I've got a donor engine for my SE that's seized, and there's a big pile of crap in the bottom of the front housing. I've gotten in there with a long flexi-light and lit up the bottom of the housing, and it looks like someone's pulling up kitchen tile in there. There's a big mass of carbon that's fallen off the rotor.

Seeing as the housings are fine, I know it hasn't puked a seal, though they could be weak or broken, as the engine's still seized. It's in an MMO bath on my engine stand, so I spun it plugs-up, filled with MMO, replaced and torqued the plugs, spun the motor 180, and filled the ports with MMO.

If I ever do get it to break free, I don't want to run that first apex seal through that big pile of carbon. Any idea how to get it out, without pulling the motor apart? My father suggested an air-powered venturi vacuum, and just pull it out piece by piece. Are there other favorite methods out there?

 

not sure ow to really help there. i've always used atf in place of mmo and it seems to dissolve the carbon instead of kock it loose. where are you seeing the carbon in the combustion chamber? through the exhaust port or through a plug hole? do you think you use a shop vac?

 

There's no way a shop vac could get in there. I might just duct tape a big straw to a vacuum and get it in the exhaust port. Basically, this engine sat for a long time and was presumed to be trash. It may be, but the housings look gorgeous. I can spit it around, drain the MMO, and fill with ATF or seafoam too, but I still need to get that pile out of there. It looks like it's just fallen off the rotor face that's been hovering above it for years. It sounds rediculous, but it's the only answer I can think of.

 

ok, can you rotate the engine on the stand to face the exhaust ports downward? if you can, once the exhaust is facing downward, rotate the engine as much as you can by hand and perhaps the carbon chunk will fall out. its a long shot but it might work. if not, i guess a straw duct taped to a shopvac hose would work. just center it on the hose and tape away...

 

It's rebuild time.

 

Yea or use it for a core swap with a rebuilt by Atkins rotary.

 

Jeff, you mean that it's gonna be seized permanently? If so, I can help a buddy out with the rotating assembly, so maybe it's time to crack it open and give the rotors and e-shaft a better home.

 

Is it seized? Nothing is seized permanently, if it can be disassembled.

 

You're going to think I'm crazy, but since it's sitting on the stand, after it's had a good soak, pour water in the plug holes while rotating it with the exhaust pointing down. There's enough lube in there to protect from rust, then use a blow gun for the last bits and to dry it out.

 

And what will this accomplish?

 

Water is smaller than an 1-1/2" vac hose. Large quantities of brake cleaner will do the same thing.

 

amsoil powerfoam will turn that carbon into liquid carbon snot which can be flushed out.

 

I don't really believe in magic elixers. Rebuilds are the way to go.

Rotaries are so easy to rebuild. Like a carburetor; just a bit heavier.

 

I thought you liked carburetor cleaner?

Oh and Crit... If you ever decide to get rid of the engine, let me know!

 

I won't be getting rid of it. I can't afford to rebuild it for the hell of it, but I'd love to be able to salvage a good engine if it's possible. I'll let it soak and see if I can free it up. If not, we'll break it down. If it's good or trashed, I'll keep it. If the housings are shot but the rotors aren't, I'll donate them to a buddy down here that needs the rotating assembly. We'll see.

 

I think you will get that crap out and it will run decent for a while at least.

 

Yes I am a believer in the ATF treatment. I was given a 1984 RX-7 with a locked 12A motor about 2 weeks ago. The previous owner was fed up up with his HOA getting on him about the RX-7. I was taking the carb and intake off and noticed all the carbon in the rotor housings. Pour some ATF into the engine and let it sit for about a hour and broke the engine loose. It runs like a "raped ape" now but smoked for like 30 minutes. I really did get lucky on this motor. Another man's junk is my treasure now.