Aluminum body heat issues insulation ideas?

[ronnieroadster]

 Discovered another issue running my race car in the heat. My race car is a rear engine modified roadster The engine cover and the cover on the body around the engine cover are bare aluminum which has a scotch brie surface finish not shinny sort of a dull aluminum.
   At the last ECTA event it was sunny and hot temps were in the high eighty's the aluminum was extremely hot to hot to touch plus this heat was also radiating into the engine compartment. Without painting the bare aluminum on the outside is there anyway to add some type of heat barrier on the inner surface of the aluminum to help with the heat transfer?
  Ron

[Vinsky]

Look at the Thermotech products. They make an adhesive backed blanket that works inside engine compartments and such.
http://www.thermotec.com/

[Milwaukee Midget]

I'm currently using this thermotec product on the footwells on the Frankensprite . . .

http://www.thermotec.com/products/14600-suppressor-acoustical-heat-control-mat.html

I've yet to drive it, so I can't attest to how well it works, but with the headers - which I've wrapped - being about 1/2 inch from the footwells, I knew I'd need to try something to keep from turning the interior into an Easy-Bake oven.

Peel and stick - easy to work with, provided you stick it in the right place the first time.

But -

While it might feel hot to the touch, even a dull aluminum finish is likely to reflect solar heat, and the aluminum should disseminate trapped heat.  Are you sure it's creating more heat under the hood than it's dissipating, relative to weather conditions?  My guess is that insulating it may create more heat in the engine bay by trapping it.

2 cents - worth half . . .

[kiwi belly tank]

I agree that insulating the inside will retain heat from all the HP you're making & the bare aluminum although hot to touch is actually bleeding the heat to the outside air. If the engine isn't running too hot & the intake air temp is ok, I'd leave it alone & use gloves .
  Sid.

[krusty]

I agree with Sid. We've been running our rear-engined roadster since 2009 with a bare aluminum body (except the '27 Ford bits) and I haven't seen the problem. That said, we run 5 miles and have a loooong tow back to the pits, so there's much more cooling time than if running a mile.  You might consider using a reflective blanket draped over the engine cover/fairing while in line.   

vic

[hotrod]

Heat loss and heat gain can get a bit complicated, bright aluminum (not painted) reflects solar heating but it also is very poor at radiating away that heat. It is what they call in the solar industry a selective surface. Its high reflectivity is matched with low emissivity (loses heat by radiation poorly). This was the reason the SR-71 spy plane was painted black. The black color was much more efficient at radiating away the heat generated by the high speeds it flew at, significantly lowering the skin temperature of the plane. The same goes for heat sinks on electronic gear, most of them are black anodized to help them lose heat by radiation as well as conduction.

Draping a light colored blanket over the body work or using a shade awning while in line would cut the heat gain from the sun. The insulation will hold heat from the engine and raise temperatures in the engine bay while running and make cool down slower, since almost all your cooling will come from ventilation of the engine compartment.

You might want to look at a setup like Stainless uses on his liner where he has some temporary uprights that support a shade tarp over the liner when it is not on the line ready to run.

[ronnieroadster]

Thanks to everyone for your input first I will leave the aluminum alone. To help in the sun we will use a covering of some type and for the long ride back from a run I will devise a way to allow the engine cover to be open a bit so air can flow over the heated surfaces. And use gloves all good stuff.
  Once again the talent and knowledge on this forum has helped me and I'm sure others learn some more you guys rock.