J-spec R5 13B goodness
 

Ray's recent thread prompted me to post these pictures.

https://www.rx7club.com/attachment.p...1&d=1354654066

https://www.rx7club.com/attachment.p...1&d=1354654066

What you see is basically the 13B version of the 12A housings Ray posted in his thread. Right down to the last detail. From the double wall exhaust sleeves to the one extra emissions hole next to the thermal reactor air injection port on the front housing only. Like a CA-spec 1980 that DivinDriver has to use. Weird! I'll get more pics up in a few minutes to show off some of the other similarities...

See the blank casting? This is where it was supposed to say Automobiles. Not sure why Mazda did this other than to tell at a quick glance which sleeves these engines had. Blank castings equals the weird double sleeves.
https://www.rx7club.com/attachment.p...1&d=1354656532

Some missing chrome at the top. Not good, but Atkins seals don't mind it. They're what I'll use to breath new life into these housings.
https://www.rx7club.com/attachment.p...1&d=1354656532

And some at the bottom. Atkins seals for the win. I'll run them till they pop. I may even go for a Camden 7" at some point... But probably the race prepped Nikki because it's so awesome!
https://www.rx7club.com/attachment.p...1&d=1354656532
Nice GSL-SE exhaust port timing, too. See it? Excellent for low end torque!

Here is a link to Ray's thread. Check out those rotor housings! https://www.rx7club.com/1st-generati...-shop-1018461/

Those look a lot like my 12A ones Jeff, maybe in just a bit better shape, mine have a little more flaking at the top of the housings. And you've got those weird little exhaust flutes, I'm watching closely to see what you do with those.

Ray, I got my sleeves out. They are welded!

The reason I took them out is one was really loose. Turns out the roll pin had worn mostly away. Not sure how the problem started but it would get worse over time if I didn't do anything. Glad I pulled it and found another set of good roll pins in the pile. This other set is a harder material. Should resist wear better.

I decided to pull the other sleeve in case I decided to remove the inner sleeves. Should I? It'll make it more turbo compatible. I can also port it out to T2 spec a little easier. Or just leave them at GSL-SE spec and run them NA in the white truck?

Gotta use Atkins apex seals with these. I have a set of 2mm. Never tried 2mm with this much missing chrome before. But 3mm has worked fine in similar wear situations. Hmm, first time for everything, right?

Why do atkins seals do better in imperfect housings than OE 3 peice seals (or whateva other aftermarket seals)?

OE are hardened at the tip. The hardened surface only breaks in well on new housings. It takes a long time on used housings with missing chrome like mine and Ray's. So on missing chrome, like all 12A housings are these days, you gotta use a seal that is designed like Atkins, in my opinion, with the wide end piece and the softer material. They may not last as long as OEM seals, but darned if you can't get some more use from your old housings. And they do a really good job, often getting over 100psi in a compression test. These days they're worth their weight in gold for lovers of R5 and other older engines.

If you think about it, the housings are old and should be tossed already, but if eveything else is in good shape and just the chrome is as you see above, might as well give the housings another chance to "rotor on".

I won't be selling this engine though. It's going into one of mine to keep. I've got another set of housings with really good chrome that's getting a set of OEMs. They're S4 NA though. Meh. I'm strictly old school.

So to take anything away from this post, let the chrome condition dictate which seals are used. Make sense?

As for 3 piece seals... no thanks. Mazda stopped making them for a while but recently brought them back. No idea why. Probably demand. But they break easily compared to 2 piece. I have never built an engine with 3 piece and never will.

^ Have you tried out Goopy performance seals? fast break-in, wider edge piece than OE, and can handle some abuse :)



Im actually considering building another 13B using some older R5 or Y Irons that ive already Bridgied and having Goopy or maybe even a buddy of mine at a machine shop, mill some O-ring grooves into some S4/S5 housings I have as spares

on a toy car, that isn't going to see tons of miles, and housings are NLA, running a softer seal to be easier on the housings is actually a good idea.

i'd even run the carbon seals.

I actually have a set of 79 12A housings that hard carbon seals. They have perfect chrome if I remember right. I wonder if I should use carbons again? The engine they were in got water damaged and some of the seals wouldn't come out or got damaged during the removal process. Carbons are cheap though, so no biggie.

I'd prefer OEMs for long life but Atkins are affordable. I wanted to build a 6 port 12A with these because they're rare in this country. It might be kinda fun and actually have some high end if I do it right. I'll probably test it in the REPU to see if it really has torque like people say they do. :)

I gotta figure out how to deal with the aux sleeve actuators as the intake manifold lacks the FC air tubes. Hmm...

funny you should say this. i recently had something of an epiphany and am considering doing just that with an old 12A that i plan to reactivate.

i built peepers with carbons, and i'm totally happy with em, although it doesn't have many miles on it

My carbons are bent. How does that happen?

I had a loose sleeve. Found out the why, but don't know how it happened. Oh well. The hunt began for another of this length (FC and 12A pins are too short!).
https://www.rx7club.com/attachment.p...1&d=1361746138

The tools used to pull roll pins: wd40, diamond tip dremel bit, a couple minutes at the slowest speed (mine does 5rpm apparently), drywall screws, claw hammer, a careful controlled tug, and it usually works. Sometimes takes more than one try and more than one screw. Lay a plate of aluminum or something on the rotor housing to protect it from the hammer. That is all I know! Don't flood me with questions, please!
https://www.rx7club.com/attachment.p...1&d=1361746138

It's a relief to get these things out. Wait, is that another roll pin I see? Crap. Do I try it at this weird angle? Or just grind the tubes down from above?
https://www.rx7club.com/attachment.p...1&d=1361746138

Well, here is a sleeve. Yep, they are welded. Gonna take some careful grinding.
https://www.rx7club.com/attachment.p...1&d=1361746138

Really careful.
https://www.rx7club.com/attachment.p...1&d=1361746138

Or just go at them with a cutting disc!
https://www.rx7club.com/attachment.p...1&d=1361746148
...and a grinder.

Got them back in! Word to the wise: swap the sleeve positions. Otherwise you have a gaping hole. Notice one is rotated funny? I think the guy in charge of making them that day had a little too much sake the night before! D'oh!
https://www.rx7club.com/attachment.p...1&d=1361746524

Notice one screw snapped off due to the angle. Had to drill! Fun. Got the tubes out, which is all that matters.

Now I have the option of filling the hole with something, or leave it open now that it's blocked from above. Can't really expect the tube to fit back in there and stay secure without rattling. Maybe it doesn't matter. I could leave them open. Heck all 76-80 rotor housings have this hole and they were designed to flow air/exhaust through them, so the tube acts like a mini heat shield. But mine are blocked above already and below with the header flange. I'm probably fine leaving them open. Thoughts?

I thought you guys might want to see this.
https://www.rx7club.com/attachment.p...1&d=1362019888

R5 goodness!
https://www.rx7club.com/attachment.p...1&d=1362019888

I had to drill and tap the oil pressure hole. Mazda for some reason didn't want people seeing how low R5 oil pressure is at idle. I made sure to fix that by adding checkball squirters out of a 12A shaft!
https://www.rx7club.com/attachment.p...1&d=1362019888

That is very awesome. If my 12A ever blows I hope I have the courage to do a rebuild

Wow, very nice. Another outstanding color scheme on another vintage motor. Nice work Jeff!

I'm inspired, though still a little confused on getting those exhaust thingy's out. But now I know it can be done, which is half the battle.

Add another running R5 to the list! The black and silver one was test ran today. It needs a little break in time now and an actual choke cable. The GSL-SE doesn't have one lol.

By the way Ray, the exhaust note is strong and throaty on a full RB "Streetport" exhaust system. I can't recall if it sounded exactly like this on the other engine with intact inner sleeves. It's been too long ago now, but I can tell you the way it sounded today, it harkens back to hearing these exhausts on friends' ported motors. The way it revs just, well, you know. It sounds good!