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Patrick (Forum Supporter)
Patrick (Forum Supporter) MegaDork
9/12/20 10:53 p.m.

It was fun to see another adult today that wasn't my wife.  Sorry i ate my shrimp tacos in front of you 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/12/20 11:04 p.m.

In reply to Patrick (Forum Supporter) :

It's okay, I had to pee since about an hour before I saw you.  So I was not in much of a mood to hang out very much.

The Speedway at Cook and Lorain had green chili burritos.  And a functioning restroom.  I took advantage of both of these facts.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/13/20 9:49 a.m.

Brain is doing stupid things.

Realized that 3-4-5-6 are really close on the RX-8 transmission.  1.65, 1.19, 1.0, .85.  Ratio drops all in the 72-85% range.  The 1-2 and 2-3 drops in most transmissions are like in the 60% "why bother shifting" range, so this is huge to me.  The last rallycross I competed in five years ago in June, I ran the entire morning heat using only second gear, walking it off the line and bouncing my 9500rpm fuel cut.

 

Let's see, I'd want to build around my current Second gear which is a total ratio of 10.6.  To use a 1-2 delete RX-8 transmission and keep that second gear, I'd need a final drive of... 8.91:1.  Nobody is close to making something that short.

 

However, if a transfer case were bunged inline, running in low range would drop the ratio requirement to 4-4.5:1 depending on the ratio.  Perfect!

 

Now there is way not enough room to fit all that under an RX-7, but it is interesting all the same.   However, I have a kind of crazy idea....

cghstang_chris
cghstang_chris Dork
9/14/20 6:23 a.m.

This is a good a place as any to post that I got behind a mostly stock appearing/sounding FB this morning on the way to work (oem 13" wheels, quiet exhaust, etc).

Got close enough to smell it and hear him wind out first from a stop.

It will probably be the highlight of my day.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/14/20 9:13 a.m.

In reply to cghstang_chris :

Wonder if it was Wendy or Mike.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/21/20 8:26 a.m.

Decided to use the "heavy" rotors because they are correct for the car, and I have an automatic counterweight for them if/when I decide to get a lightweight flywheel.  The stock '81-82 flywheel is extremely light as it is, as well.  The difference in weight between light amd heavy rotors is only a half pound.  Automatic coumterweights for light rotors are impossible to find so I'd be stuck with the stock flywheel.

One of the rotors was missing its bearing.  That's easy enough to fix.

 

 

Thing on the top right is a front pulley hub that I'd machined the OD down to fit inside the rotor, and a step to sit in/drive a rotor bearing.

 

Before we install the rotor bearing, some idiot proofing:

Lining up the tang is a pain, and if the bearing ever grabs the eccentric shaft, the tang ain't going to stop it from rotating in the rotor.  At that point you have negative clearance and a wrecked engine. So, I grind the tangs off.

Look at that old school Mazda part number.  IIRC Mazda has used this bearing from the first L10A Cosmo in '67 up to the last of the RX-8s.  There are a few other parts that stretch all the way back like that.  Mazda is nothing if not pragmatic in their engineering.

I grind a small chamfer on the rotor, freeze the bearing, heat up the rotor, smear Loctite all over the bearing, start the bearing in with taps with a hammer, then it's on to the press.

 

And then this happened.

 

fidelity101 (Forum Supporter)
fidelity101 (Forum Supporter) UltraDork
9/21/20 9:35 a.m.

did you get the irons back from Chips yet? how do they look?!

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/21/20 5:10 p.m.

In reply to fidelity101 (Forum Supporter) :

See last post of last page.

No pics because not actually been getting much work done lately because reasons.  The machining looks impeccable.  If I had to gripe about something, it's that the press in oil passage plugs on the front housing (i call them housings like Mazda does, not irons, dammit!) got tapped and pipe plugs threaded in, so they no longer look stock.   And the Nitriding affects the entire surface, including the outside, which looks ugly IMO, so I'm going to paint them, and I hate the look of painted engines.   Oh well, I drive with the hood closed anyway, right?  And the '81 at least is going to be going back to as stock as possible with the Nikki carb setup and vacuum solenoid rack and airpump and everything.

 

But still, it was only $620/engine when new housings from Mazda are in the $300-400 range, for the ones that are available, so I saved a bit.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/22/20 2:35 p.m.

Had today off work, so after some rampant consumerism buying new bike shoes (unexpected 33% off, too!) and a heart rate monitor, I went and got some work done.  First order of business was to connect up the new argon bottle so I could finish welding up my muffler.

 

Ugtacular but sorted.  Now to ruin the other side.

Cram in the rest of the packing material (1 1/2 packets, which were 12x24x1 sheets)

 

Weld up and done for now.

 

 

On to Part 2...

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/22/20 3:08 p.m.

Here you go Kevin.

 

Realized that Chip discarded the A/C bracket studs, and the engine mount studs on the bridge port's intermediate.  Oh well, I can probably find some more.  But I did need to scavenge some A/C bracket studs so I could mount this up in the engine stand.

 

Mottled appearance is anti-corrosion goop that will need to be cleaned off.

 

I decided to use the half decent rotor housings I got with the Amazing Pile of Junk engine I bought last year.  (Besides having massively worn out rotors, and used apex seals, it had one heavy and one light rotor!)  They measured 2.760" wide.  Atkins apex seals are not held to a super close tolerance, so I measured all of the long pieces:

 

Then I measured all of the short pieces (image missing).  Then combined the shortest long piece with the longest short piece, and on down the line, and measured.  Amazingly enough they were all right on 2.757-2.758", so I did not see a need to clearance them further.  Marked them with dots so they don't get mixed up.

Not posting the pic because it has the VIN, but I deshelved the hood long enough to open it so I could photograph the data plate.  Color code is RH.  When I have the 13B out, I will pull the steering box back out (more involved than it really should be) and repaint the area behind the box with the CORRECT color.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/26/20 5:17 p.m.

Well, rallycross happened.

Short synopsis:  New trans is absolute garbage.  Wore a hole in my right palm from holding the trans in gear (well there goes MY social life) and got a huge blister on my left thumb from steering one handed.  No blister on my little finger.

Now that I have that song in your head, bait and switch.

 

The Racing Beat muffler is also a failure prone POS because thin stainless is a horrible material for rotary exhaust systems and RB of all companies should know better.

 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/27/20 9:21 a.m.

NOW that I have spent $bank over the years trying to get a 12A in the '81, a 12A manifold to 6 port 13B adaptor shows up on eBay.  This would let me keep the awesome Nikki 4-barrel drivability, the solenoid rack (some of that is important!), the auto-choke, the air cleaner that actually works.

 

It's $150.  I kind of want to buy it on general principles.

 

granted, a stock port 12A would let me compete in Prepared, if I felt like rallycrossing it, which I am not sure I do.  What IS interesting, as I edit my footage from yesterday, is that the massively rough course was actually faster and easier to drive if I toned it down to about 8/10ths so the trans would stay in gear and so I could keep up with the steering.  Of course I learned that on the last couple runs.

Dusterbd13-michael (Forum Supporter)
Dusterbd13-michael (Forum Supporter) MegaDork
9/27/20 9:23 a.m.

In reply to Pete. (l33t FS) :

Do it. You'll use it at some point when 12a stuff becomes pure unobtainium, instead of the current unobtainium alloy.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/27/20 9:27 a.m.
Dusterbd13-michael (Forum Supporter) said:

In reply to Pete. (l33t FS) :

Do it. You'll use it at some point when 12a stuff becomes pure unobtainium, instead of the current unobtainium alloy.

6 port 13B stuff is also getting really, really hard to find.  Rotor housings are relatively easy but the side housings for the '86-up stuff tend to break the coolant lands off.  Nonturbo rotors also no longer grow on trees.

 

I have enough engine parts to build two 12A now.  A 12A will last about 200k miles.  Realistically speaking, barring catastrophe, I am set for life.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/27/20 10:06 a.m.

"Set for life" is a really weird concept.  I'm 42.  Will I be building Engine #2 when I am 60?  What other challenges would there be?  Would I even still be interested?

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/27/20 7:28 p.m.

 

Used the VIRB to record this.  Apparently it cuts off the last bit of video after you stop recording, I know I'd recorded myself playing with the throttle to make the shifter bounce back and forth like it was really happy to see someone.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
9/27/20 9:11 p.m.

Broke the vent off of the rearend.  Eeeeew

 

 

Cracked the bejayzus out of the muffler again.

 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/20/20 5:34 p.m.

MrChaos
MrChaos SuperDork
10/20/20 5:37 p.m.

that looks not ideal

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/20/20 6:28 p.m.

All the cursing.  This?  is transmission #2 for today.

 

The black painted "rebuilt" one was seized, and the shifter wouldn't even budge.

 

Full boost ass-haul to the Batcave for the last trans in there, make sure it turns, make sure it has threads at the trans mount (ahem), get it to the shop, discover that all the case bolts are loose and the shifter tower is seized.

 

ARGH.

 

The synchro splines look nice at least.

Stampie (FS)
Stampie (FS) MegaDork
10/20/20 6:50 p.m.

Pretty sure I have at least one I can send north from the Challenge.

Patrick (Forum Supporter)
Patrick (Forum Supporter) MegaDork
10/20/20 6:58 p.m.

In reply to Stampie (FS) :

If pete needs it toss it in mofo's trailer and i'll get it from Michigan 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/20/20 7:24 p.m.

Okay.  I'm done.

 

Trans #2 is assembled and in, and I see this.

 

 

That is completely the wrong species of trans mount.  I have no idea what it's from, or for.  The bolt pattern is too narrow for any of the three trans mounts I have here, and the pad register is 1/2" or so lower.

 

So, it has to come back out, and I play musical tailhousings.

Tomorrow.

MrChaos
MrChaos SuperDork
10/20/20 7:51 p.m.

so the RX7 gods dont like you it seems

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/20/20 9:19 p.m.

Did some research, that is an FC tailhousing.  I'd thought all FC tailhousings had the bubble for the giant damper weight.  It is definitely an FB trans from a 12A, so why would someone put an FC tailhousing on it?  Explains why everything was loose, at least.

 

Took a closer look at the three RX-7 transmissions I got from the Challenge.  One is an FC unit and not immediately usable.  One is an SA unit and may not be usable at all, because of SA idiosyncrasies FB tailhousings may not swap.  And the seal area is cracked, so it would be useless for the RX-3, too.  The last trans is an FB unit, and there is about a half inch of axial play in the input shaft, so I am assuming No User Servicable Parts Inside.

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