mwneedham

I know the vent kit modification was supposed to solve early failure of the dist. belt due to ozone build up.....but it did not cure old age. Lost what I assume was the original 17 year old belt on the track... a piston, two cylinders and two heads later, I wish I would have had the insight to replace it. To all you fellow 964 owners, if you do not have the vent kit, get it. If your belt is 5 or more years old, you might want to replace it and save yourself potential major engine issues. Hind sight is 20/20.

Porsche 964.....there is no substitute.

MWN

Weissach911

sorry to hear, that really sucks but good advice

sleder

GREAT advise and that is my plan for this winter. Anyone know where to locate a replacement belt?

sleder

Answered my question: anyone need a distributor belt check out www.ebsracing.com
No affiliation
$11.07 for the belt could save thousands

Indycam

930.602.922.00
part number for the pin .

Steve Weiner-Rennsport Systems

FWIW,..I've always recommended 60K replacement on those belts, based on all the distributors we have rebuilt for people over the past 12 years.

Its also the opportunity to check the 3 bearings, too.

No matter what, its FAR cheaper than buying new P/C's.

Dwane

Get 2 pins...
You'll bugger up the first one and drill it out.

sleder

What pin are you talking about?

TR6

Not to sound ignornat, but how does a broken distributer belt cause pistons to become damaged?

sleder

it's all about ignition timing or should I say lack there of not being there...then you will probably end up replacing a couple of heads, some valves, a couple of pistons and lets not forget the machine shop expense.

TR6

Wouldn't that only happen if the car were run for quite a while with a broken belt?

sleder

If you under acceleration that is what happens, if you aren't I have seen someone get away without an issue.

Steve Weiner-Rennsport Systems

The question of potential damage depends on where the lower rotor comes to rest after the belt snaps.

If the rotor tip happens to be aligned with one of the electrodes inside the cap, that cylinder continues to receive a spark at the wrong time causing detonation and sometimes pre-ignition (after things get too hot).

It doesn't take that long to happen for the unwary,...

Most folks simply aren't sufficiently sensitive to detect the loss of power when the lower plugs are no longer firing and if they do, its chalked up to gasoline, a hot day, or not at all.

At the very least, I like to pull the lower cap off at each oil change to make sure the rotor isn't spinning freely indicating a broken belt.

sleder

Steve, You are the Porsche answer man for sure! For everyone that doesn't know Steve, you want to! He is a HUGE asset to this forum.

Henry964

I´ve just had it done (new dist belt plus vent kit) the used belt had 8 years AFAIK but it was in rather good shape.
this was a very worrysome issue for me....