[Cliff R]

Here is the down and dirty on timing sets from what I've learned actually doing to this of thing for a while. If this information has a few folks on here get their panties all wadded up, which it usually does, that is not my intension here.

My mentor from back in the 1970's taught me well. He was one of the smartest guys I ever knew when it came to these things, a very successful engine builder and drag racer campaining a super quick SA 1968 Camaro. He swapped back and forth between a 396 and 454 but it's been half a century ago and I don't remember all the details on how quick the car was. I just know that he had next to zero issues with it aside from caving in a couple of 396 blocks do to thin cylinder walls.

Anyhow, I'm right out of High School, wet behind the ears and doing all the dump chit everyone else was doing, like removing excellent factory intakes, carbs, distributors, camshafts and such and bolting on crap that just burned your eyes when you stood behind the car in the High School parking lot and sucked down twice as much fuel! I also did the Crane Fireball cam crap, and cheap Zoom double roller timing set combined with (another dumb move) high volume/high pressure oil pumps. Those cams never worked any better than if as good as what I replaced but man did the car sound good out the back with the "menacing" idle quality!

Anyhow, I get hooked up with Gary who was a chemist by night at a chemical factory of some sort and ran a high performance automotive shop by day to make money to campaign his race car.

So I'm watching and learning, and the first time he removed the 396 from his race car he pulls the timing cover off and low and behold there is a factory type Speed Pro Morse chain timing set with a PLASTIC coated top gear! He carefully removes it to use on the replacement 396. I'm shocked. Then he removes a stock low pressure standard volume oil pump to use again.

I questioned both parts and he said that the high volume/high pressure pump isn't needed even for his over 7000rpm shift points and just cost the engine about 10hp on the dyno, the KEY to success was in the short block set-up and clearances. He also told me that the "link belt" chain and plastic coated sprocket was FASTER at the track and made more power than anything else. It "smoothed" out the pulsations between the crank and camshaft and showed less spark scatter and more high RPM power than any other timing set he'd tested.......hum?

Now I just didn't run tight out to my car and pull the engine and remove the $19.95 double roller timing set and high volume/pressure pump I had in them, but I kept a mental recored of everything he said and learned from it.

From that point on all my engines got stock pumps and stock timing sets, although I never used the plastic coated top gear version and Gary even recommended that I use steel or cast iron top gear sets for long term street use. He said that the 3/4" wide version will EASILY outlast the rest of the engine.

So I stuck to that deal until 1999 when I built my first 455. Since the engine "package" I bought came with a Rollmaster timing set I decided to use it. It looked like a decent part, and I loved the ability to move the cam around without the Mopar offset keys I'd been using.

Well that decision turned out to be a bad one and I lost the chain and damned near lunched the engine 4 years later! Now keep in mind that in those 4 years I was running the car at the track at every possible opportunity and driving it almost every day on the street weather permitting. I had just retired (the first time) and was testing all sorts of carbs and such to provide accurate information for my first book and get my carburetor rebuilding business jump-started.

The day the Rollmaster went South I was racing at Dragway 42 about half hour North of here and the car started to really slow down every run. By the 4th run it was off over 2mph and couple of tenths and the idle didn't sound just right. I went ahead and made pass number 5 and it started breaking up really bad at the top end of the track and barely stayed running at idle speed. I "limped" it back to the pits and put the car on the trailer. I thought I'd simply broke a valve spring or bent a pushrod but it turns out I lunched the timing chain when I pulled the engine a couple of days later, something I NEVER expected to see as the culprit.

Yes folks, that's the good one, same one Butler and KRE sells as the top of the line Rollmaster.

I've had two of my customers lunch theirs in similar fashion, but will note that both of them had logged well over 30,000 miles, one actually closer to 50,000 miles before theirs started slapping all over under the cover.

One of those customers was recently and he actually contacted me thinking he was having carburetor issues because his KRE headed roller cammed 455 was idling weird, missing and skipping a bit. He just figured the carb was plugged up some and was thinking about pulling it apart for a good clean-up. I told him to forget about the carb and pull the timing cover instead. He did mention at that time that he was getting a little noise from the front of the engine but nothing dramatic. When he pulled the cover the chain was DONE!

Even with all that there is nothing wrong with the Rollmater or Cloyes "high end" double roller timing sets. Zillions of them are in use and folks for the most part do fine with them. For every story about one failing you'll get 200 folks jump right in and say they've been using one since Moby Dick was a minnow w/o issues and their vehicle still leaps tall buildings in a single bound, walks on water, tucks them in at night and couple of times a week wakes them up and cooks breakfast for them. So for sure the water gets muddies quickly with discussions about some of these parts.

All I can tell anyone reading this is that I deviated from the "plan" ONCE and got singed pretty hard. I went back to using 3/4" wide timing sets and zero issues since. I even had to remove the timing cover from my 455 recently due to a coolant leak and the timing set looked brand new with very little slack in the chain and only "witness" marks on the gears. I had another ready to replace it but put it back on the shelf.

In closing I personally believe that there are a LOT of "substandard" parts in use out there, like many of these roller rocker arms, for example. We don't hear about a lot of issues with them simply because most of these vehicles don't get a lot of miles put on them. Hitting half a dozen car shows a year and a couple of short cruises on a nice Sunday afternoon is NOT going to put these parts to the test or give any of us reliable feedback as to how well they work in long term service. Also many don't completely fail, but simply crack, or even worse are grinding themselfs up very slowly while putting tons of fine metal particles into your engine. Comps roller tip rocker arms come to mind when I type this. Every set I've pulled off used engines had the bodies turned blue or even black where they pivot on the rocker balls and gaulded some with a good amount of metal ground or flaked off into the engine, but NONE had failed completely and any additional lash created by their "break-in" process was made up by the travel in the hydraulic lifters so the owner never heard any clacking from them.

Haven't pulled down a single engine yet that didn't have a BUTT-TON of slack in the roller timing set being used. I even went back thru an ill fated 455 Super Duty engine with less than 200 miles on it and the roller chain in it had too much slack for my liking so i tossed it out. So there's my take on this topic, from actually doing this sort of thing comin up on 50 years now. I'll slowly crawl back under my rock before the stones start flying!...........

PS: below is a pic (sorry not all that great) of a Scorpion Roller Rocker removed from an engine built here while it was in to be "freshened up". 13 out of 15 were cracked but none had failed nor did we have any idea they were a ticking time bomb........