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View Full Version : How hot do downpipes get?

fenris
22-02-08, 10:58 AM
No, i'm not planning on touching them!, but do they get up to 400 degrees, or higher? (reason, I am intending to clean and spray mine matt black, but there are two types of heat resistant paint, with different temp levels (and waaay different prices)

so I was wondering if anyone technical knew how hot they are supposed to get!

ta

Jim
blueto
22-02-08, 11:02 AM
not to sure, but i wouldent trust any heat resistant paint anyway. Get a dremmel and clean your downpipes the hard way
Jester666
22-02-08, 11:04 AM
I used PJ1 Fast Black to do mine.

http://i150.photobucket.com/albums/s95/jesterSV650S/SV%20Transformation/Picture002.jpg

I think I used the 500 degree one.

HTH! :thumbsup:
blueto
22-02-08, 11:05 AM
and how are they holding out jester? any blistering>?
Keith1983
22-02-08, 11:06 AM
How much was the PJ1 stuff?
Jester666
22-02-08, 11:06 AM
About a tenner on fleBay

EDIT I paid 9 quid incl P&P from This Seller (http://myworld.ebay.co.uk/ya32pp/)
fenris
22-02-08, 11:10 AM
is that 500 F or 500C? I've found pj1 on ebay, but it says only 260C (500f). If that's the case, I have some matt black 425 C paint that I can spray on instead! Hurray for barbeque paint! ha ha!
Jester666
22-02-08, 11:14 AM
and how are they holding out jester? any blistering>?

Still looks fresh. It cures as the pipe heats up so the run back from Chesterfield was enough to cure it.
Jester666
22-02-08, 11:14 AM
is that 500 F or 500C? I've found pj1 on ebay, but it says only 260C (500f). If that's the case, I have some matt black 425 C paint that I can spray on instead! Hurray for barbeque paint! ha ha!

The PJ1 Fast Black is basically BBQ paint but is also good for exhausts.
dizzyblonde
22-02-08, 12:00 PM
Polish em wid elbow grease and lots of autosol, but fainling that use the dremel like said before.

And yes they do get hot, cause this dozy bugger, saw a spot of muck on mine once ad went to rub it off, melting a hole in my glove.....doh!!!
Blue_SV650S
22-02-08, 12:04 PM
http://cgi.ebay.co.uk/PJ1-MOTORCYCLE-PAINT-FLAT-BLACK-EXHAUST-HIGH-TEMP_W0QQitemZ230202474707QQihZ013QQcategoryZ10460 QQrdZ1QQssPageNameZWD1VQQ_trksidZp1638.m118.l1247Q QcmdZViewItem

816deg C, that is the stuff you will need!! 8)
JamesMio
22-02-08, 12:19 PM
Hmmmmmmm Interesting!!!

My downpipe is a disgrace, and with a 90 mile commute (after which it's dark normally when I get home) there's little chance of the bike being scubbed after every run...

Don't suppose any of the people that've painted the pipes have got any 'after' photos by any chance?

Be good to get an idea of how it looks with black (as apposed to the skittery brown they are now!) pipes!
Jester666
22-02-08, 02:55 PM
Hmmmmmmm Interesting!!!

Don't suppose any of the people that've painted the pipes have got any 'after' photos by any chance?


Errr......3rd post in this thread? :rolleyes:

And

http://i150.photobucket.com/albums/s95/jesterSV650S/SV%20Transformation/Picture026.jpg
northwind
22-02-08, 03:39 PM
It's how it looks after a year that interests me :) There's also ceramic coating options, but naturally they're more expensive. The paint looks good on Jester's though!
Sosha
22-02-08, 05:28 PM
You need a red seat to go with that Mister...
embee
22-02-08, 05:54 PM
I can't be specific on the SV, but as a guide a typical petrol engine at full chat will have exhaust gas around the 800-900C range in the port. The outer pipe skin temp will obviously be somewhat less especially with the airflow (though the rear pipe will be a lot hotter than the front, and it shows!).

Anyway, that's the ballpark.
fenris
22-02-08, 05:57 PM
I can't be specific on the SV, but as a guide a typical petrol engine at full chat will have exhaust gas around the 800-900C range in the port. The outer pipe skin temp will obviously be somewhat less especially with the airflow (though the rear pipe will be a lot hotter than the front, and it shows!).

Anyway, that's the ballpark.


At last! Thank you. Someone technical! (well, at least compared to me!)
JamesMio
23-02-08, 09:32 AM
Errr......3rd post in this thread? :rolleyes:

I meant on a bike! :p

Thanks for the photo, that's what I was after!

:cool:
maultin
23-02-08, 01:18 PM
IMO heat resistant paints arent all they are cracked up to be
how do i know - i work for a paint company & we sell them.

they are ok on something that does not have any movement (engine block etc) that in the grand scheme of things does not get too hot.
however, on something that has some expansion/contraction, they dont perform as well as they might.

then there is the added issue of 'quick temp changes'. if you have your downpipes at top running temp & go through a puddle, the thermal shock can crack the paint, leading to it loosing adhesion.

there are ceramic coatings that you can get, but they are very expensive & ususally supplied as a coating service rather that a diy aerosol

get the polish out is my advice

Alan