35/25

I posted a few weeks ago about how I managed to break two #168731 cams in one of my HP500 motors - the first after 60 hours, the second after 75 hours. Everything looked perfect inside the motor, but for some strange reason the camshafts broke just in front of the distributor gear.

I talked to Crane tech and discovered that I am not the only one with this mysterious problem. The real interesting part to the story is this: Crane makes their hydraulic roller cams from two different types of cores. One type is induction hardened, the other type is carborized (?spelling). So far, only the induction hardened versions have been failing in this manner. The way to identify the two is that the induction hardened ones are black in between the lobes and the carborized ones are copper colored in between the lobes. I recall that the original HP500 cams that I pulled from my motors were copper colored.

If you buy a Crane Hydraulic rolller from a supplier like Jegs, Summit or others, you may get a black one or you may get a copper one. Since this will now be the third new camshaft in my motor, I was advised by Crane to search for a copper one. Crane has not done any conclusive testing as of yet as to what is causing the failures. The only thing they know is that only the black ones have snapped for no reason by the distributor gear.

Now I am going nuts trying to remember if I have a copper one or a black one in the other motor (that now has 135 hours with no problems).

articfriends

Sorry about your bad luck,a buddie of mine that builds street motors up here as a side business has had one break also,Smitty

Lmarth

At least you know what was the likely cause of your problem. Frankly, I'm not surprised. Thanks for sharing your findings with us.

mr_velocity

Being your 3rd one and they know the black ones fail you would think they would just send you a new cam no charge.