I just got my block and heads back from the machine shop and my engine kit arrived a few days ago. I'm thinking I'm good to go... then I checked the cam against the old one. The lift on this thing is .025 less than the original. Doesn't sound like much but it is about 10% less than the original. When I called the seller, MABBCO, their guy Brandon did his best to convince me that I didn't know what I was doing and cam lift could not be checked in this way. Now I may not be a genius, but I am a mechanical engineer, so I kinda think I can do a simple comparison between two similar parts. Anyway I called back and spoke with him again and he agreed to swap it out for another one, but he also assured me it would be the same. My question is, has anyone here used a re-ground cam and what was the result? It would seem to me that the one I have will probably work, but the power will be low and the upgrades I have done will be cancelled out in part by the decreased cam lift.

 

How did you measure lift?

 

I measured the base circle 90° from the high point of the lobe. Then measured the max lobe dimension and subtracted the base circle measurement from it. The first measurement on both cams was very close, but the difference in the two was where I found the discrepancy. It looked like the grinder took off enough to clean up the high point of the lobe, but only took off the minimum from the base circle instead of keeping the correct proportion to stay in spec.

 

Put the cam on some v-blocks. (or in the engine...) put your gauge on the cam directly opposite the high point of the lobe, rotate the cam to get the greatest measurement, that will tell you what total lift at the cam is. No math involved.

I am not a fan of re-ground cams. Sure, it saves you a couple bucks on the came, sometimes.... but, it introduces other potential issues. Like the pushrods ending up being too short. Or, requiring adjustable rockers, etc.....

Talk to your sales rep, see if you can get a NEW cam with the specs you want. Will cost you a few more bucks, but, it is a better alternative in the long run.

 

I would put the thing in the block and measure it.
Your going to degree the cam anyways right? You did get a cam card correct?
Then if you still have a issue you have checked it correctly and they have to make good on it.

Dave

 

Personally, I've had some good luck with re-ground cams, however, it all comes down to the skill/capabilities of the regrinder. I've used Cam Techniques and Bullet Cams with success. Unfortunately, Cam Techniques is going/has gone out of business, from what I can tell.

 

No cam card, or any specs at all. This thing was in a box with a chevy part number on it. MABBCO had put a sticker on there with 360 Mag handwritten on it. When I asked Brandon about this, he again assured me that they have sold thousands of these and it would be fine. He's already gotten my money so I'm kinda out of luck. On the bright side, the rest of the parts in the kit looked ok. I spoke with Dale at Oregon Cam Grinding and plan to send my original cam to them to have it ground correctly.