06-23-2013, 09:10 PM | #1 |
Drives: '15 SS 1LE, '69 Z28 drag car Join Date: Dec 2009
Location: Mich
Posts: 4,482
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BBC drag race motor MSD 7AL-2 Starter Cranking Question
Not sure where to put this question, but looking for someone with experience starting an old school big block Chevy drag motor using a MSD 7AL-2 box and crank trigger.
Its a 540 13.5 to 1 comp BBC. Its been through a few starters, tiltons, keeps tearing up the starter clutches. I just put in a Powermaster Ultra Tq starter and don't want to tear this one up. The crank trigger is set at 40 degs, so it wants to kick back and backfire sometimes through the carb trying to start cold. The timing so advanced is probably what is so hard on the starters. The starter switch and ignition are on separate switches in a Painless switch box. I've always turned the ignition and fuel on before cranking. So here's my question.... with a crank trigger and 7AL-2 box, can I get the motor cranking first with the starter switch and kick on the ignition switch while it's cranking? I know I can the way everything is wired, just wondering if I should? Would this be easier on the starter, or a good way to break something? |
06-23-2013, 09:25 PM | #2 | |
Drives: 1999 Pontiac TransAm Join Date: Oct 2011
Location: Tallahassee, Fl
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Quote:
dont know if its "right" or not, but havent broken anything and seems to fire substantially easier if your not on 16V already, may look into switching over. starts high comp high timing motors much quicker as well
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1999 Pontiac TransAm: Turbo 347ci
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06-24-2013, 08:50 AM | #3 |
Drives: '15 SS 1LE, '69 Z28 drag car Join Date: Dec 2009
Location: Mich
Posts: 4,482
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Thanks, I'll give it a try. I've got two real good 12v batteries, and huge cable, I think it has enough cranking power.
Just wasn't sure if that 7AL-2 box was meant to be kicked on while cranking. I don't want to fry anything in the middle of a race day. Maybe I'll give MSD a call and also see if they see any issue hitting the ign on while cranking. |
06-24-2013, 08:55 AM | #4 | |
Drives: 2012 45th Vert, 2011 4x4, 9sec Vega Join Date: Mar 2012
Location: Canada
Posts: 2,188
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Quote:
Edit: That may be too much advance too. Most race BBC's like 36 to 38 degrees.
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06-24-2013, 11:38 PM | #5 |
Drives: 67RS Camaro ,Black 2013 ZL1 Join Date: Jun 2010
Location: Alberta
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Timing is killing your starters. 40 is a lot for a BBC.
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06-25-2013, 08:53 AM | #6 |
Drives: '15 SS 1LE, '69 Z28 drag car Join Date: Dec 2009
Location: Mich
Posts: 4,482
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I've got a high gear 4 deg retard. This motor seems to like 40 degs in low and 36 in high gear.
Thanks for the tips. I may try to put in a start retard module. Maybe take out the high gear retard module and put in a multi retard module. Do both the high gear and start retard out of the same box. |
06-25-2013, 11:13 AM | #7 |
Drives: 2012 45th Vert, 2011 4x4, 9sec Vega Join Date: Mar 2012
Location: Canada
Posts: 2,188
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Just get used to the crank and hit it method. Save some bucks.
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I feel it only fair to warn you, I have a black belt in CAPS LOCK.
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06-25-2013, 11:16 AM | #8 |
Drives: 2012 45th Vert, 2011 4x4, 9sec Vega Join Date: Mar 2012
Location: Canada
Posts: 2,188
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Or dial back on that timing. Get off the kill tune.
We backed ours off from 38 to 36 and only lost 3 hundreds in the 1/4. Fattened the jets up 2 sizes and lost another 2 hundredths. Haven't hurt that motor in 13 years.
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I feel it only fair to warn you, I have a black belt in CAPS LOCK.
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