I acquired a Cosmo motor to throw in my third gen temporarily until I have the three rotor plans in order and ready to execute. I wanted to experiment with the engine a bit just to see if and how well it work. I originally intended to slap it in unmodified. I became worried that it may have unseen internal problems (based on the experience of others).



Well I cracked her open today and it was mint inside. I really got lucky judging by others experiences. It was definitely a low mileage engine. Housings were perfect, side plates were mirror.



Anyway, to try and keep costs down I'm porting and assembling the motor myself. My main question is, what can I keep? I've decided to replace the apex seasl with Atkins (but I may now go back to Mazda OEM 2mm). How about the side seals? I've removed them and labeled them as per rotor and position so I can put them back where I found them. Anything else that I can keep? I'll be upgrading to a 3rd gen planetary gear while in there and upgrading to the Atkins side seal holders which are one piece and eliminate the piece of plastic in the inboard side. Anything else I should do while I'm in there? I'm actually rebuiding it at the local rotary shop and will be receiving their help in the rebuild. I'd just like to do it as inexpensively as possible without hurting reliability. TIA.

I would highly suggest replacing all the seals and their springs if you want good compression.

also the mazda factory apex seal are the best ones your gonna find. My .02

i have heard the atkins apex seals are the best!

from other people's opinion's around here i heard atkins OR mazda OEM are the way to go...depends who you ask..just dont get hurley..baddddd

straight edge, feeler gauge, torque wrench, razor blade, carb cleaner, wire brush, and scotch brite. you might as well clean everything since it's already apart. get the atkins 2pc 2mm apex seals. you can keep the springs, side seals, and that other stuff. get new inner/outer oil rings (6 inner and 6 outer), 6 outer water jackets, 6 inner water jackets, new inner/outer oil seals, new o-rings, thermal pellet, hylomar, vasoline, tap-die set, and i can't really think of anything else you'll need. the bearings, washers, and needle bearings should all be good. do the webber 200cfm oil jet mod, you can pick those up at BAP imports. that's all i use to rebuild the engines (if they're as good as you say). have fun! https://www.nopistons.com/forums/pub...#>/biggrin.png

What did the cosmo cost you?

6 inner and 6 outer oil rings?? he needs 4 inner and 4 outer oil rings. I think he has a 13B Cosmo engine not a 20B Cosmo engine..





If your going to rebuild this engine I would agree with FD3boost.... every single seal is mandatory for good compression and reliability. Atkins apex seals work, but stock Mazda 2mm seals are better. Make sure you use a nice Micro-meter and the necessary gauges and tools to mic and clearance every single part. From your engine bearings to your seal clearances to the wear on the side housings, to the width on the rotor housings, to the end-play on the flywheel.

Arghhh, Ito how do you do all that measuring.. It's enough to make your eyes pop out. https://www.nopistons.com/forums/pub...IR#>/blink.png

How do you plan on porting the stock "D" exhaust ports? Or will you replace them with FD/FC ones?

Well that's the big question....Check out the porting thread. Setzep, since you have an RE, what did you do? Isn't it possible just to remove a bunch of the material as you would with the FD's exhaust sleeves? Ito? What would you recommend?



Yes, it's a 2 rotor, not a three. Cost was $1600 with shipping.



If porting the exhaust sleeves isn't an option, I guess I'll replace them with FD sleeves. I've also heard there are some custom sleeves available out there as well but I haven't had a chance to do any searches for them yet.



I've pretty much decided to replace all the seals except for the side seals. If the side seals turn out to be inexpensive then I'll probably replace those too. There was soooo little internal wear on this engine though.

replace the diffusers with the FD ones. I have a simple trick to pulling out the pins on the diffusers. After trying so many different ways, from drilling the roll pins to cracking open a busted rotor housing. I learn of a better way. Let me know if your intrested in the trick.



Ok when it comes down to your used side seals. Try this first. When you install the new corner seals, then, when you install the used sideseals, just measure your sideseal to cornerseal gap. Acceptable specs are .002- .006 if you have a bigger GAP then .006 I would highly recomend you replace the sideseals.

Arghhh, Ito how do you do all that measuring.. It's enough to make your eyes pop out. https://www.nopistons.com/forums/pub...IR#>/blink.png [/quote]

Honestly I really enjoy measuring every single seal and engine part. It just takes the guessing game away and makes me feel so sure of my work. But you have a Valid Point it does get to be a little Xtreme on your eyes,back and BRAIN starts to hurt after a while.

Judge - I would love to hear how you get the roll pins out of the exhaust inserts! I have tried several ways but they are sush a hard steel that I have yet to find a good reliable way.



BTW - there have been several posts in the last week on the pinned porting thread - have you checked it out?



Jason

I haven't checked the pinned thread. Ill checked it out. Ill reply later on tonight on the pin removal..

Yes I definitely would like to hear how you do it! So it's no good to just hack the crap out of the Cosmo sleeves huh? I'll be sure to measure everything as well. Thanks for the advice. And Judge, what's your real name??? https://www.nopistons.com/forums/pub...>/rolleyes.gif

Hmm you want me to reveal my Identity... no problem. My real Name is Juan Rivas. intials for J.R.'s Rotary Performance Shop. that I own. Ill let you in a little secret. for the people that know me, I have never ever been called Juan by them. Even my Mother calls me "Ito" Ito is my giving nickname by my father when I was born. In my 31 years of life, I've never heard my mother call me Juan. My dad too. For the first 7 years of my Life, I thought Ito was my real name.. I could remember my mother yelling at me: ITOOOOOOOOOOOOOOOOOOOOOOO stop taking your bicycle aparttttttttttttt!!!!!!!!! https://www.nopistons.com/forums/pub...IR#>/smile.png the Judge was added later by a good friend of mine. that in it's self is another story. So for my friends here on the forum. Ill respond faster to Ito then Juan..

I haven't opened my engine because it has such good compresson so the stock sleves are still in place. It's kind of funny, some people say they will be ok then there are others that say get those things outa there! So my question is will these sleves kill any hopes of HP with a single turbo?? Anyone?



Also I'd like to know the easy way to remove the sleves Judge if you would be so kind https://www.nopistons.com/forums/pub...IR#>/smile.png

I was wondering that too. Thanks for clearing that all up for us https://www.nopistons.com/forums/pub...#>/biggrin.png

Great story Ito! I'd show up at the local rotary shop and say "well Judge Ito said such and such" and they'd look at me like I was loco. https://www.nopistons.com/forums/pub...#>/biggrin.png



If and when you have time, do check out the porting thread as I posted a bunch of images of the Cosmo innards...Just need your opinion before I get started. Thanks to FD3's help/links, I was able to get a hold of 8 carbide bits and an electric rotary grinder(25K rpm)for well under $100. I have at least another week and a half recovery time (shoulder surgery) to sit around and port my engine and measure everything out. You can only watch so much Oprah!

You really shouldn't watch that, its bad for you

Ill keep the pin removal secret to my self for now.. I'm looking back at it, I think the answer is worth money https://www.nopistons.com/forums/pub...IR#>/smile.png

Great...where do I paypal the money? I'm doing everything on this engine myself Ito, because I'm not 100% trusting of the local shop's ability. I really don't want to screw my housings up trying to get the pins out. Any help will really, really be appreciated. Do you sell Atkins seals any cheaper than Atkins itself? Just curious given the amount of seals you seem to be buying https://www.nopistons.com/forums/pub...IR#>/smile.png

Ok friends, Here is the easiest way I have found to pull the pins out the diffusers. Just like everybody else I have tried every way in the book to destroy this pins, and found little success. Until NOW...



Take the MIG-Welder and WELD 1 round DOT on top of the pin, then weld a second DOT on top of the first dot, then a 3rd DOT on top of the first two dots, by this time you have a small row of welded dots. Take a pair of Dykes plyers and go to the first welded dot and just grab it with the dykes,twist and pull up. Works like magic. If you don't have a welder,, I would suggest to find a shop and help you with the welding of the pin. Until somebody comes up with a special type of puller, this is the easiest way I have found.



Yes I sell the Atkins apex seals cheaper then them...

this some good info, since i should be getting a cosmo soon myself!

I'm going to start a new thread about rebuilding my cosmo, just to give everyone a head's up. I'll post images and info as I go along. I'm currently polishing the housings along with a few other items. I haven't decided on a color for my side plates...if I can get some sort of "soft" gold or titanium color, maybe bronze to match my rims, LOL, I'll go that route. If not, black it is!

Thanks to all for the info.

Michel

i'm not sure how big the diffusers are... but from the top of my head i woudl drill, then nap with some NPT sized tap.

Find a bolt/plug for your tap size... then get your pilers and pull

That would be one hellofa small NPT tap, not sure if they make them that small. The whole problem with drilling/tapping is the pin is very hard, it says "**** you" to most drill bits.

hrm... i never realized they were that small... i've never opened up an engine before

I see you have tried the drill... https://www.nopistons.com/forums/pub...O_DIR#>/11.gif

i like Ito's way the best and will use it for now on!

ITO is a genuis!!! Time to break out the HH135!!!

Yup, on a old bad 87/na housing. Next time I go over to my buds house I'll bring along the housing and give the MIG welder method a try. Thanks for revealing your secret.

Glad I could be of help.

Thanks Judge!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I was VERY interested in knowing a trick for this one since I had been putting off pulling a sleeve from an old housing for the engine I am about to build. I once had luck with a self tapping screw that would go in just far enough to catch and allow you to pull the pin with a pair of sidecutters, but that was ages ago and I haven't found any that work recently. Those pins are hard!



I just went downstairs and tried the Ito trick. Took me less than 5 minutes to pull the sleeve without doing damage to anything except the 2 rolled pins!



Thank you!!! https://www.nopistons.com/forums/pub...1047683894.gif



Here are pics of the process:



http://webpages.charter.net/jlbarnes/mazda/rollpin1.jpg



http://webpages.charter.net/jlbarnes/mazda/rollpin2.jpg

I was thinking not to give up my homemade tip, but after taking into consideration how hard does pins are to pull out, I felt it was my rotary engine civic duty to help my rotary engine brothers. JLB I'm happy you already saw some success with the ITO-Spec PIN pulling trick https://www.nopistons.com/forums/pub...IR#>/bigok.gif