I've been apparently cooking starters (3) over the course of 3 years. Exhaust Y pipe is stock, so the Y is basically directly under the starter with the downpipes basically wrapping around the starter. This is my conundrum, I know they sell heat shield wrap and metal heat shields.

First my question is: What purpose does a metal heat shield serve, since metal conducts heat very well and will eventually heat up to the same temp as the air below it and radiate that same heat. Why aren't those type of heat shields made out of high temp plastic or at least an insulator?

My last questions are: I know there are insulating wraps you can use, both to either wrap the starter or wrap the exhaust. Which is preferred, wrapping the headers would allow the starter to breath, while blocking the heat, but I've heard lots of bad things about water damage with wraps around exhaust pipes. Wrapping the starter would produce the same results, but it's insulating the starter directly, wouldn't the engine heat end up causing damage or is it too low compared to the radiating heat from the exhaust pipes?

In any case, I need to do one of the options above. Has anyone taken a temp probe to the starter and measured the difference before and after installing one of the heat shield methods after a nice long drive?

 

I would think you've got another problem causing that. Like a too small starter wire or something. How's your power wire?

Don't wrap the starter, that'll just hold heat in, wrap the exhaust.

A heat shield works because the natural convection and radiation heat is transferring from headers to starter. The heat shield blocks it, and spaces the heat over a larger area (the whole shield) so the airflow can cool it down. It mostly blocks the radiation heat transfer.

Coating your headers is probably the best, long term solution. A nice ceramic coat.
But i'd be more worried about how you're cooking starters so easily.

 

changing the starter fixed the problem. So the wires aren't the issue. It's almost definitely heat slowly destroying something in the starter moter, the solenoid seems fine


A heat shield is made of metal usually though, and metal transfers heat to the air fairly well, which is what the headers were doing already, so a heat shield does exactly what the headers were doing. The only info about that left unknown is just how much of a difference in temperature is there because of the physical blocking of air flow.

I'm probably going to wrap the exhaust around the starter. If it corrodes the Y oh well, i'm due for a replacement Y pipe anyway.

 

Well yea, changing the starter fixes the problem (temporarily eh?), but what i'm getting at is the actual source of the death of the starter.

You know how high resistance wires cause a large voltage drop? And so a motor will draw higher current to make up the difference. Hence why some car audio amplifiers can overheat and shut down if the wiring isn't up to par. Basically it's straining. So this can cause the piece to heat up on it's own. If your battery to starter wire is old, corroding, and/or the ground wire from battery to chassis, engine block to chassis, these can all contribute. There are many members with headers and no problems with their starters, leading me to believe that your problem is unique. Besides, a stock y-pipe you say? And that is flowing right under the starter? So the stock y-pipe is in the stock place (right?), where on all other 305TBI motors it isn't burning out starters every year right?

Also, what starters are you using? Stock style ones, or aftermarket ones?

Your idea on the heat shield is semi correct, but also flawed. Think of double pane windows. Air gap, with glass. Kinda a crappy example, but you know what I mean? "What, air isn't an insulator! " but in this case it is eh?

I would consider the wiring issue, I have bad battery wiring issues on friends cars so often it's something that sticks in my mind. (I just did my girlfriends last week). But if you're thinking about wrapping the exhaust, i'd go for it, it'd take a lifetime for a thick stock cast iron y-pipe to corrode enough to leak (literally), and you're going to upgrade it once that 350 goes in right?

 

The problem is heat soak ans is caused by the hot exhaust heat soaking the windings on the starter to the oint they fail. Ceramic coating is the best answer followed by wrapping the starter.

 

I used to have the same problem with my stock manifolds &
Y-pipe. It was so bad, after 20mins driving in the desert heat,
Id be stranded from an hour and a half waiting for the car to cool..

But after I installed the Hedman's with the new Y-pipe
I have a ton of clearance from the starter. Ive yet to have
a heaksoak issue yet, thank god !! (100 degrees+ in desert)

Ive tried the starter blanket with minimal sucess, but again,
since the header installation, clearance and air flow improved
for me.. translating into quick easy starts.

 

My LT's run less than 1/2" away from my starter and havent killed that big SOB yet


If your cheap and want to do minimal work and minimal downtime just put in a heatshield.

If your into putting some cash into the thing and can afford to have the car down for a couple weeks or so, pull the exhaust and have it ceramic coated.

 

i run starter wrap

 

same problem went thru 3 starters in 4 months just installed heavy duty delco starter has cross pattern bolts have hedman headers n over heating bad. drive for 20 minutes on a 90 degree day n have to wait a hour to drive so think i should replace ground wires n battery cables?

 

I also had a problem with heat soak and then wrapped my starter.Problem solved. Even with ceramic coating I would wrap the starter .

 

Wrap headers AND heat shield?

Looked at mini starters, $125 - $500 (Summit)...... which ones are you guys running?