Slevin_FD

iTrader: (26)

Ok, so I was in lounge the other day, and I saw the post about the guys what took two 13B's and somehow turned them into a 4 rotor. And, since I am in the mood for a good brainstorming session. I decided to bring this puzzling engineering problem to the forums. Now I am sure that some of us have seen v-8's coupled together, so doing the same to a rotary engine should be easier. Cooling however might prove to be more difficult. Nevertheless, let the brainstorm begin.

bewtew

iTrader: (7)

use the search button many threads like these.. you need the eccentric shaft and counter weights kit which cost over 10k

Sketch_hs

Don't the 4 rotors just kinda bolt together? like where the clutch would be on the front engine bolts to where the crank pulley would be on the rear engine?

calculon

iTrader: (29)

No.

-Ted

Slevin_FD

iTrader: (26)

I'm pretty sure those guys fabricated everything themselves. I know there is a 8K 4 rotor kit. But They literally took two 13B's and bolted them together somehow.

Slevin_FD

iTrader: (26)

here is the link

http://www.youtube.com/watch?v=A2nuYyMIVao

calculon

iTrader: (29)

No they didn't. You can see that they share the centermost iron, therefore, that is a single 4-rotor engine. You are thinking that they did what you are saying simply because they are using 2 FD UIMs and TBs.

RacerJason

iTrader: (5)

Actually, you don't. Aaron Cake is experimenting currently with dowelling and keying 2 13b shafts to create a four-rotor shaft. But yes, some of the components needed to assemble such a monster will require heavy modification and/or total fabrication. A four-rotor kit from Guru would be the quickest but also the most expensive.

Slevin_FD

iTrader: (26)

Racer,you and Aaron are more on what I am trying to get this thread to be. Maybe we need to get Aaron in on this too. I'm sure that the more people we have working on and sharing ideas. We could all figure out how to make this happen in an inexpensive and effective way. Not everyone has 10K laying around, but I am sure that we would all like to have or at least be able to build a 4-rotor engine.

rotarygod

iTrader: (1)

Granny's Speedshop once built a 4 rotor race motor by bolting 2 engines together. They did modify the eccentric shaft ends so they could be keyed and had to get creative with the coolant and oil systems. They bolted them together in a way that rotors 1 and 3 fired together and rotors 2 and 4 fired together. This way they could use a standard distributor and just double up on coils. It was ghetto but it worked.

dimjo

If I am not mistaken, I believe the shaft, intermediate plates, counterweights, were purchased from Jeff Bruce.

dimjo

Look up Yashiro Iron works, on this web site back a few years. They had a 5 piece shaft. Point is, a rhetorical question: is it feasible to cut the lobes off of several 2 rotor eccentrics, bore out the centers to fit over a shaft, and have a shaft (4340 steel for example), gundrilled for an oil passage, and key slots cut on the shaft and the lobes for assembly? Cost savings would be realized in the purchase of the used 2 rotor eccentrics to make the lobes. Any one with machine shop experience among you could give a guestimate on cost? I doubt it would come to 10K.

ProjeckJay

what about scoots fd isnt that a 4 rotor engine? i tought they built it and badge it the 26bb
http://www.youtube.com/watch?v=PAGqJsKlJH8

https://www.rx7club.com/20b-forum-95/scoots-4-rotor-84156/

Slevin_FD

iTrader: (26)

I have seen used 2 rotor shafts for as low as 30 bucks a piece. I doubt that machine work would be more than a few hundred. Now as far as reliability I'm sure an N/A setup would probably last longer than a turbo, but That's actually a good idea. We would have to figure out a way to match the timing to an OEM shaft. however that would allow for expandability. Like making 3 rotor shafts and maybe even a 5 rotor shaft, although that would probably flex like crazy . Then of course there would have to be a counter weight.

brad89au

i thought the scoot 4rotor was based on two 12A engines?....

HAI-TEK7

iTrader: (31)

Heres the link from Grannys of what Rotarygod was speaking of, for those who havent seen it.


http://grannys.tripod.com/4rotor.html

TeamRX8

iTrader: (2)

the shaft doesn't cost $10k

txturbogs

I've always liked the idea of owning a four rotor, NA, not turbo. I am unsure what a shop would charge to do such a thing, if there is a reliable shop for this of course. I've owned 2 rotary Fd's and two ls1 fd's. The last one, the current one, is going to be a beast once it is done (425ci). I would buy one of these 4 rotors if the chance presented, but the question is, how much does it cost to build or to buy one already built? Another question is, how easy are they to drive on the street. I've driven all my FD's this way, and so will the current one will too. All the four rotors I've seen so far, and they've been three, are not street driven.

Anyway, just wondering..dreaming I guess...LOL. I know I will buy one or build one some day.

DPR

Check out Pulse Performance Race Engineering

http://www.pulseperformancere.com/prodpack.html

They sell a kit as well as a short block. They are in NZ, but they have powered one on the top drift cars there (Mad Mike's Red Bull FD Quad Rotor)
The cost is 37,500 NZ dollars and a 9 week wait time plus shipping to the US.
The motor sounds awesome!!!

Slevin_FD

iTrader: (26)

That's not a bad kit for 9k US. I guess the only other issue would be mounting the engine. I'm guessing it would just take a 20B subframe.

calculon

iTrader: (29)

That's the same as supposing that mounting a 20B just takes a 13B subframe.

flaco

iTrader: (7)

the kit is around 8k

PercentSevenC

Ken Durkee did something like what the OP is describing. He had a piece machined that as I understand it basically allows the front hub of one 13B to be bolted to the rear counterweight of another. So you have two water pumps, two distributors, etc. A friend of mine acquired it and will be building a car around it eventually, but he's got a "real" 4-rotor he's in the process of building first (see Jeff20B's "ghetto 4-rotor" thread in the first-gen section for details on the "real" one, but it hasn't been updated in a while).

wackaloo13

iTrader: (3)

you need a bearing somewhere in the middle.... Since i have entirely to much time on my hands, of course i have thought of doing this. What i would do is take 2 13bs and remove the front cover off of one and mill off all of the bell housing mounts on the other. take one of these http://www.guardiancouplings.com/pro...scMembrane.htm and fit them to the front/rear of the 2 eccentric shafts. I would probably cut down the front engine's eshaft a bit so that it did not poke out to much. I would join the two together on a 1" thick plate of aluminum. i would also build some sort of bracing on the top of the engine. The oilpan would be attached to the bottom of the thick aluminum plate or a dry sump could be run. A drysump would be easier b.c you could ditch the oil pump on the rear engine which would make the overall assmebly shorter.

flaco

iTrader: (7)

You could do that but no need of using 2 distributors