i see so much about them in a lot of magazines but i have no clue what they do. Do they give the car a different gear ratio? What is it...thanx

 

Cam gears are the gears under your timing chain cover. One gear is on the Crank shaft, one on the water pump and two cam gears, one on each over head cam shaft. Thats how the bottom of your engine keeps in sync. with the top half. All the gears are connected by your timing chain which drives the top half of your engine.

No, they do not give the car different gear ratios. The gear ratio in a car is determined by the tranny gears, or in the case of RWD car, the differential gears in the rear axel.

 

I'm no mechanic, but your cam gears drive your camshafts and are driven by the craknshaft via your timing chain(or belt - depending on your vehicle).

On the Maxima, you have a separate camshaft for intake and exhaust on either side of the engine in each "head". So your Maxima has four camshafts. DOHC = Dual OverHead Cam(shafts).

The camshafts are responsible for opening and closing your intake and exhaust valves.

Just my $0.02

Mark

 

You're talking about aftermarket adjustable cam timing gears. They replace the stock cam gears that are bolted to the end of the camshaft. These cam gears are driven off the crankshaft and rotate the camshafts, which open and close the intake and exhaust valves. With adjustable gears, you can retard or advance the gear in relation to the camshaft, which allows you to set the valves to open sooner or later than stock. Set up properly, they can give add more torque/power to low or high rpms. However, the power you add to, say 5000 rpms will usually result in a removal of power from, say 2000 rpm.

Cam gears are usually only effective on a heavily modified vehicle with a very competant dyno tuning shop. The gains on a relatively stock vehicle are not at all worth the cost to buy, install, and test.

 

Maximas also have their own timing system, meaning you cannot advance or retard it, this is done via a knock sensor. So aftermarket adjustable cam gears will not work and aren't available.

 

LOL! Cam timing is not the same as ignition timing.

 

...a little knowledge is a dangerous thing...

 

HowStuffWorks.com is very useful for basic engine questions

 

Aftermarket cams with more lift and duration in conjunction with adjustable gears for each cam (so we could adjust the overlap) and stiffer valve springs would be the best set-up because we would be able to tune the power-band. We would also have to figure out a way to get rid of the rev limiter to take full advantage of this but uh...wait a minute, we are talking about a factory street car right? Ahhh, forget about it...