are balance shafts supposed to be visable?

Dantilla · 05-25-2008, 07:24 PM

I'm not sure. Good or bad? What do you think?

mattdavis11 · 05-25-2008, 07:57 PM

Damn! What happened?

Dantilla · 05-25-2008, 08:16 PM

Race car. I noticed a bit of smoke in the cabin, and a few seconds later, saw a fog bank coming from my car in the mirror, and decided it was time to get off the track. I quickly shut off the ignition, and coasted to the nearest guy with a fire extinguisher.

Looks like the saddle that holds the balance shaft bearing pulled loose. It was missing. Nobody I know in the 944 world has seen a failure like this before.

Basically, the failure allowed oil to squirt directly onto the header, causing an unbelievable amout of smoke. There was about 1 quart left in the pan when we drained it. The entire underside of the car was coated in fresh Mobil 1.

The good news? The car was back on track the next day.

Anybody want a good deal on some Hoosier tires soaked in motor oil?

A wider shot shows the oil that burned onto the hearder.

mattdavis11 · 05-25-2008, 08:25 PM

Hmm.... race car eh? Did you pull them (upper lower b-shafts) altogether and block that side off, or decide the vibration is too much for the motor mounts/drivers teeth? Where can I find that rear control arm bushing? Good looking car from underneath, minus the carnage. Sorry to hear, tis the first I've heard/seen, glad it didn't completely ruin a race weekend.

fast924S · fast924S's Garage

WOW, I have never seen them do that before LOL. Well at least it wasnt the whole engine. Good think you were paying attention and saw the smoke

bholmes · bholmes's Garage

LOL you musta been makin those balance shafts work! I see what you're talking about the bearing cap/saddle missing. Musta vibrated the bolts loose and blew that puppy right out the side of the case.

Dantilla · 05-25-2008, 09:14 PM

Quote:

Originally Posted by fast924S

Good think you were paying attention and saw the smoke

Couldn't miss it.

WaA420 · 05-25-2008, 11:05 PM

My '86 951 did that same damn thing and it rattled like a sum*****. Made the oil pressure low so the rod bearing got replaced only to find out the cap on the balance shaft had come loose some how. Weird.

mattdavis11 · 05-25-2008, 11:53 PM

I'm curious. Who pays much attention to the lower blance shaft and housing? I won't even begin to lie, I pay no attention to it. However, it is in the high heat zone, and it might should. There a lot of miles on my motor, maybe gaining on 200K, but that is guess work. My speedo/odo was opened up (apparent by my own eyes by prior scribes) months before my family bought it, and at that point it was 67K. I just figured 8 years (83-91) that the po drove it like I do, but who knows. My father put 48K miles on it, but then again.... that little gear, and it quit in 99-00? He lost 2 belts after the odo quit on him, catastrophic failures both times. I'm/hopefully we are smarter now, but I know I don't have a time bomb. I hope, and that's what begs the question. Was that motor over 200K? I'm pretty damned sure mine is, but I don't race.

Slam · 05-26-2008, 11:22 AM

Well, since the balance shaft is in itself unbalanced (to counteract unbalancedness elsewhere in the motor) I could see how the bearing would wear and then the shaft would essentially vibrate/knock that bolt right out of the bearing cap.

Aren't the housings machine-matched to the block? Does that mean your engine is dead? That's a helluva failure!