Advice Needed for Tensioner Decision

[orange911]

I have a set of used carrera tensioners that I was going to put on my 72T. I opened the right side of the box and have a tensioner with the part number that looks like 930.105.501,0r. Picture is below. I am assuming this is the Turbo tensioner and that this has been replaced at least once. Am I right? If so, I am thinking that I should just leave them. I don't want to create work that is not needed.

I am also noticing that the chain tensioner is extended quite a bit. Is it? Look at the next picture. Please let me know if this is normal positioning.

Please confirm whether it is good or bad judgement to button this puppy up and drive.

[orange911]

I found a picture of the same part number and advertised as a Turbo tensioner. The difference I see is that mine appear to be cast and the one I posted below appears to be forged or billet steel. Does this post date mine? If so, can anyone help with an approximate year change?

[clear911]

This has been debated for some time. I prefer the 930 tensioners with collars. I was always afraid of the Carrera tensioners as they divert oil. Before going that route, take a close look at the oil pump specifications for your car versus the Carrera tensioners car. I never really considered doing this because I prefer the engine to appear stock and thus never looked up the pumps to see if there is a difference.

I believe the 930 style idler arm was updated to eliminate vibrational/tension issues of the earlier style. But do add the collars. Also, check the chain ramps whcih are probably already the later style in this case.

Robert

[RSTarga]

I had my tensioners collapse when the car had only 30,000 miles on it resulting in a complete rebuild. Since then I think I've gone through several different types of tensioners and currently have 930 newest edition. I am always debating myself about upgrading to the oil fed tensioners, I already have a 930 oil pump. Does any body know the failure rate statistics of 930 vs oil fed tensioners?

[sithot]

Your chains may be stretched. The tensioner will be near full extension.

I'd never use a used tensioner. An oil fed tensioner can fail too.

If you want the easy cheap fix, utilize new 930 style parts with collars.

I like mechanical tensioners, properly set up for case expansion.

Good luck,

Tom

[X-Faktory]

I use the 930 tensioners with collars.

[66S]

THE most important part is the idler pivot surface and the pin condition. The pullies gall where they ride on the pins creating friction and resistance to movement. The early aluminum 901 motors and later[1978?] had bushings in the idler arms instead of steel on steel. The wide idlers have the bushing and require narrow chain tensioners to work with them. Porsche discovered that this was the source of 911 tensioner problems and remedied it with the bushed wide idler arms. Always check for scored surfaces and replace if necessary. The pin can be removed and turned to put the worn surface 180 degrees. but be sure to peen and epoxy it back in the chain housing. I also prefer mechanical tensioners.