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SBC hot start problem

Discussion in 'The Hokey Ass Message Board' started by raj4851, Nov 28, 2012.

  1. raj4851
    Joined: Jan 18, 2006
    Posts: 95

    from Decatur Il

    It's my '39 Ford sedan again... My SBC with flat tops, comp cams 280h, dual AFBs is now running but won't start when it is hot. The timing is set at 12 degrees BTDC. My battery is in the trunk. My cables are 2 gauge and the ground goes back to the starter as well as a ground from the engine to the frame. I haven't checked the voltage drop at the solenoid yet but today I noticed that the battery is a 690 CCA from Farm & Fleet. I'm sure this is part of the problem. Where is a good place to start for CCA? Any other suggestions or test procedures welcome. Thanks in advance, Rod
  2. landseaandair
    Joined: Feb 23, 2009
    Posts: 4,409

    from phoenix

    Haven't had a hot starter issue myself but a few guys I know fixed it by jumping the start terminal to the battery post and sticking a ford solenoid inline to the starter in the battery cable. Then hook the start wire to it instead.
  3. Don's Hot Rods
    Joined: Oct 7, 2005
    Posts: 8,319

    Don's Hot Rods
    from florida

    690 is a little low, 800-1000 would be much better. You might also add one of the Ford type solenoids in the circuit. I have no experience with them but have heard they solve the hot start problem you are having.

    This link might help:

  4. tguptill
    Joined: Aug 12, 2012
    Posts: 55

    from Maine

    Is it not cranking over well hot? Try pulling the coil wire off and see if it will crank good with no spark. If the timing is to far advanced, it will not crank well especially when hot.

  5. cheepsk8
    Joined: Sep 5, 2011
    Posts: 560

    from west ky

    You might try moving your battery ground to the engine, perhaps to the alternator bracket, if you haven't tried that. I spent a ton of money on an old truck with hot start problems only to find out it was a poor ground issue. Worth a try...
  6. flatout51
    Joined: Jul 26, 2006
    Posts: 996


    I had an OT 80s tbird with SBF but built almost identical and my was my header was too close to my starter and when it got my starter hot it would crank super slow and wouldnt be enough to fire... If it sat a few min it would... I wrapped the header and got an asbestos starter blanket put a NEW not reman starter on it and never had the issue again...
  7. tommy
    Joined: Mar 3, 2001
    Posts: 14,758

    Member Emeritus

    I fought a hot start problem on my SBC for over a year New solenoid (I think I still nave it) heat shield etc. etc. all the heat soak fixes. I thought I was so smart by welding a dedicated bolt onto the frame for the ground cable when I built it. Finally I reluctantly moved the ground cable from the frame to the bolt on the tail housing just to prove that it was not the problem ....problem solved. My battery was under the seat. Never another hot start problem. Nothing is more embarrassing than driving 3 hrs to a rod run, going up to register and coming back to a nice looking hotrod that won't start until it cools down. Gawd I hated that!!!
    Joined: Mar 6, 2008
    Posts: 256


    Pull the solenoid apart and flip the copper biscuit over,
    and / or put a vat on it and see what it is actually drawing
    Joined: Mar 6, 2008
    Posts: 256


    Another endorsement for solid motor mounts.. or secondary ground straps.
  10. Don't forget to go back and re-clean all connections, make sure they're all snug and use star washers where appropriate.
  11. tommy
    Joined: Mar 3, 2001
    Posts: 14,758

    Member Emeritus

    As long as the secondary ground strap is capable of carrying the current of a starter on a hot engine. I have secondary ground straps but they are for the accessories and lights and not designed to carry the load of a hot starter motor.
  12. I use the heavy ground straps for a GMC pickup on my small blocks, as well as a remote solenoid if I am running a stock starter ( one on each head and one from the srater to the chassis). I have not tried running a ground to the tail of the transmission like Tommy has, but a lot of my engines are grounded to the block from the battery.

    Just something to think about is I had a GM high torque starter (large not mini) in the '90s that just dealt me a fit. I trieed one of everything on it and still could not make it start the engine when it was hot. I finally was talking to a friend who owns Mega Torque starters (the dirt track guys friend) and he said bring it to me and we'll figure out what it wrong with it. A simple dye test revealed a cracked field. A new set of fields fixed it.

    Now on with things of interest, while it is not a traditional solution I broke down and bought a ministarter when I first got on the HAMB. Best money I ever invested.
  13. ironpile
    Joined: Jul 3, 2005
    Posts: 915


    That is a good ,easy fix for that problem.Done it several times.
  14. 68vette
    Joined: Jul 28, 2009
    Posts: 306


    Also....there are two starters for these is heavy duty and the other NOT so heavy duty...

    I am pretty sure my ol chevy mechanic says the heavy duty one has 4 fields vs 2.

    I had the battery in the trunk on my 51 ford shoebox and never had a starting problem in 8 years...I did have about 3 grounds....the battery main ground went to the rear portion of the frame...then I had a big ground on the engine going to the frame and a smaller ground going from the engine to the the firewall.
  15. black 62
    Joined: Jul 12, 2012
    Posts: 1,895

    black 62
    from arkansas

    you stated " the battery is grounded to the starter "---- ford solenoid away from the headers should fix it if your starter checks out
  16. Heres a few to check,

    Make certain your centrifgul or mechanical advance is not sticking.

    You have the CORRECT starter bolts with the knurled shanks and not hardware store bolts.

    You can tell a High Torque GM starter by simply looking at the post that comes from the starter motor housing that atatches to the solenoid. If there is a 1 inch spacer between the solenoid and the armature post coming through the starter case, it's a H.T.

    Have the battery LOAD TESTED even if it's brand new.

  17. lippy
    Joined: Sep 27, 2006
    Posts: 5,262

    from Ks

    12 initial timing? I can't remember, isn't that a little high for a street engine? Lippy
  18. ibuild
    Joined: Nov 30, 2010
    Posts: 83


    i had the same problem with my 351 put a big battery in the trunk, i had some battery cables made up that they use on trucks, heavy duty, good ground straps, cranks over good now, motor has pop ups and a ton of compression, i blend racing gas with high test and it turns over great and fires right up, this is in my 29 roadster
  19. 3wLarry
    Joined: Mar 11, 2005
    Posts: 12,804

    Member Emeritus
    from Owasso, Ok

    I read years ago in a magazine about a project car that had the battery mounted all the way back in the trunk...they added a 10 guage wire from the positive battery cable to the starter...problem solved.
    kidcampbell71 likes this.
  20. Fenders
    Joined: Sep 8, 2007
    Posts: 3,922


    I don't understand how a "Ford solenoid" can help...
    first, it's a Ford relay -- (the Ford starter used a Bendix spring to kick in, not a solenoid)
    and the solenoid on the SBC starter is still used to kick the gear into the flywheel.
    So if the problem is a hot Chev starter solenoid, adding a Ford relay will not help.


  21. No, it would be a little too much lead for a smogger motor but a mild performance street motor lives just fine @ 12 degrees.
  22. If your exhaust is heating the starter up beyond its designed limits your going to have troubles.
    The ford solenoid trick helps a lot but still troubles if its exhaust heated.
    A mini starter and heat shield along with Ford solenoid usual fix the exhaust heated starter problems
  23. Larry W
    Joined: Oct 12, 2009
    Posts: 731

    Larry W
    from kansas

    If you're talking about the starter getting heat soaked,build a heat shield for it .A little aluminum in the right place will help..good luck..
  24. 53sled
    Joined: Jul 5, 2005
    Posts: 5,819

    from KCMO

    an old license plate or some asbestos from a heat blanket would make a fine shield. Long tube headers on a 377 in a g-body, I cooked so many cheap oreillys starters. I'll never use long tubes again, manifolds work just fine for me.

    edit: home depot has that perforated steel sheet, you could wrap that around the header with some 1/4" square stock and button it down with hose clamps. Would look less ghetto than a license plate.
  25. raj4851
    Joined: Jan 18, 2006
    Posts: 95

    from Decatur Il

    Hi guys, and thanks for all the replies. More info: I have the battery in the trunk with the positive cable going to the starter and the ground running all the way up and grounding to the engine on a bell housing bolt. I also have another ground on the same bolt going to the frame. I do have a Ford solenoid, however it is a newer small one. I'm thinking about going with an older style bigger one. I think this one was off a Festiva or something like that. I just happened to have one laying around. I thought the bell housing bolts would be a good ground. I hesitated to use the starter bolts for a ground. I think I'll get a bigger battery also. also, my vaccuum advance doesn't seem to be working. Thanks again, Rod
  26. "T'RANTULA"
    Joined: Aug 6, 2011
    Posts: 662

    from Ohio

    I also got a hot start problem with my 55 chevy. My headers are right on the solenoid and it dont seem to like that! But what I find that helps is I crank the motor over then turn the ignition on. Seems to crank easier with the ignition off.
  27. tjet
    Joined: Mar 16, 2009
    Posts: 1,272

    1. Early Hemi Tech

    My old vette has the same issue - original delco cast iron nose starter. Ford relay, heat wrap, no help. Glad it's a 4-speed. Just make sure you jump all the way in before you attempt to pop the clutch. My left foot was sore for a week after the back tire rolled over it

    Mini starter is next
  28. landseaandair
    Joined: Feb 23, 2009
    Posts: 4,409

    from phoenix

    One long cable is bad enough, two would be a lot of resistance. Might try a short cable from the battery to the chassis and another from the chassis to engine block along with a ground strap from engine to body.
  29. Drive Em
    Joined: Aug 25, 2006
    Posts: 1,748

    Drive Em

    I ground the battery directly from the negative battery terminal to one of the starter bolts making sure there is no paint where the starter bolts on to the block. I never have hot start problems this way, even on the 8-71 blown, 502 powered Chevy pickup I just finished.
  30. speedfreek155
    Joined: Sep 10, 2011
    Posts: 312


    Had an issue like this with my '68 Camaro with a 327 . Ended up pulling the starter apart , cleaning the armature , replacing the brushes and bushings . The starter worked great from there on out . This was 20 + years but it cost me like 3 bucks ! All those long waits for cool off and walks to get a jump start , then chump change and an hour or so fixed it .

    Bottom line was that the weak connections caused a huge draw and quickly drained all the juice from the battery but it would eventually recover and the starter would cool .
    Last edited: Nov 29, 2012

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