The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by Roger Sundfors, Oct 11, 2018.
I wonder whats the difference between a noisy and a quiet gear drive? Except for the sound...
Angle cut gears and clearance.
Thanx for your answer
If you go with noisy, I bet after a while you'll wish you didn't!
I had a noisy on a V8 vega. Lasted a little over a month . VERY noisy
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'Proper' clearance runs quiet & long.
Any gear drive I've ever seen...ALL are straight cut teeth..!
Angular cut teeth will load the cam in one direction or the other, a very bad thing..! NO such thing.
The "quieter" sets are hand picked for a better mesh between the three gears.
A good chain drive is a MUCH better drive choice, especially for a street driven engine. No (VERY little) noise, no crank to cam harmonics (vibration).
If you want the "best" drive method...a belt is the way to go.
The quiet ones are in a box on the shelf. The noisy ones are installed in engines.
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The amount of time it takes for you to hate the sound is slightly longer with a "quiet "gear drive
When Roger asked his question, he did not specify it was a gear drive for the camshaft of a sbc.
I was referring to any set of drive gears.
The world does not revolve around the sbc.
I rarely think of them at all, being a Ford man and all. Lol
Gear drives suck!
Wait...not so fast! Millions of engines were built with gear driven camshafts..Chevy 6's probably being the most numerous in the US. And they have angle cut gears.....the cam gear has a thrust surface for that.
Now, I think most negative responses here are about gear drive conversions. That is a horse of another color. Years ago I was heavily into V6 Buick swaps into Jap pickups and the odd fire Buick V6 ate up cam chains faster than the average engine. I tried a gear drive conversion and found what everybody here is saying to be true..NOISY! It did sound like a blower drive though....but that soon lost it's appeal....and I returned to a chain drive...buying the best quality I could find (Cloyes ?) I think it was.
You DO NOT want the noisy one, take my word for it.
After I bought mine (dumb shit), I did a little research, by my memory, found the noisy ones just didn't have a finish cut on the teeth during the machining process, seems it was like .005.
Mine is a Pete Jackson by the way, not sure if anyone else offered the noisy version.
Had a Pete Jackson gear drive in my 56 Bel Air in the 80s , What can I say? It was the in thing back then. After about a month or so every time I came to a stop light I found myself reaching for the volume knob on the radio to turn it down. It wasn't on . Shortly after that it developed a hairline crack in the oil pan sump...Its the only time I've ever had that happen . Harmonics? My buddy uses a Milodon 3 gear setup with the cast aluminum front cover on his willys. Has worked like a champ for years , and you can't hear it over the whine of the 671. I have a brand new Pete Jackson for a BBC in the shed if anyones interested?
Way back when I was doing a lot of 440 business I built a fair number with gear drives, using early 361-413 premium engine parts. Angle cut, no noise, no problem.
Aftermarket gear drives are for making show trophies.
Milodon fixed idler gear drive in my roadster engine.
The only acceptable gear drive.
I used to put cards in the spokes on my Schwinn, kinda like a gear drive for young'uns.
If you need a gear drive the fixed gear milodon is the way to go. If the set up directions are followed it can hardly be heard. A blown engine that has some real power needs a gear drive. They run big cams and alot of spring pressure. A chain will stretch out in no time. Belts for this type of application stretch also. The Pete Jackson floating type have their power limitations. You get what you pay for.
Thanks guys for all your answers. I m going for the chain drive. Engine is a 1959 Chevy 283 with a v-belt driven 4-71 blower.
Thanks again for your tips.
Best Regards Roger... from the winter cold northern Sweden
Isky offered a two gear SBC drive years ago, it was not straight cut, but the helix angle was not very steep either. Even Chevrolet used two gear sets in reverse rotation SBC’s built for marine use and I believe some of the tall deck 366 and 427 truck engines had them too. A two gear drive requires a reverse ground cam.
Balloons worked great too, deeper, more mellow sound....shorter life span though.....
I put a Pete Jackson gear drive in a 64 Nova I had. I was 20, so when I fired it up I thought it sounded awesome. The next day I drove it to work at the Chevy dealer I worked at, about a 30 minute drive. That night, I took 4 Advil for the enormous head ache that the gear drive had caused, and then tore it all back down, and put the timing chain back in it.
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