What does a cam do? How does a cam work? What is it’s purpose? How do ITR/CTR cams improve performance? What is the difference between a stock cam and a high performance cam?
How much horsepower is added with performance cams?
Very generally speaking…
Q: What does a cam do?
A: Moves the valves up and down allowing oxygen and fuel to mix into the cylinder.
Q: How does a cam work?
A: There are lobes on the cam. Imagine a long stick with oval shaped bumps on it (called lobes) that sits in the very center of the block of your engine. There are things called lifters that sit on the “bumps” (lobes) of the cam, on the lifters you have push rods, the push rods are connected to the valves. So when the cam turns inside the engine the little bumps cause a chain reaction to lift the valves up and down allowing air and fuel into the cylinder to ignite. Thus combustion.
Q: What is it’s purpose?
A: Explained previously.
Q: How do ITR/CTR cams improve performance?
A: Larger lobes than the normal teg.
Q: What is the difference between a stock cam and a high performance cam?
A: Performance cams just have larger lobes. Larger lobes allow for the valves to be lifted higher allowing more fuel and air into the cylinder.
Q: How much horsepower is added with performance cams?
A: Depends on the cam, check out the Crower 404 cams.
-Shelby
Hope that helped a little. If you want to see the valves up close you can pull off your valve cover. 
don’t forget there is also an exhaust cam that lets the combusted gas out of the engine…
As I said, generally speaking. Let’s not confuse the poor boy just yet. 
Plus it’s all done on the same rotation anyway. Shh
Ok, with that said, what do cam gears do?
Originally posted by integrAZN
Ok, with that said, what do cam gears do?
cam gears allow you to tune your camshafts. w/ cam gears you can advance or retard the timing of your 2 cams up to +10/-10 degrees… this will let you adjust the timing the cams seperately to maximaze the hp gains, etc.
My understanding of cam gears is that it basically eleminates the timing belt.
You have the crank and the cam, the timing belt runs around them which keeps them all in perfect “time” with eachother. So imagine taking off the timing belt and putting a gear between the cam and the crank and there’s your camgears.
Not much experience with them so I can’t give a perfect explanation but I did my best.
Originally posted by 92GS-R
[B]
cam gears allow you to tune your camshafts. w/ cam gears you can advance or retard the timing of your 2 cams up to +10/-10 degrees… this will let you adjust the timing the cams seperately to maximaze the hp gains, etc. [/B]
And that is what they do.
Originally posted by Shinkhi
[B]Very generally speaking…
Q: How does a cam work?
A: There are lobes on the cam. Imagine a long stick with oval shaped bumps on it (called lobes) that sits in the very center of the block of your engine. There are things called lifters that sit on the “bumps” (lobes) of the cam, on the lifters you have push rods, the push rods are connected to the valves. So when the cam turns inside the engine the little bumps cause a chain reaction to lift the valves up and down allowing air and fuel into the cylinder to ignite. Thus combustion.
Q: What is the difference between a stock cam and a high performance cam?
A: Performance cams just have larger lobes. Larger lobes allow for the valves to be lifted higher allowing more fuel and air into the cylinder.
Q: How much horsepower is added with performance cams?
A: Depends on the cam, check out the Crower 404 cams.
-Shelby [/B]
I’d be careful with your explanations. Our cars don’t use pushrods. Thats more of a muscle car thing, I’m sure. Also, cams aren’t about larger lobes. The grind is what is important. In fact, I doubt any of JG’s cams have larger lobes than stock cams. If they are, why do they want your stock cams? To “regrind” them to their own specs. Also, haven’t you heard of “regrinds” wearing out faster because the grinding takes away the hard material of the cam lobes?
Originally posted by 9integra2
[B]
I’d be careful with your explanations. Our cars don’t use pushrods. Thats more of a muscle car thing, I’m sure. Also, cams aren’t about larger lobes. The grind is what is important. In fact, I doubt any of JG’s cams have larger lobes than stock cams. If they are, why do they want your stock cams? To “regrind” them to their own specs. Also, haven’t you heard of “regrinds” wearing out faster because the grinding takes away the hard material of the cam lobes? [/B]
No actually I havn’t. I’ve owned more muscle cars than I have imports. That comes out in my explanations. He asked what a cam does and I gave it to him, import or not. That’s what they do on one side of the spectrum at least. 
Originally posted by Shinkhi
There are things called lifters that sit on the “bumps” (lobes) of the cam, on the lifters you have push rods, the push rods are connected to the valves.
coughpushrods? lifters?
umm, My father’s’ 69 Roadrunner had pushrods and lifters, but my '92 Integra just has rocker arms:D
Basically, the camshafts are what control the opening and closing of the valves in your engine, which is actually a big, expensive air pump that also produces mechanical power. They are connected to the crankshaft via the timing belt/chain and turn 1/2times for every one turn of the crank, which synchronizes the cams with the engine’s four strokes. The critical part is when and how long they open the valves in an engine. The optimum set-up will vary depending on how well the engine breathes. Performance cams for our engines take advantage of various flow characteristics at either/both high and low rpms. The point is to get as much fuel and air into the combustion chamber(cylinder). Performance cams allow more air/fuel mix to flow by providing a higher valve lift, longer duration, and in some cases, longer valve overlap. This is what allows the air to flow better, therefore producing more power.
Camgears follow the same flow principles. What they do is move the cam lobes forward or backwards relative to the crank. This allows the air/fuel mix to enter sooner or later than if the cams were at 0 degrees. What this does is give adjustability. No two engines are exactly the same so the results and the optimum setup will vary depending on the engine's effinciency. This is why they should be tuned on a dyno so that they can be set at the opimum setting for the engine they are on.
The purpose of VTEC and variable timing in general is part of this same subject, so I will go ahead and explain that too since I am sure that it will come up. It also involves flow characteristics. It turns out that the optimum valve lift and duration varies with the engines revolutions per minute. At low RPM's, it is better to have the intake valves open when the pistons are closer to top dead center and close when the pistons are near bottom dead center. For exhaust, it is the opposite. In high RPM's this changes since the engine would suffer some pumping losses if the valves open and closed the same way that they do for low RPM's. In order to get more fuel/air mix into the cylinder, the valves must open sooner, and stay open longer. This is what the second cam lobe does on a VTEC engine. Basically what this means is that the term "my VTEC kicked in" is false. In actuality, VTEC is always on, just sometimes it is using the lower cam profile for low RPM's, and in others, it is using the more aggressive cam lobe for high RPM's. It is not a fuel saving measure(althogh it can be and is in some cars), but it is simply optimizing the cam profile for the most power at a certain RPM.
If you want to read more, this is another explaination of how cams work. http://www.howstuffworks.com/camshaft.htm , although there are some errors with their visual examples(can anyone else find them?). You should also look around this site. It has alot of information written in terms that most people can understand.
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