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Gear Drive vs Timing Chain

Garys1969RR

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My 496 has a timing gear drive on it, building that into a 512 now, and considering going to a dbl roller timing chain. The gear drive is pretty noisy. It has a high lift roller cam in it. Any advantage to the gear drive? Looks like setting cam timing is pretty tricky with the gear drive, although it has quite a few adjustments for advance or retard. It is a Milodon 13000. Trying to decide which way to go with this. Any advice is helpful. Thanks!
 
The gear drive is pretty noisy.
Guess you could always wear ear plugs!:drinks:

Double row roller chain. Hate to admit it, but years ago helped a friend with his Toyota...didn't get caught! He had over 250, 000 miles on the thing. Thought timing chain had slipped. Got into it, thinking probably a rubber band in there. Dang thing had a double roller chain in it! Still tight as a banjo string...no slip there.
Wound up being a wore out clutch. Yeah, fixed it, after swearing never to touch another.
 
Guess my way of looking at it is the double roller timing chain is pretty much the go to for everyone and you hear of little issues whereas you hear mixed reviews on the gears. I always use a double roller but brand is important, tore one out of a stroker BB Mopar that had several missing teeth.. no brand stamping. Always used Cloyes or Comp Cams.
 
I believe gear drive is a bit more accurate and durable. Will you notice the difference? Probably not. Will you wear out a chain? Highly unlikely. Most go with the chain because of cost, ease of install, and noise. I’ve used both and will use both in the future depending the intended use of the engine.
If you don’t like the noise, go with the chain.
 
I believe gear drive is a bit more accurate and durable

Unless you are a hardcore racer, the answer is use the best quality timing chain setup. I would think any engine builder would tell you the same thing. A timing chain can absorb some harmonics, yet still remain tight. A gear set-up has no means to absorb, so it must pass any level of harmonics on through the motor. This is why Jesel belts became popular, because they are the best of both worlds, but at a high price. So for the street guy and bracket racer, stick with the high quality chain since proven performance and longevity cant be denied. HTH, Lefty71
 
The gear drive has some advantages like no chain stretch, and that Milodon has the aluminum cover which would be stiffer than the stamped steel cover where it comes to the cam thrust button. I'm not sure how the cam thrust is set on that timing set. From the picture of the Milodon cam gear, it looks like it has a thrust button machined as part of the cam gear hub? The down side would be the noise, and having to drill the block for the new dowl pins after setting the gear to gear clearance.
I have used four of the 440 source 114-1001 9-Way adjustable timing sets, and they are pretty nice if you go with a double roller timing chain.
Let me know if you want help installing and degreeing either setup.
 
Gary, Find a machine shop that buys from EPWi. Their main HQ is in Denver, but only sells to shops, not the general public. An EPWi brand "Quiet" gear set is PN#08-5425Q for a 3 bolt cam.
 
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For a street car - I've always used double roller timing sets --- The gear drive just seems excessive for the street and noisy (as you already know) but offer precise timing with no stretch of flex ---

Again - on a street car you're not going to see a performance difference between the two - just noise.
 
Are there any helical cut gear drives? Should be less noisy than a straight cut gear.

Most OEM gear drives are helical but aftermarket seems to be straight cut only..
 
I used the Milodon and you could barely hear it.
 
“At higher rpms, the gear drive creates too much friction, and there is a risk of transmitting crankshaft harmonics to the valvetrain.”
 
Are there any helical cut gear drives? Should be less noisy than a straight cut gear.

Most OEM gear drives are helical but aftermarket seems to be straight cut only..
Marine engines came with a two gear (no idler) helical cut setup, but then, you'd need a reversed cam and distributor drive,also. Just a FYI. 440 source used to list them as used parts from time to time, with a short article about them. Interesting setup, imo.
 
Yes, 451. I may need some help on that. Just got the results of sonic testing. I'll post a few pics on 512 build. Thanks
 
I disliked the gear drive on my 440 (that's an understatement, I F'n hated it). It was very noisy. A chain was a very pleasant fix and now I can actually hear the thump of the engine instead of the whine of the gear drive. To each his own though.
 
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