5, 6, whatever. It's kind of a pipe dream.

Now for something real... real awesome!


Here you see a front counterweight rebalanced for use in a 4 rotor arrangment, 19 long tension bolts, one long dowel pin rod and two shorter hollow dowel pins (for oil to flow through), a stationary gear machined and fit into an intermediate plate (and one below it), one front plate under the tension bolts (rear plate under it), a special rear counterweight with splines to match the splines on the end of the Jeff Bruce shaft, and finally two rotor journals that slide onto the shaft and are locked in place with a key.

The quality is superb. Jeff Bruce = class act.

 

In case you're wondering, Jeff Bruce didn't make that box. We did, so we could ship the side plates to Jeff. He needs the front and rear you're going to use and two intermediate plates for a 4 rotor, or one for a 3 rotor, as there are alignment issues. He dowel pins the plates together for an accurate cut to install the stationary gears into the intermediate plates. The box was made with an extra compartment large enough to ship the two new (front) stationary gears down to him. He was then able to fit the counterweights and rotor journals in there to ship back to us. I like his solution for all the tension bolts; looks like he drilled a bunch of holes in the 2x4 to secure them above the plates.

 

Coool. Those are some seriously long bolts.

What is the bit that looks like half an e-shaft? Or is it half an e-shaft? lol

 

Very cool, Jeff. Now get that thing together! I want to hear it run!

 

One more thing, the rear nut is 48mm, not 54mm like what we're all used to. Makes sense since the threaded part appears to be a smaller diameter.

 

DJ, you're still thinking two rotor. It's only a quarter shaft.

The next task is coming up with four peripheral ported rotor housings. We were going to use some MFR housings but Mazda no longer sells them. Looks like we'll need to get some custom ones now.

It could be as simple as aligning each rotor housing on a milling machine, drilling a hole of appropriate size (so the opening and closing match whatever port timing we want) and installing an aluminum tube with an interference fit. Then TIG the outsidem fill the water jacket with some sort of epoxy and trim and smooth the inside for a nice bevel for the apex seals. A couple of weber 51 or 48 IDAs with a tube manifold and that's basically it.

 

please tell me your documenting this and doing a build dairy?

 

Come on Jeff you got us doing backflips here,
days with no new info! I'm ready to run down
there and turn a wrench for you!

 

wow, speechless

 

wow this is a very cool project, cant wait to follow the build.

rotaries thru ITBs or carbs sound so freakign badass straight outt ahell its awesome.

best of luck on the setup, its looking damn good. what a jaw dropping idea too.

 

But i only see 2 quarters..what about the other half? lol.

Definetly a sweet project. When its up and running you will have to take some vids too! (though we all know thats a bit away with all of your other crazy projects)

 

Lots of math right Jeff?

 

Looks expensive.

 

Impressive work.

What are the tension bolts made of? I would think that with a motor that long you would want as little flex as possible. Maybe a little larger in diameter?

 

Wow, lots of questions today. The owner got back from his trip and inspected some of the parts. They look good. The next task is coming up with some rotor housings. Since you can't get 12A MFR rotor housings anymore, we might try making our own. We'll test them on a 2 rotor first. If all is good, 4 rotor.

The tension bolts look liek rod stock. He cuts threads in one end, drills out a nut and TIGs it on the other end. Normal diameter. Engine flex shouldn't be too much of a problem for us as we are using three GSL-SE intermediate plates with a motor mount bolted on each side of all three. Also a pan plate may be used.

If I do any kind of build diary, it will probably be here.

 

When you say make your own, do you mean actually CNC new rotor housings? I'd be very interested in how you do that and the proccesses you use.

 

No, he means taking good 12A housings and boring a peropheral intake port into the side of it. Everything looks awesome Jeff. You'll have to give us a total price for this once you're done so we can start saving now so in about 10 years we all can afford it LOL

 

How about if you think in this way: For about ten grand you could have the performance of a new $50,000-$100,000 sports car and the awesome 4 rotor sound which none of them posess. Interested?

I bet this project will come out to around 10k which includes the cost of the car and suspension upgrades. Not a bad price tag considering modern cars these days typically go for around $20k with modest performance (they're big and heavy these days).

This project is quite affordable for anyone who applies themselves and doesn't farm out the work (the work is half the fun! The other half is driving it!). If you can build a 12A, you can probably build a 4 rotor. If you can tune and drive a peripheral port, you can probably handle four of them. If you can drive an aluminum flywheel on the street (I'm using aluminum as an example here but only because with 4 rotors you will have plenty of rotational mass that anything heavier is probably not needed), I'm sure it will be even easier with 4 rotor pushing it. See where I'm going with this? And it doesn't have to be peripheral ported - you could figure out a side port setup if you so desire. We want to go with peripheral ports because they make sense to us in our rotor-headed world even though neither one of us has ever driven or tuned a peripheral port... at least I never have. I'm willing to give it a try though.

 

awesome stuff jeff!!! maybe you have a friend nearby who would like to document everything in detail while you have all the fun :P You could put together a book - it would definitely sell... How to make a superior performance car for under 10grand... or something like that I for one would be interested in the full story from the idea to completion and all the hurdles you had to get over and how you passed them etc.

Either way keep us updated here, exciting stuff Thanks for sharing!

 

How bout that 4 mpg, but ohhhhh what a sound!!!!!!

 

I would definitely love to do something like this in the future, money permiting. It would go in a wide body FB with RE-Speed coilovers, rack and pinion, Turbo II trans, RE-Speed big brake kit with 5 lug swap and some wiiiiiiiide wheels LOL. You think a GSL rear end would hold up behind this beast?

 

Hell yea-looking good, Jeff! I can't wait to see some more progress...I'd love to be on the West coast so I could come up and help you fab up some of the intake and exhaust components. Very, very innovative. You should start your own rotary technology school to teach us all (or just most) of the things you've learned wrenching on these rotarys over the years...

 

H4Inf, the early planning stages can be found over on nopistons in the 4 rotor thread. Lots of top notch info there (much of it added by me lol).

The car will actually be getting a widebody kit but I think it will have to wait until the engine is in. I don't want to lean over wide fenders if I don't have to.

As for the rear end, if you use stock tires and don't drive like an idiot, it can work fine with lots of power. Once you increase tire grip, things can break.

rxforspeed, that dead GSL-SE tank actually came out of this car. I thought I could use it but its too far gone. I appreciate your willingness to help me with my 20B project as that is where the GSL-SE tank is needed. The 4 rotor car will have to get a fuel cell because there is almost no way a stock tank will provide the fuel needed, at carb pressures, to support 400-500HP. Maybe at EFI pressures, but we want to use two weber 51 IDAs. They'll sound awesome!

 

cant wait to see the 2 webber's mounted. the oer side draft 51 mite be easier to tune.

 

go 55 dcoe side mounted kinda like a lake cities intake.