Just a couple questions here from a rotary fanatic. I seem to have found a couple vids online of 4 rotor rx7's like the scoot one and a red one from god knows where. Now i didn't know where to post this but since most seem to be built in fd's I figured this would be the section. Anyways how does one get such an engine is it prebuilt or is it made by simply assembling all the rotor housing and 4 rotors together. and if built in this way how the heck do you get an eccentric shaft to work with 4 rotors when built for 2 or in some cases 3 rotors. I think there is room for alot of educating to be done on this subject let the information start flowing.

 

Precision Engineering built the E-shaft for the red 4 rotor. I am not sure about the scoot car. Aside from some odds and ends (modified center housing ect) the rest of the parts are off the shelf.

 

granny's made a cheater kit to bolt 2 13b's together.

 

Granny's never made a kit.

They made some one-off stuff for one engine, that they campaigned until they figured that it was easier and cheaper to just run a small block like everyone else in the class.

Sheesh.

 

you can get a prebuilt one-------just buy a lemans car

 

There seems to be two methods of building a 4 rotor e- shaft, start from the middle and stack bearing surfaces outward or start from the front and stack them back. The scoot shaft is one long shaft with each surface removable like a 20b front section so it ends up being a 5 piece shaft. Basing it on a 12a keeps the overall length down with a resultant drop in cid as well from a 13b based 4 rotor.
Top fuel had a 4 rotor with a special irons with external oil passages, and no "filled" stock ports, they look identical to the plates used in the mazda 787b 4 rotor. The biggest obstacle is the shaft, and the shaft support bearings in the iron being fitted properly..
There are alot of shops working on "short" 3 rotor and 4 rotor engines in Japan now that being big horsepower on N/A is in vogue in Japan so there should be some stuff starting to trickle out of Japan for the home builder soon..
I would like to do a n/a 3 or 4 rotor motor, but would like to skip the step of buying a 20b, since most 20b's especially here are worn out overpriced junk...

 

Yashiro Iron Works in Japan made or is in the process of making a 4 rotor. I had a pic of their e-shaft up in the lounge... Search for my name and the word "shaft" in there.

I like it because they only used end housings, meaning there's a bearing on each side of each rotor to support the shaft. Total of 5 main bearings. I don't like that the rear two rotors are 90 deg outta phase from the front two. I'd think that putting them 180 deg outta phase eliminates the need for excess counterweights and won't stress the e-shaft as much.

 

kiwi from NZ sells 4 rotor e shafts.. no clue on pricing or anything else like that.. You'd have to do the research yourself.
www.kiwi-re.com

 

Mazda sold 13G and 13J engines over the counter.

13G = race peripheral port 3 rotor. Older than the 20B, vaguely similar in design.

13J = race peripheral port 4 rotor. Not the same as the R26B, the R26B evolved from the 13J.

Engines, when they were available, were somewhat expensive. IIRC in the $20-50k range, honestly my memory is fuzzy but definitely not cheap for a street engine, but fairly competitive for a scienced-out endurance race engine.

 

The red third gen RX7 with the quad rotor is from New Zealand.

You can read a magazine article about it here.

Magazine cover
Page 1 Page 2 Page 3 Page 4 Page 5 Page 6

 

thanks for straightening me out on that.

 

Gravy_83, the damn parts associated with a 4 are so hard to come by. not to mention expensive, but anyways... check this out , it's a great tool . use it to search for everything rotary http://www.rotary-search-engine.com
here's the results for 4 rotor http://www.rotary-search-engine.com/qry/4+rotor/

I wonder if there is a reason for that, mabye something to do with the firing order and crank rotation(clockwise or counter-clockwise). Or mabye some thing to do with the way the ports run. Hmmmmm.......


you need a prescription? JK! LOL

Those crazy kiwis are doing all kinds of wild things with rotarys.
but yeah man, check out http://www.queenstsmash.com.au/
They made that pink/red RX7, the bimmer and they have vids that you can d/l
It'll make you drool , just listen to that BOV!@


read down the page a bit. It's all old stuff, but goes into 3,4 and even 6 rotor engines. Good stuff
https://www.rx7club.com/showthread.p...3&page=2&pp=15

 

damn that red car is a monster

 

nice lot's of info. by no means am I even thinking of doing this myself though. I just wanted info just to learn more about our loved rotary engines. I can't seem to get enough of them.

 

Granny's made theirs in-phase so they wouldn't have to worry about central counterweights, and for ease of making an ignition system.

As a bonus, no central counterweighting means there's that much less rotational inertia.

 

I need help to find a 4 rotary engine[I][U]
alexis_rvd17@hotmail.com

 

pineapple racing says they have one

 

http://www.thecarricos.com/ACRE/Docu...-rotor-1-5.pdf
http://www.thecarricos.com/ACRE/Docu...rotor-6-11.pdf

Some 26B reading.

 

check on our web site. www.autotechmotorsports.com

 

check our web site. www.autotechmotorsports.com