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awa355
23rd April 2011, 20:24
Can someone tell me what turns the header pipes blue. Is it hard running?, fuel mix too lean?,

Seems to be a lot of aftermarket systems that get this bluing.
White trash
23rd April 2011, 20:32
Stainless and titanium both go blue from heat. Pipes get hot. Funnily 'nuff, closest to the cylinder is the hottest bit. Mixture means shit.
FJRider
23rd April 2011, 20:36
It's caused by/with the heat treatment of the metals ... to do with Metallurgy ....
pete376403
23rd April 2011, 20:38
Many factory header pipes are double skinned (ie one pipe inside another), so the outer chromed surface stays nice, while the inner pipe rusts away. Looks nice, weighs lots

Aftermarket pipes are usually single thickness.
White trash
23rd April 2011, 20:38
It's caused by/with the heat treatment of the metals ... to do with Metallurgy ....

You dumb fuck, if Leonardo DiCaprio couldn't turn lead into gold, then neither can you.
FJRider
23rd April 2011, 20:45
You dumb fuck, if Leonardo DiCaprio couldn't turn lead into gold, then neither can you.

Hold it at the RED line for long enough ... and GOLD will be produced ... but from your pocket ...
HenryDorsetCase
23rd April 2011, 20:46
Can someone tell me what turns the header pipes blue. Is it hard running?, fuel mix too lean?,

Seems to be a lot of aftermarket systems that get this bluing.

its caused by heat, and exhausts run REALLY FUCKING HOT these days so that they can meet emissions regs. On my Triumph it has an air injector thingy up by the sparkplug to inject fresh air into the exhaust to make it burn more. and hotter. Apparently to stop the bluing, the first thing to do is remove the air injector. I did that, but also changed the airfilter, and the whole exhaust system.

Those race single wall titanium ones go a whole rainbow of colours, they're beautiful....
AllanB
23rd April 2011, 21:34
As before, heat.

Chrome turns a fairly vivid blue.

Stainless will yellow and depending on the mix in the stainless various shades of brown near the ports.

Titanium is impressive, blues, reds, golds depending on the amount of heat.

US Harley chaps hate the bluing so just about all systems for HD's are twin walled or often covered in a secondary set of chrome heat shields to hide any discoloration.

When I was a young chap starting riding blued headers were considered impressive as it showed you'd be giving it heaps and were (hopefully) a hard-arse rider.

If your ride has more than one cylinder and only one pipe has blued it could be a sign of something wrong in the mixture department and worth looking into.
schrodingers cat
24th April 2011, 08:13
As folks have said it is heat related. They don't just turn blue however. The colouration is caused by the metals oxide layer

http://www.tpub.com/steelworker1/14250_files/image013.jpg

For a full list of metal colours see below. Up to 427 degrees C the colour is caused by the oxide coating, about that the colour comes from the metal itself

http://m4040.com/Knifemaking/PICTURES/Tutorial/GlowChart-sm.gif