Hey everyone, I recently picked up an auto reman REW that had been put out of commission a while back and then pulled from the car as a whole package. Didn’t know why until now.



Coolant seal on the front iron popped, leaving a puddle of green inside the combustion chamber. Rushed to unstack it immediately. Surprisingly, there’s mostly just rust on the rotors and not much on the housings.

(I’ve no idea why there’s so much grime and gunk inside the combustion chamber though)

So for rotor 1, here's the front iron:
-Before cleaning:


-After wiping off grime and doing a quick scrubbing with carb cleaner and a nylon brush:


Seems as though there's some light surface rust towards the bottom where the coolant settled. That, and there's a scratch that catches my finger nail on the very edge of the sealing surface by where the spark plugs are. I'll probably get it lapped... If I can fix the coolant jacket that's fubar:


I've heard someone managed to make a sort of steel ring insert that works in the case that this sort of damage occurs. Rotary Evolution I believe? I don't remember. It was a long time ago. If I can't get this fixed, I'll just replace the whole iron.

Here's the rotor housing:
-Before cleaning:



-The plugs:


They're BUR9EQPs all around and they're caked with carbon.

-After a light clean:




All of the crud cleaned off. The surface doesn't feel perfectly smooth, but nothing catches the finger nail. Nothing else to report.

 

Rotor 1:
-Before cleaning:




Bearings looked perfect, and nothing seemed wrong with the teeth. The surface initially appeared to be surface rust coating the carbon itself.

-After cleaning:


Cleaning off the rust and carbon took off the bronze-ish color you usually see on rotors, so I'm guessing the water penetrated the coating.

The center iron, rotor 1 side:
-Before cleaning:


-After cleaning:



You may or may not be able to see the light surface rust in the second photo. Most of the discoloration is an imprint from the seals of the rotor, so I think with patience it'll come out. Can't feel any different along the outline unless there's carbon accumulation I haven't cleaned off. I don't remember if this surface also had the problem significant enough for a finger nail to catch, but you can see a scratch near the spark plugs again.

For rotor 2, the opposite side of the center iron:
-Before cleaning:


-After cleaning:



I remember this one does in fact have the problem with the finger nail catching... Another one that needs a lapping.

 

For the rotor housing:
-Before cleaning:



-The plugs


Again, BUR9EQPs all around.

-After cleaning:



Seems to be in the same shape as the other housing.

For the rotor:
-Before cleaning:



This one had a much worse problem with rust. But it still cleaned up. Again, bearings and teeth look good.

-After cleaning:



Again, it cleaned up pretty well, without the coating though. You might be able to notice very minor pitting on the face near the apex seal groove.

For the rear iron:
-Before cleaning:


-After cleaning:



Cleaned up exactly like the other surfaces, and like the rest of them, had this scratch in the exact same spot. Any idea what might have caused this?

The consistency is nice. All of the surfaces seem to be very similar. I think I'm going to lap them all together if I can figure out what to do about the coolant jacket. If not, I'll go get another front iron.

Being a reman, this had the newer 2-piece seals, but most of them are disgusting and some of them broke into pieces because the only way to remove them from the rotor is to chisel them out with a hammer and screwdriver (they’re that badly stuck). I was careful not to disturb the apex seal grooves, but I’ll still check to see if they were dinged in the process. The apex seal grooves still look good despite the seals being stuck in them.

This is my first rebuild of a REW, and a rotary engine in general. I’ve unstacked an S4 T2 that was in much better shape, but never put it back together. Any pointers or rules of thumb I should be aware of when judging to reuse parts, outside of what’s in the FSM?

 

I would get a good used front iron. Trying to fix that broken coolant wall isn't easy, and you can get a good used one for far less than you'd spend on that endeavor.

Rotor housings look decent for used rotor housings.

With the rotors, see if ALL the seals, side seals included, will come out. Sitting in water sometimes they rust in place. If the rotors have a lot of pitting on them that's kind of a hard call.

Dale

 

you can save the coolant seal slot, it's been done before.

https://www.rx7club.com/group-buy-pr...ntion-1006993/

 

Yeah, I figured on the coolant seal wall. I'll look into that. Would it be advisable to have the "new" front housing lapped anyways for consistency?

Is it usually safe to use a penetrating oil like PB Blaster on a rotor or will that eat at any coatings on it? All but one of the apex seals are out now but I haven't started on the side seals.

The rotor pitting isn't that bad. It's not "a lot" and it's not deep either. I'll post up pictures when I'm done cleaning them.

Also, when it comes to getting these side housings resurfaced, is it best to entrust this with a rotary specialist or is it possible to just go to any trustworthy engine machine shop? There's no rotary specialists in town and I'm a bit busy for a spontaneous drive to California.

 

if the side seal track wear is out of spec youd be better off finding a used iron, any lapping should include renitriting, new freeze plugs, brass drifts and thorough cleaning. to properly recondition an iron isn't an easy endeavor, no matter how much some shops sugar coat it unless you want to find an iron with 5 times the wear in 10k miles. i see plenty of others claim you can just cut the surface, but then your hardened surface is now gone. the factory nitride is very thin, once side seal step is out of spec, the nitride is gone below it.