1963 timing chain change, recommendations

[Joe L.]

Re: 1963 timing chain change, recommendations

I used the Cloyes chain on my road racing engine. It was drum-tight when initially installed. 3000 track miles later, I tore the engine down for freshening. The Cloyes chain was still drum tight. That's good enough for me and I won't use anything else.

Jim

Jim------


In addition to other attributes, the Cloyes True Roller timing sets are hand-matched. With this, manufacturing tolerances for each component of the timing set will create less "stack-up" problems. The crank sprocket is machined from a steel billet. The cam sprocket is hardened ductile iron, precision balanced to very high RPM. As I previously mentioned, the chain is a very high quality Renolds chain. As with most things, you get what you pay for.

[Patrick H.]

Re: 1963 timing chain change, recommendations

I've been following along since I have to do this project if the weather ever improves around here. Right now the barn access is blocked by 4 feet of snow.
Two additional questions -

Which timing cover seals are the best?

Can you replace a timing cover chain without dropping the oil pan?

The orange 72 needs a new timing chain, and right now there is a 1 piece FelPro oil pan gasket in place, and it doesn't leak.
Some videos and descriptions seem to indicate I don't have to drop the pan, some do. I'd just like to mentally prepare before starting the project.

Patrick

[Jim L.]

Re: 1963 timing chain change, recommendations

Can you replace a timing cover chain without dropping the oil pan?

The orange 72 needs a new timing chain, and right now there is a 1 piece FelPro oil pan gasket in place, and it doesn't leak.
Some videos and descriptions seem to indicate I don't have to drop the pan, some do. I'd just like to mentally prepare before starting the project.

Patrick

No and yes.

No: If you have a stock timing cover, then you'll need to lower the oil pan slightly to get the bottom edge of the timing cover out and back in.

Yes: There are aftermarket, two piece timing covers which are made specifically such that you don't need to disturb the oil pan. I tried using one from Edlebrock once and never could get the dang thing to seal. There might be better ones, but I wasn't willing to be a Beta tester for all the companies who thought they could make a two piece cover. I stuck with a traditional, one piece cover.

Jim

[Joe L.]

Re: 1963 timing chain change, recommendations

No and yes.

No: If you have a stock timing cover, then you'll need to lower the oil pan slightly to get the bottom edge of the timing cover out and back in.

Yes: There are aftermarket, two piece timing covers which are made specifically such that you don't need to disturb the oil pan. I tried using one from Edlebrock once and never could get the dang thing to seal. There might be better ones, but I wasn't willing to be a Beta tester for all the companies who thought they could make a two piece cover. I stuck with a traditional, one piece cover.

Jim

Jim and Patrick------



From what I've been told, one of the primary reasons that GM changed the thickness of the front oil pan seal for 1975 (and a short while later for all pre-1975 SERVICE oil pans) was to facilitate the removal of the timing cover without the need to lower or remove the oil pan. If that was the reason, it was a dismal failure because I don't think there's any such benefit conferred by the thicker 1975+ seal. In any event, if the 1972 has the original oil pan, it won't even have "benefit" of this change. Basically, the oil pan needs to be removed. With the 1 piece silicone rubber gasket, which is re-useable, you might be able to just lower it. With conventional 4 piece gaskets, there's really no benefit to just lowering it because you need to replace the gaskets.

As far as those aftermarket two piece timing covers, I say forget it for a number of reasons. With most of them you have to remove both the upper and lower sections to replace the timing chain and sprockets anyway. With the cast type that has the full removable front, those usually won't clear the short leg waterpump used for all Corvettes. And with all of the 2 piece types you'll end up with more leaks and seepage than stock covers.

As far as a seal goes, the stock-type gasket is about the best you can do. These gaskets are very thin. However, an improved thicker gasket wouldn't work. That's because of the very limited clearance between the water pump backing plate and the timing cover. If the gasket were very thick, it would space the timing cover out too much and problems would result. I use the stock-type gasket with a very thin film of Permatex Ultra Black or Ultra Copper on both sides.

The GM part number for the gasket is 12369488.

[Patrick H.]

Re: 1963 timing chain change, recommendations

Thanks guys. This means I don't consider the project until one of the lifts is available.
Based on present snow cover that's going to be a while.

Patrick