Past Present and in Between in Pictures (Part 1)

Peterm:
The White cab-over-engine 700-Series and 800-Series motor truck models were introduced in 1934,and
were revised in 1937.Until 1938 most if not all of this range were powered by a White Pancake Flat Horizontally-Opposed 12-Cylinder Gasoline-Petrol Engine,which has been variously described by several different authors as being a ‘V12’,an ‘opposed piston engine’ and a ‘horizontally opposed piston engine’,but in actual fact it was a pancake flat horizontally-opposed 12-cylinder engine.It was originally developed to power White City 100-Passenger Motorcoaches,and was made in at least two sizes:465 CID-7.6 Litres and 505 CID-8.3 Litres.
At least one of the flat-12 engines was designated 24 - this was the power unit of Autocar and White
T17 pilot halftracks for the USA military in 1943.

VALKYRIE

Are you sure it was opposed which would mean 24 pistons with either one crankshaft linked by rods etc, or two crankshafts coupled with gears. Or was it simply a flat 12 with one crankshaft between two banks of six?
[/quote]
TruckNetUK . Old Time Lorries . Past Present And In Between In Pictures .653.Differences of Flat Pancake
Boxer Horizontally Opposed 2-,4-,6,8-,10-,12-,16-Cylinder Engines And Horizontally Opposed Piston Engines.
Friday,3rd July,2020. VALKYRIE

Flat Pancake Boxer Horizontally Opposed 2-,4-,6,8-,10-,12-,16-Cylinder Engines.

Horizontally Opposed Piston Engines.

Hello Peterm :slight_smile: The terminology for these above two distinct configurations of engine-types can be
downright confusing,which is almost certainly caused by the operative word ‘opposed’ :slight_smile: And this is
reflected in what I said in my above post: QUOTE:-
White Pancake Flat Horizontally-Opposed 12-Cylinder Gasoline-Petrol Engine,which has been variously described by several different authors as being a ‘V12’,an ‘opposed piston engine’ and a ‘horizontally opposed piston engine’,but in actual fact it was a pancake flat horizontally-opposed 12-cylinder engine.UNQUOTE.

As I stated in my original above post,the White Pancake Flat Horizontally Opposed 12-Cylinder Gasoline-
Petrol Engine was originally developed for use in White City Motorcoaches which were mid underfloor-
engined i.e.the above flat 12 engine was fitted.The reasons why it was a flat 12 was to provide enough
power for this motorcoach and to comply with the flat floor design of this motor vehicle.A V-12 engine
would have been impractical for obvious reasons.

Flat Pancake Boxer Horizontally Opposed 2-,4-,6,8-,10-,12-,16-Cylinder Engines share a central crankshaft
with two horizontally opposed banks of whatever number of cylinders.
WIKIPEDIA:-
QUOTE:A flat engine, also known as a horizontally opposed engine, is a piston engine where the cylinders are located on either side of a central crankshaft. It is effectively a V engine with a 180-degree angle between the cylinder banks. A flat engine should not be confused with the opposed-piston engine, in which each cylinder has two pistons sharing a central combustion chamber.

The most common configuration of flat engines is the boxer engine, where each pair of opposed cylinders moves inwards and outwards at the same time. The other configuration is called a “180-degree V engine” and have each crankpin shared by a pair of cylinders.UNQUOTE.

ENGINES.Porsche 917 Can-Am experimental flat pancake horizontally opposed 16-cylinder engine.A single central crankshaft is shared between two horizontally opposed banks of 8-cylinders each.TNUK,OTL-PP&IBIP,653.7-2020.Wikipedia.3#

Famous flat pancake boxer horizontally opposed cylinder engines include:-

BMW flat pancake horizontally opposed 2-cylinder motorcycle engines

Volkswagen Beetle flat pancake horizontally opposed 4-cylinder motorcar engine.

Ferrari flat pancake horizontally opposed 12-cylinder Grand Prix Motor Racing and sports car engines.

Jowett Javelin flat pancake horizontally opposed 4-cylinder aerodynamic saloon motorcar engine.

Horizontally Opposed Piston Engines have two opposed pistons in each cylinder,when each piston
simultaneously reaches top dead center the remaining space between the two pistons forms the
combustion chamber.
WIKIPEDIA:-
QUOTE:For horizontally-opposed engines, see flat engine.

An opposed-piston engine is a piston engine in which each cylinder has a piston at both ends, and no cylinder head.
Petrol and diesel opposed-piston engines have been used, mostly in large scale applications such as ships, military tanks and in factories.

ENGINES.A schematic of a supercharged opposed piston engine Has two opposed pistons in each cylinder.TNUK,OTL-PP&IBIP,653.7-2020.Wikipedia.2#

.ENGINES.A schematic of a supercharged opposed piston engine Has two opposed pistons in each cylinder.TNUK,OTL-PP&IBIP,653.7-2020.Wikipedia.2#.gif

NOTE:Certain engines listed below are not necessarily horizontal.
Famous opposed piston engines include:-
Commer-Rootes TS3 Horizontally Opposed Piston 3-Cylinder Two Stroke Diesel Lorry & Motorcoach Engine.

Junkers Vertically Opposed Piston Two Stroke Diesel Aeroplane Engines

Napier Deltic Opposed Piston 18-Cylinder Two Stroke Diesel Marine,Industrial and Rail Traction Engines

Leyland L60 Horizontally Opposed Piston 6-Cylinder Two Stroke Diesel Military Tank Engines.

So the four operative words in two groups of two are:-
1.
Opposed cylinder.

Opposed piston.

Simple :wink: :slight_smile:

ENGINES.White Pancake Boxer Flat Horizontally Opposed 12-Cylinder Engine being serviced in a White mid underfloor engined,Motorcoach.TNUK,OTL-PP&IBIP,653.7-2020.CurbsideClassic.Com.1#

.ENGINES.White Pancake Boxer Flat Horizontally Opposed 12-Cylinder Engine being serviced in a White mid underfloor engined,Motorcoach.TNUK,OTL-PP&IBIP,653.7-2020.CurbsideClassic.Com.1#.jpg

ENGINES.White 748,Mid Underfloor White Pancake Boxer Flat Horizontally Opposed 12-Cylinder Engined, Motorcoach.Preserved 1938 San Francico Municipal,No.042.TNUK,OTL-PP&IBIP,653.7-2020.Spicoli-Flickr-Pinterest.4#

.ENGINES.White 748,Mid Underfloor White Pancake Boxer Flat Horizontally Opposed 12-Cylinder Engined,Motorcoach.Preserved 1938 San Francisco Municipal,No.042.TNUK,OTL-PP&IBIP,653.7-2020.Spicoli-Flickr-Pinterest.4#.jpg

NOTE:A YouTube 15:31 duration film-video of the above White 748 Motorcoach (some title it a Bus :slight_smile: )
shows it carrying passengers,running on the streets of San Francisco and from 1 minute to around 4:20
its White Pancake Boxer Flat Horizontally Opposed 12-Cylinder Gasoline-Petrol Engine can be seen…
and heard running.The driver gives a good explanation of this engine :slight_smile:

curbsideclassic.com/bus-sto … buses-too/

VALKYRIE