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Okay fellas, maybe yall can enlighten me on something. My dad and other 40+ guys I have met, talk about cars they had back in the 60's and 70's, that had 3/4 cams in them. I have asked them what they mean by "3/4 cam" but no one can explain it to me. Is this just a generic term for a hot cam, or was there really such a thing?:confused: :confused: :confused:
Where I grew up (70's, Houston) a 3/4 Cam was used to generically identify a more radical street cam. Back then it was taboo to let people know exactly what was under your hood (for reasons that still illude me today). So the cam specifics were of course held confidential.
Kitz
Somebody correct me if I'm wrong, but I believe the 3/4 race and full race cam terms came about in the days of the flathead... Back then rodders were not blessed with the multitude of camshaft and valve train components we have today. As far as what the specs were, no idea... I'm just a geezer, not a super geezer!!!!
As to why I wouldn't tell what was under the hood... It cost $$$$ to find out, usually a bit of bucks up action on the old two lane north of town....If ya won, you could look, if not it was still my secret!!!!!
here's my theory on the "3/4 race cam"....
A relatively hot street cam has somewhere in the ballpark of 270 degrees duration....maybe more, maybe less (depends who you ask)...anyways,
...the "3/4 race cam" has 3/4 of 360 degrees duration (adv) = 270 degrees
Just something I thought about...makes sense to me...but then again, I wasn't around when the mysterious grind hit the market. :)
Yeah I remember now. It was difficult if not impossible at times to negotiate the purse also. :LOL:Quote:
Originally Posted by Dave Severson
Terminology was a big thing back then, it helped if you didn't know what you were talking about, you could spew a few "facts", and if you sounded convincing, the rest in the group would nod and agree. Cam lore was a "black art". Very few really understood what it was all about. Kind of like today. Stock cams were just that, stock cams, everybody just knew, that there was something better than those. Full race cams were just to much for the street. So the idea of the 3/4 cam, or 3/4 race cam was born. The grind could be anything, as long as it was hotter than a stock cam. The reason no body can tell you what it was, nobody really knows. There wasn't a set of numbers to grind a cam to that made it a "3/4". The cam grind was somewhere between a stock cam and a full race. If you can get to find some of the older ads from cam manufactures, you will likely see where the cams offered were described as 3/4 race and full race. No specs. just the terminology. That was part of growing up back then, if you knew a bunch of the key words, and if you really did know how some of this stuff worked, you could be a big shot. That's how we all learned, I personally blew more money and time on combo's that didn't work, than did. But I was busy! To busy to get into trouble, except to see if the "improvments" really worked. You can read that as "SPEEDING FLAT OUT" or running the sort of "MEASURED" 1/4 mile that's just outside of every small town, or any town for that matter. You knew it was a real 1/4 mile if it was painted on the pavement!! Yeah, we were a little naive, but it was fun. Not something you can get away with today. So, the short answer to "was there such a thing as a 3/4 cam" yep! But you'll never nail down an exact grind.
i still have a new 3/4 cam that on the cam card says " 3/4 race cam " it is stuffed away in a box in the barn . i will go this weekend and see if i can find it and grab the cam card and post a photo of it . i bought it at a swap meet only because it had the card that was printed 3/4 race cam .
Strangely enough, that math seems to work (kind of). Cran's largest cam for a 454 Chevy is advertised at 360* (exhaust only).Quote:
Originally Posted by 65cayne
Having been there back in the day, though, 3/4 race meant nothing more than something quite a bit hotter than stock, but still driveable on the street.
I kinda figured it was a terminology thing. Still waiting for Denny,Don,and uncle Bob to put in their 2 cents.
That's how I remember it. Seems like I also remember hearing about a 1/2 race cam somewhere in my youth.Quote:
Originally Posted by Dave Severson
Tech is right..... in the last century, you had an Honest Charlie catalog or an Isky catalog, etc. For an engine, the number of cam grids was severely limited. Their catalog listing didnt give a lot of cam timing data, it simply said "race" or "3/4 race" or sometimes "short track" for the roundy guys. The buyers werent as scientific as today so you bought a cam. Slicks were similar, you didnt buy a compound, you simply bought slicks.
Somebody probably has an old catalog laying around....Honest Charlie catalog would be fun to see!
Think I have one stashed away somewhere yet... sure did buy a lot of go fast goodies from them in the 60's!!!! There just wasn't a lot of speed shops in Valley Springs, SD (pop. 500 at the time), and the internet didn't work!!!!!:LOL: :LOL: :LOL: :LOL:Quote:
Originally Posted by robot
A 3/4 cam had 12 lobes instead of 16?
i actually had a 41 ford with a 53 merc flathead bronze block, 3/4 race wolverine cam, wiend aluminum heads,triple dueces,mallory dual point with 4:11 rears .Nice right? wrong -stock tranny.this was in 66. i bought it that way. Great hole shots
Yup, now I get it!!!! A V-8 3/4 race cam is for a V-6. a 1/2 race came is for a 4 poppler!!! Thanks Jack, you always explain things so well they become clear as mud to me!!!!!!!:LOL: :LOL: :LOL: :LOL:Quote:
Originally Posted by Henry Rifle
Same here and then the small block Chevy's came along and and the hot ticket was a "Fuelie" cam.Quote:
Originally Posted by techinspector1
Or a Duntov cam, or a Dempsey Wilson, then you was fast.... Or at least all them chebbie guys thought they were fastQuote:
Originally Posted by NTFDAY
Also known as the Duntov grind. Gee, it's hell to get old.:LOL: :LOL: :LOL: As in, "Don't run him man, he's got a Duntov cam in there."Quote:
Originally Posted by NTFDAY
Had the '63 version in the coupe. :3dSMILE:Quote:
Originally Posted by Oldf100fordman
When I was young a very good friend of mine ran 63 version in his new 65 Chevelle 327 and added 2 4's. That thing would fly. That was back before that S E Asian thing broke up the old crew. I wonder where the heck Gary is anymore.Quote:
Originally Posted by NTFDAY
3836151, I think, was the # for the Duntov hydraulic lifter cam. 350 horse 327. Had one or two.
I think the "full race" cams came first, then guys wanted something a bit tamer for the street, so the grinders made 1/2 and 3/4 cams for them. Back then nobody knew (or cared!) what "degrees" meant, so they had to call 'em something.
Then you had the" Off road cams."......:LOL:
was 3/4 cam on or off the road :LOL: they made them so the answers is yes. now if some can tell me if UFO,s are real **)i had one of the 30/30 soild duntov cam s the .030 /.030 was lash .love them soild cams the vave train sounded like a very loose typewritterQuote:
Originally Posted by shawnlee28
Nothing ever sounded better. It was like saying "potato-potato-potato-potato" fast with the accompanying clicking. Music to my ears in my youth....the stuff of dreams.Quote:
Originally Posted by pat mccarthy
I always felt the 3/4 race term was just used to describe a cam more street suitable than a full race cam.....it was milder, less radical. As was mentioned a lot of what came out of our mouths was gibberish designed to impress our equally naive buddies. Back then no one ran a "Chevy" engine, it was always a "Corvette" engine. ("Yeah, I swapped a Corvette engine into my rod." :eek: :eek: ) That always impressed everybody, especially if you went down and spent the $ 17.99 to buy some Vette valve covers. Also, the girls dug it. :3dSMILE: I sincerely doubt that many actual Corvettes were stripped for their engines.
It's kinda like the old saying............."the older I get, the better lover I was." :cool: :cool:
Don
Hey, I resemble that remark.:HMMM: :eek: :eek: :LOL:Quote:
Originally Posted by Itoldyouso
I've still have an Isky 30/30 in the garage. :3dSMILE:Quote:
Originally Posted by pat mccarthy
It was in the 400 I had in a '62 pickup. The 400 is also in the garage torn down because of a busted valve spring. I was going to rebuild it and put it in the Mustang, but I've decided against that idea. Someday maybe I'll find an old truck or something to put the 400 in along with the Isky and 2 fours. BTW, the Isky was in the 265 that was in the '36 coupe when I bought it but the engine had spun a rod and we short blocked it out. I didn't know about the cam until I went home for my 20th high school reunion in '81 and my step father had it in his shed. I'm not going to try and rotate the earth, but I think it will make for a good cruising engine.