Bluing of Pipes

[Garn 1]

What is the main cause of "bluing" of exhaust headers?
I have just overhauled an engine, new rings and larger bore.
I have an old 4 into one installed and it seems to be really getting "heat treated" going by the colour! I am concerned that when I fit "four into fours" they will suffer the same demise.
RegardZ.

[GEZ635]

Garn, Ive always found 4 into 1 systems go blue at the header and it looks pretty cool to me. However, I understand your concern in relation to a new set of 4 into 4 pipes. I think the pattern ones are more prone to blueing as I never really have the problem with genuine pipes. I believe the tubing is thicker on genuine pipes(some say double skinned) so they take the heat better. Ive had brand new pattern pipes go blue/yellow within 20 minutes of using them and its a pain in the arse. I have recently bought some polish called "blue job" which is powder based and it is very good and removing the blue colour from the pipes - but it only comes back again!

[zed1015]

You will never stop them blueing if they are single skinned, It's due to the heat. Most chromed factory headers were of a heavy gauge and double skinned, i.e. one pipe inside the other with a small air gap to stop the heat transference. All the after market or pattern pipes i have seen are just single skinned, probably just down to the cost involved. So it looks like you'll be busy with the - Blue Job - every time you come to clean it, But i'm same the as GEZ and think it looks ok.

[Garn 1]

I agree with both of you, that blued pipes look good. However, it looks a bit strange when number four exhaust is not quite as blue a number one!

I did notice that I am slightly retarded (about 1 mm at adv/retard mechanism markings), as it stands, awaiting to be dynamically timed, once all is complete.
RegardZ.

[Skunkwurcx]

mine have turned a nice gold colour....it looks kinda cool imo and matches the gold stripe on the tank !!

[paulmceleney]

garn i think you will find its down to your timing thats not set correct

[Pigford]

There you go...... Who needs 'colour-tune'

[PAULJAC47]

When you fit your new pipes dont be tempted to run the bike straight up to full operating temperature,do it gradually run the bike for short period and gradually build up time might be a coincidence but was told this by old Brit bike fan and have always carried this out,as long as mixture and timing is correct have never had issues with pipes blueing,Give it a go Cheers Paul J...

[paulstrees]

I agree with pauljac I fitted a set of copy pipes did as Paul recommends and had no problems