Technical POLL: Starter heat shield OR Ford solenoid on Chevy engine to cure hot start problems

There are many threads on here about installing a Ford solenoid on Chevy engines to cure hot starting problems. On some of those threads (I've read a lot of them) folks say heat shields are a better solution.

So I question those who have tried both; or who have used one or the other successfully or unsuccessfully.

Which works better in the long run?

fwiw: I've got a heat shield ordered and I can run down to the local parts house and get a Ford solenoid. I just want to know about the long haul. b-t-w; I've got a parts house 5 minutes away that stocks LOTS of old original parts so it's very likely he'll have a real Ford solenoid and not one made from Chinesium. He had a real-deal 1963 Ford ignition switch that had been on a shelf for probably 40-50 years and several other original production parts.

Note: Clarence has refused to start without cooling down four times in the last couple of years. I really don't want this to happen again.

On some of those other threads many folks suggested a mini starter but initially I'd rather try one of these solutions.

 

I had one Chevy that needed help with hot start. I used a relay..but not a big Ford relay, instead I used a small Bosch type relay.

What I found to be the problem, was that the voltage to the starter solenoid on the small purple "start" wire would drop real low when trying to start, so the starter did not do anything.

I wired the little relay, on the firwall, in line with the purple wire, to give it a boost. Totally fixed the problem.

My point in this is to first figure out what the problem is, then take the appropriate measure to solve the problem. I had checked the voltage on the small wire at the solenoid, while trying to start the engine, and found that it was too low.

 

Thanks Jim.

A friend suggested we check that very voltage to see if it dropped too much. I'll do that first.

 

I had this problem on a start system that didn't use the override circuit. Installed the solenoid and haven't had the problem since.

 

I've not used either the heat shield or solenoid fix.
The only time I experienced a hot start problem (slow cranking speed), it was resolved with a better ch***is to engine (or battery to engine) ground cable.

 

Kinda like jumping the terminals at the starter with a screw driver. Proof it isn’t heat a soaked starter issue.

 

Put the Ford style on my ‘37 Chevy and never had a hot start problem since.

 

I used to race the Olds and I had a lot of hot start issues at the track. I did install a ford style solenoid in the trunk along with the battery, a gear reduction starter (more room under the headers) and a velcro, heat shield wrap. It already had ground leads on the block (one near the starter). That was 2009, still no hot start issues.
I put one of these on my roadster and truck as well. Easy to install and remove.

 

i thought the cure for hot no-start was to clean and apply dielectric grease to all battery cable connections and the grounds too.

 

That was done recently.

 

Dielectric grease is not conductive.

It helps prevent corrosion. It does NOT promote electrical flow!

There are CONDUCTIVE greases that also help prevent corrosion.

I use NO-OX-ID from Sanchem. https://www.sanchem.com/electrical-contact-lubricant.html

It is common enough that you can buy it on that rainforest site.

 

Thank you Gimpy! I’ve seen more connectors at work recently packed full of that dielectric ****. All it does is ruin terminal pin tension as it hydraulics out. Then, they look at me like I’m an idiot when I correct them.

 

I fougt hot start issues on the 454 in my 77 C30 1 ton for several years. I did the Ford solenoid trick and that helped a bit as did the heat shield but what fixed it was going from those ****py skinny # 4 battery cables to to 2 gauge from O'reillys. No problem since even when the truck was stalling out because it was vapor locking because the donut between the manifold and exhaust pipe had blown out. I was pouring gas in the float bowl and starting the truck and going a hundred yards at a time to get to a safe spot to pull over and sit. Those bigger cables didn't have any issues at all.

If you are doing the Ford soleonid you don't need a fancy kit. Just a Ford solenoid and a copper battery cable end with an eye that is the right size for the battery post stud on the Delco solenoid. Flatten the en of the terminal out, stick the eye over the stud and s****e it on the S post to leave a mark so you can drill a hole that will fit the S post. You can trim it up to look better if you want. That has worked on three starters for me.

 

I made a heat shield for an AMC 360 with headers. It seamed to help some. If I remember right, AMCs already had a remote relay. You need to realize that heat shields work both ways, and can hold heat in, too.

Gary

 

Heat Shield!

 

I put a heat shield - blanket type on my 500 Cad w/ a hot start issue, and it may be better, but not cured. I've run extra grounds as well. Next to try is the Ford solenoid.

 

I had an OT with a Ford FE that the starter would heat soak and drag and not start sometimes when hot, you may need both a heat shield and a remote relay. The header tubing ran close to the starter.
Dan

 

You need Ford parts to even start a Chevy…

 

My 68 firebird 400 had a problem after I put headers on it.

I just took a piece of tin bent it to go around the starter but still gave it a good 1/2" to 3/4" clearance around the starter. Then bent another piece of tin strip, about 3" long and 3/4" wide, bent it into a lazy "Z" style, welded on end to the shield and the other end I put against a header tube and using a hose clamp I clamped it to the tube. No more problems.

Later on did the same thing to the 389 and headers in my 66 GTO, again no problem after that....



.....

 

Very honestly we can accomplish the same thing with a relay that is operated by the purple wire that controls a #8 wire from the battery to the Chev solenoid but the Ford solenoid costs a **** ton less money and ******** simple to hook up. When that starter mounted solenoid gets hot it takes a lot more amps to get it to work right.

 

A simple thing on battery cable size. Amperage flow in a cable has often been compared and rightfully so to water flow in a pipe or hose when it comes to size. Go get a quart container and toddle into the bathroom and fill said container with the cold water from the sink. Then dump the water turn the cold water on full blast on the faucit in the tub and see how much quicker it flows. Under that sink is a white hose carrying the water that is usually 3/8 ID. That faucit on the tub connects straight to the 1/2 inch pipe. That is the difference in flow be it water in the bathroom or electricty going from the battery to the starter with a #4 wire (sink) or #1 or 2 wire (tub) .

 

Our big 8.9 ***mins powered school buses use a dual solenoid on the starters. A smaller one operated from the key switch with 10 gauge wires off the battery to operate the much larger solenoid. It operates just like the way Jim described his using a relay. The smaller one sends current to the larger one that can handle 6 to 700 amps coming through 0000 cable. The bus sends a few amps through a 18 gauge wire to operate a 700 amp starter, it about having the right amps at the right place.

Back when I was racing Pontiac's, I took a stock starter, cut the aluminum housing in half and rotated it about 180 degrees so the solenoid hung down under the starter in the cooler air. After centering the pieces I had it welded back together. It made installing much easier, it kept the wires out in the open, and kept the solenoid out of the heat. I had zero starter issues.

 

Both. Overkill is of no concern when your ride won't start

 

The Ford style remote solenoid in my ‘37 is only used to energize the original Chevy starter solenoid (purple?) circuit, not to connect battery power to the starter, so the Bosch type relay would do the same.

 

^^^^^ Exactly

 

In my mind, a blanket type heat shield like that will help keep the heat out for a while, but after a long drive it will also help hold the heat in the starter. I think a heat shield should only be between the starter and the exhaust manifold or headers.

 

One thing that has helped me in the past…… instead of installing a relay, just replace the factory purple wire with a heavier gauge wire. I think the wire they use from the factory is pretty marginal, especially as the car gets older and the connections deteriorate a little. That’s one less thing to go wrong down the road, when the relay fails.

Once you make sure you have adequate volts and amps at the battery cable and the small wire, if you still have any problems or you think the cranking speed is marginal, replace the old style Chevy starter with a Delco gear reduction starter. That makes a huge improvement in cranking power and speed. Although that is not a 100% HAMB friendly solution. Dealing with hot start problems is very traditional.

 

Is it the starter motor that get hot, or the solenoid not working? What is changing with the heat? Why does more amps work?

 

Usually the issue with a delco solenoid (in this case) is the heat causes just enough swelling that the plunger in the solenoid sticks just enough that The amps carried in the the purple wire isn't enough to energize the coil in the solenoid to get the plunger too move.

It still comes down to Ohm's law in that you have X volts to push Y amps past the the resistance and if you lower the resistance more amps can flow from the same voltage pressure. Parts in good condition helps as do clean parts. Good clean connections in the whole starter circuit help a lot as not cranking good when you turn the key or hit the starter ****on often goes back to not having a real good ground connection. I've made at least one guy cry when I took my pocket knife out and s****ed the paint around the stud he had his ground cable to the block fastened to because he had so much paint on it with the fresh engine paint job (fresh engine) that the cable wasn't making a good ground. He didn't want his paint job disturbed but the engine cranked over good as soon as the cable was connected.

 

Thanks the explanation, I never really understood was was going on.