Perhaps help with GM ignition???

Discussion in 'Other Auto Tech' started by Nitrous N20, Jul 30, 2007.

  1. Sorry to ask on the Mustang threads, but Im having some issues with my '57 Chevy racecar ignition and need advice. Its all pretty similar stuff so I thought someone might have an answer.

    Like I said, the car is a 57 Chevy 2 door coupe witha 383 and a TKO 5 speed. Its got aluminum heads, intake, Holley 4bbl, comp cam, etc. Dynos at about 380 RWHP and 400+ lb RW torq. Its pretty quick. Before the Tremec went in, it would run 13.00 at 106 with a TH350 auto. I imagine its a bit quicker now with a 5 speed.

    So I have a HEI ignition that has been modified with a MSD blaster coil, cap, etc. I am also using a Digital 6 ignition box to get the rev limiter, start retard features and have options for some NOS later on.

    Im considering switching to a standard points type ignition. Like an MSD billet distributor and a blaster coil. Question is: Is that really necessary? I can save alot of money to spend on other stuff by just getting a new set of plug wired (which are worn) and keeping HEI. I dont even use the vaccuum advance. Is there anything WRONG with HEI on a motor like that?

    Any help is much apreciated.

  2. As long as it will support whatever RPM's youre spinning the motor to, i dont see a problem with it. There are a bunch of guys still using the duraspark ignition on thier fords because it supports some decently high rpms. I had a few chevys back in the day (78 monte carlo, 81 monte carlo, and an 83 camaro) and if i remember correctly, nothing ever went wrong with the ignitions on those for me.

    This ad (althought its modded a little) says it will support uyp to 8,500 rpms

    Edit: I talked to a guy here that is Pro-chevy (he hates that i drive a mustang :D ) and he said to make sure if youre using a stock unit to lock it out so your timing doesnt move, and AT BEST, a stock HEI distributor will top out at about 5500 rpms.
    He uses an MSD unit now that will let him go to 9,000 rpms on his circle track car, he has the timing set to 32*, but for your application, he recommended about 40* total timing.
  3. Jeebus! Im not going nearly that high with this motor. I typically shift at around 5700 RPMs anyways. Shift light blinks on at about 5600. The dyno shees says I start dropping off at about that anyways.

    Well, thats good to know. I think Im probably ok with my digital 6 and blaster coil on the otherwise stock HEI. Ill lock out the vaccuum advance and make sure the timing is dialed in right. Once I get the money maybe Ill switch over to a pro billet distributor.

    And other suggestions for improving the HEI? I think Ive probably maxed it out.
  4. Yep 40 degrees seems the magic number fro a chevy, the reason (imo) that the HEI has issues over 5-6grand is the coil, an aftermarket coil willususally fix this. The HEI is a great, no brainer distributor, that's why they make them that now fit fords and mopars. Going back to points is a step backwords, iron out the HEI issues instead.
  5. hei distributors are pretty solid for what you are doing. but dont ever go to a points style distributor. that would be like taking off the carburetor and going to mechanical fuel injection....its a step backwards as far as technology goes. if anything get a points style distrIbutor and update it with a pertronix hall effect pickup....pretty cheap upgrade and they work really good.