Head Change on new Ford 345HP crate engine

D.Hearne said:

That's ne thing I never have been able to find out, just where that term came from and what cam qualified as a 3/4 race cam? Did the 3/4 refer to the total lift? Or the duration? 3/4 the way of 360 degrees is 270 degrees. Pretty mild now. even back in the day it was as well. The cam I had in the 427 was a Holman-Moody grind with a 310 degree duration.

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i think it came from someone bragging about having a "full race" cam at some point and some guy probably said "yeah right, full race my butt. it's probably not even 3/4 of what a real race cam is" at least that's my theory anyway.

D.Hearne said:

That's ne thing I never have been able to find out, just where that term came from and what cam qualified as a 3/4 race cam? Did the 3/4 refer to the total lift? Or the duration? 3/4 the way of 360 degrees is 270 degrees. Pretty mild now. even back in the day it was as well. The cam I had in the 427 was a Holman-Moody grind with a 310 degree duration.

Click to expand...

I sell to many aftermarket vendors, and JC Whitney is one of them. In their lobby in Chicago, they have some of their original catalogs, dating back to the 50s. In the 50s, you could order one of two grinds: Full Race or 3/4 race.

I think the 3/4 was just a vague fraction of how radical the street cam was vs. the race cam. Nobody listed lift and duration in those days, much less overlap.

3/4 race was basically the hot street cam vs. an all out idles-like-crap cam.

no worse than todays "stage 1" or "stage 2" cams. Just pointless lingo.