Realizing this is an old thread . . .
I put a Comp 268 in my 440 block to check the lift and duration. That particular Comp series was the first to use assymetrical lobes. Open them quick, close them slow, results in more area under the lift curve. But what I was not expecting to discover is that the valve stayed at max lift for 10 degrees of crank rotation. I had a new Purple Shart 284/284 cam that I checked also. Max lift was only for 1 degree of crank rotation. The .050 spec also seemed to be inline with the "80% of advertised duration" rule mentioned in the Race Manual.
I believe that Lunati is also now advertising assymetrical lobes on some of their cams. Those earlier Comp HE cams did have lifter noise for a time after installation, before they got quiet (they were hydraulics and adjusted with little preload).
Many have claimed that many aftermarket hot rod cams are Chevy cams on other blanks. Hughes Engines has a line of camshafts designed for Chrysler-size lifters. Check their website.
Some cam grinds are harder on valve springs than others. Sometimes, a little less lift and little less duration can make the difference of springs breaking, getting weak before they should, or lasting a full race season.
To me, Lunati's selection has come a long way from what it was 20years ago. Haven't used one, though, but I might.
CBODY67
I put a Comp 268 in my 440 block to check the lift and duration. That particular Comp series was the first to use assymetrical lobes. Open them quick, close them slow, results in more area under the lift curve. But what I was not expecting to discover is that the valve stayed at max lift for 10 degrees of crank rotation. I had a new Purple Shart 284/284 cam that I checked also. Max lift was only for 1 degree of crank rotation. The .050 spec also seemed to be inline with the "80% of advertised duration" rule mentioned in the Race Manual.
I believe that Lunati is also now advertising assymetrical lobes on some of their cams. Those earlier Comp HE cams did have lifter noise for a time after installation, before they got quiet (they were hydraulics and adjusted with little preload).
Many have claimed that many aftermarket hot rod cams are Chevy cams on other blanks. Hughes Engines has a line of camshafts designed for Chrysler-size lifters. Check their website.
Some cam grinds are harder on valve springs than others. Sometimes, a little less lift and little less duration can make the difference of springs breaking, getting weak before they should, or lasting a full race season.
To me, Lunati's selection has come a long way from what it was 20years ago. Haven't used one, though, but I might.
CBODY67
