'Heat soak' in Chevy starters.

I've heard about this a bit over the years, and it has always puzzled me a bit. I think I may have it on my current rod, but haven't investigated yet. Sometimes the starter just gets reeaal slow, even though everything looks good, good voltage, good charging etc.

The 'Heat soak' thing is apparently something to do with the starter getting hot, from the engine, which supposedly prevents it from working, but I'm curious how millions of normal passengers cars seem to go on for decades.....

I heard before that mounting a Ford relay away from the starter can help, but surely that just adds another thing to go wrong into the system?

Anybody else heard anything about this mysterious starter illness? [S

I use the Ford relay system, works great. It provides full voltage to the starter solenoid. If you have headers or the exhaust runs close to the starter, a heat shield will work wonders. Just a simple piece of steel or aluminum that blocks the exhaust heat from reaching the starter/solenoid.

Never quite understood this one myself.Always sounds like you either need a new Sol or starter. I understand the principal ideal of adding the ford Sol but the chevy one still has to work to engage the bendix drive.So unless the heat is breaking down the chevy Sol what is being accomplished by remoteing the Sol.
Some where there has to be a breakdown in one of the components for this to be helpful?

Like Bama said, the Ford solenoid/relay setup eliminates the small wire at the Chevy ''S" terminal.

Heat increases resistance and resistance decreases current and/or voltage... so, the skinny wire (already impeded by switches, connections and running length) gets hot and resistance increases, current and voltage drop... "start fail".

A strap or bus bar from the "S" terminal to BAT terminal puts the demand on the BAT cable, no skinny wire...



... like sneaky said, the Chevy solenoid still has to function as before, only now, thru the fat cable and the cable "switched" by the Ford solenoid. (We used this system with "our" Chevy race cars as heat from the headers increased the failure rate considerably.)

Naturally, connections must be clean and tight, don't forget the GROUNDS... as my shop instructor once said, "90% of electrical problems are ground"... an exaggeration, yes, but the point was taken all the same. .

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I had that problem on my LUV truck I jammed a bad 327 in. I wrapped it in asbestos (you could still buy it back then) & that worked fine. Now the smaller hi-torque starters are smaller & air can get around them in really cramped engine compartments, I use them on all my Chev's!

Might wanna double check the wiring to your starter again... I've had a problem with that once the motor warmed up. Wouldn't crank while hot but would once it cooled down.

This is my old LUV... my daughter on the left & her friend at our place in Austin many moons ago!

BoB

Thanks for the answers guys.

I need to get my starter off and have a good look at it next time I'm home. Maybe it needs the Ford thing doing, but I doubt it as it has plenty of air around it.

When I heard about the Ford relay before there was no mention of the buzz bar mod. Now it all falls into place.

I had a 'lazy' starter on a 350 I built some years ago, and I even added a second battery to get it to spin better. It made no difference, so I pulled it apart, found the contacts inside were burnt to hell. Cleaned them with emery paper and it spun great. [cl

I'm hoping that is what is up with mine this time.

The things that can be done for a lazy starter.
1. Use good quality, large positive and negative cables, instead of the el-cheapos.
Go to a welding supply and buy welding leads for your cables.
FYI, tractor supply companies usually have both the red and black leads.
2. If you take the solenoid apart, flip the copper disc over and the good side will be the contact points.
3. Use the 4.3 V6 GM starter in place of the bulky GM Hy-Torque style.
4. Use cables with the factory ends.
The make your own style battery clamps are junk, in my humble opinion.
5. I quit using the top post batteries a long time ago and went to the side post exclusively. Since doing this, I've eliminated all the problems with getting the engine to turn over when hot.
Hope this helps ya

No


Yes

Yup, Oldiron, those repair ends are junk and always fail sooner or later, usually sooner. I use the solder on brass kind if I need an end on a complicated cable like old mopars.

To the original poster, google voltage drop test and do it. You may find out you connections aren't as good as you thought.
Also a dragging starter when warm can be as simple as worn starter bushings. The armature expands when it's hot and will drag against the fields.

OldIron, Are the Zinc ends better than the lead? Or, are they all junk? [S

I dont know what kind of problem you have on yours , but I chased a heat problem for a few years on a 84 ford 351 w if it was heated up you better not shut it off or you would be there till it cooled off .. I even took the starter off in the ADVANCE parking lot , and held it with a rag it was so hot and took it in the store to have it tested ... it tested fine , nothing wrong with it ,, i even thought timing was a problem .... nope I took the coil wire off and it still would not turn over when hot (dragging) I even doubled the grounds to two different places one was on the starter bolt,, double the hot wire ... I sold that truck ,, never did find the problem ... it would put so much power to the starter it would start to melt the solenoid I put 3 starters 2 or 3 solenoids a big ole amp battery .. I'm just not a fine tuning person .. I can do the big stuff (swapping parts ) but that small problems gets me every time .

bgbrktracer said:

OldIron, Are the Zinc ends better than the lead? Or, are they all junk? [S

Click to expand...

Yes, the zinc ends are better for being able to tighten the cable down.
As Willowbilly stated, the solder on ends are the better way to go.

Another good thing about using the Ford relay is it gives you a junction point for your hot wires on the fender/firewall instead of down on the starter by the exhaust. I have never liked GM's idea of putting all those hot wires down there where heat bakes the insulation and makes it hard to find broken wires in the confined area.

I had problems with a ford wouldnt start when hot replaced starter 3 times still the same,, some time if it dont start when hot the timing is to high so I took coil wire off still turned over like a turd ,, so that meant it was not the timing,, melted 2 solenoids trying to make it start doubled cables pos. & neg side . finally sold the truck... he said it may be a (hot) spot in the crank .. I never heard of that but it is his problem now .. and yes I told him of this problem before he bought it .. when running it purred like a kitten , just dont shut it off , unless you let it cool for about 30 min. But I always have problems with my stuff .. some I cause and some I dont .. [S[S

All wiring issues aside, I think the basic problem here is heat. Headers throw off a lot of it, wrapping them as they pass the starter or putting a shield in between the exhaust and the starter is the answer - better than wrapping the starter as that will trap heat in the starter. There's a lot of metal in a starter and as Willowbilly said, it expands and the armature can drag against the fields.
On my Hennway it has block hugger headers that pair on the passenger side feeding into a 4" pipe that runs right beside the starter, less than 1/2" away. I wrapped the pipe with Thermotec wrap, in 8 years, the starter has never failed to spin it over, and that is the original 1974 starter that came on the engine.

bgbrktracer said:

OldIron, Are the Zinc ends better than the lead? Or, are they all junk? [S

Click to expand...

IMO, if they clamp on with those 2 bolts, they are junk. Any of them that you solder on are fine when installed properly, mostly they are brass

Yankee Transplant said:

I had problems with a ford wouldnt start when hot replaced starter 3 times still the same,, some time if it dont start when hot the timing is to high so I took coil wire off still turned over like a turd ,, so that meant it was not the timing,, melted 2 solenoids trying to make it start doubled cables pos. & neg side . finally sold the truck... he said it may be a (hot) spot in the crank .. I never heard of that but it is his problem now .. and yes I told him of this problem before he bought it .. when running it purred like a kitten , just dont shut it off , unless you let it cool for about 30 min. But I always have problems with my stuff .. some I cause and some I dont .. [S[S

Click to expand...

That's when you quit throwing parts at something and pay someone who knows how to do a starter draw and voltage drop test. Cheaper in the long run.
I do realize though it's a man thing since we drive in circles for hours instead of stopping and asking for directions,lol.

WB you are correct it would have been cheaper

I don't think heat is really a problem with mine, as the hood and sides are open and the headers are the other side of the frame rail.

I'll take the starter apart, and also go through all my wire connections, as I have the solder-on versions but I simply hammered a dot punch in to compress the wires into place, similar to the large swaging machines do. Maybe I should solder them as well for better connectivity.

Batteries are an issue where I live, don't seem to last more than two years, according to my own experience and several local car owners as well. May be the heat or humidity in the tropics.

Still got two more weeks to go before I head home from the ship. Also need to do some work on my HEI to sort out the lack of mechanical advance. It only gives about 12 degrees, but I have several solutions lined up to check.

I think the mechanic advance is only good for about 12 degrees. Try just setting it all in at about 3000 rpms to around 36.

Willowbilly3 said:

I think the mechanic advance is only good for about 12 degrees. Try just setting it all in at about 3000 rpms to around 36.

Click to expand...

That gives me a bunch of static timing though, 24 degrees, which means the vacuum advance is probably way up there too. I've tried to run it on manifold vacuum but it pops and farts through the exhaust then, maybe too much with that 42 degrees added. I'm sure it can all be altered, with a grinder or a welder though.

I'm way offshore at the moment, but have plenty to play with when I get home.