uRizen

iTrader: (2)

Ok, I grabbed a Haynes manual for some bed-time reading the other day and just read through the rebuild section and came up with a few questions.

I noticed that they actually reused the onld oil, corner, and side seals and said that if they're within tolerances, move freely, and aren't ripped up that there's no need to replace them. So if I were to blow an apex seal, would it be worth spending the extra cash to replace these, or is reusing the old ones fine?

When you remove the engine from the bay, is the transmission still supported to the point that I wouldn't need to keep a jack under the vehicle to keep it from dropping? The reason I ask is because I only have a single car garage and would rather leave the chassis out in the driveway and leave lots of room to work on the engine itself.

When they have a drawing of the apex seal, the show it in three pieces, like so:

and you glue the corner and upper piece together, then it looks like friction somehow holds the lower piece on (this is supposed to only be for S4s apparantly). How the hell does that hold itself together? Maybe I'm just not seeing it right in my mind, but that looks a little dodgy to me, lol.

Ok, and the final questions is related to the coolant seals. They recommend replacing the inner coolant seals on all the sections, but don't say anything about the outter seals being replaced. Is it normally advisable to replace the outter ones as well, or are they not as prone to failure?

Oops, i lied, one more. How much does the longblock on a 13b weigh? I'm just wondering what kind of pulling equipment I should look into borrow/renting.

Overall, the whole rebuild doesn't look like it's really that big of a deal. I'm acutally looking forward to finding a crap engine to play with and try it out maybe. The hardest part looks like keeping the seals in their positions when you reassemble the whole thing, and checking the tolerances of all the parts. I'd definatly need to pick up more tools as well. I don't have a torque wrench, any micrometers, or even feeler guages right now.

If none of the housing are bad, and the bearings, oil, side, and corner seals are good, I could almost get away with rebuilding the whole deal for maybe $300 in parts (new apex seals, all the intake/exhaust, etc gaskets, and the collant seals), and some in tools (maybe $150 for all the measuring tools?).

Thanks for reading all that and any insight you can give. I'm off to go rip one apart in my dreams.

Dan H

If you're going to order new seals, Mazda has replaced them with 2 piece seals so don't worry about it. I "think" the Atkins and RA seals are 2 piece as well.

The transmission should still be on the tranny mounts but in my engine removal video, Bruce reccomends having some wire to hold it up still. Replace all soft seals no matter what. You don't want to have to take the engine apart again to replace them. I haven't had much experience but of some of the engines I opened up, most of the "hard" seals were within spec and re-usable. (oil seals, side, corner)

Expect to pay more than $300 for a rebuild though since I'd recommend replacing a lot of things.

RotaryResurrection

iTrader: (8)

Note that I do rebuilds daily, so take what I say for whatever you think it is worth.

There is your second mistake...your first was buying it. Throw it away and go get the FSM. Either buy the whole copy, or DL it and print the appropriate sections as you need to use them. It is free, after all.

Some people will sit here and tell you that there is an unwritten rule that you have to replace every soft seal and spring during a rebuild to get a good motor. This just isn't true. IF you look in the FSM, mazda themselves has provisions and instructions for removing, inspecting, and reusing all original parts, even apex seals. Now, knowing what we know today about these engines, apex seals are the weakest link, so as a rule I would NEVER reuse those. EVER, unless they had 10k miles or less and I was using the same rotorhousings.

FWIW, I reuse oil ring carriers, side seals, corner seals, and all springs in almost all my rebulds with pretty good results. I have never built an engine for myself with all new seals and springs, yet all my engines run fine and make pretty good compression. I normally replace all coolant seals/dowel orings/tension bolt seals, which come in the gasket overhaul sets. Also the oil o-rings themselves (not the metal carrier rings), apex seals, and thermal pellet for the e-shaft. These parts can be had for around 4-500 bucks. I would never consider doing a rebuild with less than this.


I personally pull the tranny with the engine...I find it easier, even with the proper equipment to do leveling/hoisting for aligning the engine/trans later. IF leaving the trans in, you'll want to support it with the jack, and then use a piece of wire or rope to support it...tie it through the upper bellhousing boltholes, to the firewall somewhere. Now remove the jack and move the car.

Dont worry about that, that only applies if you are reusing stock 3pc seals, which you won't be. Most aftermarket seals and new mazda seals are 2pc. They install much easier. Even new mazda 3pc seals were already glued from the factory for you. They can be tricky to install if you have little experience, though.

ALWAYS replace ALL coolant seals. ALWAYS. IT is possible to reuse them, but you run a BIG risk of having them start leaking in a few thousand miles. They never reseal properly after being stretched during removal (and they WILL distort some).

Longblock about 350, shortblock about 190.

Don't tear the car apart until you have a grand in hand. This will buy your parts, tools, as well as allot for unexpected ****, like belts, hoses, motor mounts, wire connectors, **** like that which you find as you disassemble the engine.

uRizen

iTrader: (2)

Ah, the master has spoken. Thanks for the reply.

The Haynes manuals are ok for normal daily stuff, and the pictures are nice. I do have the FSM here and plan on going through that in a little bit as well.

I went over the rotoryaviation.com rebuild kit list now that I know what everything is, and notice that they don't include the side, corner, or oil seals, but do include the o-rings, and new springs. I did some searches and their apex seals are supposed to be pretty bad-*** too. It doesn't look like they include the coolant seals though, where would you recommend getting a set of those, and how many are there? Is it 4 per housing?

I'm definatly going to wait until I have the money too. I'm having trouble deciding wether to buy a FC with the motor that's already siezed, or buying on ein good condition and waiting for it to die.

YearsOfDecay

The rotary aviation "Basic Kit" comes with everything but new corner seals, side seals, new oil "hard" seals (metal rings), and an oil pump chain.

I've used the Apex Seals from Rotary Aviation and I likes 'em a lot.

The R.A. kit also used the third gen style corner seal springs in all the kits (this is a MUST.. the second gens springs look like folded paper clips)

The "Master kit" has the excluded pats. Its about 300 dollars more than the basic kit and that is mainly because the metal oil contril rings are about 280 for a complete set!!!!! (which is why people will use them as long as they possible can!)

The engine in my TII has 135K miles on it.. I took VERY good care of it.. all the hard parts spec'ed out to be used again except the oil chain and the bearings. (they say you can reform the second gen corner seal springs, but i wouldn't use those damn things to scratch my ***** with). However, I decided to get the Master kit because the hard rings were a bit worn.

The Bruce T. rebuild video is excellent...

NOTE*** if you are going to have the engine apart, you might as well replace the bearings in the rotors and stationary gears if youe engine has over 100k on it, they are cheap. get them from mazdatrix.

uRizen

iTrader: (2)

So it does include all the inner and outter coolant seals then? I didn't think they were listed, but that'd be pretty sweet if it did. I even saw it includes the gaskets, rock on.

Do you have to worry a whole lot about the tolerences when buying new bearings? As long as your e-shaft isn't screwed up somehow, replacing the bearings won't throw too much off, right?

RotaryResurrection

iTrader: (8)

You know, I'll be totally honest here, and this is a matter that is somewhat up for debate among various builders. As far as replacing bearings, there are very few times when you actually need to do it. This goes back to the whole "replace every part" theory. The oiling system is the strong point of the rotary, and without some abuse or a catastrophic failure of some kind, bearings and gears usually come out looking excellent. Even well into 150k miles.

The general consensus is less than 35% or so copper showing is reuseable, so long as there isn't excess slack between the eshaft and bearing. You tend to get a feel for this after a while, and like me, for instance, I can look at a bearing and decide to use it or not. I personally like to use bearings that have 25% or less copper showing...most have that or less.

The problem with replacing bearings isn't cost. The issue is that rotors are actually pretty soft in reality. Since bearings are a VERY tight press in fit, it stands to reason that pressing them back out, and then pressing in a new one, removes some material from the rotor itself. Perhaps not enough that you can see, but enough to affect the grip on the new bearing. Also, for a first timer, bearing replacement would be a daunting task as it requires a good size press, press tools, and the ability to line up the bearing perfectly before pressing and maintain that position. IF you get it 1/16" off as far as rotation, it won't be lined up right, and you're pretty much limited to replacing it again or just leaving it as is.

IF you press in a bearing and the keyway isn't lined up perfectly, you GREATLY increase the risk of spinning it at a later time. Hell, just by replacing it in the first place, you have removed some of the material that holds it in place, and increase the risk of spinning. I just rebuild a 25k mile atkins rebuild that was in perfect health until a rear main bearing spun at 3krpm. I could find NOTHING wrong anywhere in the engine to cause this, so I can only assume a bearing was improperly installed and caused it to spin.

Another topic to consider is hardening. We all know that heat cycling a piece of metal hardens it, to some degree. Well, over 15 years and 100k+ miles, you can bet those bearings have been heat cycled quite a bit. So, it stands to reason that they are already hardened, compared to new ones.

All in all, I usually recommend against replacing bearings in a rotary rebuild unless you absolutely need to, due to excess wear. Especialy for a beginner.