[Cliff R]

"It's been said that Grumpy Jenkins used the nylon sprockets on his race motors.. He said he liked the cam retard at high RPMS."

They were used for the benefits of constant tooth contact (less spark scatter) and they tend to absorb some harmonics between the crank and camshaft. It was sort of a "hot ticket" and a secret little "trick" some racers did WAY back in the day before other ignition timing methods became popular like crank triggers and such.

Another power saver was running LOW volume oil pumps with lower pressure. High volume/pressure pumps (Chevy for example) rob power from the assembly and are not needed for 99.9 percent of the applications they end up in.

I've had HORRIBLE luck with any sort of roller timing set and even knocked a Rollmaster out of the 455 I built back in 2000. It did well for quite a while, then without warning it got loose and started slapping around one night at the track. The car slowed WAY down and I was getting some noise from the front of the engine. I pulled the engine never once thinking the timing set was the issue but that is all that was wrong with it.

I only used the Rollmaster instead of the link belt sets I'd been using here since the 1970's because the company supplying it told me they were bulletproof and I liked the ease of moving the cam around.......NEVER again will one go into one of my engines.......FWIW........

This topic is like many others out there with some muddy-water. Without exception every single high mileage engine I've had brought here where some sort of double roller chain was used in the last build showed a BUTT-TON of slack in it, but none had completely failed.

I rebuilt a 1991 Chevy 350 some years back with over 250,000 miles on it and the little 5/8" wide stock Morse timing set was fine. It had a little slack it in but could have been put back in service. I think if a little 5/8" wide Morse set will go that far without issues a 3/4" wide version will power one of these engines 20,000 miles or so over the next 30 years.

What folks need to realize is that there are quite few different levels of roller timing sets out there, and IF you go that direction for sure I'd look on the top-shelf vs the bottom one. The higher end stuff will have steel billet sprockets not cheap cast iron ones. The chains will be seamless with rollers that aren't "fixed" and actually have a bearing surface that moves around in use. The biggest benefit then becomes the ease of moving the cam around. Even with that said IF you can grinder is doing his job correctly the cam should be coming up in the right position in the first place. The last half dozen engines I did here did NOT require the cam to be moved at all, but I've had a few over the years that were off as much as 5 degrees, so never assume anything with this sort of thing.......