total timing?

[willow72]

how do you go about setting your total timing?

[Randy70C-10]

Total timing is set at 3,000 rpm's with the vacuum advance dis-connected. Should be around 32-34 deg advance for most smallblocks (I think)

[JimKshortstep4x4]

What Randy said is right but it depends on whether your mechanical advance is fully advanced by 3,000 RPM. I have run into distributors where the mechanical advance does not come in until you hit 4000 RPM.

The method I use is to set up the distributor using a distributor machine so that the mechanical advance is completely in by 2800
rpm. Some distributors require some adjusting in addition to
lighter springs. I set the distributors up so that the mechanical advance is between 22 and 24 degrees by 2800 RPM. When I adjust the timing I set the initial timing at 10-12 BTDC. This gives me a total advance of 32-34 degrees.

You can do it with a light and tape, just watch to see when the mechanical advance stops advancing the timing while increasing engine RPM. The mechanical advance that is observed, added to your initial advance is the total timing, (32-34 degrees is desireable).

Jim

[GMC Jim]

Per GM Tune-Up Spec's manual SD-100
spec for 71-72 402 eng....10-13 cent advance; 28-35 total advance at 2000 engine RPM
71-72 350 eng. ( auto trans ) ....7-10 cent advance; 20-27 total advance at 2000 engine RPM

[GMC Jim]

per Chev Chassis Service Manual.....402 cu.in eng'
Cent Advance..(degrees @ RPM)...0 @ 930; 2 @ 1260; 16 @ 2400 and 30 @ 4400. Vac advance -- 0 degrees @ 8" and 20 degrees @ 17".
350 cu. in ( with auto trans) degrees @ RPM
0 @ 865; 2 @ 1335; 11 @ 2400 and 18 @ 4200
Vac Advance-- 0 @ 8" and 15 @ 15.5"

I had my distributor set up on a distributor machine for my 402 engine specs; checked the total timing and found that the initial timing set at 10-12 degrees advance at engine idle (600 RPM) would check out to 30-32 degrees total advance @ 2000 RPM

[willow72]

thanks guys this will be alot of help