I am looking for a source for the following: I want to know exactly what all the grind numbers on a camshaft mean. Then I want to be able to have a place that tells me in great detail how those numbers affect filling of the cylinders. I also want to know the relationship of that with the heads.

I think Petersons had a "How to Build and Modify Small Block Chevrolet Cylinder heads and Camshafts" or something similar. Anyone have this book, and does it go into detail about the lesser known points? Thanks, -Matt-

 

I'm not sure you're going to find all that in one book.

On the different grind numbers, a good place to start there would be the various camhsaft manufacturer's literature. And if you understand or learn how to "degree" a camshaft, that will teach you alot. I think Comp Cams has an instructional paper or video on how to do this.

Cylinder filling is a little more difficult becuase there are many more factors. There's the obvious, which is the flow of the cylinder head/intake combination. The long TPI runners on the L98 engines create momentum from the velocity at certain RPMs which aids in cylinder filling, which is why these engines make so much mid-range torque but can't breath well at higher RPMs. But even things like connecting rod length can have an affect on cylinder filling. You might check out a couple of the books on engine building by some well know racers that tend to get very technical, like the ones by Bill Jenkins and Smokey Yunick. David Vizard is another good author, and in one of his books he talks about the difference between 30 degree vs 45 degree valve seats and how that has an affect on air flow at different valve lifts.

I think you'll just need to do alot of research and use several sources. And for me, degreeing a cam didn't really become clear until I had actually done it a couple of time.

Hope that helps. :)

 

Comp Cams web site and catalog have info on definitions, selection and setup of cams and valve train.

Dave Emanuel's book on SBC has info on cams, heads, etc as does John Lingenfelter's book.

 

The website for 'DesktopDyno' used to have a pdf file for their instruction manual (free download) that spoke very well to cylinder filling and emptying, rod length ratios, cylinder pressures, and the like.

drj

 

Speed Pro has a book on cams that is pretty good also. Check the Comp Cams and Crane cams catalogs. They cover this subject pretty well.

Its good to know from an academic stand point but you won't really be able to use it for anything in the real world. There's no undiscovered cam profiles out there. In the end, you pick the duration based on rpm range of the engine, lobe profile which includes lift based on lifter and intended usage, lobe placement based on intended usage and rpm range.

Buy a copy of desktop dyno and play around with various cam profile from cam mfrs catalogs and lobe charts. You'll get a pretty good idea of what duration, lift and lobe placement does.

 

Why don't you give COMP Cams a call. They will tell you what you need to know an suggest the correct cam for your application.

 

A good starting point is the soft-cover book "How to hot rod small block chevys". I had this book years ago; lost it, and found several for sale (used) at Amazon.com a few weeks ago. The one I bought is brand new; never opened (although advertised used).

Good section on cams, and everything else. A bit beyond my mindset; but if you're technical minded, it'll tell you what you need to know.

 

Thanks for all the responses guys. The main reason I am looking for a book or other source is because when I built up my engine a couple of years ago, I was flipping burgers, still in highschool, and didn't have a lot of cash. Everything was for my Chevelle which was carb'ed.

I needed to use that engine for the Corvette and it had less than 5000 miles on it. To make a long story short, I didn't do my homework back in the day. The heads are late 70's smog castings and the cam is a mild grind. Together, the setup chokes all over itself.

It runs and drives fine, but tuning it is becoming a real pain to tune. Before I spend money on a cam or at least swap the original '85 Vette heads back on, I need to do some studying about cylinder filling, manifold effects, runner design...pretty much the whole nine yards. It will make me feel better, whether or not it does any good! My combination of parts is not working very well. I am limited as to what I can change right now (limited meaning I either put the Vette heads back on, buy a $100 cam and lifters, or deal with it till summer). Hopefully i will be able to make a wise decesion.

Yes, the stock 85 heads are somewhat junk...but I am not trying to build a 12 seconds screamer (just yet). They do have a 3 angle, have been port matched, and I believe (check old receipts from the prev. owner) have been pocket ported.

Thanks again for the responses :yesnod:. -Matt-