So I lost compression on 2 faces on my engine on the track on Sunday...

Today I took off my turbo and exhaust manifold, and felt through the exhaust port. The apex seal is still in the rotor, but it's seized (not springy like the other seals).

Does that mean the end of the rotor pinched the seal in? Will I have to get another rotor for my rebuild?

Is there a decently low probability of damage to irons/rotor housings since the apex seal didn't go anywhere?

Thanks guys.

 

It's useless the way it is ,take it apart and see what happened . You won't know if there is any damage until you strip it and look . If you can get at it just worry the apex seal with something dull and see if it comes loose .

 

as said, teardown is the only way that doesn't involve speculation or guessing.

 

I had this happen to me once, and a friend of mine got in the car and tried revving it to 8k in hopes of freeing the seal (pissing me off though), but in the end he free'd the stuck seals, and the car came back fully to life. Maybe even try to add some ATF?

It did let ago a month later from detonation. Plus mine got stuck while cruising at light load, not at the track, so you may have really pinched yours in there.

You may also be risking damage to the engine, I don't know.

 

my thoughts (and that's all it is) if the engine lost that seal - even if you can restore its function with a solvent or other means - then something is either wrong or about to go wrong. if you're given the opportunity to get out ahead of it (disassembly and inspection) then it would seem prudent to take it. i'm really not one of those people that considers a rebuild to be financially no big deal, but in this case it may be the economic option.

 

Yeah.... last night I took another look at found this:


So I'm going to at least need a new rotor.... and it doesn't look good for the housings either

 

Yikes. Looks like something went for a ride in there and stopped at the apex, cracking the seal. Update when apart please.

 

buff it out and put one of those cool NOS stickers on it.

 

Yep.

 

I'll update my build thread when it's apart:
eage8's SSM/HPDE FC Tubo - RX7Club.com

 

Holy **** dude.

My last motor ate a spark plug insulator, and it just scuffed the housing and the motor still ran. It looks like your motor ate a bolt or a wing nut. O_o

 

You will need a rotor and a rotor housing in addition to a seal set. Go ahead and accept this and begin to budget for it now.

 

It's called breaking an apex seal, then having the fragments of that one fly around and take out the subsequent seals in the chamber. It's totally common and a normal mode of failure.

 

N318-10-b50c

 

lol

 

Totally agree with this sentiment. I tried being "hopeful" and it only delayed doing the right thing by acquiring the needed parts. I ended up deciding a on used rotor and housing, but would suggest in most cases just bite the bullet and buy a new housing. It really depends on what you find used, and the condition of your good housing.

If you really want to use S5 N/A rotors, just convert to E85. Although WI is a great idea - do you really want to risk it with your new motor?.

 

All the SSM FD guys and Jeff Kiesel are all running 9.7:1 rotors and I'm pretty sure they're not running water injection or E85... I don't really care about max hp, I just want to go 9.7:1 for the torque and better spool time.

I'd run E85 if it was widely available near me, but it's really not.

 

If you're going to do a new housing, you pretty much have to do them in pairs. You don't want to put a new housing with a 125k mile housing in the same engine. You want 2) new or 2) 125k mile housings. Unless it is a recent reman/rebuild there is no way your surviving "good" housing will be perfect. It will have significant wear and flaking.

 

The engine only has about 30k on it. (but is 10 years old) There was a mazda reman put into it just before I bought it.

we'll see what it looks like when I take it apart...

 

Not sure who all the FD guys are, but Kiesel's green monster definitely runs E85. Admittedly, here in SoCal Propel seems to be opening a new E85 pump station every month.

Interesting question about changing rotor housings in pairs. The engineer and engine builder in me completely agrees, but the cheap-*** FC owner in me wonders what I can get away with. Basically comes down to how much money you want to dedicate to the car. Hell, it's easy to say "everyone should just buy a new set of housings" for every rebuild, although 95% of the time it's probably the right advice..

 

Oh, don't get me wrong...I'm not one of the "you need new rotor housings in a rebuild" guys. Sure it would be nice if all rebuilds could utilize new housings, but no one can afford that.

I was just saying that if you do one, you generally have to do two...because there is about a 1 in 100 chance that your opposing used rotor housing will be almost as nice as the new one.

If it were one of those cases where it was a recent rebuild (that had new housings when rebuilt) and it blows up and only needs one new housing, I would put the new one in the back and the used one in the front, because over time the rear will wear more than the front, and at some point the wear will balance itself. IF you do the opposite then the wear discrepancy will only grow.

 

RR, While I get how my comment might be construed as a criticism, I really wasn't intending that at all. You made your point very clear and it was quite reasonable. I was just playing devils advocate with that voice in my own head that considered providing that advice myself. I came very close to buying a set of new housings, but found an apparently "decent" set of 60K mi FD housings. I lost both my rotors and housings so didn't personally have to decide between one or both like eage8 (likely) will have to do.

 

Can anyone shed some light on what upgraded parts I should throw in this engine while I'm rebuilding it?

FD corner seals and springs?

FD stat gears? or just the 3 window bearings?

competition rotor bearings?

pineapple racing HD water seals?

 

the best upgrade is to replace as many parts as you can with new. i've done a couple of new engines, and they ALWAYS run way better.

the FC and FD use the same corner seals, the FD spring is a good choice although the Rx8 spring is cheaper.

stat gears hardly ever fail, if you are going to run more than 8000rpm you should consider it, but under that you're fine.

the FD/Rx8 bearings are a production version of the competition bearings, they aren't needed under 8000rpm, but if you're buying bearings might as well.

you should consider the FD oil pressure regulator, its $30 new.

i've never used anything except OEM water seals, so i don't know about the pineapple ones, but the OE water seals will actually put up with quite a lot of abuse when they aren't 25 years old

 

FD springs are stronger. They have the NF01 (20B) part number. The RX-8 springs are softer and somewhat cheaper.