Bitchn7

There have been a few questions regarding Jeff Bruces 3 and 4 roto engines but noone has asked this.

The way those engines come together, you are using two, or 3 centre plates. Therefore at least one or two rotors (depending if its 3 or 4 rotor) are being fed the air and fuel through two small ports that are on the centre plates and the remaining (this would be the rotors at each end of the engine) rotors are fed by one small and onelarge port as per factory 13B and 20B engines.
Now, will this cause significant mixture differences from rotor to rotor?
The HitMan says all his rotors looked similar in colour etc after pulling his engine apart, suggesting everything was OK, what you you all think?

Jeff20B

iTrader: (13)

I've thought about this too. Some center housings have tall ports and others have short ports. Maybe you'll get lucky and find a bunch of '83 centers or something (although it probably isn't necessary).

repuguru

Do you know of a picture of one of his 3 rotor motors?

Bitchn7

Check out the Hit Man's web site. he has one of these in his RX-7. Don't be fooled by the 20B top intake manifold.
I hope this link works.

20B_FC

I'm more worried about the cooling issues. On all the mazda rotaries including the 20B, each rotor chamber has a face in contact with coolant passages. When you use the center housings as a intermediate housing, there are no coolant passages behind the center rotor chambers. I guess this will be a longevity problem because any motor will run with extra rotors attached.

PK

repuguru

Very interesting point about the special 20b creation. Has Jeff Bruce ever tried to address the cooling problem for these custom motors. Or does it matter for what he uses them for?