Topic: Any benefits of exhaust header wraps?

[messeduptriple]

Just curious if it does anything beneficial?? Or is it just a look?
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[crazypj]

stops you burning yourself when you do something dumb working on bike 
 I've used it on cars to lower under hood temps but on a bike , it's just a 'style thing' 
(however, it can quiet down a 'tinny' exhaust as it damps higher frequencies)

[Terry in Australia]

I'm not a fan and to my knowledge there's no performance advantage on a motorcycle, but it's good for hiding horrible old pitted and dented headers, and that's not a bad thing, I guess. Cheers, Terry.

[messeduptriple]

Cool..thanks!

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[754]

 Yeah, one benefit is it can turn a decent looking ride into an example of ........................................................................

..."HomelessShoppingCartChic"...in only a few hours......

[messeduptriple]

Yeah, one benefit is it can turn a decent looking ride into an example of ........................................................................

..."HomelessShoppingCartChic"...in only a few hours......

?

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[Danno]

the only benefit I can come up with is it traps more heat in the heads as it acts like insulation but on an air cooled bike I think this to be a detriment

[srbakker]

If you were transferring less heat out at the header and more heat out at the pipe end - wouldn't that (purely theoretically) decrease the ambient temperature around the head, aiding in cooling?

I have absolutely no proof of this, and I can't imagine this would be a substantial benefit or anything - it just makes sense in the recesses of my cranium.

I happen to like the look. 

[crazypj]

If you were transferring less heat out at the header and more heat out at the pipe end - wouldn't that (purely theoretically) decrease the ambient temperature around the head, aiding in cooling?

I have absolutely no proof of this, and I can't imagine this would be a substantial benefit or anything - it just makes sense in the recesses of my cranium.

I happen to like the look. 

 This makes more sense.
I would imagine there is less radiant heat going into cylinder with wrap, but it doesn't seem to be  problem on stock bikes
 It won't trap heat in the head, if that was going to happen, it would happen without wrap as well.
 I know the theory is the hotter exhaust gas moves faster and changes reverse 'pulse' timing and also is supposed to make 'stronger pulse' Never seen any difference in driveability in a car though

[754]

why do you think it was Really developed ??
 I think it was so that cars with dual turbos, and big headers, coulkd be worked on in pit stops.. that and  for protection from tubing that came close to other components, in cars, ie brakelines, MC, throttle cables.. stuff like that..
Circle track cars have thin aluminum firewalls, and high interior temps, it would help with that..

 I think it looks cruddy on bikes unless the pipes are running underseat.. Want a cool look... laverda sandblasted the pipes on the Jota, then chromed them.. they looked like wet chrome.. that looked cool..

[timbalish]

I like the look of the wrap.
I believe it was devloped for keeping underhood temps down and the exhaust temp advantages.
My NEW theory on wrap for AIR COOLED engines. - insulating the exhaust pipe with wrap keeps the exhaust pipe hotter so the exhaust gasses won't cool as fast, right? So the pipes are hotter which directly contact the head which would then be hotter.  In my theory the headers normally would act as heatsink to help cool the head, but if insulated they would be unable to help cool the engine.
I am sad to come to this realization as I like my wrap, but I don't want to overheat/cook my engine.
I've done 113 miles since my rebuild and wrap.  I did not check temps before or after as of yet.
Hopefully all is well.

[xnoahx]

I think the combustion event is going to generate far more heat than some hot pipes. 

[Bailgang]

I can't say why it was first developed for but it became a favorite with turbo users because it keeps the heat from radiating off the headers keeping more heat in the exhaust gas itself which increases the velocity of the exhaust gas which in turn allows a turbo charger to work more efficiently ...... not to mention cooler under hood temps. It's the expansion of the heat from the combustion process that creates the velocity in the first place so the more the heat is kept in the exhaust gas the greater the velocity and the quicker a turbo can spool up.

I did read an article years ago in Hot Rod mag where they showed that a down side to it all is that the heat wrap can destroy the metal of the headers themselves because it can be so efficient at keeping the heat in that the steel tubing of the header gets so hardened and brittle because it can't radiate heat they literally fall apart after a while. Not because they rusted out but because the steel can't deal with the temps, it's a metallurgy thing . It was many moons since I read that so I don't know if it still holds true today.

[killersoundz]

Does anyone know for sure if wrap will increase the head temp significantly? I wouldn't want to use it if it 'aids' in cooking exhaust valves.

[scottly]

That's the way I remember it also, Bailgang. Insulation was used on turbos as far back as the '70s.

[scottly]

Wrapping the headers won't burn valves, or increase the head temperature. It can shorten the life of the headers, as Bailgang mentioned.

[Terry in Australia]

That overheating of headers making them brittle theory makes sense, but I wonder now about ceramic coating, because one of the "benefits" of having your pipes coated is that it keeps the heat in your pipes, apparently increasing exhaust velocity.

Does that mean that ceramic coating could also reduce the life of your pipes? That'd piss me off! (Oops, sorry, wrong thread........)

[solo 2]

Actually most problems with header wrap comes from moisture, severe rust problems if you ride in the rain alot, As far as making the steel brittle, not likely. Heat treating takes hours at very high temps and special conditions and treatments. My understanding of wrap is to keep under hood temps down and to keep the velocity of the exhaust gases high which helps with scavenging. Like alot of high performance stuff, I don't think you'd get alot of benefit unless the motor was tweeked to within an inch of it's life and you were trying to extract the last few HP out of it.

I used exhaust wrap for years on RX7's which run much hotter than a CB ever will, they are also very prone to warpage if over heated and never had any problems. Can't say one way or another if it gained anything from it, made it much easier to work on hot. If you like the looks and want to change the oil hot, have at'er.

[trueblue]

FWIW, lagging or "wrap"as it is commonly referred to on this site was originally developed to keep heat in steam pipes long before the first hotrod was even thought of, let alone built.

[Magilla]

I wraps on my bike.  They are there because my headers were rusty.  At some point i will replace with a new factory exhaust, when I can afford it.  For now the wraps offer a neat clean look while I concentrate on other issues.

As for benefits?  As I understand, when used in drag racing its about regulating temperatures.  Consistent times are a must when racing and having consistency in temperatures is a must when fine tuning between runs.

[Bailgang]

That overheating of headers making them brittle theory makes sense, but I wonder now about ceramic coating, because one of the "benefits" of having your pipes coated is that it keeps the heat in your pipes, apparently increasing exhaust velocity.

Does that mean that ceramic coating could also reduce the life of your pipes? That'd piss me off! (Oops, sorry, wrong thread........)

Good point and it made me wonder too. From cars I've seen that had ceramic coating on their headers they could still be pretty hot to the touch which may mean they're still radiating enough heat to make the steel happy but that's just a guess. I also know that you have the option of having both the outside and inside of the headers coated with ceramic which if done properly would essentially protect the steel from overheating at all.

I've never used either ceramic coating or heat wrap so I'm only guessing on this but your exhaust valve is already taking the brunt of the heat during the combustion process. If your exhaust system is scavenging like it should then all that extra heat that the ceramic or heat wrap is containing will simply get pushed out the end of the exhaust pipe with no ill effects to the exhaust valve ..... but that's just a guess.