Header wrap

[300ex_#387]

I've seen people wrap there header I guess its a high temp tape or somthing. But I wondered what was the advantage of it and what do they use to do it?

it keeps the header hotter and it gives more performance so i read.

[450r51]

its to keep the rider from burning themselves. ive seen it on many lt250rs and 250rs where i race. they only do it not to burn themselves. i beleive, i might be wrong.

blue450yo how can keeping heat in make u have more performance, heat robs performance.

Originally posted by 450r51
its to keep the rider from burning themselves. ive seen it on many lt250rs and 250rs where i race. they only do it not to burn themselves. i beleive, i might be wrong.

blue450yo how can keeping heat in make u have more performance, heat robs performance.


i read it in a dirt bike mag. i think it sid it let it rev faster cuz the hotter air mooved easier. im not for shure. ill go look.

[450r51]

what are u talking about, how can it let it rev faster, if ur wrapping the exhaust in heat tap, air coming out of the engine has nothing to do with letting it rev faster.

[400exrider707]

Originally posted by 450r51
what are u talking about, how can it let it rev faster, if ur wrapping the exhaust in heat tap, air coming out of the engine has nothing to do with letting it rev faster.


300ex-#387 do not listen to this kid, he is wrong.


This is one of the few times when I've seen blue450 be right. lol. The header wrap actually keeps the pipe hotter thus allowing the exhaust gasses to escape faster. I know its hard to understand cause I too thought more heat is going to equal less power, but more heat in the headpipe lets the exhaust out faster. The downside is that its a really small gain and the wrap holds moisture in and will cause premature corrosion on your headpipe and could rust right through!

[450r51]

wow then i retract my statement, this too is the first ive seen blue450yo to be right. but his other 1000 posts were all wrong. thank you for clearing it up for me because its still hard to grasp the concept of keeping heat in will make it run better.

[300ex_#387]

soo...if it does increase performance why doesnt many people do it?....is it just cause it makes it not look as good? I might give it a try...where can I get the high temp tape?

In order to increase exhaust gas temperatures and theoretically scavenging, wrapping or coating the header is performed. Both wrapping and coating reduce the heat loss to the outside air because they are both poor heat conductors.

As poor heat conductors, classical 1-d heat transfer shows that the temperature of the wrapping or the coating is reduced from that of a bare metal header. However, the temperature of the steel underneath the wrap or coating will increase fairly close to the temperature of the exhaust gas. I can explain this if I need to, but it is a little more complicated.

When the steel temperature rises the rate of oxidation increases dramatically. Cold stainless steel will take many decades to oxidize through, where super high temperature stainless steel can oxidize away in a matter of months.

The wrap does not slow the oxidation in any way, however, the coating will likely slow or limit oxidation as the air cannot penetrate very well. Without air, water or some other oxidizer, oxidation cannot take place. So coated headers will survive oxidation effects longer than wrapped headers.

Which should you use? Since I haven't heard of any quad headers failing quickly due to oxidation, and since you are only risking maybe $200 for a new header, I would wrap since it is much cheaper. :)

[450r51]

if u read two posts above me he said the gain is so minimal its not worth it because it will keep moisture in and will start premature corrosion.

it keeps some hot air away from the cylinder which would help

[bwamos]

To explain it on a very simplistic level...

Heat transfer = Energy loss.
The exhaust particles are superheated and moving very fast. Some of the energy is transfered into the pipe heating the metal. Once it is saturated it will rlease energy (heat) into the air outside of the pipe. This heat loss is directly taking energy away from the super heated gas particles. You need energy to move. Less energy = slower moving particles.

Once those particles start to slow down the particles behind it slam into it (think interstate traffic jam), impeding the process of the entire exhaust system.

Wrapping the pipe in an insulator slows the escape of the heat form the metal of the pipe keeping it saturated longer and reducing the energy loss from the gas particles into the steel pipe and keeping them in their accelerated state.

It's the same reason that people ceramic coat their pipes. The ceramic coating also acts as an insulator.

[300ex_#387]

Originally posted by blue450yo
In order to increase exhaust gas temperatures and theoretically scavenging, wrapping or coating the header is performed. Both wrapping and coating reduce the heat loss to the outside air because they are both poor heat conductors.

As poor heat conductors, classical 1-d heat transfer shows that the temperature of the wrapping or the coating is reduced from that of a bare metal header. However, the temperature of the steel underneath the wrap or coating will increase fairly close to the temperature of the exhaust gas. I can explain this if I need to, but it is a little more complicated.

When the steel temperature rises the rate of oxidation increases dramatically. Cold stainless steel will take many decades to oxidize through, where super high temperature stainless steel can oxidize away in a matter of months.

The wrap does not slow the oxidation in any way, however, the coating will likely slow or limit oxidation as the air cannot penetrate very well. Without air, water or some other oxidizer, oxidation cannot take place. So coated headers will survive oxidation effects longer than wrapped headers.

Which should you use? Since I haven't heard of any quad headers failing quickly due to oxidation, and since you are only risking maybe $200 for a new header, I would wrap since it is much cheaper. :)

Well your typing skills have improved....but thanks for the info

[300ex_#387]

Originally posted by bwamos
To explain it on a very simplistic level...

Heat = Energy loss.
The exhaust particles are superheated and moving very fast. Some of the energy is transfered into the pipe heating the metal. Once it is saturated it will rlease energy (heat) into the air outside of the pipe. This heat loss is directly taking energy away from the super heated gas particles. You need energy to move. Less energy = slower moving particles.

Once those particles start to slow down the particles behind it slam into it (think interstate traffic jam), impeding the process of the entire exhaust system.

Wrapping the pipe in an insulator slows the escape of the heat form the metal of the pipe keeping it saturated longer and reducing the energy loss from the gas particles into the steel pipe and keeping them in their accelerated state.

It's the same reason that people ceramic coat their pipes. The ceramic coating also acts as an insulator.

So do you think it would be worth doing or not?

[bwamos]

Unless you are running a very high performance 200+ HP drag quad... no, not really.

Originally posted by 300ex_#387
soo...if it does increase performance why doesnt many people do it?....is it just cause it makes it not look as good? I might give it a try...where can I get the high temp tape?


thats y i didnt do it. if it came in crome i would do it.

[300ex_#387]

ok well I was just curious...thanks

[400exrider707]

Originally posted by 300ex_#387
Well your typing skills have improved....but thanks for the info

LOL Im guessing that was copied and pasted from somewhere else since his first post he wasn't even sure how it worked. No big deal just bustin on him


Ceramic coating is the best way to do it. The wrap seems really cobby and I dont think its worth the gain, but if I was going to do it, the ceramic coating would be the way to go.

[bwamos]

Originally posted by 300ex_#387
ok well I was just curious...thanks

No problem.

It's kind of like putting a Carbon Fiber Tank cover on a 700lb utility quad.. lol. Taking a crap would give you more benefit.. lol.

However, if you had a slip-on on an undersized stock header (like the 300ex/250x), it might actually help get that exhaust through the header a little easier.

[300exOH]

I wouldn't waste my time with the header wrap. I had it on my old pipe and while it did help to keep heat off my leg it caused the headpipe to rust badly. The header tape was only on for about a year and when I removed it the pipe underneath was completely rusted and flaking. I never noticed ANY performance gain from the header tape either. It just traps moisture and ruins the header. Ceramic coating works and looks much better.

[drgnerth]

I thought about wrapping the midpipe so i didn't burn my leg where i cut the rear fender for my kicker.

[300exOH]

If you are looking to keep heat off your leg a heat sheild works much better than the header tape.

[300ex_#387]

Originally posted by bwamos
No problem.

It's kind of like putting a Carbon Fiber Tank cover on a 700lb utility quad.. lol. Taking a crap would give you more benefit.. lol.

.

lol thats pretty funny....

[drgnerth]

Originally posted by 300exOH
If you are looking to keep heat off your leg a heat sheild works much better than the header tape.
It would be kinda hard to mount a heat shield.

[balls2da-wall]

i thought about header tape in a small section of my pipe because it keeps melting a section of my plastic and ive tried that aluminum foil tape.