From what I've read the cam is THE component that determines how much power one makes, and where in engine speed it is made. It seems however that it is one of the last choices made in many engine build-ups. Shouldn't that decision be made second, after general engine displacement?

Also, I am having difficulty understanding what components are required to run hydraulic lifters or rollers (see I can't even get the right term... not mechanical, not tappet the other one). Can someone help me out?

 

the cam isn't the main componet any more than another is, think of it as a matched package. the "best and biggest" cam isn't good for much with low flowing heads or with a factory TPI or TB sitting on top of them if you're after maximum preformance. if you're thinking about building an engine you need to first think about what you want it to do and decide on a budget.

as far as what you need to run hydrolic lifters or roller lifters, the lifters match the cam. buy a haydrolic flat cam and you can run hydrolics, buy a hydrolic roller and you can run lifters to match. that is if you have all the other pieces in place.

 

What are the other pieces?

What is a hydra-rev?

What is a stud girdle? What's so great about stud mounted rockers?

If you have a bare head, and it's going to run up to 7000rpm what pieces are neccesary? advised? high end?

Thanks,

 

Think of the camshaft in a motor as the conductor
of an orchestra.

It tells the airflow in and out of the engine when to start and stop and how long to play.

But.... the first thing to consider when planing a engine buildup , is the $budget$ then how much power you want to make/or can afford to make and then engine size, head choice, flow requirements etc ... then work the right cam choice in there some where after driveability/ mileage considerations etc.

A " hydra- Rev" is a rev kit for a hyd roller valve train.
It is an additional set of springs that help control the lifters motion ensuring the lifter follows the cam lobe at high(er) rpm.

if you want a hydraulic roller set up to have an extended
rpm range (+6000 rpm) a rev kit is a good thing to have.

www.airflowresearch.com

A stud girdle ties together all the tops fo the rocker studs to help eliminate/ reduce the rocker studs' defection as the rocker opens and closes the valve against the valve spring pressure.

racey stuff.

 

There was an experienced builder that I talked to one time who told me, "build an engine around the cam". Which is actually a good approach when you think about it. The pistons, the heads, the intake system, the headers need to be matched to the cam and what rpm range you want to operate in.

 

Picking a cam out of a catalog and then trying to piece together a motor to suite it is the wrong approach.

The "cam of the week" is usually the wrong one for you.

Forget everything you've heard here or there or what ever.

Mostly BS...

Get a good book on building good high performance
street motors.

David Vizard's "How to build Chevy small blocks on a budget" is a good place to start.

You can buy it on the internet or from many good
speed shops.

 

What F-Bird said is the best advice yet. Go and get yourself an armload of books. There's so much more to be said about the topic of engine building than could ever be posted online, it should be required reading. The material is out there.
If people read more books, then they wouldn't have to post ridiculous questions like "why can't I use a roller lifter on my flat tappet cam"

 

Thank *** I never asked that question. The challenge I have with the books is that they are very generalized and vague. I understand they are written to appeal to a large market, but somewhere along the way you have to indentify what's unrealistic, and work within those boundaries.

The other thing about the books is that they are scarce on how emissions play in this stuff. I read on a board somewhere that the higher the compression ratio the less chance of passing emissions tests, but know one has set the line. And what's even worse is most don't even care. They would rather do work arounds than actually plan the engine to be headache free in the first place.

I am figuring out what I want to accomplish. I am not sure I can get there from here.

 

I was in the same boat not too long ago.
The whole smog thing puts a new twist to it, and then there's unleaded gas, and EFI.
I built a motor out of some pieces that I already had, and it turned out good. But I wish I'd bought forged pistons instead of hypereutectic, cause if I want to use nitrous, I'll be limited to a small shot.
Take a look at what some of the engine builders are advertising for the street, also the factory zz4 is a good foundation for a street motor.
Still theres a lot of good reading to be found that can take away much of the confusion.
I've been studying car building books and magazine articles for decades, there's a lot of stuff there that's crap but there's some stuff worth knowing. Way too much to tell about in a few posts.
There's a world of difference between a basic rebuilt motor and a properly done street engine and a race engine.
If you're really interested in mechanics, you'll find the material interesting. If you just want to drive a fast car, that's cool too, that's why they have pros who build motors.
There are smog legal 12 sec cars out there, and it's really no secret how to get there, it's just that there's a lot of material to wade through before you find what you want.