What is a "Cam Gear" and how does it work?

[V8 Killer]

I've seen these for Sport Compacts roaming through Summit and Jegs...What exactly are they?

[SirShaun]

From what ive heard i know they are mostly for dyno tuning. Ive also heard from ricers that it can either give them better top end or take off. My cousin has a cam gear on his tibby and i didnt really see a difference from riding in it. Other then that it killed his top end.

From what i can guess from what ive heard it adjusts the 2nd cam timing.

[ July 26, 2005, 02:47 AM: Message edited by: SirShaun ]

[Tru2Chevy]

For cars with overhead cams, you can get different cam gears to adjust the cam timing so that valves open or close sooner or later. Easier/cheaper than going with a custom cam, not as much power increase.

- Justin

[V8 Killer]

How would you adjust it on a stock motor?

[SirShaun]

Pop the cover off. Adjust from -5 to +5.

[V8 Killer]

-5 and +5 are what? I know their timing increments but what Can you do with those numbers?

[KBeezy]

degrees advanced or retard degrees.

[img]smile.gif[/img]

[camaro_speedemon]

Originally posted by Tru2Chevy:
For cars with overhead cams, you can get different cam gears to adjust the cam timing so that valves open or close sooner or later. Easier/cheaper than going with a custom cam, not as much power increase.

- Justin

You're halfway there.

It doesn't give you more power per say, it adjusts the powerband either higher or lower. The only way it will give you more power, is if the cams aren't tuned for maximum power.

For example, my car has VVT-i(Variable Valve Timing with Intelligence), which is basically a computer controled cam gear on the intake cam. The base setting retards the intake cams for better gas milage. If the computer senses I'm putting the engine under load, IE mash on the gas, it will advance the timing on the intake cam for maximum power. This is similar to VTEC or VVTL-i(Variable Valve Time with Lift and intelligence) for toyota. VTEC or VVTL-i actually switches to a different cam profile all together which changes the timing and the lift which opens the valves a lot more.

With an OHV cam, the timing is set in stone. After the cam is ground, you can't change when the intake and exhaust valves open or close.

On DOHC motors, there is a seperate cam for intake and exhaust. With cam gears, you can adjust those two different cams to change what time the intake and exhaust ports close.

BTW putting cam gears on stock cams is pretty much useless, you might squeeze a few horses, stock cams are pretty much tuned for the most power you can get. The only way you would benefit with cam gears is with aftermarket cams.