Nylon cam gear years

[bucket]

It failed in my '78 at around 140k.

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^Iirc, that happened not long after I had the stock sprocket out of my '91 454 and I PUT IT BACK IN. Lol. So far, that sprocket is still sprocketting. Probably close to 100k on it.

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I even put the stock peanut cam back in that thing, after I already had it out.

 

[edgephoto]

This was my timing set. I have owned this truck since 1988. Not sure how many miles but somewhere close to 200K

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[Ricko1966]

It failed in my '78 at around 140k.

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^Iirc, that happened not long after I had the stock sprocket out of my '91 454 and I PUT IT BACK IN. Lol. So far, that sprocket is still sprocketting. Probably close to 100k on it.

You must be registered for see images attach

I even put the stock peanut cam back in that thing, after I already had it out.

I think it failed about 130k and you kept driving. LOL

 

[CorvairGeek]

Pontiac V8s did seem to have a higher failure rate than other GM products. Interestingly, the Trophy 4 (1/2 of a 389 V8, '61-'63) supposedly had a really good timing chain setup that was good in the V8s too. The 1/2 a V8 was entirely too rough to get acceptable service out of the V8 set.

 

[bucket]

I think it failed about 130k and you kept driving. LOL

Lol, you are sort of correct about that. I made it down to Knoxville TN when I got slowed down in heavy traffic. While creeping along in traffic with the window down, there was a noticeable lope at idle and throttle response was still fantastic. I wondered what might be going on, but it sounded great and even got a compliment from a fellow motorist. I made it to about 1 mile from my exit to Adel in south GA, then the sh¡t hit the fan. My in-laws had to come tow me the couple miles to their house.

 

[1977banana]

The nylon gear is fine as long as you don't leave it too long without changing, because they do wear and fail eventually. The real culprit is a loose stretched chain on a nylon gear as that destroys them pretty quick.
As I remember, Smokey liked them because they dampened harmonics carried from the cam through the distributor which reduced spark scatter at high rpm, and were lighter. but I am old too and that's from memory. Later on belts provided the same advantage. Trucks used to have steel gears (3 ton, 5 ton h.d. apps) because the nylon didn't last as long perhaps because of heat etc. not really sure other than that.
Over the years we always swapped out the nylon for steel because it just looked stronger, not really sure if it mattered.
With a performance cam and headers you don't hear any noise difference, but in a stock set up that's quiet you might, but who's listening for that I don't know.