Replacement timing chains on stock engines

[johnw]

I've always gone out and bought double roller timing chains when replacing the nylon cam gear, even with a single bolt cam. Why do I need a double roller? Do single roller chains like a "Cloyes Engine Timing Sets C-3010K" ever break? Single roller is going to be closer to stock I assume, less rotating mass than double.

Are double rollers really only needed for people running with big valves, lumpy cams and higher spring pressures? I'm basically rebuilding a 383 and wanting to keep it stock.

[slotcarone]

Single or double roller will not affect the performance in any way. Either one will work exactly the same on any engine. Just a different design.

[johnw]

Great Thanks! I also plan on keeping points ignition and solid core HT leads.
I plan on switching to a modern replacement voltage regulator though, at least in the beginning.

[Moparguy]

there are very few chain and gear setups left on the market that wont stretch something chronic . Check out the Hughes engines site , or learn the hard way...

[johnw]

there are very few chain and gear setups left on the market that wont stretch something chronic . Check out the Hughes engines site , or learn the hard way...

I am trying to keep the engine almost completely stock. The car is a '68 383 and has 38K miles on it from new, and the nylon cam timing gear. Is there a gear that would fit in with the original chain, is a Cloyes single roller going to stretch?

[slotcarone]

Get a set from a good manufacturer for a stock engine and you will be just fine. You are not racing the car and most likely not going to put that much mileage on it anyway. Use all three matching pieces. It is not that big of a deal!!

[kenny38]

30 years ago I had an engine relacement and the speed shop proudly told me that they had fitted double steel timing chains. "you will never have to worry about them.....ever and nylon timers are a waste of money even though much cheaper". Well, I have never had a problem with a 100K from new on clock.........mind you...Kenny38

[johnw]

30 years ago I had an engine relacement and the speed shop proudly told me that they had fitted double steel timing chains. "you will never have to worry about them.....ever and nylon timers are a waste of money even though much cheaper". Well, I have never had a problem with a 100K from new on clock.........mind you...Kenny38

Congrats on the 100K Kenny in an SP! Yes I am jealous!

I actually told a friend who's car I am working on the same a few month back! The Cloyes double roller duly arrived, and we torqued it up yesterday. The cam gear is a lump of cast iron. Nicely paired down but still twice as thick at the outer circumference as the old aluminium one. Lots of rotating mass then. It will certainly put more strain on the cam bearing, but it is a big bearing in a solid lump, and could probably take much more. So when it comes to the car I am doing, do I really want double the original rotating mass hanging on one end of the cam, when I can get away with say only 30% more with a cast iron single roller?

The double roller does go on nicely, and I now realise how much the old original chain had stretched compared to the new. Hopefully the single roller ones wear gracefully. I looked on youtube for info about wear patterns of single roller replacements, and got into which type of gear driven cam conversion is best! Floating idler or fixed! Then there were toothed nylon belt conversions, torrington bearings .

So a quality single roller is the plan for now, a decent make, so that the cam gear surface doesn't grind up the block.

[slotcarone]

I would not worry about the rotating mass of the cam gear! Almost every American V8 came with the typical aluminum/plastic cam gear originally just like our Jensen's. We never replaced them with the original style. If it was just a customer daily driver we used a single gear set up. For performance engines most preferred the double roller design which seems like it was used on all of the local racing engines too. Either way there was never a problem with cam bearing wear and of course no performance difference either on a street driven car.