• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Alternator belt...$5 Damaged caused by belt...Priceless

sugaryuk

New member
Finally got the Vega running decently, turns out that a plug boot that was wrapped in header tape was actually disintegrated under the tape. Anyways spent the week getting her ready for a big car show, installed a new used Cosworth Vega black interior I scored off craigslist and polished her all up. Decided to fill up the tank the night before the show, so headed up to the station a couple of miles away. Cruising about 40 I feel the motor hiccup a bit then I hear a fairly loud 'crack'--tough to hear because the exhaust is frigg'n loud. Soon motor feels like its stressing and loosing power and heats going up fast and oil pressure dropping. I manage to coast into the station where it begins to spew from the heat--about 260 by now. I get out and immediately see that the motor's thrown the fan belt-- but its wrapped up under the blower drive belt-- I suddenly don't feel so good :th_shakinghead1:. I manage to untangle the alt belt and it's still in one piece but the blower belt is now loose and stretched out of shape. I only had vice grips with me but I managed to get the alt belt back on and the blower belt seemed tight enough for the short trip home. I filled up the rad and started it up-- blower belt is shaking all over and the alt belt flies off. Shut her down and then grabbed hold of the crank pulley--I could move it about 1/4 " up and down-- now really feeling shiitty.

I get it towed home and dug into it today...pics tell everything. When alt belt jumped onto the blower drive it must of created enough pressure to snap the front journal off the crank--thus the 'crack ' I heard. So now I have a $18k motor killed by a $5 belt.
attachment.php
attachment.php
attachment.php
 

Attachments

  • DSC05806.JPG
    DSC05806.JPG
    139.3 KB · Views: 135
  • DSC05807.JPG
    DSC05807.JPG
    139.8 KB · Views: 135
  • DSC05805.JPG
    DSC05805.JPG
    158.8 KB · Views: 134
Last edited:


NOOOOOO! Damn. Moment of silence-

Well... if it didn't by chance have a specially intended blower crank, nows the chance to add that. Hokey Smokes I knew blower drives were tough on snouts but oh my. Condolences, positive vibes, whatever. That sucks but you'll come up with something, maybe more viable on the street in the end.
 
Sorry to hear about this. I secretly love when you post in threads i read so I can stare at the blower and bug catcher in your signature. Hopefully you rebuild quickly (and cheaply).
 
The belt didn't break the crank, more like the belt flew off after the crankshaft broke. I would definitely complain to the manufacturer of that crankshaft about the carnage, but fortunately more is not damaged.
 


The belt didn't break the crank, more like the belt flew off after the crankshaft broke. I would definitely complain to the manufacturer of that crankshaft about the carnage, but fortunately more is not damaged.

Not saying that it couldn't of happened that way but from what I felt and saw it looks like it was the belt to me. Take a look at the pic of the alt belt-- you can see some cogs missing-- previous damage from when belt was thrown due to a busted alt bracket-- my fault for being a cheap bastard and not replacing it. The alt bracket is shakey at the best of times due clearance problems from the custom motor mounts and the hood, it's the best we could figure out to work. And chrome pulleys are pretty notorious for throwing belts--not a good combination but it looks purdy. The way it happens kind of supports my theory-- car was driving fine until I noticed something acting up, drove like that for about minute or two and then I heard the 'crack' and thats when it started shutting down. The alt belt was actually wrapped a couple of times under the blower drive belt--creating an enormous amount of tension (enough to stretch the blower belt) on the end of the crankshaft-- and it doesn't take much tension to snap a crank. Either way I'm still screwed.
 


Ouch that do any look like a stock crank either. Man that sucks.

Jeff

Kinda what I thought-- apparently I was wrong. I got the motor out last week and sent it in to a local speed shop. Guy said at first glance he thought it was a forged crank, until closer inspection revealed it was a cast crank which had been polished up--wtf?? Why polish up a cast crank? Why a cast crank in a blown motor???:mad: I guess it was all about feeling pretty on the inside. Looks like the builder is talking me into getting a 'real' forged crank, hydraulic roller cam, new roller valve train and all new bearings and rings and all the machining you could ever want...$$$ Price to pay when dealing with a race shop. He said it was just a matter of time before the crank let go-- lucky for me I wasn't into it at the time! Sucks that it's going to be off the road during car show season, but gives me time to clean up things in the bay area now.
 
Back
Top