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questions about gear drives

Discussion in 'The Garage' started by jp0863, Sep 26, 2006.

  1. jp0863

    jp0863 1/2 ton status Premium Member

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    while the motor is out and before it gets installed i will be upgrading mior things. water pump, fuel pump, etc. my ? is, what are the advantages of running a gear drive on the cam, and is it worth the purchse? looking at a pete jackson quiet model. i realize there will still be noise, which i dont mind. are there any negatives to a gear drive?
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    If you ask me, compared to a double row, roller timing chain, a gear drive isn't anything to spend extra money on, UNLESS you want the noise.

    There really is no upside to them IMO except in hardcore race applications, and even then in some race applications chains live.

    Stock timing chains wear out because they have nylon teeth. Aftermarket chains do away with that "wear point" even though the nylon toothed ones typically last 100,000+ miles.
     
  3. rcamacho

    rcamacho 1/2 ton status

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    I'm curious if anyone has ever run a durability study when running dual/triple valve springs. I run a hyd roller with dual springs and have wondered how long the chain would last...
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    Dual springs are about the norm nowadays aren't they? I'd bet from the lowly 4.3L all the way up to the 8.1L including the new Corvette motor, (roller and I'm sure at least dual springs) it's all still chain driven, dual valve springs or no.

    If it was a serious concern chains wouldn't have been a GM standard since when, at least the advent of the SBC?
     
  5. 1985_K5_Silverado

    1985_K5_Silverado 1/2 ton status

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    If you're not going to go with a straight-cut gear drive (probably because they do howl like a banshee), consider the biggest negative to the "quiet" (helical-cut) gear drives - the thrust control issue. I think that you might be happier with a good double-roller chain set - and this is from someone that runs a straight-cut gear drive.

    Part of the reason I have one is that I love the (straight-cut) gear noise, which is the same reason (in part) that I have a snarly exhaust. If you don't love the howl, then don't get a "quiet"(er) helical-cut gear drive, just get a double-roller chain.
     
    Last edited: Sep 26, 2006
  6. jp0863

    jp0863 1/2 ton status Premium Member

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    thanks for the info. i have yet to find an upside to running a gear drive. ill stick with the double roller
     
  7. broc944

    broc944 1/2 ton status

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    I am a big fan of timing gears. The upside is no chain stretch, hence your timing stays more accurate. They wear much better also. I personally love the sound of the "loud gears"

    They also are supposed to absorb some of the crankshaft harmonics and reduces drag on the engine.
     
  8. 1985_K5_Silverado

    1985_K5_Silverado 1/2 ton status

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    Oh, here's a gear drive disadvantage that I forgot to mention. It doesn't matter in my application, but with an EFI engine, the gear "clatter" can mess up what your knock sensor "hears", causing retarded timing under certain conditions.

    One upside that I forgot to mention: The dog knows that gear whine means you are coming home, even when you're still a block or two from the house. They really seem to hear it a long way off.
     
  9. mountainexplorer

    mountainexplorer 1/2 ton status

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    Just about every motor I have driven has had a loose/worn timing chain when I was done with it. Ok, so maybe I'm hard on motors. I like gear drives if I can get good deals on them. I run a few and have run them in the past.

    Recently, I just put a noisy Pete Jackson in my latest 454... and maybe I'm just used to them now, but it's not all that noisy to me. An Erson one I have, in my old 396 you could hear the truck coming from a mile away.

    Main advantage is that they don't wear out. Noise can be either an advantage or disadvantage depending on the person. Disadvantage is that they don't add any HP and actually take a slight bit of power away cause your turning timing gears rather than a chain. I just like them cause they don't wear out (usually or quickly) and I don't mind the noise either.
     
  10. GotLabs

    GotLabs 1/2 ton status GMOTM Winner

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    I have one in mine like it so far (ive only ran the motor twice since buildup) price was the decision for me.
     
  11. uberbeans

    uberbeans 1/2 ton status

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    I'm running one in my 383. I wouln't do the work if that was the only reason, but only if I was doing something else at the same time (I did mine when I swapped my heads). They are more durable, timing is ALWAYS spot on, won't wear out. You can't say that about a chain. The are noisy, but who cares you drive a Blazer, not a Cadillac. I love mine, but then again it isn't a daily driver.
     
  12. FOR MUD

    FOR MUD 1/2 ton status Premium Member GMOTM Winner

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    How loud are you guys talking about ? Can you still hear your Boggers ?
     
  13. Roland_Jenkins

    Roland_Jenkins Registered Member

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    I have a dynagear (sp?) gear drive in a 70 K20 Sounds like a bad power steering pump. :(

    Advantage of gear drive, they don't stretch and thereby change the timing. Disadvantages, $$$ and rob you of a little horsepower.
    Belt drives are the hot setup.
     
  14. mountainexplorer

    mountainexplorer 1/2 ton status

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    hey, aren't you the one that was asking about that TH400/205 I was selling a while back? Says your in Newport, Wa. I'm in Spokane.

    (sorry, didn't mean to hijack the post)
     
  15. gmc4cw

    gmc4cw 1/2 ton status GMOTM Winner

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    when I had my motor done I wanted one because I like the sound. the guy building my motor went over the same pro's and con's. power loss is negligible. timing stays true. there is work involved in running one, its not as simple as slappping the gears in and putting a cover on it. something has to hold them in place. cost more.

    I ended up going with a chain.

    to the guy who likens it to a bad steering pump, think of it as a supercharger.:D
     

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