The lobes on a cam are what the lifters ride on.To be as basic of a description as possible,cam lobes open and close the valves that are in the cylinder head.When you buy an aftermarket performance cam,the lift,duration,amongst other things change to help the engine make more torque and hp.The most important thing for a street driven car is low end torque.A cam with more lift and duration creates more torque and hp.A cam with a operating range of 1500-6000rpm is best for the street.Lets say your stock cam has .400 inch of lift and .200° of duration then you buy a cam that has .500 inch of lift and .212° of duration,this means the intake and exhaust valves are gonna be opened more and for a longer amount of time.This will allow more air to enter the combustion chamber and will let more exhaust gases out once the spark plug fires.For the most part,duration is what determines what kind of idle or lope the engine will have.LCA number of the cam needs to be between 108°-114° for good vacuum

You do realize that you can't just throw a cam in a fuel injected vehicle and have it run right, correct?

$250 might work for a cam, it certainly won't cover the tuning necessary to make the thing run like it did before you swapped the cam.

Edit: A cam alone MIGHT make a vehicle faster, but you've got a truck, and it's TBI. TBI heads are low RPM/torque-building heads. You are wasting money IMO talking about a cam swap without talking about a head swap as well, plus headers, plus the requisite tune. A cam that will make more power is going to be choked by the heads and exhaust manifolds, so while it may not be a complete waste of money, you'd be leaving a TON of performance on the table without the other proper mods. Heads are the big one in terms of money and complexity, but personally I'd start there (Vortecs or similar aftermarket with fast burn, 64CC chamber, and high velocity/low CFM ports) then pick a cam that would work better with those heads. Not going to be able to piece this together, ECM is going to throw codes and run the engine like crap with an aggressive cam and/or head swap.

Apparently "Joel" is a non-mechanic. You will burn holes on the tops of the pistons if you turbocharge a *naturally aspirated engine like yours. Factory installed turbocharger engines have LOWER compression ratios than yours is now plus they have inter-coolers to lower the temperature of the incoming air to the cylinders.

We need to know the year make and model of your car or truck BEFORE recommending a replacement camshaft which opens and closes the valves in the combustion chambers. ** Be careful of the camshaft lobe centers! If the specification is under 110 your power brakes will not work very well at low engine RPM! Replacement camshafts from GM have at least 114 lobe centers for more intake manifold vacuum at low engine RPM.!

More horsepower is all about getting more fuel into the engine and getting exhaust gas out. Many was to do that, one is a cam that keeps the valves open longer and raises them higher. If a cam has a lobe that holds the intake and exhaust valves open longer and raises them higher you get more gas in and exhaust out quicker. Unfortunately the engine runs rougher the more extreme you get with the cam. So to answer your question the cam opens and closes the valves.

you want more acceleration put a NOS kit on it. there is a lot you can do to add more power but you need to research it and think on what you want to do. you can spend a lot of $$$ if you want to make a big acceleration difference. NOS, Turbo, maybe 2 Turbos or super charger, tamper the oil galilees, buy racing component's for engine, chip it, sky is the limit

Let me see if I have this straight... You want to buy something that you know nothing about and wouldn't know what it is even if it was sitting on your breakfast table right now. Is that pretty much it, Skippy... You want it just because all your "friends" say it's cool... What are you... 12 years old?

GROW UP! Before you start throwing your money away,, at least learn something about what it is that makes your engine run.

It's not worth the cost.

make sure your engine is running fine with no problems at all before you upgrade. Just buy a turbo upgrade little by little

there are lobes on a cam and when the cam goes around and around it opens and closes the valves !

I'm wanting to buy a comp cam but I'd like to know more about them. I have a 350 v8 engine and I just want to have more a** when I'm accelerating. All suggestions are welcome. Budget is between 200-500