Where’s did the old saying 3/4 cam come from

-
Not quite a full race cam. Back then there wasn't many choices.
 
1983 High school auto shop class, kid with a 1970 Chevelle his daddy bought, claimed his 454 had a 3/4 race cam, thats where I first heard use of the term. Me? I had a Direct Connection 280/.474” Street Hemi grind in my 70 Charger. Obviously we couldn’t relate! Think it started in late 40’s, Ed Iskenderian is on a Youtube video talking briefly about the terms in the early days.
 
Yeah like 4 of them, from mild to wild, and you installed the third largest one.
For street, today, we still only have about 4 sizes , given that a size is 7 or 8 degrees, from 262 down the list to 284. If you include the 292 which IMO, in a SBM, is not really all that streetable, it comes to 5 sizes; and looks something like;
262, 268, 276, 284,
and 292
 
This subject has come up before and there was debate on the correct origin of that statement but the term 3/4 race was explained to me back in the day by a local speed shop owner as being a streetable semi-max effort camshaft. Very general statement that was thrown around in hot rod circles frequently. And at the time it was generally under 500 lift and around 300 advertised duration. Cam similar to the 350 horse small block Chevy cam crane fireball, Blazer and others. But I've also heard that it had to do with the grinding of the intake profile in relationship to the exhaust profile. And the next slang term was full race whatever that means LOL
 
Last edited:
i just figured it was the cam the guy who came in second was using...
 
Good stuff Joe, that's why I always scratch my head when everyone says cam technology has come such a long way granted there has been improvements mainly due to computer technology I believe and better spring material. But the fact of the matter is the research and development of camshafts in the 60s and 70s was so much more than it is today, racing and hot riding were so much bigger and so much more money was being made in so many different areas. What you have now are some minor improvements with major marketing I know this is fairly general statement but if you look at a lot of so-called new grinds they have an awful lot in common with the old ones. My two cents
 
Brooks James said:
I remember years ago you either had a “race “ cam or a 3/4 cam
Click to expand...
i thought it was a flathead thing, funny thing is a guy I met said it yesterday. No I didn't laugh but I chuckled inside
 
seen some old clay smith advertisements from the 40s or early 50s that listed out 3 cam sizes, 1/2 race, 3/4 race. and full race cams, all probably for the flat head ford! that was back in a simpler time and dont guess clay figured they would be the guzillion lobe profiles we have to day!
 
I started my real interest in high performance mopars in the mid-70s and my technical knowledge was let's say very little. I shared that with a lot of guys in their hot rods that were out on the streets. The track guys had to know more and were into it much deeper for the most part. My point is statements like 3/4 race full race followed by an advertised duration number was about all we were interested in, or for that part kind of understood. So as dorky as it sounds it served a purpose.
 
You must log in or register to reply here.
-

Back
Top