Chain Tensioner For Roller Cam?

[Rink]

Was wondering if a chain tensioner would be used or not. I installed a roller cam with a stock chain tensioner 2yrs ago, all was fine. Late this summer while getting the car ready to go to the track heard a noise, thought it may have been the belt tensioner bearing, but after belt removal and restarting the car noise was still there. Didn't go to the track. Also the oil pressure was a lot lower. Pulled the engine to see what's up, with the pan off crap in the bottom. It was pieces of the tensioner! Most likely the noise, and with the crap being pumped though the oil system it didn't do anything good for the crank & bearings, hence the lower then normal pressure.
Thanks in advance Mike

 

[WHEEZER]

Tensioners and double rollers don't do well together at all.

 

[Audie1]

Tensioners and double rollers don't do well together at all.

Yep, When I first bought my current GN years back, the engine had just been rebuilt. Anyways they had put a tensioner on the double roller timing chain, it broke on me, jumped time, valves hit pistons, bent valves, it was not pretty. So when I rebuilt everything I left the stupid tensioner off (as it should be with a double roller timing chain)......but that is history now, nothing but a bad memory. :smile:

 

[xsbc63x]

so do you have to get an undersized chain to keep tension? how much tension should be on the chain?

 

[Audie1]

so do you have to get an undersized chain to keep tension? how much tension should be on the chain?

When using a double roller timing chain that is designed for your vehicle, a tensioner is not required. Do not use one. The instructions that come with the double roller timing chain should also tell you not to use a tensioner as well.

 

[Rink]

Yea, the instructions never mentioned about tensioner use, and I never asked Weber about it either. So with that being said, I have about 1/4" free play in the chain without the tensioner. It doesn't seen excessive to me, if it were in a SBC I wouldn't be worried. What do you guys think,---------- good to go?
Thanks Mike

 

[turbofabricator]

A double roller usually goes on tight, but loosens over time (stretch) If the block was line bored, then you should use a .005" undersize chain. (maybe even a .010" under) When the chain stretches, it will also retard cam timing, too. Somethng to think about when degreeing in a cam with a new chain. If it is comming in a little retarded than you want (but not 4*), advance the cam timing 4* to compemstate for future chain stretch. It will stretch right away, anyway.

 

[Rink]

As I recall the chain was fairly tight when new. I don't believe the block was line honed. The play I'm seeing is probably from stretch. Good point on degreeing the cam. Something I haven't done in the past, perhaps I should start. To all that replied, thanks. The tensioner will be omitted when the engine goes back together.