Join Date: Feb 2009 Location: phoenix Posts: 2,428 Re: SBC hot start problem <hr style="color:#e5e5e5; background-color:#e5e5e5" size="1"> 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. starting to think all you overposters just want to argue
The newer ones aren't solid copper but are instead copper plated. I flipped a ton of the older ones over though. Back to the original question. 1. you have to make sure every connection in the circuit both + to the starter and the ground are good clean and tight connections. 2. The Ford solenoid thing helps a lot and I have that on my 71 with a 350 and headers. You run a copper strap from the big post you normally hook the battery cable to to the S post that the purple wire normally hooks to. Then you hook the thing up like a Ford with the Ford solenoid in the middle of the cable from the + post on the battery to the Delco starter and the normally purple wire that runs to the Delco solenoid running to the S post on the Ford solenoid. I used a flattened, trimmed and drilled piece of copper tubing for the copper strap between the two posts on the Delco solenoid. The Ford Solenoid is just a 60's/70's Ford solenoid. No need to spend the extra money for a kit from one of the vendors. 3. Is the starter dragging because the bushings are worn? It only costs about 6 bucks and doesn't take a lot of time to replace the bushings in the starter. I need to change the ones in my starter this weekend and will try to put together a bit of a tech article for it. 4 A heat shield for the starter is a damned good idea, I'm picking one up tomorrow for my ot truck.
Not sure what an over poster is black 62 or who you are referencing here. ( or enlightening new guys to beware the over poster) But landseair has an awful lot to offer here on the hamb and seems like fenders asked a legitimate question because on the surface adding a Ford solenoid really doesn't make sense or shouldn't make a difference.. I know a ford solenoid helps and mentioned it myself - but why dont you take a moment and explain why it does.
The Ford solenoid is a relay that applies full battery voltage to the GM starter solenoid winding allowing the bendix to engage and start the engine. The GM starter solenoid receives it's voltage from the ignition switch, and as the starter and wiring heats up, resistance goes up as well resulting in less than 12 volts to engage the solenoid. The Ford solenoid will solve the problem.
In the mid '70's I worked as a mechanic for the Border Patrol in El Centro Ca. we had "Burbs with 454's and they would absolutley refuse to start once driven from El Centro to Calexico or vice versa, using the a/c in the July-September heat. We tried all we knew and failed. We made a call to the GM?Delco training center in Burbank to ask for help. We were shocked when they said to get a Ford starter relay, jumper the B+ terminal to the S terminal on the starter, replace the battery cable with a starter cable that attaches to the ford relay and reposition all the wires except the starter wire to the hot side of the Ford relay and then run a battery cable from the B+ post to the ford relay. Take the starter wire and put it on the Ford S terminal. We did it and no more rrrrrrrrrrrrrrrrrrrrrum rrrrrrrrrrrrrrrrump perfect starts every time. I now do that to every GM car I wire and have had no problems even using stock light duty GM starters. No high Zoot or trick gift wrap, Just a Ford starter relay and a rewire. You should see the looks I get when i open the hood on my own '68 el camino and they see a Ford relay setup!
Would one of you biscuit flippers explain how you did that. I had a bunch of them apart over the yrs. and was able to flip the top stud, and file the surface on the bottom stud, and clean the disc, or biscuit and reassemble. It has been a few yrs. but I seem to remember that biscuit had a stud and maybe a fiber washer riveted to it and would only go in one way.
Rod, this isn't necessary the long ground cable. We have street cars here in the blazing Florida sun, 632 cubic inches, and here's how we do the battery cables. Yes, they have mini-startes, but we also have high compression 540s+ running GM starters as well. Ground cable from battery right to the frame or uni-body as short of a cable as possible to a good and solid ground lug. Now up by the engine a ground cable from the frame or uni-body ground lug to as close to the starter as possible. This is all you you ever need, FOR THIS CIRCUIT at least. If you are having a Heat-Soak issue, I believe you have had several members give good tips on correcting that as well, so no need for me to go into that, all the best, TR
I had the same problem in my 27 ,had a short 12" ground cable to the frame ,battery in the trunk,replaced the weak battery to an innerstate 1000cca,ran another ground back up to the engine...5ft.and a ground strap from the frame to the engine near the starter.This car has been on the road since the 70s and both cables were questionable.Now it starts good even in 100 degree + weather.
The poster gave enough info on how his vehicle is wired, but failed to give any background. Is this a new build? Has it been on the road for a while and is a new problem? Do the symptoms just appear when the car has been driven for a while, or does it happen all the time? Has the battery been load checked? But for my bit; one thing I like to do anytime I have a starting problem is try a known good battery, one that comes out of a perfectly good running ride. This has saved me countless hours chasing gremlins, and beleive me; I learn the hard way!!!!
What starter are you using? The heavy duty GM starter Had a copper piece about 3/4" long that ran from the solinoid to the windings. The standard one just conected the sol. to the winding. I have had good luck with the newer mini starters called gear reduction. The HD starter had a longer field.
Hey guys, thanks for all the great input. To answer some questions, yes, this is a new build with all new stuff. To cut to the chase, I moved my ground from the battery from a bell housing bolt to a starter bolt. Now it starts as well hot as cold. I did put star washers on both sides of the cable end. It's great! Again, thanks for all the good input and concern, Rod
You are correct. Newer solenoids have the assembly staked on where older ones had an e clip to hold it together.
2 gauge wire is only rated at 181 amps so your 690 CCA battery can't do any good for you especially at that length. I'd use at least 2/0 which is rated at 283 amps or 3/0 at 328 amps. Maybe just ad a second leg of 2 gauge to the positive and the ground.
I fixed mine by replacing all of the battery/ground cables with welding cable. It's designed to carry a lot of amperage, which the starter wants when it's hot.
If your looking for a higher CCA battery, I got a 900 CCA battery from a "Batteries Plus" store. They have a Rayovac battery for under $100. 3 yr replacement, 5 year prorate. Never thought about Rayovac making auto batteries. Flashlites yes!
Had the usual sbc problem with hot start, headers too close to the starter, multiple gm starters, adding a heat shield never worked for me, checking all grounds etc, larger cables, ford solenoid and a quality mini starter solved the issue.
True - more than one ground strap, at least one from battery direct to motor/trans and one from there back to body. And run the fattest wires possible, I up-sized mine and it was like having a bigger battery and new starter, totaly different, no embarrasingly slow griiind.......griiind......grind (with fingers crossed it would actually start) when the motor was hot.
i run 3/0 cable on my toys, yes i know complete overkill. but they start good. why wonder if its to small, or you could know it way to big
12 Degrees ignition advance is a bit much...try 6 or 8 and tweak your centrifugal advance curve and fix your vacuum advance issue. get a planetary gear starter... 153 tooth use 1996 LT1 Caprice/Impala starter, 168 tooth use 1999 Chevy Tahoe 5.7L starter. These are the mini starters that have gear reduction in them, they are small for header clearance and have amazing torque. Available and in-stock at your local big box parts store for a fair price. Double check you wiring. run a ground strap from the starter bolt to the a solid chassis ground in common with the battery. Make sure the support bracket is on the back side of the starter. This is the bracket that attaches to the threads on the starter motor end and then to the block. The high torque starter will twist the bolts and rotate out of alignment causing poor tooth alignment and a jam when hot. The bracket prevents this. consider fabing up a hear shield if your exhaust pipe is close the starter or wires. I did all this to my 11:1 SBC and have no problem hot starting with a small 475 CCA battery located in the trunk hot or cold. I have fuel injection so I run 220 degree thermostat. There is also an HEI module that has an extra pin for a 12v crank signal that retards the ignition timing for starting if but I didn't need it.
I used big 2/0 or 1/0 cable from home depot (clearance $.19 a foot), soldered tab ends (cost more than the cable. ), and a cheap 450 cca battery in the trunk and started my 350 in the cold midwest winter. Grounded to the alternator bracket bolt. Yes, the little one on the bracket. But I had a ram horn so the pipe was plenty far away to not have heat soak.
Make sure that your bird cage ground straps are there and in good shape/grounded well on the chassis. If it was a 'body-off" resto, it's a common mistake to find the ground straps missing on the cage.
Guys, I think he fixed it. As far as adding a Ford switch, I've seen it done, but I never understood why it seems to work. Just another piece in the puzzle?
Hook up / wire it like this - 800 to 1000 CCA battery and make sure it’s the high torque starter. Then there will be no issues ever. Ford solenoids always work because its away from the heat GM solenoids are in the heat = get swelled up. The short jumper wire in place in the diagram can now carry direct un restricted voltage w amps making it (the GM part) more inclined to work.
On my 36 ford 327, I found that I had a large voltage drop in the start wire from the key, I wired a relay into it, the start wire from the column goes to the relay, the relay takes direct power from the battery, problem solved for me. I've never had a hot start problem since.
What the Delco school instructor told me was that when hot and the power cable attached to the starter solenoid, eddy current will build and cause the plunger in the solenoid to stick or bind in the housing causing an un necessary voltage drop and the rrrrrrrrrrrrump, rrrrrrrrrrrump we have all come to know and love(?). He said by removing the power cable and only applying power when starting, the plunger never got hot enough to stick. It didn't make sense then and still seems hard to believe BUT when we did his cure, BINGO! No more problems and as I said earlier the ford fix has worked on all the GM engines I've rewired to Ford. From stock to barely streetable. So I won't argue with GM engineers about it, just do what they said.
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