Topic: how hot do headers get?

[nollid51]

Is paint that is good to 500 F safe for headers and mufflers? If not, is it good for just mufflers? Thanks.

Joe

[manjisann]

I used VHT 2000 degree paint to coat the heat wrap and the first 3 inches of my headers. The paint has stayed on both very well. To answer your question, the 500 degree paint will burn off your headers. I would think it is safe for mufflers though, as I don't believe they get near that hot, but I didn't paint my mufflers, so I don't know for sure. Hope that helps.

Brandon

[nollid51]

Thanks. I was  just wondering because 75% of the chrome is intact, and I have some clear coat 500F paint. I was thinking clean the rust then just coat it and since its clear coat it wont cover up the chrome. Didn't see 1200F clear at the store, so i'll have to figure something else out.

[strangedaze39]

They get around 2000 F* (corrected).

[MCRider]

They get around 200 F* (thats what I read).

Add a "0".

http://www.teamrip.com/electronics/masc1thermocoupleinstall.htm

1400 to 1600F average.

[TwoTired]

Exhaust temps get to in the 1300-1500 F range.  The pipes don't get to that usually.  As they transfer heat to the air.  I've seen them get dull red (about 1200F) when the timing was way off and the idle jets plugged.

Cheers,

[wildcatmahone]

+1 on pipes gettin hotter than 1200 degrees I sprayed mine with duplicolor enamel rated for 1200 degrees and the crap is burning/peeling off at the first bend. NO GOOD!!

[Patrick]

You can't paint successfully over chrome. It won't stick (for long).

[nollid51]

Thanks guys. very informative!

[low-side]

That thing about painting over chrome is dead on.  At first, I sanded my Kerker; then I sandblasted it; after both of those failed, it attacked it with emory cloth and coated it with phosphoric acid (rust converter) and it finally took paint.

[Hendey]

I just measured the headers on my 1978 cb750f with a non contact (IR) thermometer.

This was after an easy 2 mile run, temperature taken at the upper elbow. (temp drops quickly at you go down the pipe.

#1  550 deg F
#2  410
#3  426
#4  390 

I'm a little surprised by the variation. This is the first time I have ever seen this kind of info so the jury is out until I get many more readings.

Has any else experimented with exhaust temp readings.

Pete

[eldar]

Well your temps seem to indicate that # is running leaner than the others and #4 is too rich. maybe try to get all of them close to 500 or so.

[jevfro]

I checked mine once w/ an IR thermometer and was surprised they were all between 350-400F after a 30 mile ride.  I think if they are getting to 1500-2000 on the outside you might be running lean?

[speedy gonzalais]

it dont matter what paint u use it will come off may take a while but its prob easier to keep pollishing the chrome

[KingCustomCycles.com]

Exhaust gas temp may be 1700 but the outside of that header is under 500 degrees or something is wrong.  Late timing or a rich/lean mixture are to blame for higher numbers.  I use the IR thermometer to tune my engines and find it more reliable than a carb balancer. I have used spray-on grill paint with good success but it seems to "cook off" over time and needs to be reapplied.  Big deal, it takes 15 minutes and I am looking sharp again for another 30 days.  I am going to look up the melting point of steel now to dispell any rumors that anyone's headers are running 1700 degrees.  Another thing I used to do was spray wd40 on a running engine to cook a glaze onto the headers to stop rust.  That created quite the fog and may create a fire or explosion hazard.  Hey, who said motorcycles were safe?   

(found it, depending on the Alloy, it is 2500F and up.)  I gues that is why lead headers are not popular 

[eldar]

Never seen a rich mix be too hot as the fuel does not burn fully. But I feel 500 would be a good temp, maybe a little high but testing will show the proper range. I wanted to tune like that and a certain member here said it was lazy. I guess it is lazy to do it quick in a way that works.

[bradweingartner]

Don't forget that ignition timing and valve timing can play a huge part in header temperature as well. I have seen mild steel headers get to the cherry red stage with heavily retarded timing. That's starting at the 1200+ F range.

So while normally they shouldn't see that, if you run paint "rated" for 500F I don't see it being as durable as 1200-2000F paint. And of course, ceramic coating > All.