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


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#1 auxilary

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Posted 26 September 2006 - 09:00 AM

Feel free to look at pics of it in the last set of pics on 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

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Parts needed for the conversion:

Engine:

-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

Fuel:

-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 :)

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

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

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

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Turbo clearance with finalized mount

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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

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Engine mount close ups:

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Linkage clearance close up. Note the reinforcement gusset

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Oil pan clearance

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

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

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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
RotaryZ.com
DatsunRacing.com

Pray - a lot! -John Coffey

#2 olie05

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Posted 26 September 2006 - 09:24 AM

I'm glad to see you are finally working on the rotaryz!!

Keep the info comming. This is sticky material.
"I heard and smelled your car before I saw it." -innocent bystander

#3 veritech-z

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Posted 26 September 2006 - 10:12 AM

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)
-Max


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#4 auxilary

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Posted 26 September 2006 - 11:43 AM

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
RotaryZ.com
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Pray - a lot! -John Coffey

#5 veritech-z

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Posted 26 September 2006 - 11:50 AM

so is it running yet, or not quite? I've been curious about your car for a long time. How much does the vehicle weigh now?
-Max


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"I put on my robe and wizard hat.."




#6 auxilary

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Posted 26 September 2006 - 01:10 PM

Not running, but getting there. Weight? I'm guessing 2200lbs
RotaryZ.com
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Pray - a lot! -John Coffey

#7 slownrusty

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Posted 26 September 2006 - 04:52 PM

Aux - Looking good bro and I am officially scared at how much fab work is required....I tip my hat in great admiration to you fine sir!

Yasin
Ole skool "wouldn't have it any other way"

#8 mario_82_ZXT

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Posted 26 September 2006 - 05:55 PM

That looks sweet! Major props!

But that's kinda weird about the oil premix... learn new stuff about them every day, but I don't think I can ever get into those engines... too "out there" haha.

Like you said, it's unique!!

Good luck with it!

Mario
78 280z | Back to L28ET in progress
77 280z | $200 parts car turned daily driver
76 280zT | Dad's car (L28ET, MSnS-E, Big IC, 14psi) DAILY DRIVER

#9 zed240au

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Posted 26 September 2006 - 09:15 PM

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

mick

#10 GrayZee

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Posted 27 September 2006 - 07:12 AM

Next can you do a post on how to drop a L28et into a Rx7? :biggrin:


LOL, I know a guy that has a RX7 with a L28et that could use the info...

Nice work btw.
76 280z with stock 1983 L28et Holset Hy35 Chipped Nissan ecu. 440cc injectors 255lph Walboro internal fuel pump 3" SS mandrel exhaust 60mmTB. 38mm external wastegate, 20+psi?

#11 Poundz9oh9

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Posted 27 September 2006 - 07:44 AM

Wow, Aux has a Z??
---Marcus---
77 280Z The typical "Work in Progress" for this site :)

#12 Alex_V

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Posted 29 September 2006 - 09:16 PM

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.

~Alex

#13 randy 77zt

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Posted 29 September 2006 - 09:51 PM

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.

#14 auxilary

auxilary

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Posted 30 September 2006 - 12:26 PM

rotaries aren't designed to run synthetic because it doesn't burn too well. I guess I can now since I won't be using crank case oil, but it'd be pointless
RotaryZ.com
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Pray - a lot! -John Coffey

#15 zed240au

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Posted 01 October 2006 - 06:25 AM

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

#16 auxilary

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Posted 01 October 2006 - 11:44 AM

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yep! i got some engine room! :) yesterday's pic with radiator, fan, and IC mounted
RotaryZ.com
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Pray - a lot! -John Coffey

#17 zeeboost

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Posted 01 October 2006 - 01:33 PM

Room for one more

1982 280zx -- 355/t56/3.9 R200 *Garage Queen* .............................................1972 240zt - T4, TEC II, 20psi *Garage Queen*

1975 280z - F1x LQ4 370ci/t56/R230/widebody project *In Progress*.........1983 280zx - L28et/T5 installed, 2jz *Pending*

***Recently Added to the stable***

1970 240z - WWII themed 220hp L28, 4.11, <2000 lbs *In Progress*............1977 280z - Terminator swap *Pending*


#18 b__sosick

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Posted 01 October 2006 - 04:31 PM

yep! i got some engine room! :) yesterday's pic with radiator, fan, and IC mounted



future plans...lawnchair...hammock...
-brandon
2002 GTi 1.8t.5spd. REVO stage 1. euro front. montes. TT exhaust, Heineken mini keg intake >:D
1999 ranger. flat black.5spd.ac/heat. some sound stuff. for sale!

HybridZ = Smiles per gallon!!!


#19 Owen

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Posted 02 October 2006 - 06:48 AM

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.
Owen
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#20 veritech-z

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Posted 02 October 2006 - 06:53 AM

I've also seen that video on Youtube, I was looking for videos of the 787 b that featured it doing more than just idling in front of a crowd for minutes at a time, and that turned up. Crazy swap!
-Max


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"I put on my robe and wizard hat.."







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