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Knurled.
Knurled. MegaDork
4/14/18 8:33 p.m.

Running out of jumping around I can do.  Now, I have to mount the E-brake cables, then install the springs so I can support the car by the axle so I can adjust pinion angle and bolt down the Watts linkage at ride height, as it is the only thing in the rear suspension with bushings besides the shocks.

 

First, the cables.  After some consternation on the left side due to the locknuts on the cables being rusted solid, I ended up just shoving it in there with the hope that there's little chance it will actually fall out because of how snug the fit is.  By the time I was done doing that, my tablet was charged enough to take pics, so I only took pics of the passenger side.

 

First, we use a Dremel to cut a notch out of the VW cable mount:

 

 

Then install the cable.  Simple.

 

 

THIS is why the calipers are mounted at such an odd angle.  It is necessary for the Mazda cables to reach.

 

Next, the springs go in, and the shocks get bolted in after searching for the hardware, and the pinion angle is set and the upper link locked down, and then the trophy shot after installing the driveshaft:

 

 

Bolted in with factory hardware, too.  Either the flange had an existing ring on the backside that matched up with the Mazda square nuts perfectly, or the machinist cut an existing taper down flat to the correct register.  Would give even odds either way.  Driveshaft bolts up like stock and has plenty of plunge.

 

 

This image looked a lot better in the preview.  What it is supposed to show is that the driveshaft is now centered in the tunnel, which means it no longer rubs on the exhaust at full droop (despite the lower pinion offset) and the pinion flange will no longer rub the right side of the tunnel.  Which the lower pinion offset would prevent anyway.  Hopefully this means no more horrible scraping noises when hitting bumps at speed.

 

Now, to put the Watts together.    First I had to take the link off the car, which ended up requiring that I jack the car off of the rearend for clearance reasons as well as pry the rearend over to clear the exhaust.  Then, I drove in the locator bushing I made to mate the 18mm ID bushing to the 16mm OD stud I am using:

 

 

Putting this back in took a solid hour of wrestling and cursing.  And, for some reason, I had Julie Brown's "The Homecoming Queen's Got a Gun" stuck in my head the whole time.

 

Now that this song is stuck in your (good) ear too, I'll elaborate.  First I had to pop the brace on.  Then I had to shove the axle over to the left with one prybar while finagling the bellcrank on over the stud while trying to clear the floor and the exhaust.  Then, and this is the hard part, I could NOT get the upper link on it.  Part of what was fighting me was the brace kept getting in the way.  After a LONG while of hammering this and prying that, something went "duh!" and it all fell into place, just like that.

 

This is the point where I discovered that the 12x1.5 nuts that belonged to the bellcrank were missing.  I should have had three of them, two from the original setup and a third from the right side Watts pivot that I didn't use because I needed a longer bolt and I used something from a box of excess Honda V6 fasteners.  I tore the Batcave apart looking for them.  I put the casters on the car dollies that I bought a long time ago.  I put away some of the stuff on the red and gray parts shelf and broke up the leftover boxes.  (The red and gray parts shelf looks kinda like the RX-7 that won PR at the Nationals in '08-ish, but loose parts boxes just seem to gravitate to it)  I cleaned and organized and never did find those damn nuts.  So it looks like I will be buying some tomorrow.  I decided, well, time to put fluid in the rearend.  That is when I discovered that the fill plug needs a 3/8" Allen and all I have is metric.  And then my bottle of camper gas ran out and my heater shut off.

 

Yep, looks like I am buying some nuts, an Allen wrench, and another bottle of camper gas tomorrow.  Maybe I'll remember to charge the tablet overnight, too.

Knurled.
Knurled. MegaDork
4/16/18 8:47 p.m.

I rebled the rear brakes AGAIN and got a big blorf of air.  It's "better" but still not what I would consider acceptable.  I bet there's air trapped in the e-brake mechanism in the calipers, and nothing to do but hope it shakes its way out to the top when driving.

 

Gear oil added.  34 degree 80W90 is difficult to pump.  I was lifting my upper body off the ground trying to pump my gallon bottle mount fluid pump.  3 laborious quarts later and it is full.

 

Installed three nuts I grabbed out of my misc. fasteners drawer at work, and then bolted the bellcrank to the rearend.  One of them may actually be a genuine Mazda nut.  Look at it in all its majesty.

 

 

 

I was hoping that I would be able to arrange things so I could drop the pumpkin out without removing the Watts and I appear to have been successful.

 

Spent a bunch of time cleaning up and went to install the wheels.  Discovered that the studs are too long for the Mazda lug nuts.  Well, I'd been thinking about converting to spline drive lug nuts anyway, and I have about 56 of them in my stuff drawer, so I went and found a 13/16 socket and duct taped it to the spline tool and stuck the wheels on.  Then, for the first time since February, the car is on all four wheels. 


 

I embarked on this rearend journey in June-ish of 2015 when I picked up a rearend from someone on RacingJunk.  This photo has been a long time coming!   I ended up using some of the housing, and the ring and pinion.  I had been expecting to cut the ends off and install new ends and have custom axles made, the aluminum pumpkin was a whim purchase, but I wasn't expecting the rear to actually be a 28 spline unit and I never actually counted, taking the seller at his word that it was a 31 spline Detroit Locker.  Oh well, I got a MUCH lighter/nicer differential to replace the 28 spline Locker.

 

I thought I took a picture of the lower links, but it's not in the tablet.  The lower links are at a much greater angle than I was anticipating.  We will see how it drives and I'll either lower the car or move the links up to a higher point.  I'm partial to lowering it, but it's nice to have both options available.

 

And for the first time since 2014, the rear brakes work.  (Yes, they were all seized up when Will and I took 2nd and 3rd in one of the largest classes at Nationals)

 

All that is left is to pop in the new spark plugs, install the 1200cc injectors, and re-tune it.  Aaaannd... it's snowing.

 

 

 

EvanB
EvanB MegaDork
4/16/18 9:05 p.m.

Hooray!

Knurled.
Knurled. MegaDork
4/16/18 9:15 p.m.

In reply to EvanB :

I'd be able to drive it this week if the 4x4.5" wheels with mounted snow tires that I used to have weren't currently on your S40. wink

 

We'll see if they salt the roads tonight.  If they do, rallycross is off.  If they don't, we'll see.  Supposed to get down to 30 degrees.

Knurled.
Knurled. MegaDork
4/17/18 6:14 p.m.

No salt trucks sighted.

Knurled.
Knurled. MegaDork
4/18/18 8:02 p.m.

Bought a mini air compressor and inflated all the flat tires I had on the car and took it for a drive up the street!

 

....Yeah, we got work to do.

 

The Locker's action in turns is REALLY benign.  I wanted to have rod ends in the lowers to keep any toe steer jacking things from happening as it locked and unlocked in corners, but with the lightweight springs you don't notice a thing, other than a light ratcheting noise.

 

HOWEVER.

 

With no bushings at all in the rear suspension, and the amount of lash in the carrier necessary for it to function at all, and the braptacular engine, it feels like the whole car is being beaten apart when under certain not-quite-coasting conditions.  And the brake pedal is sometimes there, sometimes not.  The brakes were like that before, but I thought it was due to seized caliper slides and variable axle bearings.  Looks like I need a master cylinder, or rather looks like I'm converting it to manual brakes sooner than I had anticipated.

 

As for the first problem, I'm going to put bushings in the rear suspension.  As a contingency, a long while back I bought a length of Grade 8 left hand thread 5/8NF allthread.  I'm going to weld this to a couple of OE linkage ends.  Three, actually.  Two for the lowers and one for the axle end of the inner.  Then I will be able to slot them right in to the links I have, which are deliberately right hand thread at the axle end for the lowers, and the chassis end of the upper.   I designed my 3rd link mounts (both) around the dimensions of the factory bushings a long time ago and kept at it because of inertia, looks like it was a good decision...

 

 

Knurled.
Knurled. MegaDork
4/20/18 6:49 p.m.

Drove the car around a bit today.  WOW the rearend "talks" a lot.  It bangs on accel, decel, and when shifting, like a dogbox.  Which, really, it IS a dogbox in there, that is why there is so much lash.  When one wheel needs to overrun the other, a ramp pushes a slider away on that side to disengage the dogs.

You know in WRC in-car footage when they are getting ready for a stage start, and they put the trans in gear and you hear a loud, solid "GECHUNK!"  That's what it does when I put in gear after a stop.  It definitely makes me expect to hear Nicky Grist or Phil Mills counting down from five.

 

I also had a problem with shifting, because all the lash and GECHUNK made the manual trans part of my brain expect that the car DID have a dogbox, so I kept trying to bang it into the next gear clutchless.  Which wasn't working for obvious reasons.  Clearly, I need to put a dogbox in the car.

I think it'll be more livable with different driving habits and the bushings will definitely help.  I'm also going to re-lower the rear suspension to get the lower links parallel to the ground while it is apart.

 

After the drive, i went under for a look-see and found one of the brake lines leaking.  Well, hell, that's probably where the there it is/there it isn't brake pedal is coming from.  Major order to Wilwood on hold until I rectify that.

 

No major Batcave action tonight due to some fires I needed to put out at home, and this weekend I'll be taking a trip to Secret Location "E" to play with other toys.

Knurled.
Knurled. MegaDork
4/23/18 7:41 p.m.

It's finally warm enough to work without hand numbness!  About three hours yesterday and two hours today were spent on what I call "deE36 M3ting".  Many months of not cleaning or organizing needs to be Dealt With First.  Throwing stuff out, concentrating half-empty boxes into mostly-full boxes, or putting the contents on shelves and in the toolbox.  (Got fed up with a bunch of worn out sockets at work, so I bought all new ones, which made the Matco guy very happy.  The old stuff is now in the Batcave, but they and the blowmolded cases from the new socket sets were always in the way) 

I can see the '81 RX-7 now! Can you?


Then I swept and swept and swept some more.  Lots of metal dust all over the place.

 

I still have a lot more work to do on the cleaning front, but I wanted to get going on the car.  No good pics, but what I have so far is a suspension link that used to be an upper link that I spliced in a length of 3/4 NPT water pipe to make a third link, back from the silver car.  I cut the ends off about 2.5" from center.  They are going to have lengths of that 3/4NF left hand thread all-thread stuck in them.  Those will be my new chassis-side bushings for my lower links.  I guess I'll use the now-unused 5/8 hole-3/4 thread rod ends to rebuild half of the 3rd link or something.  I don't think I will be able to bush it after all, I forgot how close some of the clearances are.  So it will just rattle and clank a bunch.

 

 

Knurled.
Knurled. MegaDork
4/26/18 8:27 p.m.

Tuesday:  After work, used the shop drill press to make a pair of holes in those sawed-off half-waterpipe link ends:

 

 

That chunk of allthread is important.  It got a pair of 3.5" long chunks sawn off:

 

and welded in place. 

 

 

Backtracking, the other thing I did at work is use my friends Oxygen and Acetylene to flatten the bottom coil of a pair of cut spring.   The springs were super long low rate springs from a Volvo 960 that had Nivomat rear shocks, which died, and I installed the ipd de-Nevomat springs so normal shocks could be used.  I'd cut them down to only 14" long, but that only worked with the Mazda spring seats, not the flat ones I put on the 9".

 

I heated up a spot 270 degrees from the end (bright orange) and then pushed the spring down.  Then after it cooled off, I heated another spot halfway between that and the end and rotated it.  This is the result:

 

 

Then I installed those springs in place of the... I THINK they were MOOG springs for the back of a '91-96 Escort wagon.  13-14" tall by calculated 175lb spring rate.  With those springs, the center of the rear axle to the fender lip was 16".  With these cut down Volvo springs, which are the same length after coil flattening, the ride height is now 14.5" center to lip.  So I dropped the back of the car 1.5".

 

Even with that drop, the lower link is still at an up-angle, but obviously nowhere near as bad as before.

 

Knurled.
Knurled. MegaDork
4/26/18 8:58 p.m.

Wednesday:  NAPA Autotech class.  Got some learn on about the Fiat/Chrysler MultiAir engines and some service update info on all the stuff we can expect to see fail on the 3.6 engine.  A bunch of which we had already seen, incidentally, and let me tell ya how FUN it is to remove the intake manifold of a RAM Promaster, which does not have an engine cover so nothing to prevent the wells that the bolts sit in from filling with water.

 

Anyway.  Thursday, meaning today.  Tried to find a brake fluid leak that I was imagining was happening, and nothing.  About quarter to seven, I left early so I could drive out to Summit and pick up some new link arms (need to be 13" long, not 15" long, if I want to use the bushings) and a pinion-mount Panhard bracket and some bumpstops and maybe some other stuff.  Rolled the window down to get my turnpike ticket, took the onramp a bit feisty, went to roll the window up and it came off track.  Persevered to the rest area between 71 and 77, where I stopped and tried to fix it.  What I ended up accidentally doing was removing the window entirely.

 

Well, crap.  Got off at the 77 exit, turned right back around and went back to the Batcave.  Throw the rear wheels back on the RX-7, find the torque wrench and torque all the lug nuts, clear out the area around it, back it out the door, pull teh S60R in right-justified so I can get the driver's door open all the way.

 

Very fortunately, I had the correct trim tools and TORX bits and had already read up on the door panel removal procedure.  I'd imagine that the dark blue leather door cards with light blue baseball stitching are not exactly easy to find, so I was perhaps overly cautious in removing the panel.

 

 

Mmmm.... modern interior assembly.  Interesting to note that the in door woofer appears to be an OE component.  Very impressive quality if so.  And up in the upper left... what's that?

 

 

Someone's been in here before.  And they put the lock rod on the wrong side of the sealing panel.

 

There's always been an occasional rattle in the door, I think this was it.   Also, the driver's door lock has been "temperamental".  If you hit the unlock button on the key fob, the door would relock itself.  Or unlock itself after locking the door.

 

 

The lock rod being GLUED to the door panel probably had something to do with that.

 

Going to try to order the broken window clips tomorrow, but for now...

 

I drove the RX-7 home.

 

WOW that ring and pinion is noisy.  Either there is a bad bearing, or I got the pattern all screwed up, or something rusted in the maybe 18 months since I put it together, or - and this is crazy talk - perhaps motorsports R&P units are not exactly manufactured to the same standards as OE type gears.  The rearend never got moisture-infected, and I'm pretty good at setting gears up, and all the bearings are new, so i'm going to assume that it's a manufacturing thing.

 

Brake pedal is still a mystery.  Sometimes it has a good pedal, sometimes it is crap.  Sometimes applying the cable brake makes the pedal better, sometimes it makes no difference.  I have no clue.

 

And just for my edification.  The tires I have on the back of the car are about 14% larger in diameter than stock.  The stock final drive from the car I got this transmission from is 3.91.   I kept trying to think of mnemonics to remember speedometer error but I decided to just come home and do the math.  Which I am doing now.

 

According to tiresize.com's handy calculator, the stock tires are 870 revs/mile and the new ones are 767 revs/mile.  Conversely, 870 times 3.91 means the driveshaft turns 3401 revs per mile.  (Which means 3401rpm at 60mph, and since speedometer cables turn 1000 rpm at 60,  means a 3.4 gear ratio in the speedo drive, which correlates perfectly to the 5 drive teeth/17 driven teeth that Solomiata.com says '79-85 12A RX-7s had...)

 

767 times 5.43 is 4164 revs/mile.  When the tach is at about 4150, in 4th gear, I'll be going 60mph.  Or, when the speedo is pointing at 73mph, I'll be going 60.

 

Heh.  A long time ago I had 4.78 gears and stock size tires.  That's about the same ratio.  120km/h is 74mph.  ALl I did back then, and all I will do now, is take the km/h reading and divide by two, to get my mph.  Simples.

Knurled.
Knurled. MegaDork
4/29/18 10:31 p.m.
Knurled.
Knurled. MegaDork
4/29/18 10:54 p.m.

So, my trip to Summit netted me the 13" long links I need to put bushings in the rear suspension (got black ano instead of golf irridited: whoops) and some bumpstops that I'd like to use.  And a pinion-mount Panhard bracket that I intend to turn into a Watts pivot brace, since I don't really trust an LS crank damper bolt butt-welded to the housing with flux-core fed by a 110v welder to handle the kind of abuse I intend to dish out.

 

And, in the scratch and dent bin, a K&N filter and housing assembly for a Weber carb, that was wildly mislabeled and thus I snapped it up really cheap.

 

It's a lot shorter than the foam filter that Racing Beat used on their Dell'Orto kit, which means I might be able to fit the Atkins manifold on the '81 after all, if I feel like losing the exhaust manifold that I worked so hard to install.

 

 

Racing Beat S4-to-sidedraft "upper", 48DHLA, and RB air "cleaner" assembly, with Atkins/Lake Cities manifold and new-acquisition K&N filter mocked up behind it.  The Atkins manifold and K&N housing would make a 12" long intake assembly.

 

There is slightly over 12" between the engine block and the strut tower.

 

Dang, that is close.  Really close.  I trust the K&N filter assembly to work better than foam and prayers, and I KNOW that the wraparound Dell'Orto manifold setup is disappointing power-wise, since I've driven one before.  But I really don't want to give up that exhaust manifold, because headers make rotaries too obnoxious for the genteel vibe I want to get from this car.

 

Decisions, decisions.

 

Mind, I do happen to HAVE a complete tip-to-tail single-pipe RB exhaust system, so this would require no monetary expenditure.  Well, no further expenditure.  I tend to buy parts first and figure out what to do with them later.

Knurled.
Knurled. MegaDork
4/30/18 9:13 p.m.

Need to get some 10x1.25 Allen bolts and spacers to use the bumpstops I bought.   They're a little short but they were the only through-bolt units that Summit had that were foam and not solid polyurethane.

 

Nope.

 

 

Yep.  (After using a triangular file to clean the weld boogers from the threads, and hitting with a shot of paint)

 

 

And sorted!

 

Not pictured:  Removing the upper link and replacing one of its thoroughly-worn rod ends with one of the brand new ones I just removed.  I'd like to put bushings in there too but it needs to articulate way too much for a bushing to work.

 

 

Knurled.
Knurled. MegaDork
5/1/18 7:50 p.m.

Drove car in to work to powerwash under the hood in preparation for engine removal.  Started to get that incipient-illness feeling, so i figured okay, i'll get it up on stands and the coolant draining, then I will go home.

 

After I pull the hood off first.

 

And maybe the intake manifold.

 

And the starter, and the lower bellhousing bolts while I am under there.

 

...

10 minutes to 8, the engine is completely bare and is held in by gravity and one very loose bellhousing bolt.  Okay I am stopping HERE.  Want the oil to drain from the oil lines overnight to minimie mess, anyway...

Knurled.
Knurled. MegaDork
5/1/18 8:58 p.m.

Oh yeah, took pictures too.

 

 

That dang fan assembly.  Background says "We have no need for organization we have an engine to rebuild!!!"

 

 

The last thing air sees before it gets Brapped.  Four 42mm throttles.

 

 

Coolant leaking out of the center ports, gritty (!) oil in the end ports.  That's not good.

 

The front two intake manifold bolts were finger tight somehow.  I did put sealant on both sides of the gasket, which of course got destroyed on removal, but I doubt it was leaking.  Nevertheless, "gritty" anything in the intake tract is not a good thing with a rotary.

 

 

Ready for me to figure out how to lift it since I don't have a chain and I don't have any lifting hooks on the engine.

 

 

 

Knurled.
Knurled. MegaDork
5/2/18 8:03 p.m.

Tired as berk, will post pics later.

 

Engine is out, oil pan and front cover off, rear end housing off.  Everything looks remarkably good.  The chrome in the rear rotor housing looks as good as it was when I assembled it, and there's no more major scoring on the end housing as there was when I put the engine together.   In 2012.  45k ago.

 

I popped out a side seal and measured its height - .119-120".  I have a thread somewhere from 2009 or 2010 or something where I noted what new side seal height is.  Part of me wants to cheap out and re-use as much as possible.  That part of me is stupid and I need to tell it to shut up.

 

Clutch is wrecked.  The springs in the hub are massively loose. 

Knurled.
Knurled. MegaDork
5/3/18 7:25 p.m.

No pictures, but numbers.

 

The bad:  One corner seal on the rear rotor was broken.  I have a feeling that this was broken for a very long time, given that the engine felt softer ever since the December 2012 rallycross and it sometimes had a weird tick/scrape at idle. 

 

There is also evidence that the rear rotor was hitting the rotor housing.  I know I checked that clearance since this was my first/only 2mm seal pre-85 engine.  Guess I need to keep the revs down.  Or open up the rotor clearance some more.  Probably that one.

 

The numbers:

All side seals had a .004" clearance to the corner seals.  I had these set at .0015".  That's not bad wear at all.

Side seal heights are all uniformly .119".  I know that the 1mm seals start at .140-ish, but these are .8mm seals and I don't know where they start.

 

Apex seal springs weren't flattened, surprisingly.  Backsides of the apex seals are worn where the springs ride, but not heinously so.  I didn't measure seal height but I did measure thickness:  1.89mm / .074" across the length.  They are definitely thicker across the top than the middle, even after a quick wipe with a Scotchbrite pad to remove the carbon crusties.  A .004" feeler gauge is a tight fit between the seal and the slot in the rotor.  This WAS .0025", set per Judge Ito.  New apex seals are .075" thick per the Goopy website.  It would appear, then, that my rotor slots are completely unworn and all wear is confined to the sides of the apex seals, which are going to be replaced anyway because they are warped slightly.

 

The rotor housings have definite wear patterns characteristic of the spark plugs being friggin' hot:  There are dull spots around the plugs where the housing was "growing" at the plug and forcing the seal to come off.  This wears the seals faster in the middle, and between the rotor housing warping and the seals wearing unevenly, compression gets hurt.  Let it go long enough and the constant flexing of the seal will cause it to crack and break in the middle.  This is 100% all my fault, I get the coolant hot and for the longest time I was running too-hot spark plugs.  The water jackets are also full of some real nasty deposits, which is no doubt hurting heat transfer.  Keeping it cool certainly got more difficult the older the engine got, this is probably why.

 

Side housings are scored a bit but they're serviceable.  They have the typical groove on the combustion side but the groove doesn't form a delta plain.

 

tl;dr version:  Engine is fine, just need to replace some seals and give everything a thorough cleaning and it will go right back together again.

 

 

Knurled.
Knurled. MegaDork
5/3/18 8:51 p.m.

Oh yeah, I did take pictures yesterday.  Between re-engineering some weirdball non-stock who the berk put this half-assed hackjob junk on a car and claimed it was "restored" clutch linkage on a '67 Chevelle (which had me removing and reinstalling the Muncie M21 two more times than one would think is required for a clutch job, and also I got the trans removal time down to sub-15 minutes because who needs a trans jack when you have adrenaline and frustration on your side) and more or less inventing a frame for a twelve year old Ford truck today, I kind of forgot what happened in the Batcave.  Seriously, look at this rust:

 

....

 

Anyway:

 

SR Motorsports flywheel, heavily glazed.  No cracks anywhere I can see, though, which is nice.  Is SR even in business anymore?  Who knows?

 

I should probably replace this chain.  Normally they are floppy but this one elicits the "daaaang!" response.  (Note RX-8 front cover gasket.  I run it because it eliminates oil pressure O-ring problems, you should too.  Leave extra part on top so you do not need water pump housing spacer that always gets lost)

 

 

Rear rotor housing..... note how uneven chrome surface is, this is indicative of problems at the spark plug end

 

Knurled.
Knurled. MegaDork
5/4/18 11:47 a.m.

Order made with Atkins.  Only $400 because after conferring with them on the phone, his opinion was "if the side seals are still flat, run 'em!"

Knurled.
Knurled. MegaDork
5/4/18 5:38 p.m.

Crud.  I forgot to order an intake gasket.

Knurled.
Knurled. MegaDork
5/6/18 7:46 a.m.

More crud.  Did a bunch of hardcore cleaning yesterday.

 

 

You can clearly see the characteristic "you need more cooling, bro" wear patterns on the chrome.  Especially on the rear (right side) rotor housing, where you can see the underlying aluminum structure plain as day.  The structure-part runs a lot hotter because it doesn't have as good heat transfer, so it expands more, which makes the apex seals lift off of the rest of the housing, causing the areas of no wear and blowby.

 

Yes, this is not only bad for compression but also for seal life since it puts a large beaming stress on the seals as they go by.

 

 

 

Knurled.
Knurled. MegaDork
5/6/18 7:58 a.m.

Now the bad.

 

After cleaning and scuffing the side housings, I found that the front and intermediate were still acceptable, meaning they were worn but they didn't really get worse.  The rear side housing, on the other hand, has the "delta wear" that is basically NFG.

 

 

This is the sparkplug side of the engine.  The line on the right is the normal primary wear location, as the side seal moves down in a knife cut like motion while being forced against the housing by combustion pressure.  All of the side housings have this to some degree, nothing much you can do about it but buy new (HA! Not available!) or have the housings ground/lapped flat and, if you want them to last, re-Nitrided.

 

The PROBLEM here is the wear pattern that the side seal makes as the rotor swipes it upwards.  This makes that "delta".  You will always be able to see the evidence of this motion, but in this housing's case, it is deep enough to catch a fingernail.  This is not necessarily bad for compression but it IS horrible for oil seal ring life.  So I am not going to put any of my stash of good oil seal rings in this engine.  The ones that cam out weren't awful, but I'm not going to waste good parts on something that I know will fail.

 

This incidentally is what destroys engines that do not have good air filtration.  I picked up a whoooole lot of 12A engines last winter for my '81.  All of them had destroyed side housings from not using good filtration, and they were street engines!

 

The other bad:  I was blow-drying the rear side housing, which still had the stationary gear in it because i couldn't remove it easily, and this happened:

 

 

Berk.  Oh well, i think I have some good 13B stat gears kicking around somewhere.  This was just a regular ol' GSL-SE component, not a hardened race gear or anything.  After seeing the SAE docs, I'm convinced that you only need hardened stationary gears if you are using old rotors that have 9 pins for the rotor gear.  I'm using 12-pin rotors.  No gear related problems.

 

I think I will stop running 5W20 and go back to using 20W50 though.  (But the 5W20 gives me more fuel economy)

Knurled.
Knurled. MegaDork
5/6/18 9:35 p.m.

Bly*t.

 

I spent far more time than I ever remember using my super secret rotor housing refinishing technique on the rear rotor housing.  (About two hours)

 

 

It looks... better?  Better than the front one.  But it's still not even, and a straightedge across the surface just below the leading sparkplug shows that the "shiny" spot is still a thou or two depressed relative to the rest.

 

Perkele.

 

At this point, I am tempted to say "berk it", send these rotor housings out to Goopy for their refinishing, and yank the engine back out of the red car and throw it in this one just so I can make the rallycross.  I have a Holley 6-port intake manifold now, and since it's an FC engine, all I'd have to do would be to remove the front cover and oil pan and re-install the FC parts so I can use the FC motormounts, since this is in fact an FC subframe so it all bolts up as long as I remember where my offset motor mounts are since I located the subframe an inch forward relative to where it should have been...

 

Sisu: Or I could just forge mindlessly ahead, refinish the other rotor housing, slap it together, and run it, and if the compression isn't so hot, well, then at least it isn't sucking coolant and it will work until I find a more permanent solution, which I think more and more is brought by the letters M, Z, and R, and the numbers 2 and 5.    But that would be a lot of money once factoring in the required intake manifold, fabricating a header, and of course buying the engine, the flywheel and clutch, and the somewhat rare NC 5-speed trans needed for it to be a bolt-in, trans mount/driveshaft-wise.

 

I am thinking of renaming my operation to Kusogane Motorsports.

Knurled.
Knurled. MegaDork
5/6/18 9:43 p.m.

In other other news, I had a really bad idea for the RX-3 which would rather negate the idea of rebuilding this 13B and running it until a better engine swap came along, then hand-me-downing it to that old metal.

 

A REALLY bad idea.  I'm going to take some measurements tomorrow.

Knurled.
Knurled. MegaDork
5/8/18 8:57 p.m.

A few hours of labor later, my rotor housings are looking great if not perfect:

 

 

I used to have a way of doing this that would have taken me at least eight solid hours of work.  I figured a new method that shaved this down to two, and these housings were the worst I have ever resurfaced.  And I think I know a way of doing it better, faster.

Ship parts off and pay someone else to repair?  Heck no, not when I have ingenuity on my side.  And thriftiness.  Gotta remember that too.  Both rotor housings are in my trunk, so they can get a nice post-action scrubbing in our parts washer.

 

My order from Atkins and my order from McMaster-Carr came in.  Atkins order included a set of their apex seals and springs, which I have had stellar luck with so far.  Housing friendly and extremely rotor friendly.  Measured the rear rotor housing at 3.148 inches, so per Judge Ito I will make sure the new apex seals are 3.146 inches long.  I dug up my piston ring grinder, set it up in the vise, got my dial dalipers out to re-measure the rotor housing, and the caliper hiccuped and now it reads roughly half the value on the vernier.  Oh well, it was a very old $6 Harbor Freight unit and it was held together with electrical tape, so quite frankly I'm impressed that it lasted as long as it did.  Will have to buy another one tomorrow after work.

 

Decided to assemble the new corner seals and springs, and oil control ring O-rings.  Started to install the oil control seal O-rings, only because I now habitually replace any time I have an engine apart.  Noticed that the stationary gear on the front rotor had scuff marks all over it.  So, it probably walked out some.  Okay, fine, I WON'T get the rotors ready for assembly, I'll strip the side seals out instead so I can box the rotors up and take them in to work for a date with our hydraulic press.

 

I don't like stripping the seals out if I don't have to, because I don't have one of those awesome seal organizer trays that I always say I'm going to buy or make but never do.  Buy is silly expensive, make requires buying more tools.

 

Well, okay, rotors are boxed, I guess I can at least load the O-rings into the oil control rings.  The odd:  All of the outer rings' O-rings came out in chunks.  They weren't broken in the rings, but trying to remove them made them sort of fall apart.

 

 

Except for the last one, which was also the not-gear outer on the other rotor.

 

 

Where did it go?

 

 

There it is!

 

Seriously, how did this engine not smoke like a chimney?  The outer O-rings were junk and the inners were basically worthless, half of the rings stayed stuck to the side housings instead of staying in the rotors.

 

And this is exactly why I just order a new set of O-rings any time I have an engine apart, I guess.

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