just heard the bad news (timing belt)...

neuronflux · 01-03-2003, 04:09 PM

Well, I had just driven back from SF to LA with no problems. The next day I go to start up the car and it didn't start. The engine wasn't cranking, so I had someone crank it, and could see the pully moving, while the timing belt wasn't. I flatbedded it to the mechanic today who verified it was the timing belt. Is there any chance nothing was damaged since the car wasn't running and the belt either broke during shutdown or attempted startup? I didn't hear any crunching metal or anything, but I am assuming the worst. Is it worth opening up the head to check? I really don't feel like pouring more money into this car at the moment..

Just for your info, the timing belt was almost at 40k, and I was planning on bringing it in for replacement 2 days after this happened.

SoCal Driver · SoCal Driver's Garage

What year and model, how many total miles?

neuronflux · 09:50 PM

Sorry, forgot that info. It's an 87' 944S w/ 108k.

Also I changed my mind already, I will look into rebuilding the head. I was just so pissed at what happened.

SoCal Driver · SoCal Driver's Garage

944S...ouch!!!!

Think at least eight valves if not twelve.

Then some of the teeth on the cams for the cross over chain might be missing too. Double ouch!!!

Hopefully the cast mounting for the hydraulic cross over chain tensioner is still there and not cracked.

I'd guess about $3,000 to almost $4,000 to have a shop fix it.

Moneyguy1 · 01-04-2003, 11:40 AM

Sad, isn't it? The 924, on the other hand would be no problem. True Story. About eight years ago, driving home from my buddy's the car quit in the middle of a country road. There was a small shopping center about a eigth of a mile away. I pushed the 924 there and under the parking lot lights installed my spare timing belt and drove home. (later I changed the lower cog wheel, it was worn and had damaged the belt, but that is another story.) I now have a 944, and shudder thinking about the same problem happening on a lonely road at midnight out in the country.

Good luck with the repair; you may want to check with some of the used parts outlets for a replacement head in good condition. It might save you a few bucks.

Bob S.

SoCal Driver · SoCal Driver's Garage

924 = 115 HP

944S = 188 HP

I'd take a broken 944S any day.

ImClueless · 01-04-2003, 03:57 PM

924 = 115 Hp
944S = 188 Hp
951 = 210 Hp

Ill take my broken 951 any day.

LOL

Moneyguy1 · 01-04-2003, 04:01 PM

A running 924 will outdistance a "broken S" or "951" anyday!!!! Plus, taking the original NA 944 as an example of a non-modified engine, the HP per liter is approximately the same as the 924. So why the interference design inthe 944? I have not been able to figure that out. Just curious...

Cheers, guys....

Bob S.

ImClueless · 01-04-2003, 04:04 PM

yeah but i can say "its a turbo" chicks dig that ****.

LOL

SoCal Driver · SoCal Driver's Garage

Quote:

Originally posted by Moneyguy1
A running 924 will outdistance a "broken S" or "951" anyday!!!! Plus, taking the original NA 944 as an example of a non-modified engine, the HP per liter is approximately the same as the 924. So why the interference design inthe 944? I have not been able to figure that out. Just curious...

Cheers, guys....

Bob S.

Because the 924's American Motors (Rambler) tractor engine had to be fixed by Joe Farmer???? Actually was an Audi design that was sold to Rambler.

An interference head improves the flow of gases in and out of the engine improving torq range. Also has a bit to do with flame path (that's the shock wave the ignited air/fuel mixture makes).

I had two new 924's and they couldn't get out of their own way. Get them up to speed and hope to heck the CIS stayed working and they were great cars.

Moneyguy1 · 01-04-2003, 04:31 PM

Hugh..The point being that the 944 engine is a full half liter larger than the 924 engine and the hp per liter is virtually the same. The concept that an engine has to be interference might hold water if the output of the NA 944 per liter was closer to 100 HP. And, if you look at the racing history of the 924, they did a heck of a lot with that old "tractor engine". I have built dozens of engines over the years, Porsche, Audi, VW, and even (egad!!) American iron. I see no magic in the Porsche designs. I too had a 924, and it was one of the most reliable iterations of Porsche I have owned (356, 912, 924, 944), despite its humble origins.. But, as I said in another post, both the 912 and the 356 were even more user friendly. Not trying to start an argument here, just stating the obvious. The NA 944 engine is NOT a high output per volume engine and therefore the interference design does not appear to be a necessary weak point.

Cheers!!

Bob S.

overkill · 01-05-2003, 06:43 AM

neuronflux, are you capable of disassembling/ reassembling the engine? Well, I thinking that it might of broke after the car was parked. Where do you live? If its cold, your belt might of been holding on by a thread. When the belt cools off it shrinks a bit. could of just snapped. Atleast it didnt break while you were driving it. You'll save alot of money if you tear down your own engine. We are here to help you bro.

neuronflux · 01-05-2003, 02:57 PM

Hey Overkill, I don't have the tools/place to work on the car myself, so I'll be paying for the labor. I live in Los Angeles, so I don't think it got much cooler than 45F at night.. but maybe that's what happened. The head will be going to the machinist tomorrow.. I'll keep ya posted.