Thread: Pro and con of gear drive timing?

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I have a 350 zz4 crate enginein my '33 Vicky. Since I can't leave anything alone I'm toying with the idea of installing a different cam to give it a "lumpier" idle, gain a bit on the power curve/hp and install roller rockers this coming winter. The engine does have Aluminum heads and I'll have them ported to the intake as well. I'll also add a set of exhaust dumps.
Since the engine will be out I've also thought about changing the timing chain out to gear drive. I love the sound of an engine Idling along hearing that "noisy" blower like sound.

Any pros or cons on using gear drive timing ? I'm thinking of using a Pro-Comp set--anyone have any recommendations or comments.

yup gear drives are junk they make harmonics they add more harmonics to the engine and in turn make neat things happen grear drive can shorten the life span of the parts like valve springs .i will not build a engine with one.when i build a engine like to take out harmonics and try to contour them not add to them. so i say no not a good ideal

With the high quality chains sets available there's no need to run anything else.
And if you're trying to emulate blower whine...those who know can tell the difference a block away........

Originally Posted by Yellow72

With the high quality chains sets available there's no need to run anything else.
And if you're trying to emulate blower whine...those who know can tell the difference a block away........

and that would be my dogs they know when i am on my way home

Like I said "blower Like sound". lol. Thanks for the input, guys. I'm still in the planning stages right now. I've talked to a few guys running them in their hi-hp muscle cars, Chevys, Mustangs, and Mopars, and a couple of guys running them in their street rods. Just gethering info right now.

If you are looking for the "lumpy" sound, (and it is, after all, a street car right?), why not try one of the Comp Cam's "Mutha Thumpr" Cams? I know they increase Exhaust duration to get the sound, but I've also heard they are using new technology on the Ramps so they also improve power too-don't know about the effects on vacuum, though-

As far as the "Blower whine", you can also get that sound with some of these:

http://www.blackmountainprecision.com/sb4.htm

35 Window, that Comp Cam was the one I was considering using, it also was recommended to me by a guy with a '32 hi-boy here also running a zz4 crate. I was asking about his engine and he said it was a basic crate zz4 and he just changed out the cam and installed roller rockers, ported the heads, he wanted the performance sound and a bit improved performance without sacrificing streetability or investing in a hi-po engine build.

Pros are that only Pros need a gear drive and 1 big con is that its not good on the street.

RE: blower whine, it really isn't all that important to me, I just liked the sound of the gear drives...but if they are not worth it I'll just forget it. Don't need to trash a near new engine.way before it's time...
And Black Mountain belt drives are way pricey... for what I'd need, a PS and A/C pulley also I'd have about $425 wrapped up in billet parts plus would probably have to have some new PS,A/C mounts made...for some reason bolt-ons never are ...LOL

Ive ran them in a couple street motors, same as you I wanted the noise they made. I never had any trouble running them, and ran one as a daily driver for 5 years on the same motor, with no problems. Ive had many friends also run them with no problems. but they give no benefit whatsoever on a semi hopped up motor other then sounding cool. So if your after the whinny noise they make then go for it.

1987 I had a 69 Camaro 327 gear drive, it also had a 350 with a shift kit, and a 411 gear that was nice too. I bought it from a guy that completely redid the car his future father in-law built the engine, and race his own car at US 30 in Merrillville In. I loved the sound and if I was to get something running in an older car I would want that sound again. I ran the car hard and never had any trouble. I sold it to a guy that ran it hard. Later the original guy got his car back, still going. I guess some hold up, and maybe some don’t.

Richard

oh they hold up they are gears but i do not see much use for them when valve springs can fail and cost up to 400+ a set i not going to put one in a mild street engine or race i build engines for sand drags mud asphalt 1/4 drags i have never seen a need for them.i guess i have no use for them i build alot of engines that get hammered very hard no grear drives to worry about one less thing that adds nothing thing but trouble .what you have to ask your self if you want to put money down on some thing that can break you valve springs and add significant amount of harmonics to your engine to say it will work yes it will turn your cam so yes it will do that and maybe more were are the guys that say there great if you suck a valve from a bad spring

I've made some good cash over the years changing gear drives back to chains. Like the man sez, they are junk.

I ran a 383sbc with 12.5:1 comperssion, solid lifter .595 lift cam, fully ported 461 feulie heads, and a gear drive in a 69 Firebird. The guy who built the engine was an old school speed shop owner who wanted to build an engine with vintage tech and a vintage feel. Sure it is outdated tech, but it ran 115mph in the 1/4 in a 3500lb car on regular street tires with ease. The gear drive made itself known for sure. For the times I took it to the track, I got a lot of strange looks because of that noise, probably out of confusion at to what was causing the blower like noise under the unmodified factory hood. Personally, I'm certain that it did absolutely nothing for increasing performance, just attitude. Frankly I was happy to send the complete motor/trans on to a friend to replace it with a bit milder(and quieter) 10:1 comp 406sbc with a double roller.
Reliability wise, Smokey Yunick swore by those gear drives for years in his race engines! They couldn't be all that bad...

George

Originally Posted by gschuld

I ran a 383sbc with 12.5:1 comperssion, solid lifter .595 lift cam, fully ported 461 feulie heads, and a gear drive in a 69 Firebird. The guy who built the engine was an old school speed shop owner who wanted to build an engine with vintage tech and a vintage feel. Sure it is outdated tech, but it ran 115mph in the 1/4 in a 3500lb car on regular street tires with ease. The gear drive made itself known for sure. For the times I took it to the track, I got a lot of strange looks because of that noise, probably out of confusion at to what was causing the blower like noise under the unmodified factory hood. Personally, I'm certain that it did absolutely nothing for increasing performance, just attitude. Frankly I was happy to send the complete motor/trans on to a friend to replace it with a bit milder(and quieter) 10:1 comp 406sbc with a double roller.
Reliability wise, Smokey Yunick swore by those gear drives for years in his race engines! They couldn't be all that bad...

George

well old smokey was wrong ?? nascar is not using them offshore engine builders not using them P M Perfomance will not use one now there is more than one type of gear drive are you sure dear old smokey was not runing a gear to gear with out the idler set up ? they will not make is much harmonics is a idler set up like pete jackson? gear to gear and one gear is alum or fiber top gear will cut down on harmonics but chain or belt drive is the best and i would bet old smokey look at his valve springs alot more then a guy that has a street car .but just think a street car will see many more miles then a race car thru a range of rpms straight cut gears are in no way great good fine or ok to hook the cam to the crank .i have seen engine blow up and every thing close to the grear drive was junk but i am sure it was just by luck??? was it bottom line you are adding harmonic and in turn adding to destructive vibration that can hurt valve train and other parts .but i am done with this .you know it like saying i smoke for 30 years and it did not kill me ..so go on and start somking it cool ? years ago maybe we did not know any better guys that try to build the best engines and know any thing would not use one.but i sure i am way off on this so all of you buy a gear drive and i will just keep building with out