Seeking advice re: 2.2 tensioners, valve covers, and gaskets.

[brseidel]

I recently purchased a 2.2 T that seeps oil within normal limits. At 58K mi. the car has never had the tensioner upgrade. I am considering installing slip prevention collars while replacing the exterior engine seals to minimize seepage.

Any recommendations on the value or necessity to further the upgrade to pressure fed tensioners and turbo valve covers? Any experience with various cover gaskets?

[Tom F.]

I suggest that you change the tensioner levers and update to the "turbo" tensioners. The original, unbushed (steel on steel) tensioner levers chatter on the pivot pins, which evidently causes the seals on the tensioners themselves to fail. The replacement levers are bronze bushed, and won't chatter. You've got to check the pins carefully, too. If they're chewed up, then you need to change the chain housings.

If you're going to drive the car a lot, I would go with new "turbo" aluminum valve covers, intake and exhaust. You can true up the magnesium covers, but they won't stay true. Factory gaskets have always worked for me, for 17 years.

[Neil '67 911S]

Tom,

I went to upgrade my 2.0 911S engine with the fatter cam sprocket arm (versus just the bushing) and turbo chain tensioners. Changing out the sprocket arm was easy enough but how does one install the tensioner?

It's easy to install pressure fed tensioners thanks to the "C" clamp they come with. Obviously if you pull the safety pin on the turbo tensioners, the tensioner flies to pieces. It's not clear to me how you can pull the pin with the tensioner in place. For now, I'm running the old tensioners with safety clamps.

Thanks!

- Neil
'67 911S (Ol' Ivory & the Rust Bucket)

[Tom F.]

New turbo tensioners come with a clip across the top. You cut it after installing the tensioner. Used, or rebuilt, tensioners must be compressed in a vice before installation. There is a tool to hold them compressed while you transfer them to the engine. The tool is not expensive, but I cannot recall the tool number, now.

[Neil '67 911S]

Hi Tom,

When you installed your turbo-tensioner and cut the clip, how did you ensure that the pieces didn't fly into the crankcase? As far as the tool goes, you probably already know that the "C" clamp for the pressure fed tensioners does not fit the turbo tensioners. If you could find me the number of the tool that you used, I would appreciate it. The point of this tool is, of course, to keep the piston retracted after pulling the pin. Indeed, the tensioners must be bled and then compressed using a vice before installation.

Any one else care to share how they installed their turbo-chain tensioners?

thanks,

- Neil
'67 911S

[Tom F.]

Neil,

I am not following your point. The c clamp is for the turbo tensioners, which are sealed tensioners, which won't come apart unless you take them apart. You use a c clamp type of tool to put them in if they're used. If they're new, they have what looks like a heavy staple across the top that you can cut to release the piston. The parts of the staple have been easy to get at, the two or three times that I've installed new turbo style tensioners.

The pressure fed tensinoers (Carrera) use the pin. Again, they don't fly apart if you pull the pin out while they are off the car, but you'll have to recompress them, and install the pin if you want to put them in.

If you have the manual, this is pretty clearly explained. If you don't, and you want to take a drive, I can show you. Also, I sent you a private mail.

Tom

[Grady Clay]

Guys,

Perhaps the most important aspect of this discussion is to replace those original rubber chain ramps with the current version plastic ones. A broken rubber ramp caused the death of way too many of these engines.

I agree with Tom’s recommendation for the later alu valve covers. Save your magnesium covers. It is possible to rehab them and they are NLA as a spare part.

I also agree with the Turbo tensioner with safety. The wide-spaced bushed idler arm is a must. While there, inspect the big pin that the tensioner and idler are on. This is just a press-fit in the chain housing and epoxy on the backside. It is not uncommon for this to loosen and the pin move about 15 mm toward the front of the car. This can cause a disaster.

Remember this pin is a bearing surface for the moving idler arm. Always inspect the running surface.

For several reasons I’m not a fan of the pressure-fed Carrera tensioners. Part is originality appearance but most is the Turbo tensioner is so easily and inexpensively rebuilt every decade or so. I also think a proper Turbo tensioner is more reliable than a Carrera pressure-fed tensioner, IMHO.

Best,
Grady

[brseidel]

I had heard that the tensioners on the old touring motors were not so much an issue as with the more powerful and newer motors that used the same tensioners.

Looking at the new Pelican catalog, it seems like one can really go full tilt purchasing upgraded: covers, sprocket supports, oil lines, oil line adapter, chain sprocket idler arms etc. to accompany the new tensioners.

It just leaves one wondering what is really necessary on an old original low mileage 125hp motor that is used for occasional drives in the countryside. Especially when my mechanic advises that the current tensioner is quiet and that slip prevention collars can be put on at minimal cost.

[Tom F.]

Guys,

Perhaps the most important aspect of this discussion is to replace those original rubber chain ramps with the current version plastic ones. A broken rubber ramp caused the death of way too many of these engines.


Best,
Grady

On the plus side, I have the failure of a rubber rail in a low mileage 2.4 engine, many years ago, to thank for the perfect crankshaft I got for my Turbo 3.0!

Good point about the turbo tensioners, Grady. I wish that my 2.4 and my 3.0 had been left original by the POs! I notice that several quality restorers follow your advice, too.

[Grady Clay]

brseidel,

I don’t think Porsche ever used anything other than standard (for the day) tensioners on race engines. I kept a close ear to that as it was a BIG issue for ‘60s-‘80s 911s. I was well connected with the Factory and both race and production engineers at the time.

There are two philosophies dealing with this today; use the latest Porsche technology or use “period” stuff. Normally my inclination is to use Porsche’s latest and best – the pressure fed Carrera tensioners.

There are circumstances where I don’t think this appropriate. First is original appearance. A close second is I think the Turbo tensioner (with periodic rebuilds and the wide idler arm) has a higher reliability, particularly with the Jerry Woods mod.

An aside benefit of the Turbo tensioners is you don’t have to replace all sorts of other parts (chain housing covers, piping, etc.)

Tom, thanks for the compliment. My perspective is professionally doing this stuff in the ‘60s to the late ‘80s. I am 20+ years retired from this silliness. I’m just offering sage advice these days (mostly on Pelican). I just wish I could transfer everything I know to a 20-year old inclined to be in the business.

Best,
Grady