...not to mention a stupid one, too.

Had my spare (running, stock) 12A in my backyard for the last 9 months waiting for the time/money to replace my blown streetport. I DID have it sealed and covered and on the back porch away from the worst of rain etc., but apparently not well enough because when I got ready to install it I discovered that water had somehow got into the number 1 rotor through the secondary port. Ouch!!!!!

Now that it's in my garage I found that it was frozen, so I filled every orifice with Marvel Mystery Oil, noted sundown and prayed. After soaking for a few days a little rocking back and fourth on the crank pully broke it free and it started to turn. YEAH!!!!!!! You should have seen the crud that came out of the exhaust ports/spark plug holes... or the tears that came out of MY spark plug holes...

So far, so good but wait, there's more... I found that I could turn it by hand only a few turns before it would lock again. With more than a little prayer to Father-Engineer St. Wankel I then put a socket and half-drive ratchet on the crank bolt and tried again. It started to turn again with very little effort and continued to rotate all the way around again (by hand) until it hits the tight spot and I'm back with the ratchet.

After numerous rotations this pattern has continued, easy for a few then tight. I haven't had the time to take the cap off and try to find out just where the tight spot is but I'm not sure that would matter alot. It DOES seem to have good compression with all the ports and holes popping and hissing in turn at least; there's just this pesky little problem with tightness. The engine that is: NOT my beltline, thank you.

I have a few theory's for the tight spot:

One: A build up of crud has one of the apex seals stuck in it's slot.
Two: A build up of crud is blocking the rotor at TDC or BDC.
Three: A build up of crud was build up in my brain when I didn't protect the engine enough.
Four: I'm screwed, blued and tatooed and heavy drinking is my only way out.

The only thing I can think to do (short of tearing it down and cleaning the living Hell out of everything, which I would hate to do as it is an original engine, not to mention MORE time/money) is to continue to flush Marvel into every hole (maybe while it's on it's side) in an attempt to clean the number 1 rotor. And turn, turn, turn.... Or just ignore it and go ahead with the install in the hopes that high rpm, the wonderful cleaning properties of Shell premium gasoline (it says so right there on TV!!) and 2000 degree exhaust temps will clear her out.

Sure.

And flying monkeys will soar out of my **** orifice.

Any suggestions (short of self flaggelation and a hair shirt) are gratefully welcome.

Please help me O Rotor Gods, you're my only hope to get my little Japanese mistress back on the road and save me from the horrors of front wheel drive. Almost two years so far........

Sanspistons for cleaner, brighter rotors. One way or the other...

 

One hint; the actual rotors turn at one-third shaft speed. So if your "tight" spot comes up at one shaft rotation out of three, you're dealing with an interference between one rotor and one spot in it's rotation.

Oh, and flying monkeys like Oreos. Better stock up; you don't want them to get angry and try to return from whence they came.

 

Rebuild time. Your front plate and/or intermediate plate bit the big one.

 

iron seal + iron rotor + water = rust

 

Good call, rust has built up on the irons and the rotor. You might get lucky and salvage the irons and rotors, but I highly doubt it. The only way to know for sure is to break it down. FWI, if you ever plan on leaving an engine dormat like that for long periods of time, occasionaly pour oil in the intake ports and turn the engine over a few times. You live. You learn.

 

yes. i'd say just pull it apart and rebuild it. it's better than trying to start it and then possibly trashing the whole thing.

even though my unused engines stay indoors and covered, one thing i always do is make sure to put oil in the combustion chambers. i use gear oil because it seems a bit more sticky, but i suppose motor oil could be just fine, too. i also make it a point to randomly turn the engines every so often. another thing you could do is make block-off plates for the intake and exhaust ports. for the future, perhaps you should try that. even if you have to leave it covered up outside as you did, it should be fine.

 

On my spare -SE 13b in the garage (inside, right next to the nice, warm water heater!), I give it 1 crank rotation every couple of weeks - this rotates the rotors 1/3 of a complete turn, and pust the pressure on a different apex seal at TDC.

Sorry to hear about your 12a with the tight spot - my bet is also that you've got some rust in there that's causing the binding. Hopefully, it's only the front rotor housing. if you're lucky, that chromed surface will have resisted the rust, and it's only a rusted up apex seal and rotor.

Either way; rebuild time.

 

I'm sure the side plate is hosed. The nitrided surface becomes soft enough to chip away with a thumbnail. The rotor might be ok. The apex seals tend to survive.

 

Gee, you guys are just BUNDLES of joy, huh?

Seriously, I kind of figured all this, and now I know. Finally got time to inspect the apex seals with flashlight and fingers and, sure enough, two were frozen. Big damn surprise. Filled it full of MMO anyway. Maybe the miracle of the Mystery Oil will solve all my problems?!

Drinking the stuff would probably work better. And faster.

Well I guess this is my accelerated learn-how-to-tear-down-and-rebuild-a-rotary lesson, after all. And I had hoped to wait to do this at leasure while driving my mistress on my good (spare!) motor.

BTW: I'm assuming I'll have to lap the side plates to take care of the corrosion? Or will taking off the nitride surface matter, Jeff20B? Of course if I have to do one I might as well do all... This motor had about 160,000 miles on it if I remember right and was still running quite well. Which means I might have to replace rotor housings etc.... Damn!!!

The whole lapping process reminds me of lapping an optical flat in telescope making; same process it seems. Maybe I should lap a little stupidity off my brain while I'm at it.

Just remember; there is nothing so well designed or built that utter neglect and abject stupidity can't break... Just wish it had happened to someone else...

Thanks for the advice, people. Now it looks like I'll have to gather the tools and/or knowledge (read: money!) to tackle the whole nine yards. Not to mention the dirty looks from my wife when she finds out my "good" motor has "problems". OUCH!!!

Thanks again;

Sanspistons; gathering courage to tell the wife...!!!

 

Did you see signs of any visible rust whatsoever through the exhaust ports? What about standing water and/or pitting on the irons at the bottoms of the chambers (through the exhaust ports)?

B

 

To paraphrase Chesty Puller: You're not a real rotard til you've rebuilt the same engine twice...

 

BDC: I'm not sure what you mean by "visible rust". I had drowned the thing in MMO before I did a visual inspection. A lot of rusty crud is visible on/around the apex seals when I rotate it. Also not sure what you mean by the "irons"; the rotors? The side plates? Please elucidate as there is not alot visible through the tiny stock exhaust ports but the rotors and apex seals.

Thanks for the helpful hints: I'm going to try to start the teardown as soon as my rotor tools arrive and I can clear some more room in my shed.

Wish me luck.

Sanspistons: face-first into the unknown!!!!!!

 

Irons = the engine sideplates, which are made of specially-treated cast iron.

Sideplates, side housings, irons... all the same thing.

 

Ah, thought as much. Like I said, the exhaust ports are too small to see the side housings so I won't know until the teardown.

Which is inching closer: I cleared more room in my shed and put my metal work table in. Now just need to decide whether to borrow the tools or buy them...

Sanspistons: now Sansrotors, too!!!

 

Sorry to hear about your problems man.

On the other hand you get to pick up some good experience at rebuilding. I did much the same thing, bought some old cheap junk engines, tore them down and learned a lot. If your irons are junk it will be a good opportunity to learn how to do your own porting too With 160K on the engine it was gettin kinda old anyway.

Lol I like your sig. Just remember the rotary never promised you a rosegarden (<--- I'm a former jarhead too)