I'm going to be doing my heads / cam swap, underdrive pulley, etc fairly soon. I'll also be installing the new Cadillac LS7 lifters, a Melling High Volume oil pump, and a different timing chain. My question is regarding the timing chain I should install.

I'm currently planning in installing a Cloyes double roller timing chain set. But I have read / heard some stories regarding double roller chains NOT fitting correctly, or rather, that the front of the timing cover has had some clearance issues when a double roller timing chain is installed. I think that some people who have had timing chain / front cover clearance issues have solved the problem by grinding some material off of the inside of the timing cover to get it to fit. I'd rather not do this. So . . .

For the guys who have installed double roller timing chains, did you encounter any problems w/ clearance between the chain and the front cover? If so how did you solve it? Should I simply go w/ an LS2 timing chain and forget about the double roller chain?

It is a 2001 coupe, and I won't be doing nitrous, turbo or blower, period.

 

I put in a double row chain from Crane that came with their adjustable timing set (I believe it is a Cloyes) and I had to grind a few spots on the cover to make sure it would seal. I heard stories of single row chains breaking when used with larger cams. I can't validate the truth behind those stories. The LS2 chain is only marginally stronger, which may be enough. You can't use a double row with a Melling high volume.

 

just a comment on the lifters, the Caddy and LS7 lifters are two different items/PN's

Cad=$220
LS7=$120 est. on both

 

When I did mine, I looked at the double but you have to use spacers on the oil pump and then stretch the pickup tube into position. I elected to go with the Katech (JWIS) single chain, which is the C5R timing chain. When I spoke to Katech on this, they told me they never had one break and it keeps all the original parts intact without issues.

 

Go with a Cloyes single-row. Still very strong, and still a Hex-A-Just. SDPC stocks them.

 

I knew that, BUT, it is always nice to have someone confirm what I "think" I know - Thanks

 

I DID NOT know that. This is the first I've ever heard of that - anybody have more information on this? Please post if so.

Thanks for the heads-up. You likely just saved me from a headache and from buying a timing chain that I can't use.

 

I have heard this too. I went looking for confirmation and could not find it in a web search, but I have heard or read it from multiple sources.

Apparently the Melling uses thicker than standard gears in order to make it a high-volume pump. Those lead to the use of a non-standard pump housing, and it does not clear a double-roller. This is just what I have read/been told.

QTP also makes a high-volume pump with thick gears, but it requires their special front cover for clearance. It too will not work with double-rollers.

All of the double-roller chains require that the oil pump be spaced out from the block. Spacers are included with the chain for this purpose. This then leads to a misalignment of the oil pickup tube, but apparently with a little tweaking it will fit. It may also require grinding on the inside of the front cover for pump clearance. SLP used to make an oil pump that had extra clearance and so didn't need the spacers, but I don't think their current one is like that.

Me, I decided that putting spacers on the oil pump was basically so I'm going with a Cloyes single-roller chain. There are other high-strength single-rollers, like the JWIS. I suspect that going to a double-roller is just habit from the old days.

If you want a high-volume pump that does not use more space, LPE makes one. I personally am skeptical of the need for any extra volume, but I got a good deal on an LPE pump so I may try it.

If anyone thinks I got any of this wrong, please speak up. I make no claims to being an expert.

 

I personally don't like the higher volume pumps because the LS1 pumps a lot of oil to the rocker arm area at high RPM to start with.

 

I see you will be using a single roller chain , so I'll post this for anyone installing a double roller.
If you have clearance issues when installing a double roller, I would not grind the cover. It is very thin to start with. When I installed my Rollmaster double roller, my cover was hitting the pump in the two spots shown in the first picture. I removed material from the pump, in the areas shown in the next two pictures, until the cover would fit properly without the gasket installed. With the gasket in place, there should be plenty of clearance. The pump casting is thick in those spots, so it's not a problem to take a little off.