How close to rotor timing mark on disti be lined up

[JamesG4381]

These questions are for a 1982 911 SC Targa

I have a quick newbie question. How close to the Distributer TDC cylinder 1 mark should the rioter point to when the crankshaft timing mark is at the Z1 location. Should it align with the end corner of the rioter contact or the end, middle??? I've not been able to get a clear illustration.

Another question is how tight should the chain be on both sides of the Cam sprocket? I see and understand that the side on top of the guide should be not in as much tension as the other side but mine seems quite loose. The side under the tensioner is very tight. Could it jump one tooth. Mine was making a lot of noise which is why I have covers off. It has old type tensioner but they look brand new. unfortunately PO lost all records. poor baby was abused.

Thanks
Jim
1982 911 SC Targa

I'm relatively new to Porsche and have been enjoin it tremendously and look forward to many years of great motoring.

[boyt911sc]

Jim,

If the ignition timing is set correctly, the distributor rotor should be pointing directly towards the distributor line marker (cylinder #1's spark plug wire) at Z1 compression. At Z1 exhaust, the rotor would be pointing 180° away from the distributor marking. HTH.

Tony

[911pcars]

The classic symptom of a loose tensioner is a loud audible sound at idle, that of metal bits rattling inside a metal trash container. The sound diminishes as the engine speed increases. Listening with a longish hose directed at each chain box cover will help isolate the noise and confirm the source. Once confirmed, DO NOT operate the engine until repaired. You may be past this point in your diagnosis.

A photo of each chain tensioner can also confirm the tensioner has collapsed.

Hope this helps,
Sherwood

[aston@ultrasw.c]

Originally Posted by JamesG4381

These questions are for a 1982 911 SC Targa

I have a quick newbie question. How close to the Distributer TDC cylinder 1 mark should the rioter point to when the crankshaft timing mark is at the Z1 location. Should it align with the end corner of the rioter contact or the end, middle??? I've not been able to get a clear illustration.

I found that one side of the rotor arm was aligned with the timing mark on the dist body.

Try installing the distributor one tooth off on each side and you will see that in those positions it is way off.

[Walt Fricke]

I'm with Aston. That mark is just there to get you on the proper teeth when reinstalling the distributor. There aren't that many teeth on the distributor, and only half as many on the crank, so fine adjustment of rotor position is not possible. Anywhere on the arm end will put you within the range of adjustment of the distributor to bring the timing in where it should be, using the regular adjustment system with a strobe and so forth. Or on a Carrera, where the distributor housing is fixed, and the timing done elsewhere.

[JamesG4381]

Originally Posted by 911pcars

The classic symptom of a loose tensioner is a loud audible sound at idle, that of metal bits rattling inside a metal trash container. The sound diminishes as the engine speed increases. Listening with a longish hose directed at each chain box cover will help isolate the noise and confirm the source. Once confirmed, DO NOT operate the engine until repaired. You may be past this point in your diagnosis.

A photo of each chain tensioner can also confirm the tensioner has collapsed.

Hope this helps,
Sherwood

Does your last statement infer I can look at the tensioner and see the defect. What does it look like. I can get a picture but not as quickly as I would like a response if possible. I would like to know how to tell definitively if possible.
Thanks
Jim

[Jesse16]

What Aston and Walt said. Mine did not point directly at the mark when I was reassembling my motor last winter but if you tried to move it to either side, much worse. It not "adjustable". Ran great in the end.

[tharbert]

No, you cannot visually inspect the tensioners for defects while they are still installed. I'm not sure I've seen a definitive test for failure once removed. I do know that my failed tensioner could be depressed with my thumb. I'm pretty sure that's not enough to make any difference. The rattle sound at idle and deceleration are fairly certain clues.

There are LOTS of threads about tensioners here. Do a little searching and read up on the issue.

You can get collars for around $20 that are supposed to save you from failure (99-0458-053-M230). They do absolutely nothing to help you once a tensioner has failed. In fact, my car's P.O. had them installed. I found one in pieces in the sump. I'd stay away from those.

You current tensioners can be rebuilt. I don't have the P/N of the kit handy. Maybe someone can chime in with that. There are a few threads about the process here.

The route I went was to install the oil-fed "Carerra" tensioner kit (10-0445-105-M260). It's a common upgrade and you will see some pros and cons about them. Cons: Kits are expensive and they have been known to fail too. Pros: They are Porsche's answer to the problem and they do work perfectly for most people: it will eliminate the noise probably forever. You can find used kits in the parts forum occasionally but the kits come with new covers, revised oil lines, tensioners, gaskets and nylock nuts.

Rebuilding your current tensioners or installing the Carerra tensioners are fairly simple DIY jobs.

Good luck and welcome!

Tom

[JamesG4381]

OK, I've decided to replace and upgrade. From what I have read since mine is an 82 SC, I should have the updated pullys and rails with no spacer required. I think I order the `$900 kit. Is there a way to tell proper pullys. I also think my guide rails are good again any way to tell? They appear to have no marks and are in good sghape. Any ideas about these replacement. The cost is not much but I am afraid the more I doi the more introduction of unknown or my screw up. Also I am having trouble identifing if cams are correct at Z1 on poully. The nots I've seen leave me dazed and confused. Any help would be appreciated. Sometimes less is more for a newbie. I tend to think I can do it all, being an automotive engineer (electronic However), It can be rather scarry at times.Just ask my wife.

[tharbert]

There is an article in the Tech Info Center about timing.

You might be best served by getting a copy of Wayne's book to fully explain setting or checking timing.

Here's a link you may find useful.

Chain ramps (rails?) are inexpensive, relatively easy to replace, and can be done without losing timing. I plan on changing mine when I pull the engine for a top end refresh but I didn't bother when I installed the tensioners. Also, my car is 10 years older...