Exhaust Wrap

[Captain Crimson]

Anyone tried lagging their exhaust manifolds with heat wrap tape to reduce underbonnet temps? My heat shielding adjacent to the manifolds has broken down and the footwell carpet singed due to the excessive heat. Reducing underbonnet heat should also help extend the life of wiring, hoses, alternator etc. Any thoughts on this??

[Sparks]

Peter Humphries will probably be along shortly, but be careful. The heat must go somewhere, and it is usually along the exhaust. GRP burns well, as many kitcar owners with wrapped exhausts will tell you!! Sparks

[Captain Crimson]

Thanks Sparks, point taken. I was only looking at insulating a short section closest to the inner wings initially, to reduce the heat radiated to the inner wings.

[campbell]

try Demon Tweeks, they have a good range of heat shelding material

[Fatboy Spin]

I heard that you had to be very careful with how you wrapped the exhaust - if you had more wrap in some areas than in others (even none at all) you get hot spots in the pipes which can cause problems. In the past with these problems (Marcos!!) I tended to shield the area that needed protecting rather than wrapping the exhaust - making sure to leave as big an air gap as possible. DT do 'aluminised' asbestos woven sheet which is useful as it reflects most of the heat. Don't glue/bond it to the area to be shielded - leave it 'hanging loose' so that less heat can be conducted. Spin Edited by Fatboy Spin on Tuesday 18th September 17:50

[Captain Crimson]

Hmmm, found this on one of the newsgroups. Seems like a bad idea after all (it's a US group if you hadn't guessed). QUOTE "We get a lot of questions about the thermal wrap products that are seen on various classes of competition cars. It's natural to assume that because racers use a product, it must have some performance benefit. the theory behind thermal wrap is that maintaining the combustion heat in the exhaust system improves scavenging. But, on street driven cars any small advantages you might gain is offset by ugly side affects. racer's don't mind replacing exhaust system components frequently -- you will. On street driven cars, you want to get rid of the heat. The higher the exhaust system temperature, the faster you'll burn out the gaskets and destroy the headers, converters and mufflers. Unless you've got money to burn, our advice about using header wraps is DON'T" UNQUOTE

[peteosborne]

Spin hit the proverbial nail. Hotspots are a complete sh*t and are practically unavoidable. Unless you wrap the whole system. Twice. Much better to shield whatever you want to protect. And duct air in (and out) from wherever you can.

[motorman377]

For thermal insulation of the non-wrap type: www.techlinecoatings.com They even have agents in England, multitude of uses as you all will see.