Is a gear drive worth it?

82 GT · 06-16-2003, 06:44 PM

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?

87BOSS351C · 06-17-2003, 03:58 PM

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.

LX XLR8R · 06-17-2003, 07:19 PM

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

PKRWUD · 06-18-2003, 03:30 AM

Quote:

Originally posted by LX XLR8R
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.

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

Jeff Chambers · 06-18-2003, 06:35 AM

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.

FritzDaKat · 06-18-2003, 03:51 PM

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

82 GT · 06-18-2003, 09:06 PM

Quote:

Originally posted by FritzDaKat
It's off topic I know, but I just had to say, thats a great avatar you have there 82 GT.

Thanks!

PKRWUD · 06-19-2003, 10:53 PM

Quote:

Originally posted by jeff chambers
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.

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

Take care,
~Chris

Jeff Chambers · 06-20-2003, 06:21 AM

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

PKRWUD · 06-22-2003, 03:50 AM

Quote:

Originally posted by jeff chambers
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

06-16-2003, 06:44 PM	#1
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	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? __________________ '82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator.

06-17-2003, 03:58 PM	#2
87BOSS351C Registered Member Join Date: Sep 2002 Location: Midland, Michigan Posts: 92	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. __________________ Black '87 LX 5.0 5 spd T-top with 450hp '71 351 Cleveland 4V, C6 tranny, "and some other stuff" Rice Haters Club Member #124

06-17-2003, 07:19 PM	#3
LX XLR8R Dirk Diggler Join Date: Feb 1999 Location: SLOATSBURG, NY Posts: 1,931	i was told not to use one becasue it carries the harmonics from one part of the motor to another __________________ 95 undecided cubes, AFR 185s,undecided cam, undecided intake, and a 150 hit 89 "turbonotch" 2.3T You might want to hold on..i saw this on a cartoon once

06-18-2003, 06:35 AM	#5
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	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. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

06-20-2003, 06:21 AM	#9
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Doesn't do anything for valve timing, no. But it does give rock solid distributor timing compared to a cam driven distributor/rotor. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

06-18-2003, 03:51 PM	#6
FritzDaKat Registered Member Join Date: May 2003 Location: Franklin Park IL Posts: 57	It's off topic I know, but I just had to say, thats a great avatar you have there 82 GT.

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