Abnormal rotor wear. Housing okay?
 

So my FC spun the bearing on the front stationary gear. Rear rotor was fine but the front was hitting around 30psi on all 3 faces. I was suspecting a stuck side seal which was somewhat right as the side seals were smashed into the grooves. So much so there is about an inch of seal on each side that won't come out. Check out this pic.

http://www.flickr.com/photos/brian_s...ch/, on Flickr

You can actually see the side seal grooves get smaller so I started looking at the rotor itself. On every side there is what seems to be abnormal wear where the rotor was contacting the housing.
http://www.flickr.com/photos/brian_s...ch/, on Flickr
http://www.flickr.com/photos/brian_s...ch/, on Flickr
http://www.flickr.com/photos/brian_s...ch/, on Flickr

My theory is that when the bearing went that rotor was spinning off axis and it started scraping the housing enough to smash those side seals right down. Here's some pics of the housing.

http://www.flickr.com/photos/brian_skotch/9062965468/http://www.flickr.com/photos/brian_skotch/9062965468/ by http://www.flickr.com/people/brian_skotch/, on Flickr
http://www.flickr.com/photos/brian_s...ch/, on Flickr

Good side
http://www.flickr.com/photos/brian_s...ch/, on Flickr

Worn side
http://www.flickr.com/photos/brian_s...ch/, on Flickr

SO MY QUESTION, is if I can use this housing in my rebuild? I know I'll need a new rotor but what about the housing. It's not a scrape that you can catch your nail in or anything, just don't know if it'll affect the performance.

Any help is appreciated. Thanks guys! :icon_tup:

I wonder if the rotor is salvageable if you had a jeweler's file and could fix the clearance on the seals.

The rotor housing.... is iffy. It's very hard to see if there's noticable warpage. Check your PMs.

At the very least, that spot in the rotor housing is literally at the least important point for sealing, but there's still a chance for exhaust residuals to come through and for the apex seal to be oddly loaded. What's hard to say is if it's worse than the blowby you'd get from a flaked housing.

Get a straight edge on the housing, have a flashlight handy. Turn out all lights in your workspace then use the flashlight and straight edge on the housing mating surface to see if light gets beneath the straight edge. Not exactly high end testing but will give you an idea of what you are dealing with. This would likely be a great housing to send off for resurfacing.

if the rotor has turned a bearing.. unusable

if the stat has dropped and those side seal grooves are pinched then it is also very difficult to salvage,, move on

.. area of concern on housing is at minimum impact to compression
and would be OK as a fix upper and possibly get better over time


expect would be totally fixed with hone process from goopy or NRS but then require new apex seals and springs for rebuild

measuring a cast housing in that fashion won't give you any definitive results at all. the thickness is going to vary a bit from any point.

the housing and rotor look fine to reuse as long as the slots are run through and won't pinch the new seals. that wear is in a non critical position and looks minimal but resurfacing should clean it up to basically new again if it isn't that deep(and i doubt it is).

the e-shaft will wobble at high RPMs when any bearing fails, this also allows the rotors to cock and run on the corners which subsequently pinch the corner seals and wear the apex seal ends. usually unless a seal actually lets go those rotors are completely reusable.


this is actually a fairly common occurrence. i've fixed about half a dozen rotors in the past several months with even more scuffing.

not necessarily true. Goopy can machine some spun-bearing rotors to accept his oversized bearings. there are limitations of course and I have no idea if this rotor would have been a candidate even if the side seals grooves were not screwed, but a spun bearing no longer equals immediate relegation to the trash.

they are probably renesis bearings. as the MSP has introduced more than just 1 standard size bearing for OE applications.

i haven't yet really looked into it as i haven't had a need to yet, spun bearings in rotors are uncommon unless you're doing some stupid shit you shouldn't be.