Rocket scientists , heat shielding

[Blueoval77]

I am sure with all the rocket scientists I see here posting someone can give me suggestions on what the best sleeve or tube would be to shield a wire going rom the solenoid back to the starter post in the gap between the headers and the block skirt.... Ive fooled with some of the sleeve material over the years but it wasnt anything to get excited about . That area in there between a set of 2" headers and the block has got to be just stupid hot..

Thanks

[Rory428]

No rocket scientist here. but on my 69, the FPA headers on the 428 require the cable from the solenoid to the starter to get pretty close to the header tubes. I can`t remember the brand name,(ThermoTec, or something like that), but the heat shielding I used on the cable is a length of shiny silver clothlike insulated flexible tubing, that I slipped the cable thru. Between that, and having the headers ceramic coated, I have had no issues.

[machyoung]

Just to confirm, "no rocket scientist" here either. I've used Longacre Racing Firebraid successfully. Summit. Multipe sizes for multiple applications.

[cammerfe]

Actually, I am sort of a rocket scientist. If you've ever seen the movie 'October Sky' you have some sort of an Idea. It pushed me to an AB degree in Chemistry, although the degree earned me a job at FoMoCo as a metallurgical process engineer. I worked at T&C Livonia for about five years altogether before... But that's another story.

I agree with the approaches outlined above. Get the cable as far from hot surfaces as realistically possible, and shield with one of the brand names of shielding made from reflective material and Nomex or similar. Any coatings that reflect heat are also indicated.

KS

[JimNolan]

When I built my airplane I used "Fire Shield" on all the oil and gas lines. It will protect from fire. I use it on my car's gas line to help protect it. It'll keep a gas line cool also. It comes in different sizes and colors. It's expensive.

[Blueoval77]

Thanks guys , I cant seem to find the fire shield yet but this thing looks decent... What concerns me is that "Hook and loop" I cant swallow that they created 3000 degree velcro.....

https://www.amazon.com/Design-Engineering-010478-Protection-Closure/dp/B002R4XMPM/ref=sr_1_73?crid=35E9QGKC992ZR&keywords=fire%2Bshield&qid=1644935929&sprefix=fire%2Bshield%2Caps%2C72&sr=8-73&th=1

[cleandan]

Is there a way you can route the cable without having it run down the block, between the header and block?
Is there a way you can duct in fresh outside ambient air to the area where the cable is run?

If you can find a good way to run the cable, even if it requires a custom made length of cable, so it is not run in the "oven" area between the block and headers I think a major portion of your troubles would be solved.
If you can duct in cooler air to help remove ambient underhood heat from heat soaking the cable it would work...and both together might be really great.

I know there are high temp cables that might help.
Thermo-Trex 500 is rated to work at 392*F, and there might be some newer tech that works even higher.

This means you could use reroute some heat shield, high temp cable, and some fresh air ducting to arrive at a very usable result.

Keep in mind there are a few different kinds of heat under the hood of a car.
One that causes lots of trouble is heat soak.

Direct contact heat can be mitigated by removing direct contact if possible, or at least limiting the amount of direct contact.
Radiant heat can be mitigated with heat refelective products.
Ambient heat can be mitigated with heat insulation products, or fresh air methods that take away the heat.

But, if the item being protected from the heat is left in the high ambient heat long enough, heat soak will eventually raise the heat to ambient, or near ambient.

I would think the headers radiate temps in the 350*F - 600*F range as a fairly standard temp range depending on engine load and time at load. They certainly radiate higher temps for short periods of time under full load.