Jump to content
HybridZ

whats a 3/4 cam??


hondabait

Recommended Posts

I bought my z recently and there is a little red plaque on the valve cover saying "3/4 cam" and under it saying "set valve lash to ....." I forget the rest. Is this stock for a early 260 z??? And does anyone have a pick of a stock ex mani of the same model, mine doesn't look stock unless 3 to 2 to 1 long style was stock.

Link to comment
Share on other sites

Does that thing sound like a true race car?

Correct me if I'm wrong anyone, but 3/4 cam refers to the lift of a cam being approx. .750" hence the 3/4 cam... I don't even think the valves would be able to support such.. You could have the biggest valves you could in there and they still wouldn't flow any more than a certain point......

 

But I might be way off....

Though's types of terms are more of old school terms.. Never really cared to learn them they are getting more outdated.....

 

 

But If I'm correct that thing should wind out nice... High rpm short power band sort of thing....

 

 

someone please stop me so I can stop rambling

Link to comment
Share on other sites

The plaque isn't stock, and there's no way to tell for certain about the cam unless you pull the valve cover and check it out.

 

The term "3/4 cam" originated in the fifties when cam science was in it's infancy. Back then, you had a stock cam, and a race cam. The term "3/4 cam" came along to indicate a hotrodder style cam that wasn't stock, but also wasn't as radical as a "full race" cam. Today we have a zillon cams to choose from in incremental steps, so "3/4" and "full race" are pretty much nostalgic terms.

 

It sounds like your car has an aftermarket header on it, not a stock exhaust manifold.

 

John

Link to comment
Share on other sites

not stock cam, not stock headers, not stock 5-speed, 2 piece rims, never used spare, great carpet and head liner, crazy louvered hood, whale tail, oil cooler, and 10 quart aluminum oil pan, thick yellow sway bars(I wonder if there stock), Malory box type coil. But an e88 head. Pretty good for a grand ehh??? It runs dead silent too, no ticking of the cam like Iv'e heard they do.

Link to comment
Share on other sites

Just remember the old adage: "Quiet valves burn".

 

You might just double check the lash. Sounds like a score for $1000! :cheers:

 

6-2-1 exhaust was stock, the collector was around where the floor meets the firewall. The stock manifold is long-ish, but then the 2 pipes are probably 3 feet long. It's a pretty good setup, which is why stock engines don't really make more hp with a header (especially a cheap crappy one).

 

Nothing wrong with an E88 head either, well the early ones anyway. Early 260 should have the last version, but judging by the rest of the parts, that may have been swapped out...

Link to comment
Share on other sites

the head says e88, I checked. If anyone has a crappy one and a few bucks I would trade them if they wanted a great start on a "resto mod". I just want a track "fun" car with good paint and no interior so I'd feel like an ass for doing it to this one. The way it sits now screams Burt Renolds. Gold rims and trim with metalic rootbeer brown paint.... you copy snow man.

Link to comment
Share on other sites

in that case, hawk the thing and try to make your money out of it!!

 

if YOU want a track toy, to have fun with and not worry about "messing anything up," then REST ASSURED someone out there is trying to make a nice driver and is interested in your proposed swap. In any case, simply posting that fact buried deep in this thread is NOT enough exposure, heh...

Link to comment
Share on other sites

And all this time I was led to believe the term '3/4 Race Cam' came from the duration being roughly 270 degrees...

 

In Auto Tech class, the instructor was wont to say things like 'It doesn't mean sh*t, it's a term bred of ignorance!" but I'm not so critical as he. I also don't throw nuts and small bolts at people for asking stupid questions before 'thinking it out on your own'!(Like he was also wont to do!)

 

Hehe heheh hehe! "Ahhh, the old days of technical education, what would today's kids do?" LOL

Link to comment
Share on other sites

  • 2 weeks later...
That sounds like a terribly inefficient way to describe the dimensions of any cam. I'd expect it's meant that it is 3/4 of the way to the full race cam. In other words, a street/track type of cam.

This depends on the phraseoogy. "3/4-Race" as one would take it means 75% of a full-race setup?

 

Doubtful. Ever hear of a 1/2 Race Cam? 1/4 Race? 15/16th's?

 

The most logical derivation is that once the duration exceeded 270 degrees, which is 3/4ths of the circle, you broke into the 'Race' designation. "3/4 Race" and "Full Race" are about the only two terms I ever heard, "Full Race" being something with a duration beyond 300 degrees.

 

For big V8's that 270 degree duration is pretty radical, and 'in the beginning' V-8's dominated terminology. For a VW, 308 and 310 degree cams may or may not be a 'big cam' depending on displacement.

 

Bigger you are, the less you are accustomed to seeing!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...