C4 Camshaft Id

[68mako]

Need some help on a C4 topic. I'm an old C3 guy that needs help on the new engine format. I need to identify a C4 cam as I'm re-building my engine. The cam that I pulled out is a hydraulic roller with a stamp on it between the front journal and first lobe set. The stamp reads “CRP” “0.490”. No identification on the face of the cam behind the timing gear. I’ve got a lot of experience on old Chevy hot rods and need to try and identify this cam for dialing it as well as selecting the correct timing chain package. Would like to understand if it’s stock or not. If so where can I access a spec sheet, if not OEM, any good guesses on its possible after-market manufacture.

 

[69MyWay]

68 Mako,

I can't help you with the cam i.d., I would suggest you referrence a G.M. performance part book, or talk to your favorite G.M. parts person.

Here is what I can help you will having rebuilt and modified several sbc type II engines. There are two basic timing chains, those with factory roller cams, and those without. If you are using a post 1987 block and a roller cam, you will need the thrust plate and screws that go on the front of the cam behind the timing gear. Also, virtually any performance parts store now carries a variety of brands of type II high performace double roller chains. You just have to specify that the block is 1987 and newer with a hydraulic roller. Of course, you need the roller lifters and rev kit that holds them all in place. Note that the push rods are a different length, and you MUST huse hardened rods if your are using push rod guide plates.

Roller cams using stock style roller equipment are pretty pricey. For example, I paid around $250 for a Crane that is in a 1990 roller block. The good news is that you reuse the factory roller stuff, and just change the cam.

For performance purposes, I would really think twice about using a factory roller cam. They may rev easier, but the grind is typically friendly to low RPM torque and they peak out way two early.

Let me know if you have any other questions about the process. Like I said, I have done it several times.