German experimentation with low Cd automobiles in the 1930's

[kach22i]

Originally Posted by freebeard

Does the Persu design have a flat-12 engine or two inline-6s? It seems over-powered either way.

Persu used an at the time available inline 4-cylinder.

The first patent drawing posted I suspect may be showing a line of batteries (Lohner Porsche-similar?), after all his first car was all electric. The cooling fan may have been to cover his butt patent wise for a gas powered version. However, didn't the batteries of the day require some cooling and venting to prevent them from exploding?

From the link in Spanish already posted.

Persu: ¡Exigid coches de menor consumo!

Go benefits!
For traction, Persu used a four-cylinder inline AGA Berlin house, with a volume of 1.410cc, developed 22 hp at 2,200 rpm. Bosch boot replaced by another brand Eisemann Mki12 type, and instead of maintaining the trademark Solex carburetor, used one from Haendler & Co., Berlin. Lacking a coherent explanation of why changes in parts checked, you can reach the conclusion that it was because these companies helped in the final vehicle refinement. He kept the gearbox AGA three gears, and braking system, whose pills only acted on the rear wheels.
AGA automobile while 6/20 CV, with its angular body, was no more than 60 km / h, the Persu, equipped with the same engine, could reach 100. With the rear wheels on an axle narrower speeds stroked up to 60 km / h on curves -a success for those years, which was clearly demonstrated an improved aerodynamic body substantially benefits or, in the words of engineer, allowed to use a much less powerful engine to achieve the same performance as a conventional car, with a corresponding reduction in the cost and consumption, which greatly lowered the final price of the vehicle.
Aurel Persu said that experiments had shown that the wheels are sticking out of the body produces a large drag and instability. He also said that with the great oil crisis looming in the coming years would be good to note that, at high speeds, over three quarters of the engine power is needlessly consume only to face air. All this wasted time and fuel was completely useless.

Persu: ¡Exigid coches de menor consumo!

Central Motor 22 hp. Maximum speed and cornering 100 and 60 km / h, respectively. Clever, no doubt.

EDIT-1
I went back to the US Patent to find out more, looks like he did have in mind a "motor" with a "radiator". Why or how the air flow would be able to pass though the engine as the arrows in the plan view show is a mystery to me.

Streamline power vehicle
US 1648505 A
https://www.google.com/patents/US164...ed=0CDcQ6AEwAA

The rearwardly disposed motor m (not a W) drives the Wheels 6 by means of a universal transmission without differential.

The radiator is indicated by is and the fuel tank by r. The inflow and outflow of air are indicated by arrows.

Click link above to view a much larger image.

Speaking out loud, Persu had quite the background in aeronautics, perhaps he knew of a aircraft based liquid cooled flat 12 which required air flow over it's cylinders at the time he did the patent drawing. In that case he was dreaming of building a monster racer - like so many other young men (then and now). In 1922 he would have been 32, young at heart perhaps?

http://www.escuderia.com/persu-aerodinamico-1922/

He entered the Technische Hochschule -the-art school in Berlin-Charlottenburg, where he learned mechanical engineering, graduating with honors in 1913. His specialties were the aerodynamics and aircraft mechanics.

Aurel Persu, in Bucharest, 1960

[freebeard]

For traction, Persu used a four-cylinder inline AGA Berlin house, with a volume of 1.410cc, developed 22 hp at 2,200 rpm.

That sounds more like it.

In 1933-34 White Truck company put flathead flat-12s in their buses. I've never been able to find a picture. Want to give it a shot?

[Joggernot]

This had some info on the horizontal 12, but no photo.

White Motors Heavy Duty Trucks - Diesel Power Magazine

"Following a board decision to return to independence, Robert Fager Black was appointed company head in 1935. Excellent with workers and the union alike, Black slowly began to return White to profitability. 1935 also marked the introduction of the heavy-duty 730, the company's first cabover. This novel platform was powered by a 7.6L (464ci) opposed-piston, horizontal, 12-cylinder engine. The powerplant was a smaller version of an 8.3L version utilized in buses in 1932; tilt-cab, 800-series versions of the truck appeared in 1937.

Read more: http://www.dieselpowermag.com/news/0706dp_white_motors_heavy_duty_trucks/viewall.html#ixzz2g5yZbuSh"

Another interesting article on engines...

The 10 Most Unusual Engines of All Time – Feature – Car and Driver

[kach22i]

I'm pretty sure Persu would have selected an aircraft engine based on his background and the considerations given for airflow over the engine.

The Wright flyer and the first car (Benz) both used horizontally opposed flat engines for the same reason I assume, they cause less vibration.

If you had a engine under your seat, you certainly would want a smooth one.

EDIT-1
Perhaps something from Beardmore (Great Britain) was on Persu's mind, maybe even a Diesel.

Beardmore Proposed 12-Cylinder Aero Engine
http://www.oldengine.org/members/die...ford/aviat.htm

The use of diesel engines in aircraft has a long history going back to the early 1900's. and started with both the British and Americans developing engines for use in airships and aircraft. The French, Germans and Italians were also active in this field.

http://www.alternatehistory.com/disc....php?p=5840541

Beardmore aircraft diesel, a flat-12 'Boxer' diesel. This was 12 cylinders of 6" X 6½" with a capacity of 2206 cu ins, and developed 505 hp at 1750 rpm, but with a weight of only 1485 lbs.

[ennored]

Originally Posted by Joggernot

This had some info on the horizontal 12, but no photo.

White Motors Heavy Duty Trucks - Diesel Power Magazine

"Following a board decision to return to independence, Robert Fager Black was appointed company head in 1935. Excellent with workers and the union alike, Black slowly began to return White to profitability. 1935 also marked the introduction of the heavy-duty 730, the company's first cabover. This novel platform was powered by a 7.6L (464ci) opposed-piston, horizontal, 12-cylinder engine. The powerplant was a smaller version of an 8.3L version utilized in buses in 1932; tilt-cab, 800-series versions of the truck appeared in 1937.

Read more: http://www.dieselpowermag.com/news/0706dp_white_motors_heavy_duty_trucks/viewall.html#ixzz2g5yZbuSh"

Another interesting article on engines...

The 10 Most Unusual Engines of All Time – Feature – Car and Driver

Some discussion of the White Flat 12

[freebeard]

Thanks, there it is. As I suspected, the flatheaded-ness allows it to fit between the frame rails. Which is what I was wondering.

What I'm wondering now is where can I get a Panhard.

It's so cute I want to pinch it's little cheek; and the engine is like a flat twin Offenhauser.

[cptsideways]

I have a slight interest in the Czech manufacturers, am often out there next time would like to visit the Tatra museum.

[kach22i]

Car Aerodynamics Part1 | Flickr - Photo Sharing!

[NeilBlanchard]

^^^

They appear to be testing the Pillbug model *backwards*...

[Cd]

Good eye there Neil !
I just glanced at it, but knew something was wrong.