I've heard old gear heads speak of this mystical camshaft and how it gave them tremendous gains in their ET's, but I have NEVER once seen one of these mystical Three Quarter cams.

Could someone clear this up for me?

 

This is a very old term, used to designate a cam halfway betweeen stock and a full race cam. It really has no technical value anymore, probably didnt then either.

 

This nomenclature is well before my time, but I always assumed it was referring to a cam having more or equal to 270* advertised intake duration, hence 3/4 cam revolution of open intake valve? If I'm right I'll have to change my underwear.

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-Jason M. 1991 Camaro Z28
"Allow me to introduce myself my name is Mud."

 

I've seen one in summit in an old issue, it was like 300 duration but only like .480 lift with a 106 lsa, basicaly just the old school technology cams.But if you hear a 50 year old talk about cars then any thing that had a lope no matter what size it realy is, is a 3/4 race cam to them.(you ever try to argue with your grandpa?!)

 

I am one of those old timers and I do vividly remember the term. Basically, it was a "bragging" term used by a person that knew nothing about cams (or at least their specs) but wanted to impress his buddies.

 

No offense about being 50 but that is usualy the scenerio: pot belly bald guy says" yea I used to have one of them there Z-28's mine was a 66'and ya know mine had a 3/4 race cam and a 4.11 posi"(under breathe) "whatever that is"
I've heard it too many times to even bother laughing anymore.

[This message has been edited by MIKES 88GTA (edited October 03, 2000).]

 

I had a guy with about 15 beers in him at the ******* bar tel me about his 5/8s cam.. He held 3 fingers out together to show high high the lobe was on the cam.. AHAHAHAHA

 

I'll add what I know, back when flathead Fords were the only talk of the town (before my time) only a few off the shelf cams were offered, everything else had to be custom ground.

You had your stock profiles, full race profiles, and "inbetween" profiles..ala the 3/4 cam for the flathead Ford...never heard the 3/4 cam referred to any other engine before.

Could just be a wives-tale too though....