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what is a 3/4 race cam?

folkenheath said:
It's not really that out of the question, there is 720 degrees per cycle in a 4 stroke engine. In fact, here is an off the shelf drag racing cam with 360 degrees of duration on the exhaust...:thumb:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=539&sb=2



vacuum issues....most likely. :waytogo:
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There may be 720* of CRANKSHAFT rotation in a 4 stroke engine but the cam only moves 360*. Also on the link you supplied that 360* duration is at .005" lift which isn't where EVERY cam manufacturer measures duration (.050" is where it's measured). If an engine had 360* duration on the cam the engine would NEVER run since there would be no compression.
 
The term 3/4 cam USED to be a good indication of the idiots. Now that y'all let the cat out of the bag, how will we know?
 
4X4HIGH said:
There may be 720* of CRANKSHAFT rotation in a 4 stroke engine but the cam only moves 360*. Also on the link you supplied that 360* duration is at .005" lift which isn't where EVERY cam manufacturer measures duration (.050" is where it's measured). If an engine had 360* duration on the cam the engine would NEVER run since there would be no compression.
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Really? You MEAN the engine wouldn't RUN if the valves never CLOSED? Holy crap I NEVER realized that. :rolleyes:

Cam duration is measured in crankshaft degrees, not camshaft degrees. You can argue all you want, but the cam card says 360 degrees of advertised exhaust duration. Heck it might actually be 361 or 362 degrees when it actually get's to .000" lift.

You know Scott, you are more stubborn than I am, and I am pretty stubborn. :D
 
USSkoval said:
The new one is "noss" :waytogo:
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yeah isn't that one funny?

when you ask them what noss is, they just look at ya...its that gas in a bottle that makes you go faster:rolleyes:

ok, and thats all there is too it huh:waytogo:
 
mr250twostroke said:
Has anyone called the cam police? There's a jackwad on the loose... :rolleyes:
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Quoted from the great Elwood Blues: It's got a cop motor, a 440 cubic inch plant, it's got cop tires, cop suspension, cop shocks. It's a model made before catalytic converters so it'll run good on regular gas. What do you say, is it the new Bluesmobile or what?

:D:whistle::pimp::haha::haha:
 
Bowtie85 said:
Quoted from the great Elwood Blues: It's got a cop motor, a 440 cubic inch plant, it's got cop tires, cop suspension, cop shocks. It's a model made before catalytic converters so it'll run good on regular gas. What do you say, is it the new Bluesmobile or what?

:D:whistle::pimp::haha::haha:
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I'd trade a microphone for that! Sounds cool... :haha:

Even when it "threw a rod" it could still do 120.

-G
 
When we used to race on the street and strip a 3/4 race cam meant it was pretty much the most cam you could run on the street and still have the car manageable to drive. It was more cam than the mfg's. 1/2 race or 1st step up from stock but less than their full race cam that was meant only for the track. If Crane offered a 3/4 race cam for a Chev. 350 then that cam was their best high performance street cam for that engine. So they had plenty of 3/4 race cams, just for different C.I. and brands of engines. Same with Competition Cams and all the rest. Once the companies started making all kinds of cams with different durations and lifts for all kinds of reasons,(towing, RV's, boats, etc.) then the 1/2, 3/4, and full terms became kind of useless. In most cases, if the box says 3/4 on it, that means at the time that cam was made, it was pretty much the best designed highest performance street cam you could get from that mfg. Meant for street cars, most not for trucks. I got this info from my brother who raced for over 30years and who built many small and big block Chevys.
 
What I believe was the birth of the "race cams" is more of a sales pitch that started in the late 60s and early 70s.

We all want to think that full race was hotter then a 3/4 or a 1/2 or a 1/4 cam but in fact they were not.

When I work at Super Shops a long, long time ago we used those terms but it didn't mean crap to the cam specs. We sold whatever was in stock. Why? Because we were told to. Guy comes in and says he wants a 3/4 race cam, guess what buddy, we got it. Out the door he went with what ever cam was on the shelf that fit the application.

As all of you know, when you open a parts book you can't find a listing for a 3/4 race cam. hahahah
 
Massboy said:
When we used to race on the street and strip a 3/4 race cam meant it was pretty much the most cam you could run on the street and still have the car manageable to drive. It was more cam than the mfg's. 1/2 race or 1st step up from stock but less than their full race cam that was meant only for the track. If Crane offered a 3/4 race cam for a Chev. 350 then that cam was their best high performance street cam for that engine. So they had plenty of 3/4 race cams, just for different C.I. and brands of engines. Same with Competition Cams and all the rest. Once the companies started making all kinds of cams with different durations and lifts for all kinds of reasons,(towing, RV's, boats, etc.) then the 1/2, 3/4, and full terms became kind of useless. In most cases, if the box says 3/4 on it, that means at the time that cam was made, it was pretty much the best designed highest performance street cam you could get from that mfg. Meant for street cars, most not for trucks. I got this info from my brother who raced for over 30years and who built many small and big block Chevys.
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Well, you just got sold bud!!! Boxes never had 3/4 race on them. Never! :haha:
 
I have a 3/4 torque cam in my engine, but would really like a full torque cam:waytogo:
 
the guys that made me laugh when I was young building hotrods where the guys that where building basically an 800 hp motor one part at a time and wondering why it ran like sh*t!

ya gotta at least try to stay somewhat incremental in your mods so ya got some correspondence with the sh*t parts.... :haha:
 
cuervo said:
Well, you just got sold bud!!! Boxes never had 3/4 race on them. Never! :haha:
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Yes they did. When I was in college, some kid was building an engine, and he was using a Crane Cam. The box had a sticker on it that said 3/4 Race Cam. We all got a good laugh out of it.

Martin
 
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