Chaparral2f Posted February 15, 2003 Share Posted February 15, 2003 Has anyone had any experience with timing gear drives? I've been through the search function and haven't come up with anything. Is there any major difference in performance or durability? Quote Link to comment Share on other sites More sharing options...
DavyZ Posted February 15, 2003 Share Posted February 15, 2003 You would have to go back manually through the archives since I'm not sure if the search function is working with the old posts in this new forum format. Grumpy says he has used gear drives for years with no ill effects on the valve train or the rest of the motor (remember that there is always a rumor floating that the 'excess vibration caused by the gear drive can have negative effects on the valvetrain') . I was encouraged to hear this and would like to use a gear drive in my NA motor at some point 8) . Keep in mind that if, by chance, you are going to efi and turbo on the V8, a gear drive is not compatable with a knock sensor---that is what I have gathered from my research. Davy Quote Link to comment Share on other sites More sharing options...
Mudge Posted February 15, 2003 Share Posted February 15, 2003 Yeah, the general "rumor" is that gear drives at high RPM (NA) cars is hard on the valvetrain. If your car has a knock sensor, then dont use one or get rid of the KS. Its been done on an LT1 using a "silent" Peet Jackson gearset, still makes noise of course, brought the knock sensor into play, and was removed after a few months. The timing cover also had to be clearanced for it. Quote Link to comment Share on other sites More sharing options...
Guest Casey240Z Posted February 16, 2003 Share Posted February 16, 2003 I have gear drive on my car couldn't tell you anything about performance or durability but it is so loud. I can't even hear what my exhaust sounds like until about 4000 rpms. So I would advise against it. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted February 16, 2003 Share Posted February 16, 2003 your very unlikely to have any problems WITH A PROPERLY INSTALLED AND CLEARANCED SILENT STYLE GEAR DRIVE, and they do last almost forever without getting slack or allowing your timeing to change. NOW THEY CAN CAUSE A KNOCK SENSOR IN AN efi ENGINE TO RETARD THE TIMEING , SO IF YOUR USEING efi WITH A KNOCK SENSOR A CHAIN DRIVE MIGHT BE THE BETTER CHOICE. (btw im useing a gear drive on my efi engine with no problems) SMOKEY YUNICK of STOCKCAR FAME USED GEAR DRIVES and found valve train stability was much better over 6000 rpm, in fact in his book "POWER SECRETS" he says "I SEE NO REASON TO EVER USE A CHAIN DRIVE TO DRIVE THE CAMSHAFT IN A RACING ENGINE!" THEN GOES ON TO SAY SOMETHING LIKE "watching a chain drive useing high speed photography its amazing that they every last five minutes" (PAGE 90) btw that old MYTH ABOUT GEAR DRIVES CAUSEING VALVE TRAIN HARMONICS IS JUST THAT..A MYTH, TRY AND FIND ANYONE WITH DYNO PRINTOUT PROOF< RUMORS, FRIENDS THAT SAY THEY HAVE SEEN PROOF, YES, FACTS ...WELL IN 33 YEARS OF LOOKING IVE NEVER SEEN ANY!!! (theres SEVERAL THOUSANDTHS CLEARANCE BETWEEN THE GEARS PLUS KEEP IN MIND THAT THERES 16 VALVE SPRINGS WITH AN AVERAGE OF ABOUT 200LBS OF FORCE each!! HOLDING THE CAM IN PLACE, THATS WELL OVER A TON OF FORCE, ON THE CAM, SOME ON THE UP AND SOME ON THE DOWN CAM LOBES THAT TEND TO PREVENT HARMONICS BUT theres nothing wrong with a good CLOYES TRUE ROLLER CHAIN DRIVE, PROVIDED YOU REALISE THAT YOULL NEED TO INSTALL A NEW CHAIN ABOUT EVERY 50,000 miles if you intend to keep the valve timeing exact. Quote Link to comment Share on other sites More sharing options...
Chaparral2f Posted February 16, 2003 Author Share Posted February 16, 2003 Once again I have come to the right place to learn the facts that I need. Thanks everyone for your input. Looks like that gear set is going in. As for the noise, back in the sixties, I ran a Halibrand quick change in a little ford coupe, and it really howled! Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted February 16, 2003 Share Posted February 16, 2003 Do not forget that Smokey specifically said to use a Two Gear drive and areverse-rotation camshaft. AIR, he said the three and four gear drives have design deficiencies (in his opinion). That said, I believe I will wait for our resident guru - Grumpyvette - expound on his setup and insights further.....I LOVE gaining knowledge from people recognized (rightfully) as authorities. Brad Quote Link to comment Share on other sites More sharing options...
Mudge Posted February 16, 2003 Share Posted February 16, 2003 Interesting. BTW Brad, I haven't seen two gear sets, have you seen them readily available? Likewise thanks for the input Grumpy I have to admit, I love gear drive, just for the sound... Am I a ricer yet? Quote Link to comment Share on other sites More sharing options...
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