cloyes true rollar timi8ng chain in my 60 Vette

[Dave #34924]

I just installed a Cloyes #9-1100 timing chain set. The side of the chain is hitting the block at the center oil gallery, not allowing the cam to go in all the way. The instructions that came with the chained says to check for any interferance all around the chain and if there is any, grind the block.
I was advised to use this chain buy a few members with no mention of this problem, I would have to trim at least a 1/16 for the cam sprocket to move into the block far enough so the 2 sprockets are lined up. I feel very uncomfortable doing this, I dont want to damage anything.......Any suggestions would be appreciated, Thanks

[mike mccagh]

Re: cloyes true rollar timi8ng chain in my 60 Vett

unless you want the 283 to turn 8500+ rpm, go with the stock gear/chain setup. i wouldn't do any grinding on an original motor. if i was gonna grind, i'd practice on a junk small block case to establish oil/coolant landmarks. mike

[Michael H.]

Re: cloyes true rollar timi8ng chain in my 60 Vett

Dave,

The problem you describe is common. If you want to use the roller chain, I don't think there is any alternative other than grinding the cast iron block. Personally, I would use the original design chain instead. The roller chain was originally designed in the 50's for low RPM truck engines and somehow found it's way into the hot rod industry because it looked fast.

The original design and the roller chains streach about the same amount over time/mileage and as far as failure, it's not an issue with either design so as far as I'm concerned, there's really no benefit with the roller, especially in a car that probably will see very limited use.

GM engineering did extensive testing in the late 60's using both true roller and conventional design chain drives. The results were a bit of a surprise. The original chain/gear design actually produced more horsepower and it was reliable enough for use in the 68 and 69 Trans Am series cars.

When all else fails, stock and original is usually best, even if it doesn't conform to the opinion of most back yard engineers.

[Joe L.]

Re: cloyes true rollar timi8ng chain in my 60 Vett

Dave-----

First of all, the Cloyes 9-1100 is not the timing set that I recommend. The 9-1100 is the "Street True" timing set. I recommend and use only the 9-3100 which is the "True Roller". Generally, the 9-3100 costs about 2 to 3 times more than the 9-1100 and there is that much difference between them. Nevertheless, the 9-1100 should be adequate for most street engines. No doubt about that, at all.

Notwithstanding the above, I don't think that you'd have any difference with fitment if you were using a 9-3100. Dimensionally, I think that both sets are virtually the same. I've installed quite a few of the 9-3100 with no fitment problems, at all. However, I do know that the interference that you've experienced is not all that unusual. I've never actually installed one of these on a 283 and that may be why I've not experienced problems. It may be that the 283 castings were "bulkier" in certain areas.

If all you have to remove is 1/16", I don't think that would cause any problems, at all. However, you might have to remove more than that to ensure there would be sufficient clearance between the chain and the block. I could understand your reluctance to do that. If the engine is just going to be used for normal street driving, you probably don't really have a lot to gain from using a True Roller. So, in that case, you might just want to get a Morse or Early-Link type chain as was originally used for your engine. These are relatively inexpensive and you can get them at most auto parts stores in a quality brand like TRW. You want to make sure that you get the type with a cast iron timing sprocket and NOT the aluminum with nylon teeth variety.

The OEM GM pieces are discontinued for your application. Also, GM does not sell a complete timing set in the early link/Morse style.

As Michael mentioned, the "roots" of the GM roller timing chain were in truck applications. However, years ago these were moved into performance applications, too. The GM roller chain is still available as a set under GM #12341093 or the individual pieces (chain= GM #3735411; cam sprocket= GM #3735412; crank sprocket= GM #3735413). This set won't do you any good, though; it will likely have the same clearance problems that you're having now. The GM set is not the equal of the Cloyes 9-3100, though. The GM set is not a true roller design. The Renold chain used with the Cloyes 9-3100 is, in my opinion, the best chain made anywhere.

The primary attribute of the stock early link/Morse chain is quietness. For most applications in new cars, this is very important, That's also why many of the stock sets use the nylon cam sprocket, too. The nylon sprocket can ONLY be used with the early link/Morse design.

The Cloyes 9-3100 is widely used in racing applications and it's also a racing piece that works very well on the street (not all racing pieces do). I've used them for years. I had one that had over 100,000 miles on it and the timing was as rock solid at 100,000 miles as it was when the chain was new. You won't find an early link/Morse type chain that will give you that sort of durability.

[KEN BUTCHER]

Re: cloyes true rollar timi8ng chain in my 60 Vett

Hi Dave, I also used a cloyes double rollar chain and it also rubbed my 1974
L-82 block at the highest point of the cam sprocket, and it was the chain that touched. I checked the whole area around the chain and found it was just the top of the chain. I took a file to it(1/4" in lenght) and abought (1/8" depth) put the gear and chain on and checked clearance, it was fine. I guess SBC are meant for single rollars.
Ken.

[Dennis D.]

Re: Joe

Just tore my 70 L-46 down for the rebuild. Have a cloyes. It has 3 keyway positions on the crank sprocket. "O", A triangle, and a dot. It's installed to line up the dot. Seems correct for TDC. Do you know what the other 2 locations reference?

[Dave #34924]

Re: Joe

retarded and advance

[Joe L.]

Re: Joe

Dennis-----

I've not seen one with that "nomenclature". Usually, there is a "triangle", and "o" and a "square". The "triangle" represents 2 degrees advanced. The "o" represents "straight up" timing. The "square" represents 2 degrees retarded. This is the only set of "nomenclature" that I recall, but it's possible that older sets (including some that I've used myself) used the system that you described.

[Dave #34924]

Re: Joe

Thank you all for the info, I spoke with cloyes today and they said I should go with their Heavy Duty, 1/2" pitch, single roller...part # C-3055 for 28.95. The guy at cloyes was very knowledgable and nice.
I called summitt and they said they would swap it out for the new part # but it would be special order because they dont stock it.
Can anybody recommend or not about this single roller timing chain set he recommended... or should I just grind down the interference and continue my mission
i'm also thinking, if I grind it in this area, that I should replace the oil gallery plug, so now I am thinking of replacing all the plugs in the engine. Any suggestions?

[Joe L.]

Re: Joe

Dave----

A single roller is fine. The rollers on a single roller are much larger than those on a double roller. In fact, many GM small blocks produced after the switch to the hydraulic roller camshaft and including the ZZ-4 engine are single roller design.

Also, the timing chain used on the new GM 8.1L engine for trucks and marine use is a single roller. As a matter of fact, I'm using a single roller chain on my "ZL-1" engine; there's no double roller made for an OEM-type roller camshaft for Gen VI and 8.1L engines.