Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 23

Thread: Timing control with GM large cap HEI.

  1. #11

    Default

    To setup the distributor, you want to make sure the reluctor is lined up with the center of the magnet with the engine at the Reference Angle you choose, and the rotor lines up with the center of the terminal when the engine is at the center of your ignition timing range. When you check rotor-phasing (using a spare cap that has a hole cut in it, so you can see the rotor as it crosses the #1 terminal), you generally want it to be so that at idle the rotor will be off to one side of the terminal when you aim at it with the timing light. You then want to see the rotor sweep through the middle and end on the other side of the terminal at your max timing. One thing you do not want to see is the rotor straying too far from the terminal in the cap. Also, are you not running more timing at cruise?

  2. #12
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    15,862

    Default

    MSD rotor-phasing technical document:
    http://documents.msdperformance.com/8644_tb.pdf (MSD Rotor-Phasing Document)
    MSD has a good video on why it's important:
    http://www.youtube.com/watch?v=aWMlNwGW0tM (MSD Tech Rotor-Phasing Video)
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  3. #13

    Default

    Thanks guys. I've read the links and seen the videos in doing my research, so I have a good understanding of rotor-phasing. Just trying to fully understand & figure out how to get the distributor setup when I don't have an adjustable rotor. For now, I'll be using the stock canned timing that's set in the Sniper ECU. Once I get the thing running right, and I'm happy with driving it, then I'll look into making some changes.
    '73 K5 Blazer, built 350 SBC 375 HP/425 TQ, 12" F/18" R suspension travel. Deaver springs with King shocks, D44/12 bolt, 3.73 gears, lunchbox locker F/Auburn Posi R, crossover steering, 35" BFG Mud Terrains, Vintage Air system, PRP suspension seats, lots of custom work, all built by me.

  4. #14
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    15,862

    Default

    Quote Originally Posted by Crusty Old Shellback View Post
    Just trying to fully understand & figure out how to get the distributor setup when I don't have an adjustable rotor.
    Forget about the adjustable rotor aspect. Install the distributor and synchronize the ignition timing. EFI distributors don't have adjustable rotors, so you'll install it like one of those. People often convert their prior distributors to a cam sync (crank trigger applications), and they don't have adjustable rotors.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  5. #15

    Default

    As Danny said - forget adjustable rotors. You can easily phase the distributor by 12.5 or so degrees distributor when locking up the vacuum advance.

  6. #16
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    15,862

    Default

    Good point, Dr_Grip. So when locking out the vacuum advance, make the lockout plate adjustable.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  7. #17

    Default

    OK, thanks guys. I appreciate all the help.
    '73 K5 Blazer, built 350 SBC 375 HP/425 TQ, 12" F/18" R suspension travel. Deaver springs with King shocks, D44/12 bolt, 3.73 gears, lunchbox locker F/Auburn Posi R, crossover steering, 35" BFG Mud Terrains, Vintage Air system, PRP suspension seats, lots of custom work, all built by me.

  8. #18

    Default

    I did the same thing. I made it so I could adjust the vacuum advance plate to change the rotor-phasing. It makes it easy to adjust when installed in the engine as well. You just set the engine to your Reference Angle that you need, line up the reluctor wheel and lock down the adjustment.

  9. #19

    Default

    Can you provide a picture or diagram of what you did to modify it? Thanks.
    '73 K5 Blazer, built 350 SBC 375 HP/425 TQ, 12" F/18" R suspension travel. Deaver springs with King shocks, D44/12 bolt, 3.73 gears, lunchbox locker F/Auburn Posi R, crossover steering, 35" BFG Mud Terrains, Vintage Air system, PRP suspension seats, lots of custom work, all built by me.

  10. #20
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    15,862

    Default

    You can cut/remove the vacuum canister off the distributor, but keep the metal linkage long, and attached to the baseplate for final rotor-phasing adjustment. Or you can purchase a vacuum advance lockout/delete kit (LINK).
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us