axl911

Broken at 80K miles on my former 964. Not broken at 135K miles on my 993 when I changed it.

IXLR8

I got mine from Pelican.

I tried Sunset but they're not available from Porsche anymore.

Ocean Blue C2S

Porsche "blew" it on our 993s. Remember on the Fuhrman, 4Cam engines you could "stop" one of the distributors from firing. These Porsches had a "kill" switch for each of the distributors, that would prevent misfiring as to alluded to here. A switch on the dash for each of the distributors would allow the driver to "test" the dual-plug engine. I remember testing a 1964 Carrera 2, stopping one of the distributors from firing dropped the RPM by about 200RPM, at speed.

It would be good to have... any technical wizards able to convert our dual plug 993s to a similar system?

Bert

IXLR8

Sounds like a mag check on aircraft.

1pcarnut

Just what I was thinking. Might be nice.

Mike J

That would be no big deal, since each distributor has a separate coil. Just put a switch in that effectively disconnects the coil, no coil to charge, no ignition...

Cheers,

Mike

Mike J

Thanks Steve, but what is "plenty"? Since you mostly see cars when there is something to be fixed, it biases your count. Out of the pool of cars that come in for issues, what is the rough % of those issues related to a broken belt?

Gunter makes a good point, the bearings are odd-ball, and apparently the source is consider confidential, but this is something that us DIY types should have available.

Cheers,

Mike

IXLR8

Well if that source thinks I'll bow at the ankles, they are dreaming.

If I don't mod a bearing at home, it'll be done at work.

MarkD

only belt we've seen available is a Gates product.
as previously mentioned, Porsche does not supply it.

Seen failures but not on my own 964 or 993s over the years. Fortunately, no catastrophic results but as Mike J outlined, this is a matter of luck.
Voted no...

csertich

Seems the age of the belt in our cars should be considered. I had mine replaced a couple of years ago at 40k miles. I guess that could have been premature but it made me feel better.

chuck

MarkD

oh, and the belt itself is like $7 or $8

pcarhombre

Figures I would be in the "had-it-happen crowd." If you search you can see pic of my cap that looked like some alien death ray got ahold of it. It went at about 112k. Fortunately, nothing else seem to be amiss. I noticed there wasn't as much power as before and took it right in.

briefescape

Replaced belts in my 993s even though still look good but like you said Steve I too had bad bearings in one of them .

here was the fix
used ball brg NSK 6201-08DDU, but there are SKF/NTN/*** equivalents.
Basically a double rubber sealed 6201 ball brg.
These brgs are the same dimensionally except for the ID wich is 0.5mm dia. larger.
Prepare the brgs in advance by wrapping 0.25mm thick shim stock of appropriate x-y dimension around the shaft, and apply a bit of retaining compound to the ID of the brg so that the shim/sleeve is glued to the ID of the brg.
You will need a blind brg removal tool to remove the olds brgs.
I think the brgs were around $15 ea.

Cheers Guy

Slow Guy

No belt problems on the 2 993's I've owned. Now vincer77's '97 w/ 72 kmi. and current '97 w/ 35 kmi.

Jeff96-993

My bearing crapped out at 57K miles, which caused the belt to snap. I was ready to replace the belt at my 60K service, but the bearing problem pulled that in by a few thousand miles.

When it happened I got the random-misfire code immediately. Pulled into a parking lot, diagnosed it pretty quickly as secondary distributor problem, and pulled the coil. It was down on power on the way home, but no additional damage.