MTFCA Forum

Bob Shirley in his recent post,...."What Happened? It Just Quit",....talked about fiber timing gears,.....

Now don't mis-understand,.....I am "NOT" recommending the use of todays fiber timing gears, because in my opinion, they are absolute "junque"! However,.....

Here's something that has bothered me for a long time, and I'm thinking that maybe somebody knows a lot more about this than I do, but heres's something interesting:

Back in the '50's & '60's, while in high school and for several years after, I had a Model A Ford. I used a fiber timing gear that had come from a Sears Allstate rebuilt engine, and I used that same fiber timing gear on two more engines and it never did give any trouble, and never showed any appreciable wear. Since then, I have read other accounts of fiber timing gears from back in that era that were very good quality.

Every time somebody mentions the poor quality of today's fiber timing gears, I think about this, and wonder why the fiber gears of old were so tough and such good quality, and why the modern ones are so poor and, again, in my opinion, absolute junk!

I really wonder if somebody still makes the good quality ones, and if so, how to identify them and where, or from what supplier to get them from,...??? It's a shame that the modern ones are so poor, because as Bob Shirley said, the fiber gears really do run very quietly. I would however, add that nowadays, I would never use a fiber timing gear, because I don't know if anybody still manufactures the old good quality ones, and if so, I would not know how to identify the good ones as opposed to the ones we know to be junk.

Does anybody know any more about this? Thanks,.....harold

Harold
I’ve had one in use since 1979 and many thousands of miles on my 27 roadster. Another one since 2000 in my 13 touring.
I am VERY careful about gear mesh when I build engines. I recently installed two more in my own engines. These are ones that I have had for years and are almost black in colour.
That is all I can offer

I believe the fiber gears from the "era" - "CYLENT" was one, and the later Allstate gears (I have both NOS in the original boxes) were produced with "macerated" fiber - whatever the material it was saturated with, it must been some tough stuff.

I also believe that most if not all modern fiber gear failures can be blamed on the generator load put upon the gear and as Les eluded to - gear mesh is critical for longevity.

I believe this one was installed in the seventies or before. As you can see, it was in a generator engine. Would I ever install one? No way, Jose. I'm not expert enough to tell a good one from a bad one, and prefer not to gamble on this. Oh, but they're so quiet! Yeah, this one sure is. Actually, when I drove my touring into town yesterday I noted that it's pretty quiet for a Model T. It has a McEachern aluminum gear.

I line bore all my own engines and I use the “LINK “ method of locating at precisely 100mm or 3.937” between the camshaft and crankshaft. Additionally I use the shim gaskets to accurately set the generator gear lash. Additionally I NEVER “torque “ across the gear teeth tightening stuff. So far it has worked for me!!
All the best

On cars from Model A on, the timing gear was run by the crankshaft to turn the camshaft. On the Model T, it also turns a generator on the cars after 1919. So it is both being pushed and pushing. This gives you two areas where the gear must mesh properly. It also gives you double wear on the teeth. Although it is initially quieter, and depending on how many miles you put on your T, might last a long time. It is something that when it breaks, you must be towed home. It can break suddenly anywhere. I personally use aluminum gears.
Norm

I've used fibre timing gears on most of my rebuilds because at the time they were the only gears made either 3 or 5 thou oversize. I was always careful to fit them closely and have never experienced a problem in thousands of miles of driving. I made sure the cam journals had 1 to 1.5 thou fit in the cam bearings and the bearing shells fit snugly in the block. The mains were all newly poured. The cars were all nongenerator cars.

A little bit of noise is a small price to pay for reliability. I don't know about everone elses T's but mine make enough noise from other places to more than cover up any noise from the timing gear!

I had a fiber gear in my 26 and found it perhaps 30 percent gone after about 4 years of use. It was replaced with an aluminum gear which subsequently (11 years in) has shown no appreciable wear. I will never again use a fiber gear.

The old man changed one in someone's driveway, after the teeth peeled off...
I think it's a steel gear now, but there's a spare under the back seat.

2 kinds of fiber gears, ones that failed and ones that are going to fail, IMHO

Macerated fibre gears are made with chopped up fibre moulded together with some kind of binder. Laminated fibre gears are made with sheets of fibre laminated together, so they are much tougher. I know of no laminated gears available for T's.

Ask a boat builder which is better, a hull made from chopped fibre held together with epoxy, or a hand laid hull using sheets of fibre and the same epoxy. The difference in strength is like chalk and cheese.

Allan from down under.

When I was a kid about 12 years old back in the early '60's, my Dad and a couple of other guys from our Church replaced a fiber timing gear on a '56 Chevy six cylinder that the Preacher had. Needless to say, the teeth had stripped off. Even as a kid, I realised then that the fiber gear was junk, I couldn't understand why any car company would use them, I still don't. As far as noise is concerned on a T, there is way more noise going on with everything else than I can hear with the timing gears. JMHO Dave