shims

[Ron Hamp]

any body that has bought the hot cam shim kits and has found some of them tto be soft can heat treat them some more i found heating them to a cherry color and introducing some carbon with the flame brings them about 10 points higher to read the same rockwell as a the honda shims about 65

[Baron Von Beard]

I had no idea this was an issue. Is this only on the small shims?

[Bustphat]

RHC,

We Rockwell tested Honda OEM, K&L & Hot Cams shims and found the following:

OEM- 61-63 RC B scale

K&L- 41-43 " "

Hot Cams- 37-40 " "

We also found that certain aftermarket valves that don't micropolish the tips but DLC coat the tip will effectively bury into the softer RC shims w/ aggressive lift cams.

bustphat

[smf919]

i am ordering the HotCams shim kit tomorrow. should i be worried?

[Dark]

I already have one lol.....should i be ? Although I did reshim all my valves when I put in the hotcam and they've been perfect ever since.

[emoney]

So are you wearing out shims Ron? Any particular spring rate and valve material combinations? Pretty much only Honda exhaust side right?

[Dan CRF250]

pfft i just use the same shim everytime, take my serface grider with the automatic base and takes me about 30 seconds per .001 for each shim, not bad for free

[Ron Hamp]

even with the tip of the valve micrho polished and dlc coated they will wear into the softer shims also the dlc coated valve stems are hard on vale guides compared to crohmium nitride .

[Bustphat]

Sometimes it's hard to beat OEM quality. Honda's material & processing are second to none. It's a tough call when matching surface toughness values, too hard & the guides wear, too soft and goodbye valve stem

Bustphat