Hi Guys, I have searched and have not found this spec. What is the cam centerline to crank centerline distance on a 350? I have measured mine and have 5.046". Reason I'm needing this is because I recently bought a Cloyes Billet True Roller chain and gear set and it is too short by 0.050" or more. So does anyone know this or know where I can find the spec? I did not see it in the service manual and an online searched netted nothing as well. Thanks.

 

The sprocket diameters would also fit into the equation.

 

Right, but if I have a chain and gear set for the olds 350, it should fit. If it has the wrong chain or gears, it is still on them. I need this spec because I had the block align honed and want to be sure the cam to crank distance is still in spec.

 

Just want to make sure, you are installing it with chain on both gears, all at one time? Not trying to put the chain over one of the gears,with both installed? correct?

 

Yep. Correct. I measured the chain and gear set under tension and get 5.010". So this set is 0.036" shorter than my center to center distance. So as long as my distance is factory, then I have a defective set from Cloyes.
So no one knows this spec? This should be known somewhere.

 

I don't mean any offense, but to cut through the questions about whether I know what I'm doing, I do. That is why I need the cam to crank spec. If the machine shop incorrectly honed my block, I don't want to get a different chain and gears only to find out they won't fit either. This has to be somewhere. Oldsmobile has this spec somewhere. Where does one find the engine blueprints?

 

Kevin:
Align honing will shorten the center-to-center distance between the cam & crank, not make it longer; but typically only .001" - .015" shorter. This would make the timing chain a bit looser after honing. If I remember correctly the stock distance was 5.044". What is the part number for your Cloyes timing set? Cloyes used to make a shorter chain set for engines that were excessively honed, maybe this is what you have?
Rodney

 

They make undersized cam timing sets to specifically deal with this issue.

See the following URL: OLDSMOBILE V-8 260F, 307, 330, 350R, 400, 403, 425, 455

They list stock center to center as: Center Distance = 5.044"
while the .005 undersize is: Center Distance = 5.039"

 

Thanks Rodney. Yeah that's why I was leaning to the Cloyes set because it didn't make sense that it should be longer. The kicker is I just went back and read all the way to the bottom of the spec sheet for the set and it specifies 5.044". Sheesh wish I'd have seen that earlier. So my center to center is only 0.002 greater. Should have slipped right on. The Cloyes set is 9-3513X9. No mention of any deviation from original spec application, so I just got a bad set. At least I can go back to them instead of questioning my machine shop. I don't like to point fingers until I have all the information. Thanks.

 

 

Kevin,
I have found that a lot of times the brand new Cloyes sets are fairly tight. You almost have to put them on as a set with no angle at all between the two gears. Hard to describe but I bet you can get it on there. I have a 350 block and a 307 block at the shop I can measure Monday morning. I dont think the .002" should make it not work.

 

Kevin:
.002" is not very much and could certainly be measurement error or tool accuracy so I don't think you are that far off. I used the Cloyes PN 9-3113 timing chain set for my engine assembly in 2015 and the chain was really tight. It's been a while, but I vaguely remember having similar issues. I installed the crank gear first and couldn't get the cam gear and chain to slide into position. I think I had to slide the crank gear out just a little so that it was in line with the cam gear just before it mounted onto the cam pin. I lightly tapped both gears back a little at a time until the cam gear was fully seated and the chain was straight.
Rodney

 

^^^This has been exactly my experience as well. The cam and crank gears need to be slid on simultaneously, which usually requires you to use your third and sometimes fourth hand. The prehensile tail helps also.

 

You guys missed the 5th post where I posted the measurement of their set. It is 5.010" for a total of 0.036" too short. Not gonna happen. Someone grabbed the wrong chain or something. You would destroy your cam and the cam gear if you try to make this work. Not to mention the tension would eat the chain in very short fashion while wiping your cam and main bearing.

 

I got the .002" number from Kevin in Post#11. Something is really wrong if his set is .036" too short.

Rodney

 

Kevin,
Please keep us updated as to the the results with this. I am very curious to see what Cloyes says.

 

It never got to Cloyes. Summit sent a replacement immediately. Told me to toss the bad one. The new set arrived yesterday. I made an assumption that the issue had to be the chain. I couldn't see that there would be much variance in the machining of the gears. I was wrong. I took the chain from the new set with the first gears and was off by the same amount. I swapped out the first set of gears for the second set and it went right on. So the chains were the same. There was variance in one or both gears. Surprising to me. I'm sure those gears are CNC machined. Either way, I'm good to go.

 

Thanks for the update. I remember reading somewhere that when they made up the shorter gear sets the difference was in the sprockets. I guess you proved that

Personally I would have to get in touch with Cloyes and let them know. They might even want the set back to examine. It would help prevent other issues in the future.