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Hi my name is James and thought i might share the build of my 4 rotor powered Eunos Cosmo. Ever since i saw and heard Mad Mikes Rx7 at a D1NZ event a few years ago i just had to build my own. I started the build earlier this year. The car is a 1991 Eunos Cosmo Type E. I purchased the car as a rolling body, which was originally a 20b. Its only got 68000kms on it and the body is really straight.
First thing was to strip the interior, must have removed about 50kgs of wiring and computers. I have done a manual transmission conversion using a FC master cylinder and Rx8 clutch pedal. I have included some pictures of the car. The engine is a Peripheral port based on FC plates, housings and rotors. i will be adding more details on the engine the next few days.
How the car used to look
Surge tank install, 2x 044s
FC booster and master
Teaser
Turbo from my Rx7, destroyed at track yesterday haha.
now all you need is two EFR 9180s
.. sequentially.
Thought about turbocharging it, but turbos will muffle some of the noise and heat management starts to become a problem.
Originally Posted by KKMpunkrock2011
What are you planning on doing with the car? Sounds awesome, can't wait to see it finished.
The plan is to have a street legal N/A 4 rotor Cosmo. Basically its going to be used for track days, powercruise events and just generally making heaps of noise.
So specs on the engine are as follows:
Series 4 and 5 centre and end plates
Series 5 rotor housings Peripheral ported
Series 5 rotors (9.7:1)
Precsion Engineering eccentric shaft
Rx8 Stationary Gears
NRS Apex seals and springs
Peterson 4 stage dry sump pump
Efi Hardware individual throttle bodys
Link ECU.
Most of the work has been done by me apart from the e shaft, centre plate stat gear mods and balancing. Attached are some images of peripheral porting the housings. The timing is based on MFR timing.
Practise housing, took hours to set up in the mill.
Turned out all right apart from having to use a sledge hammer to get the insert pressed in. Some adjustment needed in the tolerances haha.
Holes cut in 4 brand new housings.
Inserts started out looking like this
Then this
Then this, ready to be pressed in. All the machining has been done with a maual mill and lathe with no digital readout, so takes bloody ages.
Inserts pressed in, heated the housings in the oven and froze the inserts using a 50/50 mix of methylated spirits and dry ice. Surface areas sand blasted for a good surface for the devcon to stick to.
Mean bro. Where abouts in NZ are you? I miss all the dope rotors back home aye haha
Thanks mate, i'm in Christchurch. The earthquake on Monday gave me a decent wake up call.
Originally Posted by Johnny Kommavongsa
nice.
Where are you getting the eshaft?
And do you have a goal in mind on when you want to have the engine running?
Precision Engineering Ltd in Auckland, New Zealand makes the eshaft and does the centre plate stat gear mods. The Goal is to have the engine running mid next year.
Purchased some bits. A couple of centre plates, 1 front plate and 4 rotors. The rotors are FC n/a which are 9.7:1 compression, really hard to get hold of second hand in NZ which why they are new. Not much modification required on the plates, just fill the intake ports and make up some blanks.
Intakes filled
Few simple blanks made up
Eccentric shaft turned up, just need to fit oil jets and get it balanced.
This is the alternator i will be using. Its a 140amp from a LS1 Holden Commodore. Scored it for $120 and gave it a tidy up.
Decided not to half **** the oil system. On the left is a S5 oil pump. On the right is a 4 stage R4 Peterson oil pump. Should provide plenty of pressure and flow at 10000 rpm.
Made up a few bits. An alternator bracket, oil pump bracket and drive mandrel. Since i am on gearbox number 4 in my Rx7, i decided to use a Tex Racing 4 speed dog box on the 4 rotor. I imported it from North Carolina a few months ago, worked out cheaper than a tremec and should be a lot stronger. I will use an FC bellhousing and make an adapter. Also made an engine assembly stand. Going to use a car jack to set the e shaft height to get the centre plate on.
Diy powdercoated, more details on this in my next post.
The gearbox is a Tex Racing T101 which has a magnesium case so it weighs about the same as a factory rx7 gearbox
Yeah it sure is. I haven't seen it done this way but should work alright.
Most of the accessory parts on the engine are going to be polished or powder coated, thought i might show you guys how i do the powder coating. Its a cheap Chicago Pneumatic rig but it works really well.
1st step is to sandblast the parts.
Next step is to clean the parts. I use methylated spirits.
Wired up so each bolt is grounded.
Next step is to spray the parts, bit difficult to take a photo while spraying.
Parts are then cooked for 10mins at 200°c.
Finished
Did the CAS aswell
The coating is durable enough to coat fastners with.
i would ditch the CAS if i were you, you really don't need your timing wandering on something you put this much money into.
Thanks for the advise. I understand that this style of CAS can wander, but because im not going to try squeeze every last bit of horsepower out of the engine it shouldn't matter to much. I have added an oil squirter to the front cover which sprays oil directly at the CAS gears, this should limit a bit of the backlash. Also pretty much all the 4 rotors down under use an FC style CAS, even the 6 rotor uses the same setup.
you will be fine on an n/a then, i just would never put a turbo(s) on it with the CAS, 4 rotors with all of them bouncing around would be fairly bad compared to a simple 2 rotor which usually manages to get by(somewhat, though still not ideal).
Rotor housings all cleaned up waiting for assembly
Seals and springs
Got the rotating assembly balanced and rotors side clearanced, thanks to Grant at Rotorsport Racing & Engine Balancing.
Machining the out oil groove in the rotor bearings.
Clearancing side seals. Set up this jig on the drill press using a scrap rotor. The grinding wheel is for a dremel. Used the fastest speed on the drill and it worked really well. Only messed up 1 side seal out of 24 which isn't to bad.<br/>
11-12-16, 11:09 PM
