Initial/Total Timing

With an initial timing of 10 degrees BTDC and a total of 35 degrees. When does the # 1 cylinder actually fire? At 25 BTDC or 35 BTDC. Thanks!

Each cyl will fire at 10 degrees before top dead center, and up to 35 degrees before top dead center, depending on rpm.

At or above the RPM where your springs are maxed out at if you are showing 35 that is 35 BTDC and is your total (checked w vac adv unhooked/plugged) Zero (TDC of the piston) on the balancer is just a reference point and initial fires 10 deg b 4 that and mech adv makes it fire an additional 25 b 4 (the 10 deg point) for 35 total. It's a linear amt (initial amt to total amt) from start to finish EDIT & vac adv will add to the # (circumference degrees on the dampener)up higher yet past the 35

I know this has been discussed a lot before but just for clarification- for total timing
1)Disconnect and plug vacuum advance
2)RPMs up to 3000
3)Timing gun set at 35
4)Timing mark on balancer should be at 0

Only if your distributor has been recurved so that the advance is fully advanced at the specified RPM's. If it hasn't it will still be advancing past that RPM and may give you more than you planned on.

No prob on any repeat, holler as much as you like. yes if the springs are maxed out at 3k (or earlier), then zero on the balancer/35 on the dialback. SB I'm assuming. If you want it spot on I would suggest setting (w vac adv disconnected/plugged), (1) initial (vac gauge method) then w that figure in hand (2) shorten the slots to get 35 total (SB) then (3) play w the springs staying just under the pinging point at WOT up thru the gears on your hottest/driest day then (4) reconnect the vac adv and start it's slope as fast as possible but again staying just under the pinging point at PART (high vacuum) throttle at an RPM high enough to where the springs (mech adv) are maxed out. CW w a 3/32" allen wrench makes it's curve start sooner (less in hg) and the total is fixed unless you file the notches longer (for more total) or shorten the notches w strips of feeler gauges epoxied on (for less total) or you can get a can w less adv (dist amt is stamped on the arm so double that #). The vac adv helps mileage and cleaner plugs and takes the most work to get it spot on as your dealing w 2 things, it's total it can add and when it starts advancing.

Thanks guys! Time to go play!

You didn't say what distributer you were using. IF it's a stock unit you'll want to remove the real heavy stock spring from the advance weights. Just leave the lighter spring alone and don't replace the other spring. Your timing should be all in by 22-2500rpm. Without removing that heavy stock spring it may not reach full advance until 4000+rpm. Dave

Stock distributor with Pertronix, 71 318 with 340 J heads and Torker II intake, purple cam(don't know which one). Presently 625 Road Demon Jr. but have a 625 Road Demon ready to install. Sanderson headers, 518 auto, 2100 stall, 8 3/4 with 3:55 gears. Check out article Moparts-Members in Print "Back Burner Mopar"

Keep in mind..
If he is using an MSD box, it fires 10 degrees before and after up to 3000 RPM..

Just my $0.02...

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Keep in mind..
If he is using an MSD box, it fires 10 degrees before and after up to 3000 RPM..

Just my $0.02...

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