OK guys and gals, I've searched for this and came up empty.
What is the point of using a timing gear instead of a timing chain? I've heard mention of it a couple places, but I still can't figure out why anyone would bother.

Thoughts?

 

More accurate, no chain stretch, and more advance and retard options. Plus, it sounds cool.

 

Me personally, for a daily driver, I'd stick with a good double roller timing set. The gears transmit unwanted harmonics/vibrations between the cam and crank.

 

If you are spending the money to rebuild an engine, go with a good set of double roller timing chains & gears. Hardened & prestretched are the best. I usually use timing sets from the same company that I get the cams from (ie. Comp, Crane, etc.)

Now if you are building a race/high performance engine, gears are only way to go. More timing options, (degrees of advance or retard). And with gears and you don't have to worry about high RPM's, fast rev.'s, or high temps. stretching the chain. But they do make noise.

 

FYI, if you chat with most engine builders who own dyno's, they will confirm the gear drives cost you about 10 hp due to inherient friction. Cloytes double roller nylon coated timing chain (which is what Crane and others sell under their own lables IIRR), is the best way to go.

 

I ran an Edelbrock gear drive on a previously owned and built F-150, no problems whatsoever. I put over 50k on that motor, had all crane roller valvetrain, headders and 4bbl. I drove it year round. The gears made a lot more noise at -20F than it did at +80F. Motor pulled real hard all the way to 6k. Not sure I buy the 10hp power loss due to friction. It seems like there would be less friction ...

 

I'm In The Middle Of Building A Blowin 73 Nova, We Will Be Running A Gear Dive For The Noise.

 

AMEN BROTHER!!!!!!

 

if you decide to go with a gear drive..don't go cheap..i would suggest a pete jackson..i put one in my 351m and love it..the noise gears are not as bad as people think..

 

I'm not too sure about the 10 HP either, but gears are about the least efficient means of power transfer. Chains are the best (when adjusted properly).

Cody

 

Gear drives come in two varieties: Spur cut which are very noisy are fairly efficient. Helical cut are less noisy but they loose some power to friction in the gears and the thrust bearing. Chain drives have friction losses also.

 

[QUOTE=Blurry94]Me personally, for a daily driver, I'd stick with a good double roller timing set. The gears transmit unwanted harmonics/vibrations between the cam and crank.[/QUOTE

Waaay back when, Honda motorcycles went from gear drive back to chain or belt on the V4 race motors for the exact reasons stated above.

I understand that was for motors that pulled double (or more) the RPM's a V8 would pull but I'd bet the same principles apply.

 

there are chain sets out there that have much more timing adjustability than gear, ex. the cloyes hex ajust, double true roller, and you can adjust anywhere from 6 deg adv. to 6 deg ret., also has the 3 keyway sproket.actually around here, i seen a lot of the big dogs running dry belt systems, way better timing they say. not very good for street use though.

 

never could figure out guys that use the gears for the "noise" if thats what u want put on a blower!

 

I a'm, gear drive and blower