Header color

[81xsproject]

are blueing headers a definate sign of a lean mixture. If so, once I get it richened up, can you un-blue them?

[DiverRay]

Yes, blue is from heat, and a lean mixture. There are some products that claim to remove the blue, I'm just not sure how well they work.

[Geezer]

It depends on how far they are blue... Single wall headers always blue up near the head.

With a lean running condition. they can blue more than half way back to the muffler.

Geezer

[SG-Olli]

Lean or rich

Single wall headers will get blue, no matter what you do. It is just a matter of temperature. The temperature of the exiting gas is around 1200°C. You can remove it, but it will come back.
On mine '78 with 4 in 1 the headers are blue until the hit the collector. And the engine definitely does not run lean.
But going 120 mph for two hours will turn them blue.

[Geezer]

Re: Lean or rich

Originally posted by SG-Olli
Single wall headers will get blue, no matter what you do. It is just a matter of temperature. The temperature of the exiting gas is around 1200°C. You can remove it, but it will come back.
On mine '78 with 4 in 1 the headers are blue until the hit the collector. And the engine definitely does not run lean.
But going 120 mph for two hours will turn them blue.

You must have thinner headers than I've ever seen here in the USA. I don't think I've ever seen a set turn blue past the second bend on a good running engine but we don't have an Autobahn either.

Geezer