C1 "high lift cam"

[Joe C.]

Re: C1 "high lift cam"

John,
Respect your knowledge a lot, but here's where I'm coming from: Lift patterns for 30-30 and the 151 cam are almost identical(taken from a diagram in an old issue of "Corvette News") There are some differences in duration and overlap. 30-30 duration 446*13", overlap118*13"; L79 (151) duration342*, overlap114*.L79 cam(and 30-30 cam) i much different from the Duntov cam as I'm sure you know. Was just letting other poster know this difference.

William,

Appreciate your attempt at analysis, but you're directly comparing lobe lift versus cam angle of three very different cams: one hydraulic (151) and the other two solid. Further the 097 is a dual pattern lobe and the 30-30 is not. The lobe lift patterns of the 30-30 and the 151 may appear similar because the 30-30 lobe must rise about .021 before the valve begins to move; those first .021 are taking up valve lash. The valve lift v cam angle data for the 346 v the 151 takes lash into account and will show that the 151 has about .040" less valve lift than the 30-30 as well as about 25 degrees less duration at .006" valve lift.

[William F.]

Re: C1 "high lift cam"

Joe,
This is getting a little out of hand. My original post was to inform that the 30-30 and L79 cams are NOT alike. Any argument here? My "attempt", as you called it, of cam analysis comes from a GM diagram entitled "comparison of valve patterns" comparing Duntov, 30-30, L79, and 250-300 hp cams. Diagram shows lift pattern(the thing I was talking about) of L79 to be very close to 30-30. Durations and overlaps I gave also come from GM.This article from an old Corvette News was in part gathered from remarks by Zora Duntov,authors said. Look it up. All I'm gonna say.