Hi everyone,

I've read on some websites a rotary engine can also be made in a diesel version. As I live in Belgium (were 90% of the cars are diesels because taxes are way too high for a gas car over 150hp and fuel prices are more than € 1/liter for 98 octane unleaded fuel), I thought it might be very interesting if mazda would experiment a bit with a relatively powerfull rotary diesel for the RX-8. Not that I like a diesel more, but it's just less expensive and it will increase sales a lot in Europe.

So tell me, what do you all think about this?

Here (http://www.der-wankelmotor.de/Motoren/UAV/Pats/pats.html) is a link to an existing rotary diesel engine used as a power generator

Greetz,
Beemer

i've heard that it's quite difficult to get a Wankel rotary working well as a diesel engine because of the low compression ratio...
if Mazda were to do this, they would have to decrease the width of the rotor A LOT in proportion to the stroke (which, i believe, in all Mazda rotaries has been a mere 40mm...) to raise the compression ratio enough (what is it, 20:1?? more??)
basically, this engine wouldn't be very well suited, 'cause you'd not be left with much displacement to work with, or if you had a good amount of displacement, you'd have one helluva rotor to try and cool off... it would work, but i sincerely doubt it's as good a solution as a piston-type engine.

btw, 'cause no one read the information when i posted it in the "How Does RENESIS Make More Power?" thread, i'll post it again here...

that 40mm stroke, which yes, i know that's crazy, but it's TRUE!! guess what the "bore" is... c'mon, guess...

got a number?? think it's big enough?? are you sure??

the "bore" of the 13B and RENESIS wankel engines is a monsterous 144.3mm!!!! :eek: :eek: :D :eek: :eek:

man!! talk about OVERSQUARE!! i'm SURE that these rotaries are far more oversquare than F1 engines, not being hindered by the design detail of having to have a stroke at least equally as long as the vertical travel of the lifting valves... ;)

I think they should do it.:) But, I would use a larger version of the rotary( maybe 21a w/huge rotors and high compression). It would have tons of torgue with that setup. With the 21a the engine wouldn't have to rev that high. Mazda could use this in the American truck market. Only problem is, Americans would never buy it.:( I would:D

Thanks for the replies.

What I also have been thinking about is the evolution the piston diesel engines have gone through. In the beginning they also were extremely underpowered compared to a gas engine. Now there are all kinds of technologies (e.g. common rail) that makes a diesel engine almost as powerfull as a gas engine. Maybe if someone dares to invest into developing a rotary diesel, they'd also achieve good power results.
The latest designs of a rotary diesel I found on the net are from the seventies. They were from Rolls Royce.
I really think they can do better than 55hp/4500rpm out a 1.6liter rotary diesel engine.

HERE (http://www.der-wankelmotor.de/Motoren/Rolls-Royce/rolls-royce.html) you can find the info on the rolls royce engine.