Hello all!

I blew out the apex seals on the front rotor of my FC a little over a month ago. It took me about a month to diagnose with certainty what had happened, and then a little longer deciding what I should do about the problem.
Right now I'm taking some auto classes at the local university, and one of the professors approached me saying he'd help me rebuild (!) using the school's tools and facilities (!!). He has 30 years of experience as a journeyman mechanic, including many rebuilds. He doesn't have any experience with rotary engines, but he's only volunteering because he's curious about them - I doubt he'd have volunteered if I was complaining about blowing a gasket on a '93 civic (:
I got a rental unit for the car, a friend has been helping me dolly the car back and forth between the unit and the auto lab, and last week we pulled the engine. Very excited to be starting on this job. While I'm inside the engine I intend to do a streetport.

If there's any interest, I'd love to keep you guys updated with my progress! Here are a couple pictures; sorry for the low quality, we were rushing due to limited shop time. That's me on the left.

 

gl i have yet to open up a rotary engine.

 

There's a specific 3-prong engine stand adapter for rotaries that you should look into picking up. Pineapple Racing has a 12A/13B adapter that can be attached to a conventional engine stand, or if you've got access to the tools, you might be able to put one together yourself for much less. (mazdatrix indicates that they have a guide here, but I'm not finding any clickable links leading to said guide. Further rummaging might turn something up)

Another special tool you'll need will be a 54mm socket for the flywheel nut. I'm not sure where the best place to get that is, but any rotary specialist will have it. Some organizational tools (rotor stands, seal case if you're planning on re-using some of the seals or springs) might also be helpful. I've heard a lot of people indicate the importance of keeping old parts properly matched, so make sure to label your front and back rotors and housings. (if there's visible wear on any part, replace it. The FSM offers some specific values for how much wear tolerance is allowable before a component is unusable.

Best of luck with your rebuild. Keep us posted with updates.

 

I got the stand adapter from Mazdatrix, I've been trying to read everything I can find on the subject + I have the Mazdatrix video, one thing I noticed. I'll see what I can find on the 54mm socket. I'll have to watch the video a couple more times to familiarize myself with everything + take notes - the first time I watched it it put me to sleep -_-

Trying my best to stay organized, I'll be sure to properly label everything. I've already been labeling all the nuts and bolts I've had to pull off the engine. Trying to be super cautious as this is the first rebuild I've done of any kind. Luckily Carroll (the guy helping me) has many more under his belt.

Another thing I'm interested in doing is any performance upgrades that I can do while I've got it apart. I'll definitely be doing a port, not sure which template is best to follow (I've heard Judge Ito's referenced, not sure how to get one of those). Any suggestions?

 

interesting thread, i also purchased the mazdatrix video for my fd. I want to pick up a spare engine and do some internal work so i can have it ready due to the fact that i believe that my current engine isnt long for this world. Nice lookin ride though bud, keep us updated.

 

I have a 13b that I just bought. In relation to what he is doing, are the seals and oil control rings worth reusing and just replace the orings and gaskets throughout. Or are all the seals necessary too? Motor has compression, but I have not seen it run myself yet.

 

Good luck with the build ..id love to see your progress!

 

If I had my engine out and in pieces, ready to rebuild, i would NOT reuse the seals, get new ones, that way you are 100% sure that they will do their job.

 

Keep us up to date. Sounds like a good project. Good luck.

 

GL man. I will be starting a rebuild of my own here soon. It is always a good idea to replace as many seals as possible and get any custom work (like porting) and/or upgraded internals while the engine is already being disassembled the first time around.

 

Yeah, I'm definitely going to replace pretty much everything while I'm in there, the trouble of opening everything up is definitely greater than the cost of whatever seals, etc.

I should have more updates in the next couple of days, I'll be tearing down the engine tomorrow.

 

Defiantly upgrade to the 2-piece apex seals.

Also if your porting the intake ports, you could smooth out the oil passage on the front iron, and another safety mod would be to shim the thermo pellet.

Could swap out the NA oil pump for a turbo oil pump.

Throwing stuff out there!

Keep updating as you go.

 

Thanks, MrGoodnight! Those are all things that I'll likely do. I need a place to write down all the things I'll need to do, WAY too disorganized right now. Anyway, after a solid 4 hours of work last night, here's where I stand:

Where we left off - engine removed, still mated with transmission. Got the transmission off quickly, next was getting the clutch + pressure plate off. Had a little trouble pulling the flywheel off due to using a non-mazda puller, but off it came after a little while.

Next was the intake manifold, under which was the impressive collection of vacuum hoses - using this guide I hope to simplify some of that as I build the engine back, in addition to replacing any and all hoses via this company . Is there any performance benefit from emissions rat's nest removal? I've read up on some of it, but I'm still unsure.

 

I got it onto a stand using mazdatrix's stand, it doesn't come with bolts to the engine (I assume you're supposed to use the bolts that came out from there (?), but I had most of that stuff stored in a different location. Instead I managed to rethread some bolts to make it work .

Intake + exhaust manifold... still trying to wrap my head around the complicated throttle + intake setup

Taking the front housing off

 

Front housing off! When we pulled the rotor out, the broken apex seal immediately fell out, confirming what I feared as soon as the car first had bad idle. In this case, I'm not sure I'm glad I was right. Pretty cool to finally see the rotor in person after only having ever seen pictures or models before.

This is my organizational system - many labeled ziploc bags. Should help with the reassembly. Also you can see the mess we made. I'm doing the rebuild in the Auto Lab of my university, definitely a huge plus to have all the space and access to tools. If only there were someone around who knew about rotaries, though that may be too much to ask...

And finally, the magic triangle. How does it work? No one knows!

 

good stuff man. just make sure to mark front and rear on assymetrical components as well as the zip loc bags

hot damn! 10 posts.
will be checking in on this thread for sure. my engine is ready to be pulled as well. just held by couple bell housing bolts. see you opted to split the trans outside the vehicle. probably would be the easier route to go for reinstallation.
good luck on this! just make sure to have a really good look at the housing(s). apex seals clanging around in a 25YO engine can sometimes tend to leave them beyond reuse. i'm sure you'll be looking closely at everything though and breaking out the precision measuring utensils

 

hello all! I've got everything apart now, currently trying to determine the state of my housings; I think I'll have to replace most of them, but I'll post some pictures here, mostly because I'm not sure how best to determine whether they're salvageable or not.

Here are some pictures of one of the housings:

 

and here is the rotor that failed - all three apex seals were stuck down

 

Also, two of the end housings had broken through to the coolant chambers.

Any advice about which parts look ok and which look too worn is appreciated. Also, I'm not sure where is best to buy a new rotor / new housings. Ebay?

 

Easiest way to get engine parts, well at least easiest for me.
I just bought "blown" kegs and torn them down for parts.
You can us usually find some or cheap.
Just an idea

 

I want to keep up on this thread, One of my 7's needs a rebuild and I haven't ever opened a Rotary up. Can't wait to see your progress.

 

Im definitely going to be keeping an eye on this too! My 7 is most likely going to need a rebuild and I've never done any kind of a rebuild before. This is giving me a good idea of what it entails. Keep the pictures coming! They help A LOT!

 

@MrGoodnight - the only problem with that is I'm in Alaska, so shipping is ridiculously expensive - not sure if it's worth the shipping cost alone to be getting an engine that for all I know doesn't solve my problem. I might try getting some better pictures and making a thread in the main forum to try determining the state of them.

Thanks for the support guys! Helps to keep me going. That and wanting to drive my car again someday, of course.

 

Didn't know you were in Alaska, that makes it a little hard to find cheap kegs locally.

 

Seems like the rotors are pretty gummed up; any idea what caused some of the wear? Oil type? Ever try to de-carbon it with Seaform? Run it at redline much to blow it out? Use pre-mix for better lubrication?