Carrera Chain Tensioners on early 930

[RDG]

Currently getting a top end refresh done and planned on doing the Carrera tensioner upgrade, Ive been around these cars for a while and this had always been a upgrade that you just did in the pre 84 cars, Is this still the current thinking, my shop thinks it might be best to stay stock with the collars, also dosent like the way the tin need to be notched for the install. I'm trying to keep things as stock as possible but am doing some light mods, Cams,Turbo,Intercooler,lightweight clutch, would you stick with the stock with the collars (this is what I have) or do the Carrera upgrade. This car is a 79, 28k
R

[wildturkey]

I see it as a sympathetic upgrade and will do it on my 76 930 in time.

I'm not sure anybody makes the old type any more?

[lee88]

Carrera tensioners on my '77 930 when the engine was rebuilt a few years back and K27 and exhaust put on. FWIW my '74 Euro/MFI Carrera has them too and they were installed many moons ago by prior owner (prob '90s sometime).

Unless it's a pure concours / museum car that will almost never be driven and where bone stock is a real need, I think nearly everyone does this for peace of mind.

[lite75]

You can get the rebuild kits for around $40. from our host. As long as the seals are fresh I wouldn't be to worried about running the stock type.

[ficke]

The oil pressure fed Carrera type chain tensioners were such a common upgrade for so long that it is not even viewed as a distraction or minus now. That might change. But I find it hard to believe it will.
Cars that now sit and are not driven as much will benefit even more from the Carrera tensioners which is another reason I believe they will continue to be viewed in a positive light.
Personally from a mechanical point of view it was Porsche finial upgrade and I like having the best Porsche had to offer on such a critical part of the engine.
But, If your car is a nice bone stock example, I mean original stereo, no engine mods, etc, then yes you should probably go with the original tensioners and not have your sheet metal cut up for the Carrera install.

[tonypeoni]

This is one mod I think is acceptable even at a concours level.

[Miguel Antonett]

It makes no sense not doing it... under any circunstances, unless you don't drive the car.

[jwasbury]

Seriously guys...original tensioners has got to be worth, I dunno, like $100k to the serious ultra bone stock collector market...

Make sure you put the original tires in a hermetically sealed chamber while you're at it

[mark houghton]

Had a tensioner fail on my old '73 911T many many moons ago. Not pretty, bent an exhaust valve, but that was the extent of the damage luckily 'cause it happened in the driveway and not under full tilt boogie. New valve and guide - and a boat load of work - fixed her up. Sold the car before undertaking the tensioner upgrade. To me, the answer to the question is a no-brainer.

[kenikh]

I actually prefer rebuilt 930 tensioners with safety collars. Pressure fed tensioner do fail.

[RDG]

Stock Stereo, Check, Stock tires, In Hindsight i guess i should have kept them, Im not going for concourse at this time, but don't want to do anything that i wound regret later, with that said i think I'm going for the Carrera setup, is it possible to just get the tin from a later 930 and save my uncut stock with the rest of the stock parts i have. Thanks all for the replies, Oh and a couple pics..R

[ficke]

Yes, easy to get the tin and then you can save your tin and chain box covers and easily go back to original if the world does go truly crazy with these cars, you will be ready.

[timc]

I've had both fail over the last 30yrs. Pressure Fed twice, and hydraulic (930 style) many times. Never any damage, you just have to keep a load and don't rev then lift to create slack when (and they will) fail. I'd go with the pressure fed, as they just don't seem to fail as much, but look into adding collars on the PF's.

One of my pressure fed's failed 500 miles from home. Drove it home just fine.

[Rob 930]

I would go with original tensioners and not the pressure fed variety. I will echo what others have mentioned: the pressure fed tensioners are (perhaps equally) prone to failure. As such, they actually provide a false sense of security. Original tensioners, handled properly are safer in some respects, because they can't catastrophically fail as long as you use the collars, and having the collars will alert you to impending collapse without allowing calamitous failure. Also, all those little external oil lines and connections have been known to leak onto hot exhaust components and cause smoke -- or worse. And concours or not, it's nice to leave the tin alone and not cut it.

I have worked with literally every version of tensioner since the 1965 911, when they had an open oil reservoir and couldn't be inverted. The early tensioners were quite failure prone. But the latest and greatest sealed tensioner is a very reliable part if you handle it properly.

[copbait73]

Originally Posted by kenikh

I actually prefer rebuilt 930 tensioners with safety collars. Pressure fed tensioner do fail.

Agree, I've experienced several tensioner failure before the pressure fed were available and had no engine damage. Pressure fed fail also, I install collars.

[timc]

I totally agree both fail, but I personally have had more than twice as many of the 930 failures over the pressure fed's, with more miles on the pressure feds. If it's a concern, just add the collars to the PF's...it's a gamble both ways without the collars...

tim

[onboost]

Since its not aftermarket, but part of the Porsche evolution, I've always gone with the pressure fed tensioner. Yes some have failed, but with far less frequency than the earlier style.
Many feel that collars are the savior,. However, they have their issues too as seen in the photo below. This is what I found in one of the motors during a disassembly last year.