Technical SBC nylon Cam gear. More common than you think

So anytime I suggest someone replacing a timing set on an SBC in case It still has the nylon Cam gear I get a bunch of guys trying to jump up and say there's none left.... despite me mentioning that I regularly come across them. Anyway here's one from today. Up till around 2 pm today it was sealed in a greasy timing cover where it'd been decades till it quit running last week. Lot more common than you'd think. And this is from a car commonly chosen as a cheap SBC donor for budget rods

 

SBC , BBC , Pontiacs all suffered this problem , probably more .

 

Yup. SBC is the main one I still see on a regular basis. Haven't seen a non Chevy nylon Cam gear in years

 

probably haven't seen an original non Chevy engine in the same number of years?

 

Saw one let go on a Pontiac at 6,800 miles ...

 

Just changed one out on a Chrysler LA318 the gears were ok? But the chain was stretched a whole lot.
Dan

 

Around 1978 I had Pontiacs 350s come in on the reg for a "tune up" that barely ran.

One had the distributor cranked with the advance against the firewall and the wires clocked on the cap quite creatively.

We had a guy on the staff that could change 2 timing chains a day.

 

Have not seen a plastic gear in decades. I do recall a few SBC's that came in the shop for a ticking noise. Sounded similar to a lifter tick, but from under the chain cover. Found the nylon cracked, and one tooth broken off and stuck in the chain. Good to catch them before the gear looked like the above pic.

 

Took a minute to catch this for some reason. But yup lol

 

I have an old early 70s Dodge truck motor laying in my bottom garage (its been there 23 years), I kept it because it ran great all those years ago and I thought it would be a good one to rebuild. I wouldn't at all be surprised if it has the remains of a plastic cam gear. The Chrysler plastic gears were usually good for 120K miles.

I had a Dodge 4x4 truck years ago I had the fun of sliding into, and back out of a very deep ditch, a few hundred feet from my driveway one winter day. The experience smashed the oil pan. While I had the oil pan off the motor, I noticed the timing chain hanged loosely off the bottom edge of the crankshaft gear (I could almost see the entire bottom gear tooth). I decided maybe I should check the condition of that top gear. When I got it apart, all the plastic was gone from the aluminum gear base. I have no idea how that motor ran as well as it did! After replacing the timing chain, both timing gears, and the oil pan and pickup tube, the old motor ran fantastic!