Jet Hot Coatings

[GregoXB]

I'm going to get my headers Jet Hot coated. I can't decide which coating level to get. Extreme 1300 vs 2000 vs 2500. Basically the 2500 has the highest heat management and insulating properties, with the 2000 and 1300 each having a step lower in terms of heat insulation. The 2500 also has a slightly rougher texture with the 1300 having the smoothest finish. I called and talked to their customer service and they are really cool and recommended the 2500 because they told me it would manage the heat coming off the pipe the most and it is not much more $ on a small pipe like the one found on the XB. I am looking for feedback from Buell guys who can comment on whether it is even a good idea to have extreme heat insulation on the header or whether it is better for the header to let off heat via the header. Does anyone have experience who can advise? Thanks.

 

[djs2k2]

Can anyone tell me why this would be bad for the bike?

 

[Sirius815]

I can only think that scavenging would be improved (hotter exhaust moves faster) leading to slightly leaner conditions.

 

[mrlogix]

^^ this.

http://www.sdsefi.com/techegt.htm

another good article about egt's and cht's

http://www.jpitech.com/press_releases/Bush_Article.pdf

Best to coat internally and externally if exhaust temp heat transfer is the desired goal

 

[mrlogix]

f#cking rep point system. Tried to give you one Sirius. How can I spread it around when the same people impress me? Just my .02

 

[GregoXB]

I'm sorry guys but you lost me.

Would you recommend ceramic coating the header with the extreme 1300, which would make the pipe look nice and be the closest to the OEM header in term of heat dissipation. Or go for the Extreme 2500, which will drastically reduce the amount of heat radiating off the header?

 

[Sirius815]

Are you after looks or performance or both? looks = 1300, performance = 2500, both = 2000.

 

[mrlogix]

sorry, didn't mean to get off on a tangent from the original question. Sounds like 2000 is a good compromise for looks and effect. Maybe Dean will chime in.

 

[Disturbed1]

I have gotten several items Jet Hot Coated. But I have always done it for the aesthetics, not for the insulating value. If you have an item that has welded on flanges that bolt together with gaskets, you can use the highest temperature rated coating. If you have an item that has slip fittings or joints, you may want to consider the lower temperature coatings, as the thickness interferes with the connection. You feel a little like a hack when your grinding the coating off to make it fit. Additionally, wherever you grind down to make a slip connection, under high exhaust temperatures, it will discolor and possibly rust depending on the material that was coated. This really stands out when you have a bright silver perfect looking exhaust and rusty crappy joint connections. Just my 2 cents.

 

[GregoXB]

Thanks guys the feedback was useful. I'm going to get the Extreme 1300. Joint fitment and aesthetics will be best.

Now I can't decide weather to go with regular black vs flat black. What makes it tougher is I can't see the finish in person. Anyone running a black or flat black color on their headers who can chime in on that?

Thanks.

 

[Simplymichaeljr]

From my little knowledge about headers, I understand that header molecules are lost from the heat of exhaust gases. Coating the headers internally and externally protects the headers from hairline cracks, thus increasing the lifespan of the headers. Also, I understand that wrapping headers is a bad idea because it prevents the heat from radiating, which makes the headers hotter, creating more lost moleclues from the headers. Bike headers get really got, so, if you have expensive headers that you want to make last, jet coat them.

I just had my stainless full beson exhaust coated with a satin black 2000° finish. The exhaust has spring couplers for the muffler and installation was seamless. Since it's stainless, I won't have any rust issues at the coupling. Here are some pictures of the satin black finish.

 

[GregoXB]

Wow, those look sweet.

 

[mrlogix]

I understand that header molecules are lost from the heat of exhaust gases. Coating the headers internally and externally protects the headers from hairline cracks,

a lot of headers use stainless steel for the material. All metals heat fatigue. As they heat and expand then cool and contract stainless work hardens is addition. As far as everything I have learned about metallurgy so far and material sciences, no 'molecules' are 'lost'. The expansion and contraction is like taking a thin piece of metal and working back and forth over a bend. It finally starts to crack and tear. Coating the header inside and out helps reduce this characteristic of the headers. Coating the outside reduces the headers capability to heat exchange to the outside air. Coating the inside reduces the header material from absorbing as much heat from the exhaust gases to begin with. A side advantage of this in either form is higher exhaust gas temps which increase gas velocity and help cylinder scavenging as Sirius mentioned above.
Header wraps insulate from heat transfer to the air and other components of the bike, but can dis-color stainless and trap moisture and start corroding other materials.

I would venture to say that Dean here on the forum has forgotten more about exhaust materials, header design and coatings than most of know.

 

[Sirius815]

^^ What Mr. Logix said

 

[user_deleted]

I understand that header molecules are lost from the heat of exhaust gases. Coating the headers internally and externally protects the headers from hairline cracks,

a lot of headers use stainless steel for the material. All metals heat fatigue. As they heat and expand then cool and contract stainless work hardens is addition. As far as everything I have learned about metallurgy so far and material sciences, no 'molecules' are 'lost'. The expansion and contraction is like taking a thin piece of metal and working back and forth over a bend. It finally starts to crack and tear. Coating the header inside and out helps reduce this characteristic of the headers. Coating the outside reduces the headers capability to heat exchange to the outside air. Coating the inside reduces the header material from absorbing as much heat from the exhaust gases to begin with. A side advantage of this in either form is higher exhaust gas temps which increase gas velocity and help cylinder scavenging as Sirius mentioned above.
Header wraps insulate from heat transfer to the air and other components of the bike, but can dis-color stainless and trap moisture and start corroding other materials.

I would venture to say that Dean here on the forum has forgotten more about exhaust materials, header design and coatings than most of know.

brilliant write-up john and with info i previously never knew. thanks a ton.

 

[mrlogix]

Thanks John. I've learned a lot from the past 8 years in the aerospace industry. The company I work for spends a ton of money on R&D. Material sciences has been a big deal around here for a while now. :eagerness:

 

[Simplymichaeljr]

a lot of headers use stainless steel for the material. All metals heat fatigue. As they heat and expand then cool and contract stainless work hardens is addition. As far as everything I have learned about metallurgy so far and material sciences, no 'molecules' are 'lost'. The expansion and contraction is like taking a thin piece of metal and working back and forth over a bend. It finally starts to crack and tear. Coating the header inside and out helps reduce this characteristic of the headers. Coating the outside reduces the headers capability to heat exchange to the outside air. Coating the inside reduces the header material from absorbing as much heat from the exhaust gases to begin with. A side advantage of this in either form is higher exhaust gas temps which increase gas velocity and help cylinder scavenging as Sirius mentioned above.
Header wraps insulate from heat transfer to the air and other components of the bike, but can dis-color stainless and trap moisture and start corroding other materials.

http://www.centuryperformance.com/exhaust-header-heat-wraps-do-not-use.html

 

[mrlogix]

yep, sounds about right. Good link. :up:

 

[SEXT9]

Thanks guys the feedback was useful. I'm going to get the Extreme 1300. Joint fitment and aesthetics will be best.

Now I can't decide weather to go with regular black vs flat black. What makes it tougher is I can't see the finish in person. Anyone running a black or flat black color on their headers who can chime in on that?

Thanks.

I have the Satin Black 1300 from Jet-Hot. Here's a before and after for you.

 

[Simplymichaeljr]

I like what you've done to your bike sext9. Looks nice with those pipes coated. :up: