3/4 race cam

Other than the back-and-forth between me and JG, you just don't hear that term as much as you used to.

Only from guys who were wrenching in the muscle car glory days. Goes with a "Full House" motor build.

Many engines have so many cam offerings now, it's a wonder they don't use more fractions like 25/32 or 13/16 race cam. Back in the ancient times, it was stock, 3/4, full-race, and that's it.

ultraclyde wrote: Only from guys who were wrenching in the muscle car glory days. Goes with a "Full House" motor build.

Nah, you need to use a full race cam for a full house build.

When I was a kid I'd page through the J.C. Whitney catalog. It seemed like every item in there was guaranteed to increase horsepower by 10 or 20 or 30hp, so I figured you could just buy them all and then you'd really have something.

That would be called a "Stage 2" or maybe "Stage 3" cam nowadays.

Do you have to balance and blueprint an engine if you put one of those in it?

I like that 25/32 cam idea. We might have to steal it. In fact, I think I just did.

Now does that mean it was intended to be run in an engine that was destined for a 3/4 mile roundy-round track or does it mean it has 270 degrees of duration?

The_Jed wrote: Now does that mean it was intended to be run in an engine that was destined for a 3/4 mile roundy-round track or does it mean it has 270 degrees of duration?

It means you could only come up with 3/4 of the price of the full race cam...

I hate that type of nomenclature. Just tell me the berkeleying stats.

In reply to ultraclyde:

Looks a bit over 75%, but there's usually a pretty generous tolerance for fractional dimensions.

That was 'the' hot rodder buzzword back in the day. E36 M3, I think everybody claimed to have one.

It doesnt mean anything from what Ive been told. It was essentially people saying it is 75% of the way to a full race cam.

Around here I hear it when someone is talking about cams and they have no idea about basic cam specs.

This is how it normally goes

"What's the duration (or LSA or Lift) specs on that cam?" "uhh......It's a 3/4s race cam."

Occasionally I get it when talking to a racer who isnt keen on giving up his setup.

"RV cam" seems to have a bit better staying power than 3/4 race.

Possibly had something to do with the fact the the original cam grinders had to re-grind OEM cams.

There was a lot of double talk back in the day. Iskendarian had their '5 cycle' cam

(What's better than a four cycle engine? A five cycle engine, of course.)

I put a 3/4 race cam in an RX7 in 1983. It would run in the nines on street tires. True story.

Nick (LUCAS) Comstock wrote: I put a 3/4 race cam in an RX7 in 1983. It would run in the nines on street tires. True story.

Competition crank, too?

David S. Wallens wrote:

Nick (LUCAS) Comstock wrote: I put a 3/4 race cam in an RX7 in 1983. It would run in the nines on street tires. True story.

Competition crank, too?

Ported and polished, blueprinted and balanced rotating assembly. You should have seen the work we put into the valve body of the five speed.

In reply to Nick (LUCAS) Comstock:

In your Camero, I bet.

In reply to The_Jed:

AFAIK RV cam is just the stock LT1 cam

When I used to sling parts, I used to hear this term getting tossed around a lot by all the Tall Tale Tellers (we called them "Triple T's"). And you haven't heard it correctly until you heard it come out of the mouth of a true MA-hole.

"Yahh dood, it's gotta three-quatahhh caam guy. That's what my mechanic said dood."

or...

"Doood, it's wicked fast. It runs pissah. The formah ownah tossed in a "Ahhhh Veeee" cam"

Nick (LUCAS) Comstock wrote:

David S. Wallens wrote:

Nick (LUCAS) Comstock wrote: I put a 3/4 race cam in an RX7 in 1983. It would run in the nines on street tires. True story.

Competition crank, too?

Ported and polished, blueprinted and balanced rotating assembly. You should have seen the work we put into the valve body of the five speed.

Hey now, my Volvo does have a sweet valve body in its 5 speed.

It's also a dual overhead crank engine. Has a full spool too.

Iirc it came from flathead ford era before consumers understood specs so stock, 1/4, 1/2,3/4 race and full race was just easier for them to sell them. Now we're more in tune so we want to hear exactly what the specs are but there's still the whole "stage whatever" thing everyone does these days which is equally dumb.

chiodos wrote: Iirc it came from flathead ford era before consumers understood specs so stock, 1/4, 1/2,3/4 race and full race was just easier for them to sell them. Now we're more in tune so we want to hear exactly what the specs are but there's still the whole "stage whatever" thing everyone does these days which is equally dumb.

I'll never forget shortly after I put the new cam in the 360 in my Jeep having some idiot VW kid ask me what "stage" cam it was... All I told him was that if parts come in stages, they're probably E36 M3ty parts.