Ok, this should be a pretty simple question...

I've been looking around at cams for when I build an engine for my Camaro (probably my L69) and almost all of the good brands (Comp, Crane, etc) all rate the rpm power ranges of the cams, something like "2000-6000 rpm".

Anyway, that is what My question is about. I don't have any one particular cam in mind yet, but since I have a 5 speed, the only time my car is below 2000 rpm is when it is at idle, so a cam with a powerband of oh, say 1500-6500 (just picking numbers here) should be good, right, since I will always be in the powerband as i am always between 2000 and 5500 rpm? I dont plan to rev past 5500 or so rpm BTW. 6000 would be the extreme limit for me.

Any and all input welcome. I think I understand this right, but I want to make sure.

 

Its a vague guideline that can be affected by compression, RPM, drivetrain, etc.

Probably be best to post what other stuff you are planning on using, and tell us what cam you plan on. Also, both Comp and Crane have semi-ok tech advice, neither of them will sell you too much cam, thats for sure.

 

I don't know how i'm going to build it or what cam. I just want to make sure I understand this first.

 

High rpm ull need anything light, and parts that reduce friction.

A light rotating assembly, aluminium heads with big intake valves, a good cam, roller rockers, and a single plane manifold.

Thats my guess.. tho I know theres more

 

A camshaft simple? Now I've heard it all lol j/k. Actually most cam companies(especially comp) have good tech lines that will help you through it all. Not only do you have to look at the power band of the cam but also important is the recomended compression ratio. If you run a cam ment for 11:1 and have 9:1 your going to loose a good bit of cylinder pressure because of the longer duration. Like I said though before you buy the cam give the companie's tech line a call and they'll help you out.

 

Yea, I realize that. The ones I have had me eye on typically have a powerband around 2000-5500 rpm and are for CR's around 9-10:1, which is just right, since I plan to use the stock L69's 9.5:1 CR.

Basically, what I want to know is, will a cam with an advertised power band of about 2000-5500 rpm or so be a streetable cam? I've also seen the specs of the cams, and the duration and lift numbers seem streetable, but its the powerband numbers that are confusing me.

Will a cam with a power band of about 2000-5500 be able to idle below 1000 rpm? Or will a cam like this be a chore to drive on the street?

 

Thats why I called them vague guidelines. Is it a 305 you are building up? If so, stay below about 218 or so on the intake duration, and it'll idle just fine. It would take something like 240+ intake duration to force the idle RPM up that far.

 

Ive called comp 3 different times , 3 different techs giving me 3 totally different cams for the same combo. I just choose my own.

If your using stock heads you probably want a split pattern cam giving more dur. at the exhaust. If you care about idle smoothness and good vacuum go with a lobe seperation 110-114
if powerful brakes are not a huge concern or a lopey idle go with a 110-106 .
Dur. will depend on cubic inches and rpm and heads.
Stock heads on a 350, anything more than 225 dur would be a waste of good power.
Hope that helps.

 

I don't really need the idle to be silky smooth, actually I want it to "rock and roll" a little, but I just want to know if something like 2000+ is too much for a street engine.

Yes, it is a 305, but I want it to have a nice top end, like the L69 did, but just with some more "oomph" than it had. I'm hoping for about 250-300hp and about 275+ ft-lbs of torque. Nothing outrageously high, but something I can have some fun with.

 

Not at all..

 

Thought I would add that getting a program like Desktop Dyno for your computer will help selecting a cam. No it's not 100% accurate but it'll show the power curve of a cam and it's fun to screw around with.

 

I do have a program like that.. Engine Analyzer 3.0

Its doesn't really list many cams though, so I have to enter cam specs myself anyway.