Howdy all, just wondering if scratches like these are common on rotor gears, if not (or if so aswell) what causes them?







Would it be from the shattering apex seal that happened on this rotor? https://www.nopistons.com/forums/pub...DIR#>/wink.png

guessing here but i'm thinkin something in oil or hard carbon build up on housings?

I've seen that before too. Weird.

the rotor gears are pinned to the rotor, they CAN come out if u overrev the engine, check the clearances of the rotor width and rotor with with gear. and the housing u have used that rotor in.

Well both my rotors on both sides are like this, so im thinking oil contamination... I don't know exactly what I should be measuring, but they're definatly well 'inwards' compared to the oil control ring.. so I don't THINK they've walked??



Would you all reuse these in a rebuild? I mean to me at least they don't look structually effected by this, but im certainly no expert..

he means take a micrometer to the rotor measuring on the gear in multiple places and record to see variances, also measure the width of the rotor housing and compare data. i doubt they came out and are probably in reusable condition. unless cracking or deep scratching is obvious. p.s. i fixed your pic

you need to measure the rotor width at the points closest to the apex AT the gear so its closer to the inside of teh rotor toward teh bearing, and then measure the rotor housing. the standard is .0047-.0083 of an inch and the clearance is .0039 of an inch

Hmm.. okie dokie.. Looks like its time I go out and buy a micrometer then.. https://www.nopistons.com/forums/pub..._DIR#>/sad.png



But no theres no deep scratching, I can't even feel it with the tip of my fingernails..

Also some very light scratches on the bearings that I didn't see before, so yeah oil contamination is what its looking more and more like.

The rotor is still OK after an apex seal broke up?



It is common to have a gear walk out of the rotor and drag on the center iron.



I just keep them slicked up with a piece of fine paper on a disc sander.



Wash out the rotor, and blow air around the area where the gear moving will leave a small gap. A chunk of crap under the gear may become a problem.



Place a block of aluminum on the face of the gear. Place the rotor on a piece of 3/4" plywood and us a press to push the gear back into place. With no press, just swat the aluminum a few times with a hand sledge.



Kill some 600 wet or dry paper by rubbing it against itself under a stream of solvent. Gently sand the rotor bearing with the killed 600. It will just shine things up a bit. Just take off the rough area around any damage.



Remove any carbon build up from the side seal, and apex seal grooves.



Wash throughly in solvent and blow dry in the open wearing safety glasses.



No problem.



Lynn E. Hanover

Yeah the rotor is otherwise in pretty good condition, i've nearly finished cleaning it all up, and i'm just about to order some new apex seals, so i'll grab so more pics for you all in a few weeks.