In a message dated 3/5/2008 2:19:44 A.M. Eastern Standard Time, gregw@onestopdesign.biz writes:

 

Most racers are squirrels. Cute and fuzzy I mean....

 

I had the stock Racing Beat headers on my racer. They were .120" mild steel SAE 1010 or 1020 steel.

The bend makes the wall thickness go way down. I did not think of that when I wrapped them with hot rod shop heat tape. I overlapped it by 1/2 each turn, so it goes around turns nice and does a great job of containing heat. Then you wet it and run the engine up to temp to cure it. I stitched it on with safety wire.

 

I could hold my hand on the headers with the engine running. Before the season was over, the sound changed and I saw a hole in the tape in the bend out of the engine. The metal had turned to dust. I crushed the pipe with my hand.

 

This was my fault. I know the EGTs. About 1650 is good for me. And SAE 1010 steel is just about crap for any high temp work. I should have used thick wall stainless if I wanted to wrap the tubes. I now have .140" wall 1010 header tubes with no wrapping tape for the first foot out of the engine. A scat tube blows on the headers. After that the tape is on everything, including the muffler. It is amazing for reducing the in car temps. We used to blister paint on the interior sheet metal. Now you can touch it right after a session. And the carb doesn't boil over as soon as the car stops. The tape has little strength after it cures, and must be held in place with safety wire every 2 inches or so. I won't build a car without it. Never under estimate the energy an exhaust system can dump in a closed space.

 

In the picture the primary tubes are cooled by fans blowing on them. On back from there is the picture you would see under your cowl. This is a turbo charged V-8 running on Methanol, with slightly cooler exhaust than you will see. These headers and tubes all the way back are Inconel. About $10,000.00 a set. Used for three heat cycles, then into the dumpster. I have two complete sets.

 

Lynn E. Hanover