timing chain question

[TURBOELKY]

were there any double roller chains ever made that you still used the factory tensioner? The one on my engine is a double roller, but still uses the tensioner, and lately, seems like its in need of being changed out. The engine starts to jump around really bad after it warms up, and is in park. under load its fine??? fuel pressure does not drop, idle fluctuates +/- 100 rpm, spark is good, timing is good, no vaccume leaks, every thing is perfect. Seems like maybe tension on the chain is causing this problem? maybe some slack gets in there, causes the timing to jump around a little? cant figure it out, but car runs great, just does this at idle in park only. In drive, its fine. any thoughts?

 

[gofstbuick]

You really should not use a tensioner with any DR timing chain. I though I could use the tensioner with a Edelbrock true roller chain, but 10,000 or so miles later, there was this nylon material that clogged my oil pump pick up. That material is from the tensioner deteriorating from riding against the chain.

 

[TURBOELKY]

Yeah

that's why i'm asking. It was already on there, but the chain would be too loose without the tensioner. thats why i'm asking if anybody has ever bought one that still used the tensioner I'm going to change it asap, good thing its winter, not much driving going on well, not much in the summer either thanks man.

 

[87we410877]

Once you get it apart, take a measurement with a caliper from the center of the cam to the center of the crank and call weber racing. They will provide you with the correct DR chain and you will not need a tensioner. If you cannont accurately take this measurement, unload all your lifters, slide the cam out a little bit until you can see the front journal but leaving the cam still in the bearing race. Measure from the top of the cam journal to the bottom of the crank snout. At the same places on the crank snout and cam journal, measure the outside diameter of both. Divide the OD's in half and subtract the combination of the two halfs from the overall measurement from the top of the cam to the bottom of the crank snout. Then call weber. He'll hook you up.

 

[oddfire6]

Once you get it apart, take a measurement with a caliper from the center of the cam to the center of the crank and call weber racing. They will provide you with the correct DR chain and you will not need a tensioner. If you cannont accurately take this measurement, unload all your lifters, slide the cam out a little bit until you can see the front journal but leaving the cam still in the bearing race. Measure from the top of the cam journal to the bottom of the crank snout. At the same places on the crank snout and cam journal, measure the outside diameter of both. Divide the OD's in half and subtract the combination of the two halfs from the overall measurement from the top of the cam to the bottom of the crank snout. Then call weber. He'll hook you up.

hell, that even confused me...

 

[87we410877]

hell, that even confused me...

Crank snout OD divided by 2. Then cam journal divided by 2. Add the two numbers together. We'll call this number A. Now, measure from the top of the cam journal to the bottom of the crank snout. We'll call this number B. To get the distance from the center of the cam to the center of the crank, subtract A from B. Hope this helps a little. Theres no easy way to explain it.

 

[Turbo6Smackdown]

thank god there are technical guys like this... life must be sooo easy driving a mustang or camaro.

 

[TURBOELKY]

Thanks

that was a little technical but will do.