I am putting a Weiand 142 roots blower on my freshly rebuilt 355 motor. I am not sure what to look for in the optimal cam for it, however. It was recommended that I use the ZZ4 cam. I have included the specs on it. I am not to familiar with camshafts and how to choose a good one, so if anyone could clue me in, that would be great.

ZZ4 cam

Duration @ 0.050 (I/E): 208/221
Lift (I/E): .474"/.510"
1500-5500 RPM range
hydraulic roller tappet

 

The problem with GM cams is that they do NOT supply a cam card with their cams. No cam card, no vital specs. Lift and duration only tell a small part of the story (not enough in my opinion). For a blown application, overlap needs to be nil. Overlap is an indicator of a "good" blower cam, but it doesn't tell the entire story. Most critical are valve timing specifications. Without these specs, normally included on a cam card, there is no way to determine if any specific cam is good for a blown application. This is THE reason why I chose not to go with a GM cam.

 

Comp makes some great blower grinds. Look for something at with at least 112* LSA.

 

If you knew the lobe separation angle you might have an easier time figuring out if that cam would work well with a blower. If it's in the range of 114* or more it would probably work pretty well with a blower.

BUT..... like Willie says, if you don't know the actual valve events it might be tough. If it's ground with 8* of advance in it and you don't know it, it could quickly turn into a very bad choice.