 GMT -5
Base timing - It is defined by setting your timing @ idle, without vacuum advance connected. Base timing varies by engine, being anywhere from 6 - 10 degrees. It has been a common practice to advance the timing 2-6 degrees from base timing if using a higher octane fuel.
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Post by monkihead on Apr 27, 2011 12:29:25 GMT -5
2. Full advance timing To properly set, vacuum advance must be disconnected and engine must be revving above 2500 rpms. Timing light with a "dial in timing" feature makes this easy. On timing light, set for total advance - ie 34, 36 or 38 deg, etc. Match the "0" of the balancer to the "0" on the timing tab. Once set, check by revving the engine to 3k rpm. IF it moves away from "0", adjust distributor to match both zero marks. This can happen if full advance isn't reached at 2500 rpms.
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Post by monkihead on Apr 27, 2011 12:41:38 GMT -5
Distributor advance Most distributors have both, vacuum and mechanical. The vacuum unit helps during idle, cruising and light tip in/low rpm throttle. The mechanical assists in mid throttle, light loads and WOT. The mechanical can be adjusted via tension springs. As pictured is a common HEI distributor, pointing the springs and weights under the rotor. Spring kits usually include weights and 3 sets of springs. heavy springs - don't allow advance to come in quicky and spread across the rpm band. Full advance is normally seen above 3-4k rpm. Medium springs - commonly included with stock distributor. Light springs - full advance is seen quickly. Engine will rev hard. CAUTION - listen for ping/knock/detonation. This is bad and can severely shorten engine life.
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Post by EricFormula350 on Apr 27, 2011 16:11:29 GMT -5
Great Writeup! I'll have to mess with it some more when I come back from my trip. You all take it easy! See you guys in a few weeks!
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Post by monkihead on Apr 27, 2011 17:24:33 GMT -5
thanks, I felt a contribution was in order.
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