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So you want to swap a ROTARY into your Z! (how-to)

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Feel free to look at pics of it in the last set of pics on http://www.rotaryz.com, should give you a clear idea.


Don't forget that there's no swap kit for this, it's all custom. When the engine comes out of the car one more time for paint, I will get a cad schematic of the engine mount. This is a solid mount design, so do not expect this to be very comfy for daily driving


I used a 13b-re 2 rotor twin turbo from a japanese cosmo sport coupe. They cost about 1500-2000 depending where you buy it. Those only come in automatics, so you'll need to source a 2nd gen rx7 turbo2 transmission.


Why a 13b-re, and not an REW from the 3rd gen rx7? The REW unit had poor quality apex seals in the US version, and japanese versions are more expensive. The RE also has bigger secondary intake ports (30% larger than REW), and provides more low end torque. These were rated at 230hp/210 ft lbs of torque with stock smaller turbos than the REW (more low end torque). Why a rotary? Because it's unique, light weight, costs a lot of money, and it sounds like ass.


Why not to do it? Because it's unique, costs a lot of money, and sounds like ass.


Alternatively, you can also use a series 5 turbo 2 motor (13b from 89-91 rx7 turbo 2, rated at 200hp, single turbo.) Mine is converted to a single turbo, because stock twin turbos won't clear the Z frame rails. I used an OBX (crappy, but mine is reinforced thanks to 73botiz) SS manifold, garrett t04s turbo, tial 44mm wastegate. Adapting 12lb flywheel and ACT street/strip clutch to go with that. You will need the light flywheel because the automatic flywheel that comes with the stock motor is counterweighted for 12lbs, so it works out quite well. I am also using a 2nd gen rx7 oil cooler, JTR chevy radiator, ford taurus fan (pics coming, just mounted it), and a bar/plate aluminum intercooler with 12x21x3" core


Parts off the 13B-RE unit you won't need:


-Metering oil pump

-oil pan and pickup

-front engine cover

-oil injectors

-stock ECU

-twin turbos and exhaust parts

-turbo piping

-PS, smog, and AC pumps

-rat's nest (vaccuum lines) components

-automatic flywheel

-blow of valves (2)

-water pump and waterpump housing, and thermostat housing

-secondary 550cc injectors


Why aren't we using the stock ECU? Because the turbo solenoid that switches from smaller to larger turbo is actuated by the ECU, as well as the metering oil pump. This also means you’ll need to run PRE-MIX in the tank. (yep, like a 2 stroke!)


Stock motor. You can see how much space the stock twin turbos and smog junk take up




Parts needed for the conversion:




-84-85 RX7 GSL-SE 13b front engine cover, oilpan, and pickup

-86-91 RX7 turbo 2 transmission, starter, alternator, and clutch slave

-86-91 turbo 2 ACT clutch and lightweight 12lb flywheel (you can use regular 20lbs flywheel, but you will need matching counterweights)

-86-88 RX7 NON TURBO water pump housing and waterpump

-84-85 GSL-SE 13b thermostat housing

-86-91 RX7 CAS (crank angle sensor, what RX7 uses instead of a distributor)

-86-91 RX7 coil packs (2, leading and trailing)

-JTR front crossmember spacers

-Intercooler, single turbo, AN lines, custom driveshaft, and everything else that goes with a custom swap.

-stand alone engine management, ie. Microtech LT8s, AEM, etc




-secondary 1680cc injectors from marren injection. Cheap, and flow a LOT of fuel. Remember, rotary + rich = safety!

-255lb fuel pump. External walbro unit GSL-392 (I think?) is $140

-6 and 8 an lines. Depending how much fuel you want delivered


To make the front motormount, I used the engine cover off an 84/85 rx7 GSL-SE (this is important, because that's the only model that has front mount points and a matching 13b motor). It bolts right on. I also used the matching gsl-se oilpan and pickup, they are a direct bolt in with that combination, and oil pickup is moved to the front. You will also need to ditch the stock metering oil pump (rotaries use this to squirt oil into the combustion chamber) from the front engine cover, and drill/tap GSL-SE engine cover for the turbo oil drain. This also implies that you need to run gas/oil pre-mix like a 2 stroke


Things to worry about when making the mount: oil cooler line feed from the front of the engine, and steering linkage clearance


JTR spacers, notice oilpan hangs a little low... key point here to make sure you don't fly over speed bumps :)




Finalized mounting location, you can see the clearances and final spacing








Transmission position: Look! stock crossmember! just make the hole bigger




Shifter position (rx7 transmission is 36" long, shifter is straight, not angled)





Turbo clearance with finalized mount




Front picture of the engine mount. Note: this picture has the WRONG waterpump on it. It's protecting the internals from dust. It's not the final product. Everything else is correct






Engine mount close ups:






Linkage clearance close up. Note the reinforcement gusset






Oil pan clearance




Marren 1680cc injector on left, stock 550cc injector on right. it will require modifications to fit and sit correctly






Left to right: stock marren 160lb/1680cc injector, aux-modified injector to fit the rotary, stock injector




I will add more later, and provide more information as I go along. I started working on the Z again, after a year of a hiatus. Really. (Z-dreamer, eat my shorts!)


Huge thanks to my friend Rob, Jon (JUMBO30EZ),Davyz, and especially Mike D (73BOTIZ) for helping me with the mount

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So there's no way around having to run pre-mix? What is your plan for that, to just get 2-cycle oil and put it in the tank, or are you going to use regular motor oil? I'm not really clear on why you have to remove the metering pump, just because without the stock ecu you have no way to control it? Why won't a US spec turbo II ecu work? I guess once that turbo gets some miles on it and the clearances start to go, it would feed some oil in there for you...(j/k)

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The stock turbo2 ecu is wired for a different MOP and different jets. If you use a series 5 turbo 2 motor (13b) you'll be fine and can get away with using stock ECU and oil injectors.


As far as for my swap, use pre-mix 2 stroke oil, I believe ratio is 50:1


The ECU I'm using is a microtech LT8s unit. The advantage here is that I can also dial in correct fuel maps. Something I wouldn't be able to do with the stock 13b, as well as the huge secondary injectors

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aux looks great well done there a great motor


im actually running synthic 2 stroke at 100 to 1 in the fuel thats what my engine builder recomend mines a 13b jport in my rx4 rally car builder said for every day use non stress ful driving you could run higher ratio but 100 to 1 is easy to do just 10 ml for every 10 litres fuel got a chainsaw bottle with measurer in the corner of the bottle just tip it in when i refuel


be running the rx4 again in a rally in november my ls1 zed is not quiete finnished just have to piss some more people off being beaten by a rotary


luv to see your car running



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Something to think about, I was reading a while back some guy on rx7club converted his mecanical oil injection pump to use an external tank. Then he ran some oil that bruned better and oiled better and ran like 50:1 premix like one a month.


Sounded like it was perfect as you didnt have to worry about burning engine oil or clogging fuel injetors and filters with oil. Or mixing it every time you fill up. Something to consider if you can still do that.


Nice project tho, Im a big fan of the rotarys.



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2 stroke oil can get expensive but since i have a boat with a mercury high perf outboard i can tell you what good price for good oil is.i run penzoil full synthetic-its $25 a gallon.another good oil is yamaha bulk watercraft oil.the yamaha shops sell it for $15 a gallon.the boat is running redline full synth right now because i got 4 gallons when i bought the boat last winter.that stuff is $40 a gallon.most people dont know that mazda burns off some of the crankcase oil aand the oil should be checked every 500 miles.my dream motor in my z is a 20b 3 rotor turbo-the socal sand rail boys run these and get 600hp out of them.

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the main advantage of the synthetic 2 stroke oil is that it does not go off once mixed with fuel like mineral 2 stroke oil does so if u dont use all the fuel the day u mix its still ok


back when i was motor cross racing we used to mix 2 stroke fuel on the day u wanted to use it since it goes off

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Get that thing running! Good to see you're working on it again:-) I like the new mounts, BEEFY!


Did you guys know there was a 350Z with a 20B turbo in Australia? I saw the vids on youtube, crazy. I think he parted it out to do a race car or something.


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Whoa, I saw the title of this thread and thought it must have been something someone dug up from the archives, but NO! Aux is working on the car again! YAHOO!


I really want to see this thing in person once it's on the road. Go aux, we're cheering for ya.

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