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There has been question on IF this can be done, and if so what needs to be done to accomplish it. I am well into the build at this point. The motor, both turbos, the transmission, and the radiator are in.
I will be going back and sort of going step by step in the issues that I ran into, as well as continually updating as I go. To cap it all off I plan on posting the Youtube vid of it running.
I went with the rotary until my oil control seals blew up and made the engine not run. Then I found out you cannot "machine" any rotary pieces to make them new. I chose the VG30DETT because I love Nissan motors, plenty of upgrades, hasn't been hit by the drift tax yet, not many people have done this swap (none made a thread), a V6 would retain SOME handling characteristics of a stock rotary car, an N/A wouldn't satisfy my desire for speed, plenty of potential, mechanically a very sound platform, and above all else: I can.
Last edited by jd88; 08-17-17 at 05:41 PM.
Reason: Title change
Not sure what machining has to do with anything, just because a rotary doesn't have a block and head to machine or cylinders to hone doesn't mean you can't rebuild it.
Hopefully you know your VG better than you knew your rotary.
Not sure what machining has to do with anything, just because a rotary doesn't have a block and head to machine or cylinders to hone doesn't mean you can't rebuild it.
Hopefully you know your VG better than you knew your rotary.
The oil control seals got so bad it kept fouling plugs out inside 5 mins. My rotor housings were chipped on the edges, and only one side of my center plate did not have excessive step wear. The rest were beyond being able to lap. My point is you cannot surface them and get factory longevity like you can with a piston engine.
Interesting. I picked up a junk yard single jammer VG for my vert, but got sidelined with my Tii so its still sitting. Would like to see how this goes.
Clearance issue #1, IAC system. Little twisty-bendy and we're good.
Passengers side I used the stock Z32 mount bolted to the stock RX7 mount which bolts to a perch.
Driver side I had to make a mount. Coildnt use the same points on the subframe because the steering rack was in the way.
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Subframe in with my perches on. I have poly bushings I will be using on the final product.
After a mock fit or five, several hours of cussing, lots of tack welding, breaking free, measuring, etc. I came to the conclusion that Xcessive Subframe lowering kit for the 2JZ would be needed.
Here's how tight the clearances are. Wastegate to steering shaft was the closest. I had to move the motor over about 1/4" from center to make it work.
THIS part however, not so much. But after about 3 tries it goes into all gears.
And as a side note, I am currently waiting on a new pair of turbos before fully tackling the cooling system, particularly around the heater core area. Step 1 is converting to an expansion tank with a constant air purge.
After eye-balling a few things in the junkyard, a 97 Audi A4 looked too good to pass up. (this is for mock-up only, a new one runs $20 and I'll be doing so for the final)
Again, SCARY how well it fits. Might be something for rotary guys to look into, purge-flow tanks have many advantages over traditional overflow tanks.
Next up is the radiator
Now this just isn't going to work. So after a few hours of cutting VERY close to this $500 radiator that I REALLY don't want to give up, all I did was make the stock tilt not as extreme
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Aaaaaaand we're good. Next up was the fan. Now I didnt want to cheap out and stick zip ties through my core..... And I really wanted to flex my creative muscles so I fabbed up a bracket to go with my fan
Modern plastic push-pins work GREAT here
I did have to space the hood mounts with a stack of washers, which does require minor bending of the fender ro pull off, but the motor, trans, and radiator are in and my hood closes securely with no rubbing.
Next up is the piping for the turbos. I currently have one side done but I'm going to get the other side done and part of the intake system before another update. Lots of fab work.
Since right now this is a "get this vehicle running ASAP" kind of build I decided the cheapest and fastest way was going to be to use stock side-mount intercoolers and make custom piping. I went with 2.5" piping in the thinnest gauge I could get my hands on.
I do not have access to a TIG welder or that's what I would have used. It's on my list of things from the tool truck so that one day soon I will be able to redo all of this with TIG welds and more precise pie cut bends.
Driver side
Carbon steel 1/4" flat bar is what I used for the mounts. I also beefed up the bumper support, but that's another matter.
Side 1
And after several hours of cutting, grinding, test fitting, removing, more cutting, a few places I took a hole-saw to, both sides are done. And no it was not a straight through cut with a hole saw on the cold-pipe section.
That is a stock S5 front bumper that I have made a few alterations to. I am still debating on covering the intercooler and center openings with some sort of fine wire mesh. I also have in works to stick a couple very small puller fans on the back of the intercoolers.
Polyurethane bushings. Once the motor is in I can shake the whole car and they dont move. (not being paid to promote who they came from)
Bottom is some stock late 80's and early 90's connectors that have those metal C clips that are also found on RX7's and are a pain to remove. Half they time they break or the metal clip vanishes. Above is a connector off a 2000's Audi. With a little modifying they clip right on and make removal a breeze. Something I think everyone should look into. Go to your local junkyard, BMW, Volvo, Audi, and VW all have some variation of this style and most are fairly compatible. At worst you'll need to break out a razor and trim a little plastic to make it fit.
One problem the VG30 motors have is in the electronics. One power wire feeds several components. I'm making a fuse box to go to my injectors and coils so that if one shorts out I can still drive with a misfire instead of paying for a tow.
Engine side of harness. More was wrong with the harness I got than was useable so I just made one from scratch.
This is a upgraded turbo since one of mine was seized and stock ones are no longer available. I also didnt want to chance rebuilt ones. (not being paid to promote)
Z32 throttle cable does fit the RX7 pedal. Drill a pair of holes in the firewall, nut and bolt, and it's in. The pedal geometry and pivot point have to be changed to work properly though. At best I get 25% actuation. More on that later.
It's extremely close, but everything clears.
And this is where I'm currently at. Next update will include the power steering dilemma (the motor came out of a HICAS equipped car), oil cooler lines, and blowoff valves.
Last edited by jd88; 09-03-16 at 02:14 PM.
Reason: adding descriptions
Stock clutch master works, however I modified a Z32 one to work in the same spot. Hydraulics are the same on both.
Custom driveline from a variety local driveline shop.
Custom pie cuys and welding and I have a dual exhaust. One resonator and one muffler per side. I'm going to be installing and X-pipe at a later date.
I had a midnight think and realized my subframe based mounts would not work as well as I wanted, so I welded a plate to my frame, bolted another plate to that one and put threaded rod through the mounts. It holds VERY well with surprisingly little vibration transmission.
Add some radiator hoses
Custom hoses made with RX-7 ends to fit the cooler that I just flipped upside down.
Had to re-shape the stock RX-7 gas pedal to achieve full actuation of the throttle plates.
I spent about 130hrs making this harness. All the gauges of wire are stepped up a couple sizes from factory, all my injectors are individually fused, all my coils are individually fused, and diagnostic techniques are very simple and, in fact, have already been useful.
I added some color, blow-off valves vented to atmosphere, wiring harness installed, etc.
Obviously there are a lot of little things here and there, and this is very much a MkI design. I hit the point of GET IT RUNNING.
And now the moment you have all been waiting for...
Nice build up this crossed my mind when I picked up my fc but wasn't so sure how'd it come out. Now it's quite interesting but still leaning towards the rotary.
Good stuff! I like the thought of this engine in an Rx-7. I actually knew of one in an FB decades ago, but the guy that build did a while front clip as opposed to just engine, it was nice, but what you did here, getting the engine in an FC deserves respect. I have loved the VG30DETTs since they came out and combining that with an Rx-7 seems to be an almost natural fit.
How many miles on it now? Any refinements or modifications?
04-05-16, 10:05 PM
