"Does the aluminum spray reduce radiated heat? Aluminum is not known for that particular property, if fact it is known for just the opposite. Perhaps someone did not read the entire thread?"

Hi Carl.

I had the parts coated with flame sprayed aluminum only as a permanent rust preventative. In 40+ years on the restored '36 Chevy pickup that has worked out. Aluminum is definitely an excellent conductor of heat. That becomes obvious when welding aluminum. Much higher heat input is required than welding similar pieces of steel. So I would definitely agree with you that aluminum coating would not reduce radiated heat.

Many people have never seen flame sprayed aluminum so seeing it for the first time on my '36 Chevy or '32 Ford starts some interesting conversations. I first saw flame sprayed aluminum on radial aircraft engine jugs at an aircraft engine rebuilding facility. In addition to looking very cool, the shop foreman told me it prevents rust. That was the place that I had coat my exhaust parts.

I have not personally had any adverse effects of radiated heat. On my street rod '32 I built a cold air duct that feeds the air filter ambient air. That makes header heat irrelevant. Another problem I have not personally had is header leaks. That is probably because I had a summer job in 1967 welding at Doug's Headers and learned how to make headers that fit properly and don't leak. I would guess that the leakers are imports from China.

What "thread" are you referring to?

Ray