ders of
the pair are staggered by an amount equal to the width of the connecting
rod bearing, to afford accommodation for the rods. The crankshaft was a
nickel chrome steel forging, machined hollow, with four crank pins set
at 180 degrees to each other, and carried in three bearings lined with
anti-friction metal. The connecting rods were made of tubular nickel
chrome steel, and the pistons of drawn steel, each being fitted with
four piston rings. Of these the two rings nearest to the piston head
were of the ordinary cast-iron type, while the others were of phosphor
bronze, so arranged as to take the side thrust of the piston. The
cylinders were of steel, arranged in two groups or rows of four, the
angular distance between them being 90 degrees. In the space above the
crankshaft, between the cylinder rows, was placed the valve-operating
mechanism, together with the carburettor and ignition system, thus
rendering this a very compact and accessible engine. The combustion
heads of the cylinders were made of cast-iron, screwed into the steel
cylinder barrels; the water-jacket was of spun aluminium, with one end
fitting over the combustion head and the other free to slide on the
cylinder; the water-joint at the lower end was made tight by a Dermatine
ring carried between small flanges formed on the cylinder barrel.
Overhead valves were adopted, and in order to make these as large as
possible the combustion chamber was made slightly larger in diameter
than the cylinder, and the valves set at an angle. Dual ignition was
fitted in each cylinder, coil and accumulator being used for starting
and as a reserve in case of failure of the high-tension magneto system
fitted for normal running. There was a double set of lubricating pumps,
ensuring continuity of the oil supply to all the bearings of the engine.

The feature most noteworthy in connection with the running of this type
of engine was its flexibility; the normal output of power was
obtained with 1,150 revolutions per minute of the crankshaft, but, by
accelerating up to 1,400 revolutions, a maximum of 147 brake horse-power
could be obtained. The weight was about 5 lbs. per horse-power, the
cylinder dimensions being 5 inches bore by 7 inches stroke. Economy in
running was obtained, the fuel consumption being 0.58 pint per brake
horse-power per hour at full load, with an expenditure of about 0.075
pint of lubricating oil per brake horse-power per hour.

Another Wolseley Vee typ