Cam installation questions (When/Why to degree a cam)?????

[Psycho71]

I'm really just seeking info right now. I'm not in the process of building yet, but I am planning a motor build and want to understand this.

Background: Right now I'm planning a build; 383 w/forged bottom end, Hyd. Flat or Hyd. Roller cam, 10:1-10.5:1 comp., 200cc 2.02 heads. N2O of course. I'm not really wanting to twist the motor very high (6500rpm max) so I can drive it regularly. Planning on MSD 6al Plus ignition control as well.

Here's my problem: I want to keep my rpm around 2500 at 70mph in O/D with 3:73 gears. Or as close to it as possible. I want a moderate cam that will flow the N2O (up to 200hp) and pull like a monster to about 6500rpm. As the juice will only be used a fraction of the time, I also want as good of performance as I can get on the motor. Most of the cam info I read (summit & jegs) recommends a 2500-3000 stall coverters for the grinds (280+), I THINK, I need? My logic says this converter will be on the verge or slipping (not locked up) at desired hwy speeds, right? Some also advertise "power bands" starting and ending higher than I want.

My Questions?: Can a cam be degree'd to "move" it's effective power band up or down the RPM range? Does this also effect the min. stall speed required? If I'm thinking wrong, can someone please explain this to me? What is the purpose of degree'ing a cam? Benefits? Drawbacks? If I'm right, get ready for more questions. Either way, there will probably be a few more.

I'm not looking for a part#. Although suggestions will not be shunned. I am looking for the information I need to make an informed decision. Any literature suggestions? Thanks in advance for helping to wipe out ignorance.

Jay

[Billla]

Originally Posted by Psycho71

My Questions?: Can a cam be degree'd to "move" it's effective power band up or down the RPM range? Does this also effect the min. stall speed required? If I'm thinking wrong, can someone please explain this to me? What is the purpose of degree'ing a cam? Benefits? Drawbacks? If I'm right, get ready for more questions. Either way, there will probably be a few more.

Yes, a cam can be advanced/retarded to move the powerband. It's typically done via the timing sprockets and chain - either a simple advance via a different keyway in the crank sprocket or "infinitely" adjustable via adjustments (bolts or offset bushings) in the cam sprocket.

The purpose of "degreeing" a cam is to ensure the cam events are happening when you want them to. It's worth doing even if you're not changing the cam as a check on your assembly work.

[Psycho71]

Thanks for the info. I'm glad I am on the right track.

Now: How much can the "power band" be moved reasonably? I figure at some point, internal parts are going to start running into one another. Or a different cam altogether would be in order. What are the practical limits here?

Any other advice?

Thanks again,
Jay

[Billla]

I'll acknowledge my limited experience here - I have never advanced/retarded a cam beyond 3 degrees. Only one of those engines was dynoed, and the only comparison I had was a "similar" engine with the same cam installed at the factory advance...a suspect comparison.

The curves didn't just move, they changed shape. GENERALLY, advancing will improve low-end TQ at the expense of peak HP. If there's interest, I can take a shot with DD to see if we can get some (simulated) real-world numbers.

I've always been able to find a cam that fit the needs of the engine without having to resort to this. There are SO many choices in today's cam and relatively inexpensive custom grinds so that you can get what you want without having to change timing during installation.

slightly reduced peak power