Norton’s Rotary: 1989 Norton Commander

Built in small numbers and never sold in the U.S., the Norton Commander rotary represents an unappreciated chapter in the story of the fabled British marque.


| September/October 2014



Right-Hand Side of 1989 Norton Commander

Invented by German engineer Felix Wankel in 1929 and further developed in the 1950s at NSU, the Wankel — or rotary engine — offered simplicity and smoothness thanks to its lack of reciprocating parts as well as high power-to-weight ratio and compact size - desirable attributes for a motorcycle engine.

Photo by Robert Smith

1989 Norton Commander
Claimed power:
85hp @ 9,000rpm
Engine:
588cc liquid-cooled twin rotor Wankel rotary, 9:1 compression ratio
Top speed:
125mph (est.)
Weight (dry):
517lb (235kg)
Fuel capacity/MPG:
6gal U.S. (23ltr)/40-49mpg (observed)
Price then/now:
£7,500 (approx. U.S. $13,300)/$5,000-$10,000 (est.)

As most people know the story, Norton quit making motorcycles after Norton-Villiers-Triumph declared bankruptcy in 1975. Yet that wasn’t the end, because while Norton did indeed disappear from the U.S., the company continued for almost 20 more years developing, perfecting and producing rotary-powered motorcycles.

Beginnings

It’s not surprising that most U.S. motorcyclists have never heard of — much less seen — a Norton rotary. Built in very small numbers and never sold here, the Norton rotary represents a mostly unappreciated chapter in the convoluted story of the fabled British marque. Yet once upon a time, Norton believed the rotary was its future.

Invented by German engineer Felix Wankel in 1929 and further developed in the 1950s at NSU, the Wankel — or rotary — engine (see sidebar) offered simplicity and smoothness thanks to its lack of reciprocating parts as well as a high power-to-weight ratio and compact size — desirable attributes for a motorcycle engine. In the 1960s, interest in rotary engines blossomed, and by the end of the decade BSA Group started development on a suitable rotary engine, hiring engineer David Garside to run the program. Starting with a fan-cooled, single-rotor, 294cc Fichtel & Sachs engine, Garside’s team established their basic requirements for a Wankel motorcycle engine, building a prototype fitted into BSA-group cycle parts.

To move forward with the project, BSA either had to buy a license to build Wankel engines or contract F&S to build engines for them. Although BSA was in dire straights, in the summer of 1972 BSA’s board of directors voted to purchase a Wankel license from Audi-NSU, and by 1973 Garside’s team had designed an air-cooled, twin-rotor, 588cc rotary engine making around 70 horsepower.

Although Garside’s unit was small and compact for its power output, heat buildup was a major issue, especially around the combustion zone. To avoid the extra weight and complexity of liquid-cooling, Fichtel & Sachs had tried cooling the rotor by drawing intake air through its center before feeding it into the engine, but this meant the charge was heated in the process, reducing combustion efficiency. Though an intercooler would have been ideal, Garside opted instead for a plenum chamber in the intake tract where the air could lose some of its heat. It worked well enough and allowed the engine to run efficiently without a cooling fan.

tonyc
9/19/2014 1:29:23 PM

Thanks for filling us in on a bike, which as you state, very few of us Americans even know about. More choice is always better. Too bad we never had this option.


davidm
9/19/2014 11:03:37 AM

The lead to this article made it sound as if Norton was busy producing rotary motorcycles for 20yrs. In fact less than 300 were produced which leaves me wondering how Norton survived those 20yrs. They must have had GOV funding because any private backer would have shut them down much earlier.


geralde
9/18/2014 10:43:35 AM

nicely written article and yes, the rotary is just as durable as any other 2 or 4 stroke (leisure craft) engine. chalk up 1 seized rotary omc / johnson snomobile to my credit. 2 up, trying to maintain the pace of the others in our group and a minor slip up on the part of the fueling crew, pre mix was not used > und kerblam...pretty sure it was under warranty. thnx mr n, godspeed.






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