hey everyone, i was just wondering if it has been done?
ive been looking in the the three rotor swaps and the 4 rotors conversions, but i noticed the 4 rotor builds are always based on the 13b motor. i was just wondering if anyone has ever built a 4 rotor engine using the 20b motor as a basis? would it be benifitial at all or no? i have tried searching but didnt find anything.

 

just make it a 40b

 

6 rotor ftw!

 

that would be insane i wonder if it would fit in the bay?

 

dude, they're making fun of you. i don't mind you asking questions, but if you ask the questions you've asked ... forgive me ... you're clueless!!!

read the FAQs on 20Bs. then read the threads on 26B projects ... you'll see an even smaller success rate and why.

for the record ...

20B (or 13G) = 3 rotors
26B = 4 rotors

though there was a 6 rotor (39B) project, from what i gather it never materialized into a working engine.

do some research and refrain from posting here for a while.

 

oh yeah ... and your original question about the 20B 4 rotor ...

no, it has not been done. though, you can feel free to head it.

 

you know, it's funny, when i read this last night, i took a whole different meaning from what i took from it just now. that's my fault, i guess.

anyway, i don't have a yes/no answer to your question. i'm not aware of a 20B-based 4 rotor, which is not to say it doesn't exist. i'm simply aware of it.

my thoughts would be no though. i'd imagine the lobe phasing of the 20B eccentric shaft and tension bolt setup of the 20B thick housing might be issues that would make it much more difficult than using the 13B as a starting point for a 26B build.

sorry for my confusion.

 

i never heard or found anything about it being done either thats why i was asking. just curios since the 20 b is a 3 rotor it a bigger motor didnt know if it would be easier to just addapt one more rotor to it, rathert than take 2 13b and join them. (and yes i now theres alot more work involve beside just sliding together and putting in the car) never thougth about the 6 rotor tho, but realalisticly i dont thing it would work to well. but thanks fot the imput on the 20b

 

I always thought a 4-rotor engine was called a 26B...?

There is a guy in Melbourne, Australia named Rohan Ambrose from Extreme rotaries that builds his own 4-rotor engines with aluminium side plates etc

Sells to anyone.

 

it is. the thread starter worded the title awkwardly.

 

right the 4 rotor is a 26b or 26bb som call it. 13b+13b= 26b/26bb

i didnt word it awkwardly i was asking about a 20b 4 rotor build. meaning instead of using 2x 13b motor, why not use 2x 20b motors since the rotors and housing are bigger than the 13b.

 

You are confused. The rotors and housings (save the thick intermediate) are the same size. There are 3 rotors, hence the additional displacement.

 

Well, if you want to keep the side ports, then that is the only way to do it, i think. BY using 2 20b centers. But this would make the block longer/hevier than a PP 4 rotor.

 

26BB? lemme guess ... 13 + 13 = 26 and B + B = BB??? maybe in your circle, but i can't say i've ever heard it referred to as 26BB ...

to each, their own, i suppose.

anyway, Calculon already showed that you DID word your title awkwardly and why. all i will add is confusion could have been minimized if you had said a "20B-based" 4 rotor in the title. obviously, you agree that you won't yield 2000 cc from 4 rotors, so hopefully you see why your title didn't mesh well with your actual question.

furthermore, you do seem to need to read a little more on all these engines. there's nothing wrong with that and i don't mean that in a judgmental or condescending way, but your defense of why your title makes sense as is, was what actually made your confusion clear.

 

i understand where you coming form yes the title is wording awkwardly, and can cause confusion. but as for the motor i did reseach the motor a lil and i thought i read the 20b came with differnt size rotors and housing as well as bigger side ports. however the side port design was changed after a certain year (not positive) but since it said the motors are the same size there would be no benifit to using the 20b as a base. Correct?

as for where the 26bb came from when i searched google on 4 rotors a number of videos and site came up with the name 26bb in them for the fact of the 4 rotor. they use the same theroy u did "13 + 13 = 26 and B + B = BB???" i believe on of the build i read was (red bull drifter) mad mike i believe with the N/A 4 rotor wide body fd. they reffered to his motor as the 26bb. just saying tho thats why i called it the 26bb also the same thing as the 26b

 

having never had the pleasure of owning a 20B of my own, i can't speak to comparing port sizes to 13Bs. what i can say is that they use the same 80 mm rotor and 654 cc chamber though. as i said, i don't see any benefits using the 20B as a starting point due to the reasons i outlined previously. people smarter than me, may disagree and if they show me that i'm wrong, i will gladly yield.
all i can say is people can call their projects whatever they want, but i've only ever seen Mazda refer to 4 rotor engines the 26B or R26B.

 

Perhaps the front, rear and non bearing side plates are aluminum, but I'm sure the rest are all iron unless he is casting or machining his own or can source them from some other place besides Racing Beat. I know there are a few shops working to develop alternative alum side housings but am wondering if they will they be designed to carry a load from the stat gear/bearing.

 

Rohan does machines up his own side plates, front, middle and rear. Might be worth having a look at his web site. Just do a google search, might see something you like.

 

FYI, the 20b (primary) ports are about 15% larger than the 13REW (FD) ports. I am using a 13b rear iron on my 20b and had to do quite a bit of porting to make it match.