Results 1 to 10 of 10
  1. #1
    The man in the box Jukebox Hero Champion My House Is Bigger Than Your House Champion Smaugs Treasure Champion Lash's Avatar
    Join Date
    Apr 2003
    Location
    Mukwonago
    Posts
    6,566

    SBC timing issue

    Got kind of a weird issue. I bought a car a few weeks ago that has a pretty mild Goodwrench LM1 350 in it (old owner told me it was a 355 but I haven't verified it yet). It's nothing special... shit 624 heads, Holley 650 4brl, HEI ignition. Long story short, I was checking into a issue with it running rich all of a sudden just to find a piece of an o-ring in the secondary float. While I was screwing around with that I decided to verify the timing. I brought it up to TDC on #1 compression stroke. Timing tabs lined up with crank marks, but the distributor rotor was pointing more near the #8 post instead of the number #1. The car actually ran ok for the most part with it that way, but with a shit ton of timing advance (no detonation though and probably because it was triggering the light early) and you could hear occasional fluttering through the exhaust at idle. I reset it so it would fire #1 at TDC, fire the car up and it runs like shit. I can get the timing to around 12* initial and 37* without the vac advance, but it runs bad. Sounds like it has a big ass cam in it. I roll the rotor back to where it was and it runs somewhat ok again. I was screwing around with it again today and the distributor stopped giving spark. Found it is a bad module.
    Any ideas. I don't think this could have been from a bad module. Do I have to pull the timing chain cover to make sure the cam and crank are in line? The #1 piston is at compression stroke TDC with the timing tabs at 0* TDC on the crank, and both intake and exhaust valves are fully closed on #1.

  2. #2
    Not a big deal. Sounds like the timing was set with the distributor 180 off. Bring the piston up to TDC on number one and set the distributor in and RECHECK your plug wires. Sounds like some one missed the mark and moved the plug wires to make it run.

  3. #3
    The man in the box Jukebox Hero Champion My House Is Bigger Than Your House Champion Smaugs Treasure Champion Lash's Avatar
    Join Date
    Apr 2003
    Location
    Mukwonago
    Posts
    6,566
    It's not 180* off. I've checked several times. With #1 at TDC on compression it runs better with the pointer closer to the #8 post. Plug wires are all hooked up right (checked at least 10 times) I know it seems impossible, but it's happening and I can't figure out why lol.

    I ordered a whole new distributor, rotor, and cap. I guess we'll see what happens.

  4. #4
    Reread post number 2 again. If the exhaust valve is open on number 8 when the pointer is at TDC then it is 180 off. It needs to be closed and then set the distributor at number 1.

  5. #5
    The man in the box Jukebox Hero Champion My House Is Bigger Than Your House Champion Smaugs Treasure Champion Lash's Avatar
    Join Date
    Apr 2003
    Location
    Mukwonago
    Posts
    6,566
    I'll check it again. When I set the distributor I made sure the #1 piston was at TDC and pushing air out of the plug hole to make sure it was on compression stroke.
    It wasn't spitting back out of the carb like it was out 180* either

  6. #6
    Senior Member..now yer posting! bikedad's Avatar
    Join Date
    Sep 2011
    Location
    In the Depot
    Posts
    343

    I'm assuming the engine has been rebuilt. Very possible they didn't degree it. Your cam might be off. Your pointer could be off. Also what was specified before is the dizzy was maybe installed 180° out.

  7. #7
    Jack of all Asses Wagonbacker9's Avatar
    Join Date
    Apr 2011
    Location
    Menomonee Falls
    Posts
    1,784

    Have you verified the pointer is set correctly? Sounds like you're basing everything off that and who knows if that got messed with.
    2006 M6 QSM GTO SOLD
    1993 Chevy K2500 SOLD

    2004 Chevy Tahoe - Kid Hauler
    1999 Camaro Z28 - Traded
    2008 G8 GT - 'Dad' car

  8. #8
    The man in the box Jukebox Hero Champion My House Is Bigger Than Your House Champion Smaugs Treasure Champion Lash's Avatar
    Join Date
    Apr 2003
    Location
    Mukwonago
    Posts
    6,566

    SBC timing issue

    Yes. I verified TDC on cyl 1 with the pointer on #1 post.
    Got the new distributer today. Plopped it in quick and it fires up and runs like shit unless I add a TON of timing (25-30* initial) and even then it's still not perfect. I'll play with it tomorrow but I think bike dad has it. I cant imagine the timing chain jumped so somebody must not have lined things up and just fudged the timing to make it run halfway decent.
    Last edited by Lash; 07-29-2015 at 08:44 PM.

  9. #9
    Jack of all Asses Wagonbacker9's Avatar
    Join Date
    Apr 2011
    Location
    Menomonee Falls
    Posts
    1,784

    Quote Originally Posted by Lash View Post
    Yes. I verified TDC on cyl 1 with the pointer on #1 post.
    Got the new distributer today. Plopped it in quick and it fires up and runs like shit unless I add a TON of timing (25-30* initial) and even then it's still not perfect. I'll play with it tomorrow but I think bike dad has it. I cant imagine the timing chain jumped so somebody must not have lined things up and just fudged the timing to make it run halfway decent.
    By process of elimination, kinda sounds like that's the only thing left it could be.
    2006 M6 QSM GTO SOLD
    1993 Chevy K2500 SOLD

    2004 Chevy Tahoe - Kid Hauler
    1999 Camaro Z28 - Traded
    2008 G8 GT - 'Dad' car

  10. #10
    The man in the box Jukebox Hero Champion My House Is Bigger Than Your House Champion Smaugs Treasure Champion Lash's Avatar
    Join Date
    Apr 2003
    Location
    Mukwonago
    Posts
    6,566
    Power valve is blown....Dur.
    :P

    Pulled the timing cover anyway just to check things out. Double roller set up, dots are lined up correctly, but chain is stretched enough to show 10-11* of play on the wheel. Looks like I'm throwing in a new set while I'm at it.
    We'll she how it goes after I put it back together.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •