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While we're on the subject of car-related expressions, can someone tell me exactly what the subject description means ? It was seen frequently in engine and car ads of the '60s and '70s. I can figure out "full-race" as being not suitable for the street, but would 3/4 mean "street and strip" ?
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Re: 3/4 Race Cam
Mornin' Wayne,
I'll give you my "read" on this subject. I think it goes back to the early days of grinding high performance cams. Most buyers of a hp cam in the 40's and 50's had no idea how to compare the numbers on a camshaft timing card. It was all Greek to them. (me included) I believe the cam grinders, in an attempt to simply things for their customers, began to describe their products in as simple a term as possible. ie, 3/4 race or full race. This lasted until the "cam wars" were started by ISKY. Ed Iskienderan (sp) discovered advertizing and five cycle cams.
All this is well and good though, because the cam grinders have educated us to the point where we at least have some idea of the results from changing the cam profile. It will be interesting to see what others have to say on this subject. Bill -
Re: 3/4 Race Cam
I agree with Bill. The term "three-quarter cam" was generally applied to the wildest cam you could run on the street that still had a modicum of driveability. In this context the Duntov cam was considered a "three quarter grind". With the zillions of different grinds available, today, the term has lost its meaning and I don't hear it used much anymore. I interviewed Ed Iskenderian a few years ago (article for another car club magazine). He gave me some great insight into the design of high performance cams from the old days, before computer generated profiles. We talked about the Duntov cam and the cams ground by the legendary Ed Winfield, but he wouldn't tell me everything. Ol' Ed is a little cagey and a real character.
DukeComment
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Re: 3/4 Race Cam
Hi Wayne:
If my memory serves me correctly, ( and it usually doesn't any longer ), 3/4 meant 3.4 strip leaning more to a race oriented grind, 50/50 was a good all around profile, given that did Duntov attempt to indicate to us that a 30/30 meant 1/3 street, 1//3 strip and the remaining 1/3 in the garage trying to keep it running ? Possibly in the backseat not worrying about it, have to ask Terry here.
jerryComment
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Re: 3/4 Race Cam
Jerry, Bill & Duke --- Thanks for the insight and the stories. At first I thought the 3/4 (of full race) referred to 75% of the LIFT of a radical cam (say 0.520" for a small block), but even the mildest 250 hp cam (say 0.39") is 75% of the full race lift, so that theory is out, and I never heard the expression ½ race cam.
Jerry, your description of the 30-30 and Duntov cams made me think of the movie line "no...no...anything but the lash".Comment
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Re: 3/4 Race Cam
Our take on this subject, was that the car ran like a bat out of he-- for 3/4 of the track, then reverted back to stock for the finish so it could pass emissions on Monday morning.LOL.Comment
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