8.1 L Vortec permanent Plug-Wire Burn-out cure.

[garyspang]

After two wire replacements I decided to put my thermodynamic knowledge originally acquired during the thermal analysis of tires to work.
It was obvious that the radiant energy near the exhaust manifold was in excess of what can be tolerated by the plug wire and connector.
A 4 in wide and 5 in long infrared radiation shield with convection cooling was constructed from aluminum roof flashing and placed around the spark plug connector and plug wire. Fins extending out from the radiation shield dissipate the intercepted radiant energy by re-radiating it in a cooler environment and by being cooled by convection air currents.
Conventional plug wires were used for any replacements, and they survived very well so far (10K mi). No visible or electrical damage from heat has been observed.
See the pictures for infrared heat-shield construction details.

[JohnRR]

That looks like to will radiate some heat

[NRR]

Materials used?

[Midniteoyl]

Originally Posted by NRR

Materials used?

constructed from aluminum roof flashing

...

[WeatherTodd]

whats the r value on that stuff?

[edgray]

VERY COOL. Pun intended. What holds it in place?

[garyspang]

Hi Weather Todd
R does not apply.
This is not a thermal insulator. R may be 0.001 or so.Aluminum is a very good thermal conductor, almost as good as copper.

This approach is a radiant heat interceptor and diverter scheme.

Next time you get a chance place a piece of aluminum foil between you and a flame or cook top. notice the total elimination of radiant heat reaching you.
Aluminum foil would not survive and is to thin for effective thermal conduction to the fins so aluminum roof flashing was used. The baked on paint prevents the aluminum surface from oxidizing (rusting) over time.
If you make it from copper, silver , gold or platinum it will be more effective, but be an expensive overkill.
The Lunar Excursion Module (LEM) was wrapped in gold surfaced Mylar for similar reasons.

[garyspang]

Hi Edgray
The cooler wants to expand and is held by friction in the spark plug well. Notice the sharp points at the seam have been cut off to facilitate insertion. A single fin can also be lodged behind the existing manifold shield for a positive restraint.

[DriVer]

Hummmm .... very interesting!

[pkmesser]

I like the idea, as OP pointed out, copper or higher value heat conductors would conduct the heat to the "cooling fins", better, but the thickness of the material also goes into that calculation. ie, thicker aluminum will work better. If you double the thickness, you will double the amount of btu's that can be carried away. The "cooling fins" still have to transfer that heat to the cooler air. One thing I might change, for the color of the material selected, the white should be turned inside, and the brown to the outside. The reason, the white will not re-radiate heat to the plugwire as much as the brown will. (black body radiation effect) That also then puts the brown to the outside on the fins part, where it would be more effective at re-radiating the heat. Choice of color will affect efficiency somewhat.
(From, second semester physics, "Light, Heat and Sound", and these laws have not changed in the intervening 47 years)

[garyspang]

hi pkmesser
Your reference to color is generally correct. The exterior of all spacecraft by NASA is white. It is actually Titanium Oxide white. It reflects as much as possible, and re-radiates long infra red wavelength almost as good as a black body. Because of the durability of roof flashing, I estimated that Titanium Oxide was the paint pigment.
Besides, I like spacey stuff.

[max49]

I did the same thing, but about 3" long and I did'nt cut in the 2 or 3" fin heat sinks. If mine burns another plug wire, I'll redo them with the fins, good idea.
I also have manually operated bilge blowers on both sides of the engine too.
I won't assume it's fixed til I cross the mountains in hot weather at least a few times.

[Midniteoyl]

Basically a heat shield...

[DriVer]

Originally Posted by Midniteoyl

Basically a heat shield...

I disagree. This device is best described as a heat radiator or heat sink but not a shield.