More Lo-Buc Tech: Eliminating Hot Start prolems on GM starter

This may be a little long and detailed but I cut it from an article I posted on another board a few years ago before I saw the light of the mighty HAMB.

Hot Start Problems



A lot of us at some time or another have experienced problems with the solenoid on a Chevrolet starter not working when it gets hot. This is caused by the high amperage required to engage the Chevy solenoid. The problem is compounded by headers and high ambient temperatures. I like to head off these problems by installing my own hot start kit from the get go when building a rod. Many kits are available to do this in the price range of $35-$75. For the price of a $15 Ford remote mounted starter solenoid you can do the same thing yourself.
Mount the Ford starter solenoid in a convenient location between the battery and the starter. I located the one on my 38 Chevy coupe under the floorboard on the passenger side since I have the battery mounted in the rear of the passenger side fender. That way I can use the shortest battery cables possible and the extra solenoid is out of view.
Attach the + battery cable (along with any other wires that would normally be attached to the large post of the Chevy starter) to the large terminal on the Ford solenoid which is next to the start switch terminal.
Remove the wire from the small starter switch terminal on the Chevy starter solenoid and attach it to the corresponding starter switch terminal (usually labeled 'S') on the Ford solenoid. Next, a jumper needs to be placed from the large battery cable terminal to the small starter switch terminal on the Chevy starter solenoid. I simply flatten out a short piece of 3/8" copper tubing and drill a 7/16" and a 3/16" hole in it to serve this purpose.
Finally, purchase a battery cable with a 3/8" lug on each end and attach it from the other large terminal of the Ford solenoid to the large terminal on the Chevy Solenoid where you removed the original battery cable and attached the jumper. If you have an original point type distributor, then you can attach the 16 ga. wire that goes to the coil terminal on the Ford solenoid.
You can purchase a Ford solenoid with this extra terminal if you plan on doing this or this wire can be simply attached to the large terminal that goes to the starter. Don't attach it to the battery side or the engine will continue to run with the switch turned off! Having the start circuit wired in this fashion can serve several purposes other than just eliminating a hot start problem.
You now have a place away from the heat of the starter to attach power taps such as alternator leads, amplifiers, fan relays, etc. You also have a more convenient location to attach a remote starter switch for bumping over the engine. Also, a 12 ga. wire is no longer needed in the start switch circuit. Other pluses are that the Ford solenoid takes much less amperage to engage than the Chevy solenoid (which can burn out the neutral safety switches of most aftermarket shifters) and the cable on the Chevy solenoid is no longer HOT at all times eliminating the need to remove the battery cable to replace the starter. Although this is a good idea anyway.

 

Printed and filed under MUST DO.

 

Great tip and great post. I'm going to put it on my "to do" list, too.

 

using FORD parts to fix a chevy....excelent tech!!

 

I've been doing the almost exact same thing to all my chevy starters for about 15 years. It also makes a convenient point to pick up voltage for a timing light. Also really easy to use a remote starter button when adjusting valves.

I thought everyone knew this trick.



jerry

 

Does anyone have any pictures or schematics for us visual people who can't read so hot?

 

Maybe these pics will help. The first is a shot of the starter with the jumper from the battery cable post to the S terminal where the wire from the starter switch would normaly attach. The second is a pic of the ford starter solenoid with the wires and cables attached. The large red cable connects to the + Battery post, the large black one goes to the starter. The 12 ga red wires go to the bat terminal of the start switch and to the charge terminal on the alternator. The 12 ga purple one on the s terminal goes to the start terminal on the starter switch. The last is a clearer pic of a ford solenoid. There are two styles of ford solenoids, this particular one is the later style. Both hook up the same.

 

I just had to do this one a few months ago...if I remember correctly, this is how I did it. It works SO well, and is a very easy fix!

 

Sometimes after my truck warms up, it tends to act like there is too much advance in the timing and the motor fights the starter. is this considered a hot start? and would this idea fix it?

 

Sorry, but I still don't know why this would help, the chevy solenoid is still called on to pass the current to the starting motor. If this is the problem, would'nt you by-pass it? Maybe send the current to the lower lug (the actual motor connection) and do a jumper from down there to the "S" terminal so the Chevy solenoid would only have to engage the Bendix?...................LEE

 

The problem is two fold. As the starter heats up, it is harder to operate, couple that with a small guage S wire, the solenoid may not be recieving full battery voltage, which means it might not have enough juice to apply. Putting in the ford sillynoid is a way to hit the starter solenoid with full battery voltage ensuring its engagement.

Personally, now this depends on how your vehicle is, when I retro fit a ford sillynoid to a later model GM I do not jumper the two terminals on the starter. I relocate everything to the ford solenoid, but run a live battery feed from the hot side of the ford solenoid to the batt terminal on the starter. The switched large lug on the ford solenoid I run to the S terminal on the starter solenoid. Works like a charm for me, and takes some stress off the ford solenoid (won't be carrying full load when starting, so it lives a little longer).

Alex.

 

Thanks lobocrud
I could have sure used this info back in the day when my chevelle ss-396 would not start after a hard run down the boulevard. let her cool down and away we'd go musta put five starters on that while I had it.
Mortecai

 

That's not hot start and this won't fix it, as I've tried.....My 'A' pickup does the same.....and the starter is NOT hot....I think it has to do with the fact that the motor is fresh, with high compression and the bore "tighening up" a little when warm. I've changed starters with no luck....I was told to get a newer DELCO starter for a Vortec, as they are a gear reduction starter=more power. Needs to be Delco, as the cheapie replacements don't hold up.
But at @ $150, haven't bought one....yet. Got to before summer!!!

 

This will fix the problem of the solenoid not operating when it gets hot which keeps the starter from working at all.
Your problems can be caused by high compression, too small gauge on the battery cables, not enough cranking amps on the battery, poor ground connection between the battery and the engine, or a combination of any if these.
I would suggest using the largest guage battery and ground cable available, make sure your grounding the battery to the engine not the frame and using good engine to frame ground connectors, and use at lease a 800 amp/hour battery. The cheapy 500 amp/hour batteries wallmart sells dont cut the mustard.
I made the mistake of putting 305 heads on a 350 with flat tops in a chevy pickup a while back and ended up having to put two batteries on it like a diesel in order to start it when it got hot. Changed the heads later and took the extra battery off.

 

yep try zero deck block 305 heads and 350 flat tops and I needed 0ga batt cables and a 1500 ca marine deep cycle batt in my '76 chevelle but man it had some pop in the exhaust note with about 11.5-12:1 compression now it has dart heads and is in my coupe at 11:1 and 1000 ca with 4 ga cable and still have a problem i'm gonna try this and see but I may need a gear reduction starter. hopefully not though!

 

I think the NAPA number for the solenoid switch is ST81 I will check Friday at work.

 

Great tip. I did that on my old T roadster drag car. It had a big block Chevy. I`ve also done the same thing on VW`s. It helps the old 6 volt one`s a lot.

 

I have had some trouble recently with my 55 not starting (blown big block), I did some checking and the voltage at the S terminal on the starter was about 6 volts when it was not working properly. I put a little Bosch relay in the S circuit and fixed the problem. The ford starter relay is way overkill for this.

 

I do this to all my GM stuff - have;t had to wait for a starter to cool down in years!

 

this is a great remedy if your engine compartment has restricted air flow and has tendancy to heat up. the heat causes the piston inside the solenoid the swell causing it to bind. in a real pinch a can of pressurized CO2 works great to get you going, every GM powered car should have one in the roadside bag with the triple a card!

 

I don't buy the theory that the piston swells up in the solenoid...because the piston is probably not hotter than the housing, and the housing swells at the same rate. Also if you shoot cool stuff on it, you will cool the housing, and the piston will still be hot and swollen, so shooting cool stuff would lock it up!

but I do agree that heat is part of the problem...

 

Try pumping the gas a couple of times, and they will usually turn over and fire right up.

 

Another quick and easy tip is to run the ground cable from the battery directly to one of the starter bolts, by doing this you are ensuring the best ground possible for the starter. Also, make sure that the place on the bellhousing or engine block where the starter bolts is free of paint,rust,oil etc.

 

the secret to good auto electrics
when temperature rises resistance rises,then current rises, voltage drops. and that will slow things down. with only 12 volts in the starting circuit every volt counts, so every connection counts, [including ground wiring]large wire and good connections are needed in starting circuits. Cant afford to lose a volt! this is a good circuit Just ask the 6 volt guys.

 

the starter is mounted on the engine block,and is near the exhaust manifold and soaks up lotta heat, also the solenoid contacts are located inside the solenoid and they degrade from the higher amps. the ford sol. operates in a much cooler area and isnt affected by high temps, and is able to deliver full voltage to both the GM solenoid and
starter windings.

check out this site for wiring tips http://www.madelectrical.com/

 

one problem. cannot explain how, but the Ford solenoid "confuses" some mini starters, causing them to not disengage fully. I had this problem with a mini-starter and the first thing the seller asked is "do you have a ford solenoid" to which I replied in the affirmative. "Take it out". I did and the problem was solved. I like the Ford solenoid because unless starting, there is no power in the wire that passes through/under the exhaust system, and no short when it hits the pipes and melts through.

 

Chevy's are a lot like blondes, easily confused but that makes them endearing.
Fords are more like brunettes, sassy, fun and intelligent.
Dodges are the red headed step children, fun, fast and a bit on the crazy side.

I like them all.

 

Here's a remote starter relay kit made for GM based motor homes. Relay, wiring, terminals and instructions.

http://www.madelectrical.com/catalog/st-1.shtml

Seems like a bargain for $30.00!

 

I wrote about this situation long ago. I was a mechanic for the U S Border Patrol in El Centro in 1975. Our Calexico station had 3 Suburbans with 454 in them. Every day they would transport a load of detainees from Calexico to our detention facility in El Centro. With 105-110° temperatures the norm from May until September, when the suburbans would deliver their loads, the trucks would get the typical rump-rump-rump and refuse to crank. They would have to sit for 3-5 hours before the trucks would start. I called the A/C Delco school in Burbank to see if they had a cure. The guy on the phone said yes and began to explain why it did that and how to cure it permanently. The first thing he said was to get a Ford starter relay. I immediately questioned him why he was recommending Ford part for a GM application. His reply was blunt and to the point, "Do you want to fix the problem or not?". He explained that there was a basic flaw in the GM wiring with all the power for the vehicle flowing throught the one stud on the solenoid and that eddy current would develope on the plunger and make it drag instead of easily transfer current to the starter coils. His recommendation was to remove ALL wiring from the starter, install a starter cable from the Ford relay to the big terminal on the GM solenoid and fabricate a short jumper wire from the large terminal to the S (starter terminal) on the solenoid. Then attach all the system wiring to the battery post on the Ford relay and attach the start wire to the s terminal on the Ford solenoid. We did just exactly as he said and never had a hard start problem with the suburbans after that. I have wired up every GM vehicle in that manner since then. Hot Rods, high hp motors, stockers made no difference. All of them using the standard GM starter. No high zoot gear reduction starters or any other aftermarket "cure", just the everyday GM original equipment starter. I have done dozens maybe hundreds or them that way, plus recommended the conversion to guys doing it themselves. Not ONE problem heard from anyone. To show that I practice what I preach, I inherented a 68 El Camino upon my father's passing in 1990. I still have the car, now with over a half million miles on it, and three different hot rod motors in it with varying degrees of extra horsepower. It still is the same starter that was on the car when my father bought the car new April 4th, 1968. Twenty years ago I was teaching auto mechanics to inmates at the prison here in Tehachapi. One of the guards on our yard had a brop dead gorgeous 67 El Camino that da the rump-rump problem and he had used all the trick starterstwhile to no avail. I told him what to do and looked at me like I was nuts, but put a stock starter on it and rewired it as I suggested it. Twenty years later, he has put a new motor in it, ran the snot out of it and is now owned by his son that shows the car no mercy. We have both retired bad see each other ofter. He almost always remarks about that Ford starter relay and the goofy wiring that is still performing for his son today. All because a GM engineer gave me the method for a permanent cure way back in 1975 that has been been proven to be virtually foolproof since then. All it will cost to convert is a Ford starter relay, a starter cable ( not a battery cable) two ring connectors and a short piece of number 14 wire and less that two hours of work. Something to consider. Also, if you don't believe me, Ford figured it out on their early 70's 429 and 460 engines. They used a GM starter with a jumper wire from the large post to the starter post and a starter wire to the Ford starter relay on the fender. When I open the hood on my El Camino, I still get some guys asking what a Ford starter relay I'd doing bolted to my fenderwell.

 

Hello,

It is one of those things that just happens. There are plenty of tricks to get things going again. We tried them all and nothing worked on our starter motor for our 671 supercharged SBC motor in our 1940 Willys Coupe.

It was running fine and when we stopped the motor after a run and it was sitting in the pits, we had to turn the motor over for some reason and the whole thing had no action. The starter did not click as if the starter solenoid was stuck and tapping on the outside shell did not magically make things better. So, my brother told me to drive to the local Chevrolet dealer and get a new starter. As simple as that.

But, it was not just that simple. While we were trying to get a handle on the starter problem, my brother was under the car. I was leaning over the fender. We both were in the process of removing the old stuck starter. As the last bolt was ready to come out, my arm was under the hot header pipe, grabbing onto the starter with a death grip. I certainly did not want the starter to drop in my brother.

When the last nut was out, I pulled the starter out slightly and it dropped down. I quickly grabbed the starter with a better iron grip and consequently, my bicep got automatically straightened out due to the weight of the starter dropping down toward my brother. So, when I got a stronger grip, it did not hit my brother and he, too, raised his hands to stop the falling starter motor.

My bicep was the only thing damaged in this incident. The weight of the starter motor, the outstretched arm and geometric angle of the arm/starter/gravity action made my bicep go right into the hot header. I knew if I let go, the starter would fall on my brother. So, I kept holding it as long as I could. It seemed like a super long time in pain from the hot header burn. But, it was just enough time for my brother to raise his hands and slow down the rate of the falling starter motor.

Jnaki

The result was a 2.5 inch oval burn on my bicep from the hot header pipe. It was raw and oozing, but at least I saved my brother from a weight falling on his face. I was in pain, but there was nothing we could do, except treat the burn. Our supplies had no ointment for burns, the Lion’s Dragstrip Pits station did not have supplies to treat burns. So, I sat around digging into our own stuff to see if anything could work.

I found a new can of STP engine oil additive. So, I opened the can and applied the oil directly to the wound. It was instantly cooling and nice. I remember my old Boy Scout training on First Aid. A soothing ointment will seal the wound and keep out the infections as a result. I certainly did not want to leave the eliminations and go to our family doctor.

My last job was to go to the nearest Chevy dealer to get a new starter. With the installation of the new starter, the 671 SBC motor fired up on the first crank. A job well done, despite the initial pain of the burn. We had no time to take apart the starter or solenoid to see what was the matter. But, just enough time to treat my burn and go to the local dealer to get a new starter. No junk yard replacements this day/night.

Note:

Our family doctor said that it was healing nicely and it was good that I kept the infections low with the air sealed oil coverage. Besides, I had to walk around with my T-Shirt rolled up showing my bicep and to keep the STP away from staining our jackets.

So, 60 years later, I still have an oval burn mark on my bicep. When I flex it, Ha! It stands out more than normal. But, it is almost gone. So, one more reminder of what it took to keep us in the races at all costs. YRMV

Note 2:

I was very enthusiastic about wire wound electric motors when we were involved in slot car custom frame and race car builds. We took apart everything as if it was a 283 motor and build most of them from scratch. (Including the electric wire wound motors.) We even created different versions of modified wire wound spinning armatures to see which one would give us the edge in the highly competitive, fast, scale model version of drag racing. Some armatures had lots of tight winding wires, while others were thicker wires, but less windings around the armature.

But, while all modifications were going on, the solid epoxy coverings, shaped to fit inside of the magnetic walls of the motors were also created to keep everything together for that instant 120 v shock at the beginning of each race and the 1 sec runs. Yes, 1 second runs with extreme power added causes some cracks, leading to full explosions of those dinky motors. All for the aspect of being able to go fast and faster…

So, had we known about spinning armatures and wire windings on the armatures, we could have repaired our own SBC starters, instead of throwing them away. Ha!