exhaust wrap - interesting results

[onegammyleg]

Hi lindermant

Be aware that wrapped pipes usualy fail at a much faster rate than unwrapped pipes.
People that turbo v8s or old volkswagen beetles sometiems wrap the long pipes (going from one side of the engine to another) to keep the gasses hot and fast inside the tube.
It works - but within a few thousand k's the pipes have cracked and need replacement.

May no tbe good economy if you factor that in.

[GasSavers_Kraig]

I know a guy that wrapped his cheap carbon steel headers and they had holes in them from heat erosion in a matter of days.

[onegammyleg]

Hiya Kraig

Yeah , normal tubular extractors don't last long at all . but i think that guys ones were already gone anyway. - they should last more than a few days.
Either that or they were prety dodgy in the first place.

[JanGeo]

Exhost pipes do get hot - my BMW pipes exit the heads going forward and bend 180 under the heads to the rear of the bike. If I idle it for a few minutes reving it a little at night the pipes start glowing red hot. Any highway driving with heavy throttle would result in the pipes getting really hot. To keep it cooler you need to shield it from the coroplast with reflective metal and allow air flow around the pipe. Protecting it from water spray will help the pipes last longer however. Remember the warnings about overheating cats if allowed to idle too long starting grass fires etc. The IR temp probe measures radiation from the surface and shiney surfaces will read a little lower than a dark surface but not too much of a difference.

[lindermant]

took the exhaust wrap off today.... $20 and 35 minutes of my time - one of my cheaper automotive "lessons"

[GasSavers_Kraig]

I think they were "Blackjack" headers .... low dollar junk

[red91sit]

Another thing to consider, I've herad exhaust piping traps moisture in there speeding up the oxidation process.

[JanGeo]

I have a hard time believing that moisture will get trapped in something at 700+ degrees - if anything it will protect it from water spray in the rain which is the worse thing for a hot piece of metal. Actually when the tool and die shop heat treats some metals they actually wrap it in stainless steel to keep the oxygen out.

[red91sit]

Originally Posted by JanGeo

I have a hard time believing that moisture will get trapped in something at 700+ degrees - if anything it will protect it from water spray in the rain which is the worse thing for a hot piece of metal. Actually when the tool and die shop heat treats some metals they actually wrap it in stainless steel to keep the oxygen out.

It's only 700+ degrees when it is or has been working. Here is a direct quote from a header manufacturer

Q: Why should I not use header wrap?

A: Wrapping headers should NEVER be done. Wrapping headers will destroy them and there is no header manufacturer that will warranty a wrapped header. The heat wrap will trap moisture or condensation between the header and wrapping causing it to rust. Heat wrap can also destroy any Ceramic Coating. The best way to keep anything from the heat is to wrap the part you want cooler, like starters or fuel lines. Another way is to have them "ceramic" coated.

http://www.tribaltubes.com/faq.htm

BTW, BIG difference between stainless steel, and exhaust wrap. Ceramic coatings would work great for exhausts by keeping in the heat, and protecting them at the same time. Exhaust wrap? No

[JanGeo]

ok that's for headers how about the exhost pipes and is the wrap breathable or not? How about painting them white to reduce the radiated heat?