Can someone be kind enough to explain how to chose/read a camshaft?

What does lift (.474 for example) for intake & exhaust valves, duration and grind mean??

What to look for, what not to look for?

TIA!

 

Easy, you take out the little card that comes with the cam and read from left to right, top to bottom. Don't forget to ask about lobe separation and the difference between advertised and actual duration.

 

Seriously now........

 

I would tell you, but then I'd have to kill you. PM the Tool, he'll fill you in.

 

Why kill me i thought we were buddies hehe

I wanted some info on cams, and possibly share it with everyone.....looks like i am starting something eh?

 

Hosrom okay I’ll bite, when it comes to cams, there are a zillion opinions and depending on the type of induction, the rules of selection and comparison vary widely. You also have to take into account for RPM range, compression, drivability, final drive ratio, ect. Just like turbo selections, experience will always beat charts, graphs, and theory. Most of my comments are listed as “in general” because there are a ton of other factors to take into consideration when selecting a cam but here are a few basics……

Camshaft Duration
Basically it’s the period of time, measured in degrees of crank rotation, that a valve is open. Duration is essentially what decides engine's basic RPM range will be. In general, lower duration = lower power band, higher the duration = a higher power band. The only good point of reference when comparing cams is to use the value @ .050 lift (also called actual) because "advertised" durations are not necessarily taken at a standardized point of valve lift so if you’re going to compare one cam to another you should do it at .050 lift.
Lobe Separation
Also known as overlap is the distance that the intake and exhaust lobe are spread apart (from a centerline). Lobe separation helps determine where peak torque will occur within the engine's power range. Wider separations help produce the torque across a wider portion of the power band and shows better power through the upper RPM. Tighter lobe separations cause the peak torque to build earlier within the power band and tend to produce it quickly and then peak.
Lift
Lift (the .477 you referenced) is the distance in inches the valve actually opens. The amount of lift you have and the speed at which the valve moves is a key factor in determining the amount of torque the engine will produce.

Personally, I haven't done any cam selections or experiments on Turbo cars but have done quite a bit on N/A, supercharged, and nitrous applications. I hope this helps.

 

It helped me. Thanks!

 

Thanks Himself, that did help, a lot.

One more thing (don't kill me just yet ), what is grind??

 

Grinding is essentially how the cam lobes are shaped, it's just not as simple as the term sounds. Some cam vendors refer to "Grind" as in stages such as a stage 1 or track grind. All that means is they have a particular duration, lobe separation, and lift and instead of giving the individual specs they list it as a particulate "Grind". Kind of like a stage 1 turbo.

 

I have stage V trim lift @050.

Hos - below is a section of my cam from Andial - this drawing clearly shows lobe separation, for clarification.

 

 

Wow, i should get me one of those!!!

 

does the andial cam come red with the smiley or did you put it on with caliper paint

Btw great info jeremy