Valve springs discoloured

[Caprimaniac]

Hello.

Taking my heads apart to check for leaks, renew seats and guides etc.

When undoing the springs, I noticed a few, 4 of 16, had a gray colour, whereas the rest has this bronze colour. Springa has been in use for approx 10 years. Good dbl springs with dampers. Never had any signs of valvefloat. Never overheated.

What puzzles me even more... the inner springs were loose, as came out easily, on all bronze coloured sets. The inners were kindbof stuck and needed to be pressed out (fingers only...) on all the greys. Coincidence, or???

Will measure spring pressure to see if there’s any difference.

Anyone care to comment?

505FB31B-2E15-421C-914E-DB882B533D95.jpeg

[Kevin Johnson]

WAG
Two different manufacturers producing a specified spring for a distributor, each with a different formula coating.

[Caprimaniac]

Maybe, maybe...

BTW this is a set of Crower springs.

[Caprimaniac]

Measurements showed no difference in spring tread diameter. But the damper on the grey was somewhat 0.05mm thicker on the gray ones, making innner spring stick.

[Baprace]

I agree with Kevin , you may have some springs out of one batch and some springs out of another batch.