Thought you guys might enjoy this: 1965 Mustang fastback prototype

Someone on my vintage mustang forum posted this, a rather unusal prototype(there were a lot of early mustang prototypes):

Interesting. The Rotary has long been the automotive equivalent of El Dorado, the lost city of gold. A friends dad worked on the AMC Pacer, which believe it or not was kinda interesting early on, with, you guessed it, a rotary engine. But only Mazda has rushed in where the angels fear to tread.

Is this 3.9L total in the same way that a 13B is actually 3.9L or is that 2L per chamber? That would be a big wankle! I like it.

A 13b is a 1.3l but I always thaught it was effectively a 2.6 if you based it on displacement of the power stroke per crank shaft revolution or in the rotor us case eccentric shaft rotation. 
 

Am I wrong on this?  

I was thinking 13b is ~650cc per combustion chamber times 6 combustion chambers being 3.9L total. Just wondering how this one is measured.

In reply to dean1484 :

Rotaries are weird.  IIRC The 1.3l comes from a single face of each dorito and what it displaces as it rotates.  This isn't at all how any other engine is measured as they don't take a single cylinder and measure it, they take all.

Therefore you have to measure the displacement of all faces as it makes a complete pass through all four stages of an ICE cycle.

1.3L?  2.6L?  No, a 13b is not these.  It is a 3.9L and that is why it is so inefficient. 

Fight me.

This Hemmings article from a few years ago indicates Curtis-Wright just went out and purchased the car from a dealership, so I wonder how much Ford was actually involved in the build and evaluation.  https://www.hemmings.com/stories/2019/10/21/this-is-the-only-rotary-powered-mustang-ever-built

Kreb (Forum Supporter) said:

Interesting. The Rotary has long been the automotive equivalent of El Dorado, the lost city of gold. A friends dad worked on the AMC Pacer, which believe it or not was kinda interesting early on, with, you guessed it, a rotary engine. But only Mazda has rushed in where the angels fear to tread.

Umm... NSU RO80, Citroen GS Birotor...

Honourable mention, Norton Classic, Norton Interpol, Norton F1, Suzuki RE5, DKW Hercules, a bunch of outboard motors and snowmobiles.

In reply to ShawnG :

How many of those were made in significant volumes and/or the last 30 years?

Kreb (Forum Supporter) said:

Interesting. The Rotary has long been the automotive equivalent of El Dorado, the lost city of gold. A friends dad worked on the AMC Pacer, which believe it or not was kinda interesting early on, with, you guessed it, a rotary engine. But only Mazda has rushed in where the angels fear to tread.

Amc was going to buy the engines from gm who were developing them then but like most everyone except mazda stopped. In gms case it was due to the gas crisis it got worse gas mileage then the v8s it was to replace and making them get the mileage made them not pass emissions.

In reply to Kreb (Forum Supporter) :

Not in the last 30 years but the NSU was in production for ten years.

You forgot the Curtis-Wright version.  It was, you could say, rather large

In reply to Mr_Asa :

You are correct. The 13b has 3 combustion faces. Each face sweeps 1.3 liters.

3 x 1.3 = 3.9

My kind of freak show!

buzzboy said:

Is this 3.9L total in the same way that a 13B is actually 3.9L or is that 2L per chamber? That would be a big wankle! I like it.

TWSS

Thanks to MB and the C111 I'm very interested in everything about large wankles except the even larger fuel budget. How cool is mercedes mechanical fuel injection on a rotary?!

They're incredibly efficient at turning fuel into noise.

There were also several attempts to develop rotaries for General Aviation because of the small size, high horsepower to weight ratio. Norton was involved in the development of a rotary with a general aviation engine suppler to develop a rotary for unmanned drones. There were also rotary engines used in the experimental aircraft market. Remember seeing the engines and talking to people at EAA in Oshkosh many many years ago.

My uncle worked for Curtis Wright and was involved in development of the rotary. I remember him telling me a little about it, but never really pursued getting more info at the time. The irony is that I now race and RX7 with a 13B. 

MotorsportsGordon said:

Kreb (Forum Supporter) said:

Interesting. The Rotary has long been the automotive equivalent of El Dorado, the lost city of gold. A friends dad worked on the AMC Pacer, which believe it or not was kinda interesting early on, with, you guessed it, a rotary engine. But only Mazda has rushed in where the angels fear to tread.

Amc was going to buy the engines from gm who were developing them then but like most everyone except mazda stopped. In gms case it was due to the gas crisis it got worse gas mileage then the v8s it was to replace and making them get the mileage made them not pass emissions.

It's simpler than that.  The catalytic converter was invented.

The big push to Wankels in the early 70s was because the automakers were freaking out over the emissions limits coming for the 1975 model year.  The Big Three were calculating engine life in the 3000mi range.  Reducing NOx was the big problem. 

Wankels are naturally low in NOx because they have fairly cool combustion, have no hot exhaust valves in the chamber to induce preignition, and the high mixture motion makes detonation almost impossible.  You can run them as rich or as lean as you'd like to the limits of stable combustion in either direction and you won't hurt them, so you could calibrate for emissions without risking engine life.  So everyone was interested in the Wankel, either peripherally or gung-ho.

Then the catalytic converter was invented, and perfected enough for mass production, and everyone just sort of kicked their feet and walked away from the solution they no longer needed.

Mazda stuck with it because they sort of made the engine part of their corporate identity, like Subaru and boxer engines.  The other automakers (aside from NSU) had no such attachment.

Pete. (l33t FS) said:

The big push to Wankels in the early 70s was because the automakers were freaking out over the emissions limits coming for the 1975 model year. 

I don't recall when Mazda had to put cats on the rotaries, but didn't early one meet emission standars without them?

In reply to Brett_Murphy (Agent of Chaos) :

Mazda did not fit converters in the US until 1981, and IIRC that was only because they were made mandatory.

They used thermal reactors on some FCs in Europe!