DEL

Hello,

A few questions. I recently bought a 1982 911 SC Targa.

1. Do I need a pop off valve? I don't have one that looks like the one you get aftermarket however my air box has what appears to be a rubber plug on the lower right hand side. It may sound silly but it looks like this plug would pop out in case of backfire. Is that what its for or does it serve some other purpose. I was wishful thinking that Porsche may have corrected the problem by 1982.

2. When washing the car, how concerned should I be about getting water in the engine cover vent?

3. I know where the jacking points are on the outside edges of the vehicle. Is there another place I can jack it up in the front and/or rear? I have a standard floor jack and I'd like to get her way up in the air to get a good look underneath.

4. The previous owner installed urethane bushings in the rear (I believe they are the in the torshion housing) They squeak badly, is there an easy way to lube them up so they'll quiet down? What lube should be used?

5. How can I tell for sure that the tensioner upgrade has been done? I can look down on each cam chain cover and see an oil line connected. I got a lot of records with the car but I can't find one for this work. The previous owner said it was done but I want to be sure before I buz the thing to redline

Thanks all!

Dean

1.It can't hurt to have a popoff valve
2.No
3.Buy a jack plate.
4.There is a grease but I don't know how to get it in there easily.
5.I think you got them.
Enjoy
Dean

Bill Gregory

Dave,

Here's an excerpt from a 911SC FAQ I'm working on that hopefully answers some of your questions:

Pop off valve:

Speaking of the air box, in 1981, Porsche updated the CIS air boxes to deliver the cold start fuel directly to each intake runner. Previously, the cold start injector dumped gas into the air box to mix with intake air to the cylinders. Porsche determined that, when combined with either a lean mixture or other mixture problem, this was a contributor to blown air boxes. A blown airbox, caused by a backfire in the airbox, creates a giant unmetered air leak, and usually keeps the engine from running. This change greatly reduced, however, did not eliminate, the problem. Many have installed a pressure relief, or pop off, valve in the airbox to provide a path for backfire pressure. You can easily check for this by removing the air filter and looking to the left side of the air box immediately under the air filter. That's where the relief valve will be located, if it's been installed. When installed correctly, it should open towards the back of the air box. If you have one, you might periodically put some silicone paste (not silicone sealant) on the rubber o-ring in the relief valve, to keep it lubricated. It's a good idea to put some epoxy on the left and right side of the valve hinge, to keep the hinge wire from working it's way out. If you don't have one, the pop off valve itself costs around $45, and is pretty easy to install. A new air box installed by someone else can run you $750-$1000, so if you don't have a pop off valve on your CIS air box, install one now...it's cheap insurance. If your air box has blown up, there's a technical article at tech.rennlist.com under 911 engines, describing do-it-yourself replacement, including Porsche replacement part numbers.

Tensioners:

There are several updates that should be considered. First, oil fed tensioners. Prior to 1984, the two chain tensioners used in the 911 engine were mechanical devices, keeping tension on the cam chain. However, they occaisionally failed, usually with expensive consequences. In 1984, Porsche introduced oil pressure fed tensioners, which have fixed the majority of tensioner-related problems. In these, the oil line to the camshafts is tapped to keep pressurized oil on the tensioners. You can tell if these are installed already by looking at the oil lines that come out of the engine block on both sides of the fan and continue to the cams in each head. If the oil fed tensioners are already installed, there will be a "T" junction in each line, with a hard metal line going into the cam chain housing on the left, and going down past the metal engine tin into the cam housing on the right. Parts are around $350-$450 and with labor, the total installation may be $750-$1000 total. This is an important upgrade, and if not already on your 911SC, should be strongly considered.

Paul H

In response to the second part of Bills post:What about the 'add-on' mechanical stops sold for hydraulic chain tensioners. I assume they prevent a complete collapse if the oil fed tensioner fails. Are they worth the effort?

As for the grease: Apparently this is a common complaint with Urethane. Automotion sells a Weltmeister 'Magic-Lube' grease for their bushing. I would suspect that the issue is the absence of grease rather than an unsuitable lubricant. I am not sure why the bushings do not have a) grease grooves to help retain lubrication and b) grease nipples to re-lube more easily. Both of these would help.

Don Plumley

Regarding the jacking points - the jack pad that plugs into the jacking point on the side of the car is a good option - just make sure there is no rust down there! You can get one from AJ-USA or Pelican Parts for $15. I have one and find it really makes jacking the car up easy. Then I use the jacking points for the jack stands.

Alternatively, there are a number of good jacking and or jack stand points on the suspension members - like the torsion bar tubes. Some folks use a block of wood and lift the car using the bottom of the engine case, but personally, I won't do that. Otherwise make sure you don't jack/support on the pan and stay away from the oil lines on the right side (and AC lines on the left).

The view from under the car is great - enjoy!

Don

Bill Verburg

1)You do need a popoff valve, it should be visible inside the air box when the air cleaner has been removed.

2)I've never worried about it in 30 yrs of 911 ownership

3)there shoud be no room under the front spoiler. Some folks jack on the transmission crossmember in the back.

4)Zerk fittings can be fitted prior to installation, after try some non-silicon spray lubricant

5)Here's a pic of the right side tensioner upgrade.

DEL

Great responses guys, thanks!

I definitely have had the tensioner upgrade (whew!) and I'll be getting a pop off valve very soon.

Thanks again,