Is it alright to have a machine shop "boil" rotors & irons (like they do with blocks)
 

I have a set of rotors with some surface rust in the cooling jackets but are near perfect otherwise, I've checked them with the appropriate measurement tools as per the FSM. I'd like to avoid throwing them into the bead blaster. Will it hurt to have them boiled by a machine shop like a piston engine block? I'm concerned that it may cause an issue with the rotor gears. I'm not even sure how the rotor gear is held in place and don't want to mess with it. If you know an easy/safe way to remove/reinstall the rotor gear please share it with me.

BTW I am replacing the bearings anyway... I realize that they will be destroyed.

I don't think having the irons done will be an issue at all. Bead blasting won't be a problem but having a machine shop do the work will be so much easier and faster.

never separated a rotor from it's gear before, but i believe it's held on by those little pins you see around the circmference. perhaps they are similar to the pins that hold the exhaust port sleeves in?

anyway, what i really wanted to say is that if you do separate the gears, i'd be concerned about them tending to walk after that. i know RB has a process where they add circlips or something. check with them to see.

I thought the gears were held on by the 8 or so bolts on the outerside of the outermost endplates. Unless you are running a crazy amount of power, just retorque according to fsm.

As far as boiling, i wasn't aware that would take off surface rust. If I were you, I would just get any debris out that may clog things up. Maybe use a small wire brush on a dremel too or drill to get the surface rust off if you so desire.

As far as I know boiling is an acid bath that strips everything off to bare metal. Rust and all. I left my brother a voicemail. He built a Chevy 355 about a year and a half ago and had it done (plus hes a deisel and automotive technology dual major). I saw the block... it looked like a fresh casting of iron.

I think we are talking about two different sets of gears. The ones on the endplates are stationary gears whereas the rotor gears are in the center of one side of each rotor.

as far as the boiling/acid-dipping goes, the only thing i can say for sure is that i don't know enough about metallurgy to answer with certainty. i know it's good for engine blocks and car bodies, but i'm not sure about rotors. i suppose if it were done, i might be very concerned about the surface of the rotor faces, but if no ther harm was done in the process, then you could just polish the faces.

i've read a few of Rxbeetle's threads and he seems to know a great about metallurgy, maybe you could shoot him a PM. others that come to mind that may be able to better help you are: Rotarygod, Bluetii and Peejay. i'll go out on a limb and say any one of them may be happy to advise you on that subject.

good luck and post any answers you might get. i'm interested, too.

on an aside, i usually store my rotors in oil or vaseline and newspaper.
yes, those are the stationary gears, not the rotor gears. they are what the rotor gears traverse in their rotation.

DUDE... just get them cleaned in a sonic bath. Put the rotor housings in there while you're at it. (read if from some smart dude on here)

Will sonic cleaning remove rust?

yup

I had a four cylinder dipped about 20 years ago. As I remember it came out very clean, but there was 'grit' in a lot of places that had to be cleaned out with pipecleaners.

For a rotary, I would worry that this grit (if it is the same process I used) will get into seal and spring recesses and may clog up the works when the engine is assembled.