[jhein]

It cranks easy when cold, when hot it struggles badly. It seems like this is a common problem although, I never had it with my old birds back in the day.

There are a bunch of options for high torque starters, some with original look. What's the best option for performance and reliability?

Will heat shields help?

Thanks.

[padgett]

Back then GM had many problems with starters not reacting to heat well. The fix back then was a shield designed for Corvettes.

[napster]

My '70 had the same problem. My mechanic installed a high torque mini starter. It fixed the problem.

[gto4evr]

Lots of factors can affect this. Possibilities beyond just a weak starter: timing too far advanced, crappy gauge cables, cable routing too close to the block or manifolds. poor ground on the block.

[keith k]

Originally Posted by gto4evr

Lots of factors can affect this. Possibilities beyond just a weak starter: timing too far advanced, crappy gauge cables, cable routing too close to the block or manifolds. poor ground on the block.

Ditto.
Definitely check the grounds. Seems common on restored cars that stuff gets painted separately, and when reassembled the paint interferes with good metal-to-metal connections.

[unruhjonny]

Now, I am not old enough to recall these cars as new, or late model cars, but I had a crash course in this in the mid through late 1990's when I started driving mine daily.

After looking to ensure everything is well grounded, you should look at your starter;
The common rebuilt starters do not use the better core starter - there are visual cues that the one you're looking at is a better one, or a run of the mill one.

With the RA manifolds, there is virtually no clearance for heat shields, so that leaves you to needing a high heat solenoid.

From my experience, the run of the mill starters will have a reduced diameter on the front, and the copper lead will pop through the case right at, or closer to the solenoid;
The better ones have the full diameter of the starter carried right up to the front, and the copper lead for the solenoid will pop out near the very front of the case - and need an adapter to extend the connection to the solenoid.

There are legitimate high heat solenoids both with GM part numbers and 'Standard' brand numbers, but I don't have any of those handy.

Now, going away from original or OE replacement stuff, I have heard that the high torque mini starters work fantastic, as their smaller mass effectively helps them stay cooler.

I hope this helps.

[Wick]

Originally Posted by unruhjonny

Now, I am not old enough to recall these cars as new, or late model cars, but I had a crash course in this in the mid through late 1990's when I started driving mine daily.

After looking to ensure everything is well grounded, you should look at your starter;
The common rebuilt starters do not use the better core starter - there are visual cues that the one you're looking at is a better one, or a run of the mill one.

With the RA manifolds, there is virtually no clearance for heat shields, so that leaves you to needing a high heat solenoid.

From my experience, the run of the mill starters will have a reduced diameter on the front, and the copper lead will pop through the case right at, or closer to the solenoid;
The better ones have the full diameter of the starter carried right up to the front, and the copper lead for the solenoid will pop out near the very front of the case - and need an adapter to extend the connection to the solenoid.

There are legitimate high heat solenoids both with GM part numbers and 'Standard' brand numbers, but I don't have any of those handy.

Now, going away from original or OE replacement stuff, I have heard that the high torque mini starters work fantastic, as their smaller mass effectively helps them stay cooler.

I hope this helps.

Not sure if true or not, and has maybe changed over the years, but the solenoid with the brown end is much better than the black solenoid.

I remember identical setups with very different results for whatever reason.

[JAL71TA]

Glad I am not the only one having this issue, my 71 is still stuggling even with the RobbMC mini.

[unruhjonny]

one thing many people forget when upgrading from standard "log" manifolds to the RA units that the 70 RAIII/IV & 455HO/SD use is that they are a fair share larger;
Larger hold more heat, and the larger size puts the inside face closer to the starter

[padgett]

OTOH my Judge has never been a problem cranking. Have a vague memory of a different solenoid spring but was at least thutty yar ago.

[unruhjonny]

Originally Posted by padgett

OTOH my Judge has never been a problem cranking. Have a vague memory of a different solenoid spring but was at least thutty yar ago.

if you have the correct starter, with all the correct parts, that's the way it is supposed to be - but not a single parts store in the last twenty five or so years has had a different listing for a starter for a RAIII/RAIV/455HO/SD455;
At least not to my recollection;
I had decades ago, help by one knowledgeable parts counter guy on getting a high heat solenoid - iirc they come with their specific spring.

[jhein]

Originally Posted by unruhjonny

if you have the correct starter, with all the correct parts, that's the way it is supposed to be - but not a single parts store in the last twenty five or so years has had a different listing for a starter for a RAIII/RAIV/455HO/SD455;
At least not to my recollection;
I had decades ago, help by one knowledgeable parts counter guy on getting a high heat solenoid - iirc they come with their specific spring.

I don't think the solenoid is my problem. I say that because it is obvious that the solenoid is engaging. You can hear it, and the starter motor will still (sort of) crank the engine just VERY slowly. So I think it's the starter motor itself that is the problem.

I also happen to know that there was an episode when I had a mechanic inspecting this car for me where the owner's people were not able to get it to start. Turns out the points were stuck and it wouldn't start. They didn't know that and kept cranking it until the battery died. I don't know but could that have damaged the starter?

I'm going to check everything else too, of course, but one of the last things I need is a car that won't start. So since I don't have confidence in this starter, it's gotta go.

Anyway, I have a new Powermaster Powermax Plus on the way from Summit.

[U47]

Originally Posted by jhein

It cranks easy when cold, when hot it struggles badly. It seems like this is a common problem although, I never had it with my old birds back in the day.

There are a bunch of options for high torque starters, some with original look. What's the best option for performance and reliability?

Will heat shields help?

Thanks.

I'm a original owner of a 69 H-O LeMans. Never had a problem with the starter motor. In 1992 I went through the whole car and installed a 455 with RA3 manifolds. At first it started hot or cold fine. After a few months the car would start easily when cold, and struggled when hot. That lasted for a couple of months and then I got a intermittent no crank when hot, still cranking good cold. I didn't want to get stuck somewhere so I pulled the starter and found parts of the Bakelite plastic in the solenoid were missing and the rest in there cracked.
Replaced the solenoid and fabricated my own heat shield out of sheet metal.
Still doing fine after all these years.

[1965gp]

I’ve always had a lot of luck by upgrading to ‘0’ gauge cables. The best are bought at a stereo shop and often you need specific battery terminal connections for it but man what a difference!!

I’ve done this on several cars and it always makes a huge difference

Take a look at this example- much better than anything your going to get at a parts store or reproduction.

Just make sure to loom it… can’t have blue wire under the hood (you can get it in red/black)

I promise you will see a significant difference


https://www.amazon.com/KnuKonceptz-K.../dp/B004Z0WQZS

[Formulajones]

Like mentioned above, it's difficult these days to get a good rebuilt starter.

Most of the hot start problems I've seen are due to a worn armature, and those are almost never replaced with the cheap reman starters purchased at your local chain store. Almost all of your rebuild kits for the starters don't come with armatures either.

I prefer to rebuild a good original GM starter myself with all the parts necessary, including the armature.

I did the starter on my 70 RA III bird almost 25 years ago. I don't run heat shields, (As I recall, I don't believe 70 RA birds ever came with any heat shields of any kind. That didn't come along on the birds till later) I just have standard size battery cables, nothing fancy. It has buzzed the engine over without complaint for the last 100k miles or so. I drive the car regularly and the AZ heat doesn't bother it.

Just something else to think about.

[Baba O'Riley]

I deal with this too, especially in hot weather.

What's a good heat shield for a 400?

[76TA462]

I have run headers since the 80's in my 76 455. Always had hot start problems, and maybe it was simply due to the headers. I went through a variety of fixes over the years. Rewound OEM, new OEM, heat shields, better cables, wrap (both the starter and the headers) and etc. The heat shields and wraps improved things but did not solve the problem. I went to a high torque mini starter a few years ago and never a problem since.

[jhein]

My car has the OEM style spring clamp terminal battery cables. I have to replace those anyway so I can attach my trickle charge cables. But, I'm also putting in a Powermaster Powermax Plus mini starter.

[R 70 Judge]

Originally Posted by 1965gp

I’ve always had a lot of luck by upgrading to ‘0’ gauge cables. The best are bought at a stereo shop and often you need specific battery terminal connections for it but man what a difference!!

I’ve done this on several cars and it always makes a huge difference

Take a look at this example- much better than anything your going to get at a parts store or reproduction.

Just make sure to loom it… can’t have blue wire under the hood (you can get it in red/black)

I promise you will see a significant difference


https://www.amazon.com/KnuKonceptz-K.../dp/B004Z0WQZS

I agree with this. The factory wires are lacking. I'd use pure oxygen free copper (OFC) though if you decide to go this route. If you know the length you can buy pre-terminated wires here. They also use a very good crimping process and they will custom make any length you want if you call.

The "big 3" upgrade makes a difference with charging as well. I have a large stereo system in my Tahoe and I'll tell you that wiring can make a huge difference.

https://gpcaraudio.com/1-0-awg-pre-t...p-merica-ofhc/