Thread: Pro and con of gear drive timing?

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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 Sure it is outdated tech, but it ran 115mph in the 1/4 in a 3500lb car on regular street tires with ease.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 Sure it is outdated tech, but it ran 115mph in the 1/4 in a 3500lb car on regular street tires with ease.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