And THAT, is why you turn your rebuild over by hand a few times to make sure that things are seated.

My guess goes along with the "He didn't bolt the gear down" crowd... that's the only possible explination! It would take upwards of 10,000 RPM on S4 stock internals to reproduce that, I would think...

ouch... :eek: that gear got raped. the rotor looks perfectly new though...bummer, let us know how it happened.

Nope that gear is bolted down perfectly.

fuckin shit. . . not much else to say

You know it looks like the aligning pin that holds the stationary gear was prob. in place.
If you look at this pictre where the pin fits in you can see where the pin bucked up against it. So, it was prob. there.
http://wreckedyouth.com/modules.php?...view_photo.php

Best I can think of is some how the rotors were not put in correctly and didn't mess correctly against the teeth of the gear in the rotor and the stationary gear.

Kinda intresting in this picture how you can see the INSIDE of the teeth messed up. Maybe that was after the intial failure and it started hitting the eshaft.
http://wreckedyouth.com/modules.php?...view_photo.php

Its amazing how destroyed the bearing is inside the stationary gear.
http://wreckedyouth.com/modules.php?...view_photo.php

James

I was studying the pictures, too Wankel7.. I can't come up with a good explination, especially since it was bolted down right..

Curious indeed.

The condtion of the extrernal of the engine leads me to beleive that it wasn't a fresh rebuild, alot caked on oil on the blolts, housing, caked on gasket on the housings.. And apexseals on the front rotor seems to have been broken in due its nice smooth curve. Also the impression the guy gave me.. made it seem as if he was running it for a while before it went. I'm pretty sure it had a few thousand miles..but defintly rebuilt receintly.

Still waiting on the guy to respond.

All emissions were removed, removed OMP and premixed.. maybe thats why the lack of carbon build up?

You can't really judge mileage of a motor just based on carbon buildup on the rotors.. I can show you pictures of rotors that came out of my motor that had 50,000km's on it .. it came out just as clean, if not cleaner than the rotors that came out of this motor..

yeah, but visible Hylomar? That stuff has a tendancy to "absorb" into the car.. looking like just more oil/gasket junk. When I had to tear down my engine @ 5000ish miles, I couldn't really descern hylomar anymore.. I'm saying the engine had less than 6k on it.

We neeeeeeed to know HOW that actually happened :confused:

i cant get over how SMASHED the tips of that rotor are.

man that is the worst engine failure ive seen so far

WOW!! I bet you that made a pretty noise ;)

Overreved or lack or oil...maybe rear OPR failure?
The burned rear stat gear bearing looks suspicious...


-Ted

I would like to see the pics.

Well I'm the one he got the engine from, so here's the story (already sent the basics to him via PM).

I bought the donor car intact. The thing drove poorly. Lots of hesitation/bogging. I thought at the time that it was mostly caused by bad timing/TPS. I drove it about 100 miles home, and basically babied it the whole way (limited to about 3k rpm).

Got it home and started the swap to my base. I knew the engine was suspect but for the price I paid, just getting the rear end and tranny was worth it (had just chewed up my previous NA tranny.... that one was my fault). Anyway, swapped the drivetrain over. New fluids. Premix. Replaced TPS. First thing I did then was check the compression. Front rotor looked okay... rear rotor was low. I then took it out for a drive. Again, I babied it... first while I was warming up... then because it just didn't sound right. Didn't go above 3k once.

I drove about 10 miles... and then appearantly this is what happened. Basically the engine seized completely. Tach dropped to 0. I pulled it out of gear and coasted to the side of the road and called up the tow truck. That's the last time it ran.

The guy I bought it from said it had been rebuilt but didn't say when or where.

I'll admit I've done some dumb things with a wrench in the past but all I really did with this engine is move it from one chassis to another (something I've done a good half dozen times now with no problems). At this point I'm as curious as everyone else as to what may have caused the damage.

If it wasn't overreved, then it's almost guarantee lack of oil in the rear stat gear bearing.
In one pic, the bearing is burned, so it tried to seize there.

Was the OPR on the rear iron still intact?


-Ted

My thoughts exactly.... rear OPR failure, even extreme rear rotorbearing play can not cause the damage in the pics.

A quick question tho, i've seen "lack of oil failures" (thermal pellet, ect) but never saw OPR failures, and for sure no "only rear" OPR failures, i can't even understand why only the rear.

Anybody? Ted?

Oh, I have. :(
I seen the rear OPR fall out, and this drops oil pressure to the rear stat gear to drop first.
Although it wasn't as catastrophic as the pics, that particular engine burned the rear stat gear bearing and the rear rotor bearing; the engine was in the process of being broken in after a rebuild, so the easy driving miles probably is what saved it.
The front stat gear bearing and front rotor bearing were both in perfect shape...


-Ted

cant the wear on the bearing be cause by the collasped stationary gear instead of oil?
i mean - when the clearance on the rear is none - it wouls squeeze the shaft pretty hard and create lots of wear.... might not have anything to do with oil? maybe the last owner who rebuilt it left someone hard on the part where the gears that touches the stationary gear there... i dont know, a piece of metal or whatever and when it moves, it crushes the gear, bends the stationary gear, forces it against the e-shaft, create the damage? and when it turns..........?

You said "it just didn't sound right"

I guess not..

Well then I guess it wasn't do to over reving, rather some kind of oil failure.

Hard to tell from the pics, but the burnt sections of the rear stat gear bearing looks almost uniform?
If the rear stat gear wiggled loose, it would tend to wear at certain spots first?


-Ted

not sure, but im sure you would know more about this than me
i just would not think just lack of oil would cause that kind of damage... it looks like something was caught in the gear and forcing it... it looks like something was jammed between the gear and pushed the rotor gearing upwards - the rotor itself looks like it got the gears banged outward... - and at the same time, pushed down at the stationary gear itself... - along the gears are all chewed and it looks like it had been chileld and shavings were everywhere....

maybe a gear broke - and that little triangle moved, jammed against one of the rotor gears and when teh thing turns around.. .chewed off more gears, breaks, etc etc????