Ignition upgrade??

Discussion in 'Race 400/430/455' started by dan zepnick, Apr 27, 2017.

  1. dan zepnick

    dan zepnick Well-Known Member

    As the title says.I've been running a 6al msd box with a 8289 start/retard box.it about 15 years old. Having a backfire issue when restarting after a run.I think the start,retard box is throwing the timing around.my question is,what are most using ? I have a msd distributor locked out at 34 degrees. I like the retard on startup feature. Not sure I want to spend $800 on a msd3al.let's hear what your running..thanx
     
  2. Bens99gtp

    Bens99gtp Well-Known Member

    I run the digital 6 plus, pulls 20* out under 500 when you set it for start retard. Has top in Rev limit, 2 step for my transbrake, has another retard that is settable for nitrous, easy to wire, clean, compact, not pills or chips just easy to adjust dials, long wire leads to get to battery and coil. Can be used with mag pickup, points, hall effect
     
  3. Jim Rodgers

    Jim Rodgers Well-Known Member

    Old 7AL3 here.
     
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Check the rotor phasing.
     
  5. dan zepnick

    dan zepnick Well-Known Member

    Did that larry.looks good.
    Was thinking about that digital 6.has it all in one box.Ben do you use the retard fir hi speed,rpm feature? How do you like it?
     
  6. hugger

    hugger Well-Known Member

    Give ICE a look, Digital6 and programmable 6al2 are nice also
     
  7. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    Dan,

    How and why are you shutting down after a run? When is this restart that you are having the backfire?
     
  8. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Since it's on my mind, $369 for a Microsquirt ECU, wire it up to just control timing. Lock your mechanical advances if you have them, then four wires to to control timing anyway you want including 2-steps and rev-limiting. I think it may even have a feature to pull timing in high gear if you wire in a switch to let it know it's in high gear.

    For full timing control that is just rpm dependent like mechanical advance:
    +12v
    Ground
    Tach-in wire from points, hall sensor, pickup coil, etc.
    Ign out wire to the negative side of the ignition coil (full +12v to the positive side)

    Three wires and a MAP sensor for vacuum would be needed to use a full map and have the equivalent of a vacuum advance.

    Then you can decide if you want to wire in other things for data logging, like temperature, speed, oil pressure, manifold vacuum, etc. Run radiator fans, control a switch pitch transmission, etc. It'll even control an electric fuel pump to prime with the key then shut off until it sees a rpm signal. $369! (Beware, gateway drug! lol)
     
  9. Bens99gtp

    Bens99gtp Well-Known Member

    I don't use any top end retard, the other retard in the digital 6 is 12 volt triggered ment for nitrous.

    I have often wondered if pulling 4 or 6 out on top end would help, would do a micro switch trigger on 2nd or 3rd gear to activate the retard. We are looking at going to a grid system soon
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I have the Digital 6 for years. There is a pink wire. When it sees 12 volts, it retards the timing by whatever you have dialed into the box. 0-9.9*. You could rig up a switch. I made mine adjustable. I used an MSD RPM switch. I wired it up to ground a relay that sent 12 volts to the pink wire. I then bought a module selector (3000-5200 in 200 RPM increments), and plugged it into the RPM switch. So I can select the RPM at the module selector, and the amount of retard at the box. Haven't done that much testing with it. Every time I have taken 3-4* out at 5000 RPM, it has lowered my trap speed. Right now I am running 35* locked out timing. I might need to up it to 38*, and pull 3* out.
     
  11. Bens99gtp

    Bens99gtp Well-Known Member

    I think Im was soft on my timing anyways, pur 11 to 1 iron head motor was run at 32 locked out. Our new te heads will get us 12 to with .038 gaskets and almost 12.2 with .027 gaskets, but since this is our old motor it still has the stk rods and not sure how much squeeze I want to put on top of them.
     
  12. dan zepnick

    dan zepnick Well-Known Member

    Gary,when I make a run,pull back in my pitspot,shut engine off,let sit say 10 or 15 minutes,maybe 30 minutes,when I try to start to make another round it backfires out exhaust....load bang!! Sometimes it backfires out the carb.it I roll it over with my starter button and turn on ignition it seems better? ? Starts ok cold.my 6a and start/retard boxes are at least 15 years old.I think the timing is intermittently firing wrong cylinders?
     
  13. Bens99gtp

    Bens99gtp Well-Known Member

    Are you sure you not getting some fuel piddling while sitting? If you go to start it after sitting like thst with the ignition on, does it knock right off or is there an extended crank before tries to fire. Loud bang in the headers is the fuel lighting there, if really rich from the carb dripping while sitting could cause this.
     
  14. TORQUED455

    TORQUED455 Well-Known Member

    Have you tried not using the start-retard feature?
     
  15. Bens99gtp

    Bens99gtp Well-Known Member

    With timing locked out at 32 or 35 degrees, without 20 degrees or so of start retard when warm it will make a motor hard to roll over.
     
  16. Jim Weise

    Jim Weise EFI/DIS 482

    That may be true with some combo of high static compression/small camshafts/incorrect sizing of battery cables.

    In my experience, we could start the typical race motor, up to 15-1 compression, with the typical large race cam 260*+ at .050 with locked timing in the 30 to 34* range. No problem at all. I used to start my iron 13-1 race motor with the stock GM BB starter.. Battery cables were the key here. 2 gauge is the minimum required for batteries up front, 00 gauge should be used for trunk mounted batteries.. Fine strand welding cable even better..

    I never saw the reason for the start retard, although several of the cars I have owned or built/run have had that feature available.
     
  17. hugger

    hugger Well-Known Member

    We just would run a switch inline to the MSD power wire, spin the starter for a sec then throw the switch, this was on little 302's with locked timing
     
  18. Bens99gtp

    Bens99gtp Well-Known Member

    We have a stk starter motor about 11.5 to 1 ta 308s cam, after about the 3rd or 4th round Robin run gets hard to crank. Ours is front battery, key switch in column just lie stk, the 20 degrees retard brings the crank down to the 12 or 15 degrees just like stk, no extra switch for ignition power nothing just hit the key pops off before 1 revolution
     
  19. TORQUED455

    TORQUED455 Well-Known Member

    Start retards have been known to blow nose cones off of starters due to kick back from rotors phasing issues.
     
  20. Bluzilla

    Bluzilla a.k.a. "THE DOCTOR"

    Used to run a 308s with 14.56:1, iron heads, 20* initial timing, Tilton Super Starter, no start-retard..... never had a starting problem hot or cold.

    Larry
     

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