I have a 427 with the usual Heat soak starting problem. Will not restart after hot unless I wait 1/2 hour or run a hose over the solenoid to cool it off. I replaced my old solenoid with a NAPA one, and this one did not last. I ran it Without the Heat Shield until it started having problems then put the shield on. It helped a little but I think I ruined the NAPA solenoid. My question is What Solenoid would be the best for these Big Blocks? I have read through the archives but found NO specific recommendation. This is the 2nd one for me.(YES I have learned my lesson with the heat shield)
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Re: 427 heat soak solenoid recommend
Neil-----
I don't think you'll find any solenoid that will solve the problem you describe. I suffered with this problem for YEARS on my 1969 small block. As far as solutions were concerned, you name it, I tried it. Only one solution proved to be 100% effective in resolving the problem; the others were, at best, marginally effective. So what was the 100% effective solution? The installation of a remote (slave) solenoid. That installation ended years of hot-start frustration. Re-starting the car in the middle of August in Death Valley after short shut-downs proved to be no problem, at all.
Yes, I know that such an installation is not "correct" or "original".
Remote solenoid kits are available in the aftermarket. These include everything you need, including instructions. Want to put a kit together yourself? Use REMOTE solenoid GM #1114532. However, it comes with no instructions for the remote solenoid installation.In Appreciation of John HinckleyComment
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Re: 427 heat soak solenoid recommend
So joe, I am definately interested in the remote system. Is this basically a ford Solenoid? Do you know how to wire it in? This sure sounds like a solid fix for my heat soak problem.Comment
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Re: 427 heat soak solenoid recommend
that was the GM fix for 454 motorhomes BUT these cars started fine when new. make sure the battery cable you have is pure copper not copper plated aluminum as this is a big problem with replacement cables causing hard starting.Comment
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Re: 427 heat soak solenoid recommend
clem-----
1969's with side terminal batteries originally used copper plated aluminum battery cables. Although I never changed my battery cables as one of the attempted fixes for the hot re-start problem, I could never understand how a remote solenoid would "overcome" an electrical conductivity problem rooted in the battery cables. But, I know for sure that the remote solenoid cured my problem 100%.
Also, at some point, the battery cables were changed to pure copper (1970 or 71, I think). However, 1970+ Corvettes often suffer from the same hot re-start problem that I "lived with" for years.In Appreciation of John HinckleyComment
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TerryComment
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Re: 427 heat soak solenoid recommend
So back to the question, What to do. My cables are in good condition, critically cleaned lugs, inspected and cleaned grounds, etc, using 1050 CCA Optima. (YES fully charged) When I replace the solenoid, the problem goes away for a long time. I have read that inferior spring tension, along with corrosion, loose parts in the solenoid will result in Heat Soak problems. Is there a Heavy Duyty Solenoid that I should be using or will that NAPA replacement work just fine, (which it has not) CONFUSED!!!Comment
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Re: 427 heat soak solenoid recommend
Neil:
Another thing to try is to give John Pirkle a call at (706) 860-9047. John rebuilds and restores Corvette starters and alternators, and comes across this question frequently. He advertises in the DRIVELINE. John recently rebuilt the starter from my 1967 327/350 HP car that had a hot start problem like yours and corrected the problem for me. Although John is extremely busy, and typically has a 2-3 month lead time for rebuilding starters, he may be able to suggest a few things or recommend the best parts to solve your problem.
I know that John faced this same heat-soak issue early on with some of his rebuilt starters, and learned what was needed to solve. Worth a call or e-mail.
Also, there is a special solenoid spring to help solenoids/starters that experience heat soak. I believe that it is a light tension spring. The GM part number is #1978281, but it may be discontinued by now. However, John or NAPA Auto Parts may have a current replacement part number, or someone on this forum may know where to obtain.
LarryComment
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Re: 427 heat soak solenoid recommend
Terry-----
I do not know, for sure, that the battery cables on my 1969 are, in fact, copper clad aluminum. However, it was my understanding that all of the cables used for 1969 Corvette side terminal installations were the copper clad aluminum. In other words, these were the "test batch". The side terminal 1969 installations began about mid-June, 1969, so there were about 16,000 1969's built with side terminal. The part numbers for all 1969 side terminal applications were GM #6297644, positive, and GM #6297645, negative. As far as I can tell, these are the only cables used for 1969 side terminal applications.
It would SEEM that if both copper clad aluminum and solid copper battery cables were used for 1969, then the part numbers would have been different. It's certainly possible, though, that might not have been the case. However, if not, then the only way that the 2 different types could have been differentiated would have been through some sort of printed-on coding.In Appreciation of John HinckleyComment
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Re: 427 heat soak solenoid recommend
Hi Neil I would replace the starter with one from "power master" its much smaller with more power, the street, strip guys all use them. Phil 8063Comment
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Re: 427 heat soak solenoid recommend
Neil-----
I changed my solenoid several times in an attempt to solve the problem. I also changed the solenoid spring. The "low tension" solenoid spring was, as Larry mentioned, GM #1978281. I tried that one to no avail, at all. GM must have discovered the same thing as the 1978281 was discontinued in May, 1992 and replaced by GM #1958679, the same spring used in PRODUCTION for all 1964-81 Corvettes.
One thing to keep in mind: some of the various solutions may APPEAR to solve the condition for awhile. The problem is, one has no "experimental control". In other words, you don't know if the new part has resolved the problem or if the the conditions that cause the problem to manifest itself do not recur for awhile. The hot restart problem is somewhat "sporadic", after all.In Appreciation of John HinckleyComment
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Re: 427 heat soak solenoid recommend
Neil-----
Yes, it is basically, a Ford-style solenoid. To wire it in, first disconnect the purple wire to the solenoid "S" terminal. Then, use heavy gauge wire from the BATTERY terminal on the solenoid to the large input lug on the slave solenoid. Using similar heavy gauge wire, connect the other large lug on the slave solenoid to the "S" terminal on the solenoid.
Next, connect the purple wire (formerly on the "S" terminal) to one of the small lugs on the slave solenoid. IF I RECALL CORRECTLY, the other small lug on the solenoid goes to ground.
The fellow that told me about this years ago is, as far as I'm concerned, one of the "high priests" of automotive electrical systems. In my entire life, I have NEVER known anyone who was more competent in the field of automotive systems, especially electrical, than Ron. Never. Ever. And, I never even expect to meet another one as competent.
Ron explained to me that the problem is caused by heat-induced resistance in the purple wire that carries the energizing voltage to the solenoid from the starter switch. By installing the slave solenoid (in a non-high heat area; I used the upper surface of the "triangular" shields below the fender louvers), one ensures FULL CURRENT to the "S" terminal on the solenoid, regardless of temperature.
Now, I don't know if Ron's theory is correct. However, I do know the following:
1) The installation of the slave solenoid has completely eliminated my hot re-start problem for over 25 years. Not even once since I installed the solenoid have I experienced a hot no-start. Even in Death Valley in August (yes, I've actually taken the car to Death Valley many times in July and August and the car doesn't have C-60);
2) If Ron's theory regarding the source of the hot re-start problem were not correct, then the slave solenoid would have done absolutely nothing to correct the problem. In my mind, the fact that it cured the problem 100% for over 25 years proves that Ron's theory regarding the cause of the problem is 100% correct.In Appreciation of John HinckleyComment
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Re: 427 heat soak solenoid recommend
I had John Pirkle rebuild the starter on the '72 LS-5 because of this problem. He builds a special high torque starter that will cure the problem. You cannot crank very long at a time with this starter due to the heat it generates. But it spins the engine like there is nothing on the other end of the starter. And the engine has LS-6 pistons in it and a true CR of 9.0-1Dick WhittingtonComment
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