Chucker

Cruzin through the local paper today I found an 83 928 for sale. Red 80,000 miles, new custom exhaust, new wires, and all the parts for the timing belt/water pump change. $5,900.00 When I spoke with the guy he mentioned that the timing belt was not done yet because someone in Calf.(one of the big three) told him that the engine was a non-interference engine and that the timing belt was not an issue. I was ready to do mine (82 928 w/71000 miles) because I thought that it was/is an interference engine and I do not want to run the risk of smashing it together at 100 mph. I know that there has been some discusion about this. What years do you need to worry about? And if anyone is interested in this car I can look at it and the phone number is 1-231-276-6682. This car is in Northern Lower Michigan. <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Chucker
1982 928 White

Bruce Sinclair

I have an 82 and the day I bought it the timing belt failed on the way home. It was just like I had turned off the key. I put on a new belt and associated parts and the car ran better than before. Apparently my engine suffered no valve damage as that was 15k miles ago. So maybe it was just luck or my engine was not an interference model. If you are unsure of the history of your car change the belt and waterpump.It's cheap and major engine work is not. Peace of mind when driving a shark is priceless

Chucker

Thanks for the responce Bruce. I would love to put off the timing belt/water pump cost for a few months if I was sure that damage would not happen.

Chucker
1982 928 White

tdelarm

Chucker,
I did a little research for you on this subject and at this point have yet a confirmed answer. But here is some info I found from the guru's of 928's you may want to check out. Quoting Wally Plumley-928 specialists "At some point, the 928 engine changed from a "free-wheeling" to a "interference" or "valve-crash" design, but there is no universal agreement on exactly when this change occurred. This means that on all except the earliest two-valve cars, timing belt failure of slippage can cause the pistons to hit the valves, resulting in major damage to the engine. "A toothed belt tension warning system, which can give early warning of a belt problem, was added in MY 1985"

Porsche recommends replacement every 60,000k or every 4 years, but many owners prefer replacement at 40,000k with a re-tension at 1500k-2000k timeframe.

<a href="http://members.rennlist.com/v1uhoh/checking.htm" target="_blank">http://members.rennlist.com/v1uhoh/checking.htm</a>
<a href="http://928oc.org/journal/T-belt1.pdf" target="_blank">http://928oc.org/journal/T-belt1.pdf</a>
<a href="http://www.928intl.com/tips/artcl_02.html" target="_blank">http://www.928intl.com/tips/artcl_02.html</a>
<a href="http://members.rennlist.com/pirtle/svc.html" target="_blank">http://members.rennlist.com/pirtle/svc.html</a>

Hope this helps out. I’ll keep researching the issue.

Tim Delarm

Chucker

Thank you Tim, I think that tomorrow I will call Dave Roberts at 928 Specialists and get his idea on this. I did look through the search topic and could not find a definite answer. I have read somewhere in all of this searching about two other 1982 928 owners that had belt failure and lived to tell about it. I wonder if it might be possible to get all of the 928 owners who have had belt failure to give their results along with the year of the 928.

Chucker
1982 928 White

Snowball the 81 white 928

it all depends on where you live and how you drive. manual tranny, hard shifts, desert = shorter interval. auto tranny, grandma technique, garaged = longer interval. my belt is 6yrs old w/40k miles and tensions fine with no visible wear. not going to mess with it for another season or two.

i heard the 78-79 are non-int. everything after is the bonecrusher.

tdelarm

HA! I knew I had seen it somewhere.

Per Kim Crumb, the PCA's 928 tech guru;

The only engines which can turn over with a broken or slipped belt and not experience valve-to-piston contact are the 1978-79 engines with 8.2:1 compression ratio. All other 16-valve engines, and all 32-valve engines, will experience damage.

ALSO;
The belt's tooth profile was changed in 1983. The new belt (called "HTD" for high torque design) requires changing the sprockets on the camshaft, oil pump, and crankshaft.

Boy's...(and girl's)...my work here is done. I now must sleep.

Chucker

Thanks to all. So I have to change it. Does anyone want to go on vacation this summer and come to Michigan and change it for me? I'll buy the beer. Just kidding.. I think.

Chucker
1982 928 White

Randy V

Mr. Crumb's assertion does not jibe with first-hand accounts of early 80's car owners.

This is one area of 928 lore that has never been completely debunked.

tdelarm

Hmmmmm? Damn Randy...now I'm puzzled. There must be an answer to this tho? Let's all think about this now. <img src="graemlins/c.gif" border="0" alt="[ouch]" />

Dan Bise

Randy is correct. 928 International has also confirmed that they have never found crashed valves on any of the broken t-belt US engines they have disassembled starting with the 4.7L and older.

That's good enough for me. It's hard for me to understand why that's not good enough for a lot of folks. Makes the brain itch, I guess, these inconsistencies.

If Porsche themselves shot you an e-mail saying that MY '80+ US 928 engines were all inteference *designs*, would that invalidate the practical experience of so many?

Dan
Pasadena, CA
'83S

Chucker

Now I'm confused. I would love to start driving it and not have to worry and spend the $1,000 on other toys for the shark. I think that everyone out there knows this feeling (fix that or wait and buy that because it looks so neat). Who would know the true answer????

Chucker
1982 928 White

Snowball the 81 white 928

you're going to have to get something from the factory if you want a definitive answer, all else is anecdotal. i would however put great weight into the statements of 928 intl as who else has that kind of experience in parting out and repairing these cars. perhaps if an authority from this board would e-mail pooch there might be a decent response.

Chucker

So Dan, you would feel comfortable driving your car until you get around to doing the belt or it goes? Because I'm thinking of doing that. Just driving it as is, and if the belt breaks I don't need to sweat. Then this winter I will tackle the job of replacement. <img src="graemlins/yltype.gif" border="0" alt="[typing]" />

Chucker
1982 928 White

Dan Bise

Chucker, I guess I wouldn't be losing sleep or white-knuckling every mile around town for fear of the car blowing up.

But if your car needs a belt, it needs a belt. If you're at 71K on the original belt, then the change is long overdue.

After all, the goodies you were going to put on instead won't be much good if they're attached to an immobile car. :-)

Dan
Pasadena, CA
'83S

Dan