Valve Clearance with stainless steel valves?

[BigValvedEX]

Does valve clearance have to be adjusted differently on Kibblewhite Blackdiamond valves. They are made of stainless steel and I think the stock valves are made of carbon steel, and the expansion rates are different on the two metals (stainless has an expansion coefficient of 17 while carbon steel has and expansion rate of around 12) so i was wondering if the valve clearance would have to be adjusted differently since when they get hot they expand more?

[BigValvedEX]

or is it such a small difference that it doesn't change anything?

[underpowered]

it is most likely .00017m per degree celsius. so since since it is so small, it will not make a difference. if it did, the valves should come with the new settings, but i know my kibble white valves did not so i just used hot cams suggested setting for my cam when i installed my black diamonds.

[bwamos]

Expansion values between Stainless Steel and Hardenerd Carbon Steel is minimal. Just use the stock settings. Titanium valves is where you see the most difference.

[BigValvedEX]

wicked sweet

[cals400ex]

yeah i would set your clearance to what your cam manufacturer recommends.

[wilkin250r]

I'm not so sure.

I'm not as up-to-speed on my metallugy as I should be, so I'm just looking at the numbers, and those numbers are putting up a red flag.

In theory, you put a small gap between the rockers and valves when the engine is cold. As the engine heats up, the valves expand and close this gap to almost zero, in theory.

If the stock setting is 0.004 inches, this would seem to indicate that the valves get approximately 0.004 inches longer. ( I can't remember the settings on a 400EX. Isn't it 0.004 intake and 0.005 exhaust?)

I don't care what the actual units are for the coefficient of expansion. I'm looking at the difference between the two. 17 vs 12 is about a 30% difference. This would mean that same 0.004" of growth we saw earlier is not going to become 30% longer, or just a tad over 0.005"



I can't tell you for certain, I'd have to spend a bit of time researching. But so far, my recommendation is to widen your gap by just a tiny amount. I'd suggest 0.005 intake and 0.006 exhaust at least.