The Best Damn "3/4 Race Camshaft"

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69 Cuda 440

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3/4 Race Cam

Generic Term = High-Performance Street Camshaft

* Somewhere between '1/2 Race' and 'Full Race'
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Back-in-the-Day

* Stock 273/235 HP Camshaft > .415"/.425" Lift ~ 248*/248* Duration ~ 20* Overlap

Usually recommended for the 'Small Block Mopar' {1964 thru 1968} 'V-8 273'

It was the Chrysler Marine Camshaft design > .430"/.450" Lift ~ 260*/268* Duration ~ 36* Overlap
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After-market,

'Engle Cams' had developed a popular 'Solid Lifter' design that was pushed by the Speed Shops.

* .441"/.447" Lift ~ 260*/ 268* Duration ~ 32* Overlap
 
Often a term I heard that had the owner knowing nothing about the cam.
 
i read early circle racks were 3/4 mile.
3/4 cam had specs for this style of racing but i have heard other
theories on this too...who knows?
 
I managed a speed shop in the mid 70's and the 3/4 race cams were gone by then. We were getting serious about numbers although most of the street cams were what we would now call "old school" and made their power with duration and not lift. Many guys would put in cam and lifters and use the stock springs. Except for serious racers, not too many guys knew how to make a .550 lift solid roller work and no-one ran something like that on the street. Crane and TRW had 300 duration/.500 lift cams that were real radical. Comp Cams wasn't even a company yet back then. Crane Fireball cams were $49.95.
 
Last edited:
Most of the knuckleheads where I grew up thought it meant .750" lift......
 
'Engle Cams' had developed a popular 'Solid Lifter' design that was pushed by the Speed Shops.

* .441"/.447" Lift ~ 260*/ 268* Duration ~ 32* Overlap [/QUOTE]

Not too much different than the Isky E-4 that many of us run in our 273's with 260°/.425.
 
T-M-R,

Back-in-the-Day,

For a 273 Mopar, a '3/4 Race Cam' was in the neighborhood of .450 Lift and 260* Duration.

Most of the Catalog Companies that advertised in the Car Magazines {ie; Super Stock and Drag Illustrated}
would never list the 'Specs' of the advertised '3/4 Race Cam'.

Some would just print that the Camshaft was {+25 Horsepower over Stock}.

J.C. Whitney was classic for that stuff.
 
..having thought about this i remember now it was the guys on a Barrett Jackson auction that made the comment on 3/4 cam and 3/4 mile circle track racing.
..now what about those 7/8 cams?
 
Going back to the early-1950's

The Cam Grinders usually listed their Camshafts as;
* Stock
* 1/2 Race or 'Semi-Grind'
* Full Race

As there was a demand for more Street Rod Performance, Ed Winfield the
Father of Hot Rodding helped design the '3/4 Cam'.

Basically, by using the Intake Lobe from the 'Full Race Camshaft' with the
Exhaust Lobe from the '1/2 Race of Semi-Grind' unit.

Hence a 'high-lift' Intake with a slightly 'above-stock lift' Exhaust.
 
69 cuda 440 said:
t-m-r,

back-in-the-day,

for a 273 mopar, a '3/4 race cam' was in the neighborhood of .450 lift and 260* duration.

most of the catalog companies that advertised in the car magazines {ie; super stock and drag illustrated}
would never list the 'specs' of the advertised '3/4 race cam'.

some would just print that the camshaft was {+25 horsepower over stock}.

j.c. Whitney was classic for that stuff.
Click to expand...

tmm
 
Kanuder valves and magnetic seat covers come to mind...throw in a couple muffler bearings,stainless steel ones of course...lol
 
Does anybody have Crane Fireball specs from back when?
 
I grew up in the 60's and 70's, and yep, back then they were 3/4 or full race cams. Started changing in the early 70's. And yeah, I'm old too!!
 
Order of Price {Back in the Day}

Sealed Power
TRW
Engle Cams
Camcraft
General Kinetics
Norris
Competition Cams
Chet Herbert
Cam Dynamics
Lunati
Crane
Crower
Racer Brown
Sig Erson
Iskendarian
 
With out looking at the links provided....I understood a race full race cam to be 40-80 or bigger, 3/4 race was 35-75, 1/2 race was 30-70 and a mild was 26-65.
The factory cam in an aussie E49 spec Charger with 265 Hemi was 40-88....with 88* overlap......and yes, they had a vacuum tank for the brakes.
 
Crane 'Fireball'

* 272-H ........ .450" ~ 272*/272*

* 286-H ........ .450" ~ 286*/286*

* 296-H........ .449" ~ 296*/296*

* 314-M....... .443" ~ 314*/314*
 
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