12a SP Build-Up Winter Project
 

The cold weather is here once again in NYC and for me that usually signifies that it is time to freeze my balls off building something. This winter I thought I would take a different approach. Instead of being outside where I am fighting short daylight hours or inclement weather, this winter I will be putting together a motor in the climate controlled bliss that is my basement. :nod:

I have been slowly gathering parts over the last few years, and finally have enough pieces to put this together
here are some of my key pieces...

First up are some nicely ported and lapped plates I picked up from Sean (82 Trans-am) on here I think
http://imageshack.us/a/img580/2849/img2012112400022.jpg
http://imageshack.us/a/img100/884/img2012112400023.jpg

for you Jeff :)
http://imageshack.us/a/img132/8631/img2012112400024.jpg


To compliment I was thinking of using some early 12a housings from a half bridge motor I took apart a while back. They are in fair condition, with the rear housing starting to show just the tiniest bit of flaking. I have housings nicer than these, but I figured that since they were ported already (and I have NO SKILLS in this area) that these would be a nice match.
http://imageshack.us/a/img805/7849/img2012112400025.jpg
http://imageshack.us/a/img547/7421/b...2112400029.jpg


here is a pic of the flaking one
http://imageshack.us/a/img585/9399/img2012112400027.jpg


since these came from a motor that was BP there are notches in the housings but they do not extend into the water jacket so I figured it would be ok to use in this build
http://imageshack.us/a/img706/9857/b...2112400032.jpg
http://imageshack.us/a/img33/2598/br...2112400031.jpg

hmmm...not sure why the pics are coming up as links...

My rotating assembly will be from 83-85 fb with a lightweight steel flywheel and counterweight to match
http://imageshack.us/a/img195/1006/b...2112400033.jpg
http://imageshack.us/a/img705/1714/img2012112400035.jpg
http://imageshack.us/a/img547/2034/img2012112400036.jpg

here is my work area...its no monster garage, but at least I will be out of the elements for a change
http://imageshack.us/a/img545/1093/img2012112400037.jpg

I have a rebuild kit that consists of new apex seals and springs, new corner seals, fd corner seal springs, new side seals and springs, and new oil control o-rings.
http://imageshack.us/a/img571/803/img2012112400034.jpg

I am considering using goopy or atkins apex seals since I may have a tough time during break in with a less than perfect housing. I havent really measured my oil control rings yet either and might have to spring for a set of those as well...ouch 300 bucks!

I am hoping for about 165hp or so. I will be running a weber IDF carb setup from Rotary Engineering and long primary exhaust with RB prima flow muffler, as well as all the supporting ignition upgrades (1 msd box and direct fire on leading with all msd coils and stock trailing with msd coil)

Looking good, I look forward to seeing your progress so I can copy it myself.

I have 5 sets of oil control rings from my 12A tear downs that look pretty good, show me how to measure them and if there's more than one good set I can send you a set.

Ray, he's going to need a good set. Later. After his engine has been together for a few miles, because it will smoke at startup and then smoke all the time.

Why would I predict such an unpleasant outcome? Remember what I said about resurfaced nitrided irons?

Sorry to be a downer.

I don't like the port job on those housings either. Looks uneven and I don't know what the port timing is.

cfamilyfix, use those plates and housings since you have them, but plan on another rebuild after this one starts to smoke. Things get better with practice, right?

Can I re nitrate the plates? Yeah I was reading what you were saying in one of Ray's threads about that...I look at it this way...none of my rotories are daily driven, in fact the GLC gets driven the most and in 3 seasons I have put at most 1700 miles on it so if 10k is the limit on a engine with non nitrided plates I might still be in good shape lol. How does mazdatrix and racing beat do it? Don't they insist on resurfacing with even a base rebuild? They have to offer some kind of a warranty as well. As for the port timing on those plates...I am a little concerned as well, but maybe putting them next to a stock plate will help to determine the ports timing. I will just have to see. Thanks for the concerns and keep them coming. I also read something you posted about using fd corner seals as being a bad move as well especially with non nitrided plates. Wish I read that before I purchased

Like I said, build this thing. It's your first time. It doesn't have to be perfect. Use your parts. Like you said it won't be daily driven, so have fun. Blow it up. Or baby it. It doesn't matter. It's a wear item. It's just that your particular engine will wear everything out a lot faster than a better selection of parts would have. So don't worry about it.

My first build wasn't all that great, but it ran. Then the guy overheated it. The second build was better and is still together and alive today.

You know, I'm curious how well a resurfaced engine will actually run. I know it will have higher friction on all seals on the sides of the rotor, leading to hotter temps, leading to quicker spring death, but that won't happen for a little while yet. I wonder if this engien will be harder for the starter to crank? Especially on cold days?

Oh to answer your question about why big shops recommend resurfacing, it's how they make their money. It's a service. Lots of shops charge big bucks for "service".

Racing Beat also insists that only the GSL-SE came stock with a so called high volume oil pump, in order to sell you one if you've got a different model, thus placing the mighty GSL-SE on a pedestal. But we know the truth that there were a lot more models that had this pump, mainly all 83 and later 12As, which are easy enough to grab. And that's just one example.

Another is the RB prepped Holley where they perform 500 dollars worth of mods to make it run on a separate runner manifold. But we know that any off the shelf Holley will work on a rotary with just an open spacer under it to allow the reversion pulses to lose their strength and act more like an open plenum on a V8, which the carb was designed for in the first place. RB was just after big numbers like 550cfm and later 600cfm. But how do they run? Hit or miss. I've got an RB 600 I got in a trade and it seems my Nikki is more fun to drive - the race prepped one I posted about a month ago, and would much rather use it in my MG, if I could make it fit under the low hood. Currently working on a solution for that...

They also push "streetable ports" or streetports which honestly work better on the track than they do on the street since you do lose noticeable amounts of low end torque - my personal finding. I prefer 74 spec ports for the street, but these are stock on some models (74-75 and all T2 and FD) so no money can be made unless you're just selling a template which anybody could make themselves with access to a stock 74 port to copy.

So buyer beware.

But we as a community wouldn't be where were are today without them, well without the forums and the internet as well I suppose. We've come a long way. With every noob building an engine, that's one less sale for the big shops. You're taking food off their tables, man! You're supposed to be made to feel guilty, I guess. I don't know, maybe this is becoming tangent talk now. Well, have fun with your build!

You know Jeff, no sooner than I had a set of irons lapped (to the tune of $280) I read your comments about losing the nitride being a bad idea, and then just a few days later I tore down a 12A that had crappy rotor housings (what else is new?) but almost perfect irons, the nitride surface still in great shape. Just my luck, now I'm in the same boat as Colin, a great set of freshly lapped irons that probably won't perform as well as if I'd left them alone.

And your analysis of the "big shops" is spot on, I'm convinced the folks who lapped my housings were much more concerned about providing a "service" than about the quality or expense of the rebuild I'd end up with. (I'm sympathetic with the professional rotary shops, they do need to make a living, I'd just prefer it not be my dollar).

The lapped irons do look great, however, just like the one's in Colin's pics, and this does seem to be an ideal starting surface for a rebuild, if it weren't for the friction and softness.

So is there any way to:

A) get the freshly lapped surfaces retreated with nitride? I read up on this, it seems to be a fairly common procedure in the industrial world, although it involves using a pressurized plasma, a procedure that would be hard to reproduce without the specialized equipment usually used.

B) otherwise treat the surface to harden it and reduce friction? I'm thinking cermet here, a metallic-ceramic treatment that some claim works for rotor housings.

And thanks Jeff and all you other wizened rotor heads for sharing the street knowledge!

I definitely appreciate the advice. I will keep this updated as I move foward with assembly. I just kicked out for my last order to mazdatrix for all the little stuff...corner seal plugs, front and rear seal, pilot seal etc. The only other money I may spend at this point is on a different set of apex seals (goopy etc) I have brand new oem that I waas gonna use but I will save those for the 85auto's rebuild since that engine will likely not see any additional porting and will be using my minty housings if need be. With this build I am already so far out of the box, what's one more variable???lol. Plus I figure since these housings have just a minor bit of flaking that I will need all the compression I can get and a shorter break in time to boot

Well since I posted in Ray's thread, I figure I would update hear as well. Just ordered a fresh set of Atkinks apex seals, since I too, am committed to using less than perfect rotor housings. Also got in my hylomar and front a rear main seals so assembly will begin as soon as the Atkins seals arrive

Perfect. Post lots of pics, I'll be following in your footsteps in a few weeks.

Sounds awesome! I'm looking into doing the same thing as well, will keep tabs!

Well the last bits of engine rebuild stuff has arrived so it will be time to start assembling this monster pretty soon. I'excited to finally start. The only part of this process I am a bit unfamiliarwith is grinding the the side seals to fit properly. I;m half tempted to take a junk rotor and make a jig to cut the proper angle on the seals, but I might just do it free hand alla Aaron Cake. Here are the new apex seals that arrived yesterday from Atkins...

http://imageshack.us/a/img13/4347/img2012120700014.jpg

Maybe this is why they cost 47 bucks to ship.....

http://imageshack.us/a/img402/2255/img2012120700015.jpg

here is the bill to prove it...

http://imageshack.us/a/img651/318/img2012120700019.jpg

and some other bits from mazdatrix that have arrived...when did hylomar not come in a permetex container any more???

http://imageshack.us/a/img15/8662/img2012120700020.jpg

When I did my side seals I used the old ones for reference. I marked them, then grinded very carefully I ruined two before I got it right. Like they say "Measure twice, cut once"

The "new" side seals are the only thing that has me worried. I never did have to clearance them before. I have a dremel and a clamp so all "should go well" but you guys will be the first to know if it doesn't...lol

All those new parts are making me drool.

I'm still a little confused by that shipping charge though, should have been about $5.00 for second day air and Atkins ships the stuff they sell on ebay for free. Weird.

All I can figure is that they priced the seals low to make you feel like you are getting a deal and then make their money back on "shipping and handling"

my advice: if this was a business for you, then you might have to consider time, but since this is a winter project, i would say do what i do. get like a 100 or 220 grit wet/dry sandpaper and setup a space with a nice flat surface. go to town, maybe do 1 or 2 a day. that's how i do mine. it's fairly simple to get the right angle with clean sheet of paper. just be cautious because your two dangers are being cut or breaking the seal if you are two forceful with it.

Glad you're getting some use out of those irons!

I got massively overcharged for shipping with atkins last time I bought some gaskets from them as well. Charged me over $20, and tacked on a fee for using paypal and then sent it in a postal envelope to the tune of $3.... I emailed them about it and never got a reply. What a joke.

Anyway, good luck with the build! I'll have to check it out once you're done.

Well time to update this a bit...got my rotors all pre assembled, cutting down the side seals wasnt all that bad. I found it fairly easy to get the perfect shape by using a fine file and a feeler gauge...ummm I believe .02 to.05mm between the side seal and corner seal is correct but dont quote me as my manual is not in front of me, lol. still want to paint my rotor housings and then final assembly can begin. Also I got a few front spacers (T, V, Y amd I think X) as well as some torrington bearings from mazdatrix so when it is time to set my endplay I wont be fishing around for what I need. I found a nice set of oil control rings to install my new orings in and a fresh set of used springs...oil control ring protrusion was right where it needed to be so I went for it. Pics to follow later this week as well as painting and final assembly.

Time to move this along...the weather has been so bad outside that the only place to build was in the basement...

painted my housings

http://imageshack.us/a/img839/6126/img2013012500037.jpg

and started assembling...

http://imageshack.us/a/img407/593/img2013012500036.jpg

http://imageshack.us/a/img132/727/img2013012600048.jpg

http://imageshack.us/a/img688/8008/img2013012600049.jpg

The keg is finally complete...there were a couple of "o shit " moments along the way. I managed to break a corner seal on the front rotor and had to remove the rear rotor after rear housing install due to corner seal miss allignment. Called in a friend's help along the way and all is well. Here is the video of me turning over the motor by hand after torquing it all down...


it turns smoothly and makes all the correct noises so I think it will turn out ok.

still have to set my end play and install my flywheel and counter weight as well as my oil pick up and oil pan, but I think the hard part is behind me. Not sure what vehicle this is going into yet, but I think the 81 is the best candidate since that is my experimental build anyway

End play and flywheel should be done this weekend, but undecided on a clutch set up. I have a very extreme brass button clutch that I could use with a very heavy pressure plate, but I am thinking of going for something along the lines of a street/ strip set up from mazdatrix

I tried setting the end play over the weekend...no matter what spacer I use, this motor is too tight. Im figuring my lapped plates might have a lot do do with this. I will take my Z spacer and gently file it down over some sand paper to get my .04mm of end play.

Does it rotate freely with no thrust bearings? E- shaft could be making contact with the stationary gear. If it is too tight then a wider spacer should do it not a thinner one... Just rambling with my fingers here.

+1, how much endplay does it have with no spacers?

I will set it up with no spacer and report back...thanks. Don't know how I got it all backwards???

ok so a bit of panic set in and I removed the rear counter weight and all the front spacers, bearing pulleys etc to make sure my eccentric shaft moved freely in the engine


Thank god! I then proceeded to test endplay with a x spacer and a z spacer...and yes I actually got a bit of a reading on the dial indicator. Can someone confirm I am setting up my indicator correctly???

http://img580.imageshack.us/img580/8...3030600070.jpg

Uploaded with ImageShack.us

Sorry the video is so dark, but I was just trying to ensure that there was play in the eccentric shaft...is it ok to run multiple spacers to achieve a specific endplay?

The dial indicator won't measure anything like that. The magnet needs to be on the plate. The indicator tip can be on the flywheel. Or vice versa.

I use a feeler gauge. Most don't but I like the feeling right between .002" and .003" as a bit of drag where .003 is too tight but .002 is a light drag. So about .0025"

Multiple spacers won't work. Do you know the order and placement of the various parts? A while back I blew this up and printed it out.
http://www.mazdatrix.com/pictures/b5-engft.jpg

I think part of your problem is the spacer that sits on the shaft stat bearing journal (the thick and small one). It has a taper on one side. This taper fits against the shaft bevel where it expands to the stat bearing size. The needle bearing rides against the flat other side, as does the thrust spacer. The spacer needs a flat surface. The rest is pretty easy. Or it should be. Let us know and take another video. That one, while dark, clearly showed the movement and sound which looks and sounds fine.

Ok so the spacer you are referring to would be number 1 in the illustration you provided...correct? If that were upside down I would obtain an incorrect reading. I see what you mean about how my gauge is set up...the equivelent of holding my foot on the door while pulling on the knob to open it lol. When I get home from work tonight I will inspect and retry. I did have my parts in the right order...hope that counts for something. When you use the feeler gauge method are you measuring between the flywheel and rear stationary gear??? That looks like a difficult place to get a gauge in and get an accurate "feel" Thanks again for all the help guys and sorry bout all the questions...

Correct.

I measure between the thrust bearing and the big thrust plate. Between numbers 2 and 4 above.

Thanks Jeff...you were exactly right about that spacer being upside down. Had 10 minutes to play around with this tonight and got .0032" with a x spacer so still have to sort out the correct end play but am def headed in the right direction. Thanks all again and video and pics to follow.

Here is just a clip of my latest attempt at endplay from the post above. I tried with a "z" spacer and got to about .0030", but I would like to get it to about half of that. Since the z spacer is the smallest it seems I would need to grind down this one to get the end play I am after.


"three hundred thousanths"...lol...should have said thirty thousanths of an inch. sorry bout that. Juggling act between holding phone, moving the flywheel and trying to speak sensibly

I will be back at it this weekend and hopefully buttoning this guy up.

Cool, glad it was upside down - a simple fix.

You are looking for .002" to .0025". I usually don't like making them tighter than .002". Don't make them any looser than .0035".

.027 FTW!!!! got he front cover all buttoned up. Will be switching out the stock flywheel for a racing beat lightweight steel and 83-85 rear counter weight. It was easier setting the endplay with a flywheel in place. Thinking about an fd oil pressure regulator and then this motor should be ready to go in a vehicle. I cant wait to hear it run!

Cool. I'm going with an FD pressure reg in my SP 12A too! Currently in the process of masking the side plates for paint. :) I'll probably make a thread about it so I don't clutter up this one.

I figured I would update this here too. Finally got this engine in my 79. There was a lot of "re-wiring" to do on the later style alternator upgrade and properly doing the electronic distributor upgrade. The good news is it runs. The bad news is it howls like it has a gilmer drive on it.

Sounds like bearings! Slight possibility its the carburetor or a huge vacuum leak around the manifold. Did you pressurize the oil system prior to startup? You should pull your ENGINE fuse and spark plugs and crank for 30 seconds. Unscrew the oil filter and check that theres oil making its way through the engine before starting.

Like front cover bearings????? As in Torrington bearings????? uggghhhh. Its hard to pin down where the noise is coming from since Im the guy behind the wheel with my foot trying to keep the engine running. I guess the only thing I can do is get it all in running condition, belts, gear oil in tranny, alt hooked up and go through it with a stethoscope listening to where the noise is originating from. I went through a whole saga priming the oil pump so I do know there is oil pressure.

I had a fresh rebuild do this once. It turned out to be a bad intake manifold gasket.

I had a chance to spend an hour with the car tonight and the noise is def coming from the intake manifold area, so fingers crossed. I tried cranking down on the bolts to the manifold which improved it a little but it looks like I will have to butter the manifold with rtv or use a thicker gasket or something. I will be out there with it first thing in the morning...updates to follow

I had one do that once. It was an intermediate plate that wasn't machined perfectly accurate from the factory. It made the primary area of the gasket sound like a piece a grass you hold in your thumbs and blow. You know the sound, like a reed from a sax or something. You could push on the gasket and it would change the sound. A little RTV fixed it.

When I got this RE setup it had rtv smeared all over it with the gasket still stuck to it...now I know why. A lot of their parts never seem sturdy enough...maybe its just me