How can I electrically and thermally protect starter wires?

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robroy
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How can I electrically and thermally protect starter wires?

Post by robroy »

Good day and Merry Christmas!

I'd like to finish these wires this so that:
  • They're protected from the header heat.
  • They're securely anchored in position.
  • Their terminal ends are electrically insulated.
Here's the background, and there's a list of specific questions at the end of the post.

I asked about starter wire protection in my main engine thread last Spring. On April 16th Jamie (Ranchero50) replied with some helpful advice, yet there was so much action being tracked in that thread that the topic was never concluded. In retrospect I should have made an independent thread just for this.

The RobbMc starter has two wires: a skinny red one and a fat black one. The skinny red one connects to the OEM starter relay's always-hot side, while the fat black one connects to the relay's switched side.

Here's how the wires go from the relay to the starter. I zip-tied them to prevent rampant floppiness.

Image

Here's how close the wires get to the headers. In addition, they're only being held at that angle by the nuts on the starter.

Image

I read from Jamie that I should fasten a loop-style anchor to a nearby bolt to hold the cables in place. I also read about testing the wires by running the starter for thirty seconds, after which none of the wires should feel hot. That was an awesome idea that I haven't tried yet.

Since I was concerned that the header heat would melt the wire insulation, I bought this heat-shield tubing.

ImageImage
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ImageImage

Here's an extreme close-up: IMG_7259x.JPG

Later I realized that the wire terminals didn't look sufficiently insulated from one another. And since this heat-shield tubing could be conductive, I didn't want to risk getting it too close to the terminals.

Here's how it looks today; you can see that it's quite unprotected.

ImageImage

Today's Questions:
  1. Does this tubing look like it'll provide ideal heat protection? If not, what else might be better?
  2. How should I electrically insulate the wire terminals? Should I install rubber hoods?
    ImageImage
  3. Where can high quality, super heat-resistant rubber hoods be found?
Thank you all so very much for your guidance, and I wish y'all a very Merry Christmas!
Robroy
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Re: How can I electrically and thermally protect starter wires?

Post by Racer Z »

The terminals themselves are fine. The only time they have current is during the start mode for a few seconds. If you want a cap anyway, you can. My concern is the heat from the header will melt the insulator caps. The factory did not use an insulator here and how many times have you experienced or heard of this being a problem?

On the heat issue, I see two possibilities, and you may want to both.
1) A heat shield. This could be a 1/8 inch steel plate (sheet metal) cut, bent and shaped to fit the area. It provides a heat barrier mostly. Shape it as a "shoe" to deflect the hot air away from the starter and the wires.

2) Wrap the headers in "Exhaust Tape'. It's about $50 a roll and available at most auto parts stores. You may need 3 or 4 rolls to do all of you headers. This would be each runner from exhaust port to the collector and back further if you think there will be heat issues. If you only want to wrap a 6 inch section near the starter, that's fine. Most of the guys at the track swear they have better performance with a full wrap.

Heat wrap for the wires:
http://www.summitracing.com/parts/DEI-010408/

Exhaust wrap:
http://www.summitracing.com/parts/DEI-010127/
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Re: How can I electrically and thermally protect starter wires?

Post by Mancar1 »

The thermo flex should reflect heat and not absorb it. I have foil on the wall behind my shop wood stove, about 10" between the stove and wall. No matter how blazing hot the stove gets the foil stays cool to the touch.
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Re: How can I electrically and thermally protect starter wires?

Post by 71highboy »

i would use the thermo flex.header tape will lessen the life of you headers and not very good. :2cents:
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Re: How can I electrically and thermally protect starter wires?

Post by Thunderfoot »

:yt: I too am personally not a big fan of it for a street application... :2cents:
The RobbMc starter has two wires: a skinny red one and a fat black one. The skinny red one connects to the OEM starter relay's always-hot side, while the fat black one connects to the relay's switched side.
:hmm: Are you sure you have it hooked this way? The fat black one should be on the always HOT side of the trucks stock starter solenoid on the fender and the skinny red one on the switched side of it... otherwise the solenoid on the starter is always activated and will drain your battery...

I would just use the Thermo-flex, this is similar to what the factory does on starter wires. I would just run it to within a 1/2 of the terminal ends. I would then get some clips as Jamie suggested and run the wire along the pan rail (use a couple of the pan bolts) to the front of the engine then up to the starter relay on the fender to keep it away from the headers as much as possible.

A cap/cover on the Big black wire would be a good idea as that wire has power to it all the time and makes it safer to work around and not short out wrenches to it. :wink: but it is not really a necessary thing just a good safety thing.
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Re: How can I electrically and thermally protect starter wires?

Post by Ranchero50 »

Robroy, I would suggest doing a one hole strap to the bottom engine side engine mount bolt and dressing the wires up towards the alternator wiring, possibly bringing everything from the engine to the inner fender in one bunch. When you do use a metal strap (even if it's rubber coated) use some spiral wrap or other abbrasion resistant plastic or rubber.

For the metal terminals on the solenoid I wouldn't worry too much as long as the cable can't bend the big lug over time causing it to short out against the case.

If you keep the wires tucked down by the block and run them up to the alternator harness I doubt you'll ever have heat issues with the wiring and if memory serves, I think your starter guys said they are heat proof.

If you are looking for high quality rubber hoods I would go junk yarding for something OEM.

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