Is a gear drive worth it?
 

Is there any real advandage with running a gear drive instead of timing chain. I know there's no chain to stretch but is there any performance gain?
I'm thinking about getting a Pete Jackson gear drive or should I spend the $220 somewhere else?

I have the Pete Jackson "Quiet" gear drive in my Cleveland. It is just loud enough to hear it at idle, but it isn't loud and obnoxious like the noisey ones. Gives that nice "race car sound". I don't know of any advatages over no chain stretch and many will clain you get crank harmonics tranferred to the valve train, but there were an awful lot of gear driven cams used in production engines in the past that lasted for many miles. Just my view/experiance.

i was told not to use one becasue it carries the harmonics from one part of the motor to another

Arguably the most dependable engine Ford ever built, the 300ci six, is gear drive. 300,000+ miles before replacing any internals is very common. Unless your engine is seriously out of balance, you won't experience any negative effects from using a gear drive.

Even the very best timing chains start to stretch the first time you fire the engine, and are visually stretched, meaning you don't need any tools other then your eyes to see it, after 10k miles. By 50k miles, your performance is noticably down, and by 100k miles, your valve timing will vary as much as 4 degrees each way while driving, and your ignition timing becomes very sloppy, costing you power, reliability, and high rpms.

Honestly, timing chains should be replaced every 75k miles, tops, but most people figure if it isn't broken, it must be okay. :rolleyes:

A quality gear drive will maintain the valvetrain geometry and the ignition timing much better, and will keep it within specs much longer than any chain. It will also allow you to reach higher rpms consistantly.

Of course, that's just my opinion.

:)

Take care,
~Chris

Gear drives suck up precious horsepower....their main drawback. On a SBF you can expect around 10hp loss with the gear drive; we've seen as much as 25hp loss between a gear drive and chain drive on a high RPM SBF. If you want real timing stability, go with a crank trigger. If you want to kill the harmonics on the valvetrain, look at the FRPP/Comp Cams belt drive. I wouldn't put a gear drive on my motor if you gave it to me for free.

It's off topic I know, but I just had to say, thats a great avatar you have there 82 GT. :D

Thanks!

A crank trigger doesn't much for your valve timing.

:)

Take care,
~Chris

Doesn't do anything for valve timing, no. But it does give rock solid distributor timing compared to a cam driven distributor/rotor.

I completely agree. I love the belt drive, too. I was just pointing out another of the shortcomings of using a chain.

:)

Take care,
~Chris