"Moon cam"...any information?

d.j. moordigian

d.j. moordigian

Well-known member
I have a reground B cam done by Moon speed shop. I called to get some information from them, but got zero feedback from them. I also talked with
Jim Brierly on the phone, that was a GREAT chat, but also no help.

Any of you run a " Moon 3/8 Super" and have any information, event numbers
and lash setting? Any of you have real info would help. I do know somebody
with a "cam doctor" as a last resort..

Thanks,
Dudley
 

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I cant help with real numbers, and if Jim Brierley couldnt, well you may be SOL.
I would think if you had a bare block, a dial indicator, and a degree wheel you could get pretty close. I'd do that, then hit up the guy with the cam doctor and see how close the numbers are. Good Luck!
 
I do appreciate the help,...I can run everything and get all the numbers. But my B block
has bushings for the cam, and this cam will not fit in my B.

The biggest problem for Jim and I was the valve lash,..which could be from .012" too
.028",...gee, you pick a number, that's just wrong and I'm not going to do that,...yet.
 
You should be able to get reasonably close by measuring the clearance ramps. You will see a gradual lift as the valve begins to open, then change to a more rapid rise. Play with it until you find the point where the rate of lift increases and read the amount of lift on the dial indicator. This should be the approximate desired lash. This is assuming the cam was ground with clearance ramps. Or it could be like Isky's first cams. He didn't know about this so his cams just slammed the valves open. He said they were quite noisy but must have ran good. Moonshiners in the South liked them.
 
Last edited:
I believe Moon was grinding Potvin cams (Bill Jenks).
Potvin Super 3/8 for the V8 flathead would be .375" lift at 280 degrees duration.
.010 & .012 clearance.
 
42merc said:
I believe Moon was grinding Potvin cams (Bill Jenks).
Potvin Super 3/8 for the V8 flathead would be .375" lift at 280 degrees duration.
.010 & .012 clearance.
Click to expand...

Pete1 who has Potvin [Moon] profiles may be able to help. Bill Jenks ground a couple of Potvin 3/8's camshafts for my 296"V8 in the 80's. Unfortunately Bill passed away several years ago. 42 Merc's specs are correct as he posted. I just went though my 296" and checked valve timing and reset valve lash. Bill Jenks did change lobe centers - the one I just checked is 114 degrees and another one I have is 118 - he stamped the info on the gear end - I can't remember why but it may had to do with idle RPM and lope. Pete1 is usually on the 'Early V8' forum.
 
42merc said:
I believe Moon was grinding Potvin cams (Bill Jenks).
Potvin Super 3/8 for the V8 flathead would be .375" lift at 280 degrees duration.
.010 & .012 clearance.
Click to expand...

Offy 220 said:
Pete1 who has Potvin [Moon] profiles may be able to help. Bill Jenks ground a couple of Potvin 3/8's camshafts for my 296"V8 in the 80's. Unfortunately Bill passed away several years ago. 42 Merc's specs are correct as he posted. I just went though my 296" and checked valve timing and reset valve lash. Bill Jenks did change lobe centers - the one I just checked is 114 degrees and another one I have is 118 - he stamped the info on the gear end - I can't remember why but it may had to do with idle RPM and lope. Pete1 is usually on the 'Early V8' forum.
Click to expand...

Ahhh,...Bill Jenks' did grind this cam, according to Moon. This gives me a
good starting point when I get a block too run the numbers. Boy!..280°,..
not really what I was hoping for. The numbers @ .050" should tell the story.

Thanks for the help,
Dudley
 
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