SSSSSSteam
Heat.
One of the great things about the VW engine is that there are so many ways that it can
be modified. It seems that some people are always trying to use it in a different way from
that Dr. Porsche intended. One such person is Bill Britton, a tinkerer par excellence. He
has modified a Beetle motor into a two cylinder steam engine.
Bill's extraordinary engine came to my attention through Bob
Hickman, who asked me if I was interested in seeing a VW motor that was a bit different.
The offer was too good to refuse! We met Bill at John Pride's residence in beautiful
Picnic Point. John is a friend of Bob Hickman and is also an avid car nut. He owns not
only a Model A Ford but a 1921 Stanley steam car in perfect working order. As an appetiser
we were treated to a spin around the block in the Steamer and after riding in the car, it
was obvious why this method of power was so popular in early part of this century. The
smoothness of the power delivery had to be experienced to be believed. It was quite eerie
accelerating away from a standstill in a car with no clutch or gearbox and an entire lack
of vibration.
Simplicity of construction and
operation were the trademarks of the Stanley steam car. A kerosene-fired boiler produced
500 psi (3450 kpa) of steam pressure which was used to drive the horizontal single
cylinder engine, located below the rear seat as a unit with the rear axle. A spur gear on
the crankshaft drove the differential gear directly, with valves able to reverse the
engine rotation and provide a reverse gear. The Stanley was throttled by a lever on the
steering column and for extra speed the boiler pressure could be increased up to 1500 psi
(10350 kpa)! After leaving the engine, the steam goes to feed the water heater, then to
the top of the radiator, upon passing through which it condenses into water and this water
flows back to the main tank. The 76 litre water tank beneath the car frame gave a range of
about 320 - 400 kilometres. The thought of an accident with another car while carrying a
pressure vessel beneath the front bonnet, however, doesn't even bear thinking about
drivers then must have had more respect for each others' cars than they do today...
After the very impressive demo in the Stanley Steamer, Bill showed us his
steam engine in greater detail. Having converted the engine over 30-odd years ago, a lot
of the specifics were a bit hazy, however the actual layout of the engine is very
straightforward. A 1200 industrial case (we think - there was no tapping in the left front
case half for an oil pressure switch) simply had cylinders 1 and 2 removed and a blanking
plate installed on the case. Cylinders 3 and 4 were used to provide the power. The
cylinders themselves are made of pearlite, with cast aluminium 2.765 inch (70.2 mm)
pistons being used to withstand up to 1000 psi (6895 kpa) of steam pressure. The pistons
use 2 compression and 1 oil control ring, as in a petrol engine. These, combined with the
standard 64 nun stroke, gave 495 cc.
Unlike most steam engines which utilise the double-acting cycle (where
steam is introduced into the cylinder above and below the piston to push it up as well as
down), Bills engine uses a single acting cycle for simplicity. The cylinder heads contain
the inlet valve gear connected to the high pressure steam supply. As a piston approaches
TDC it operates the inlet valve to allow steam to enter the cylinder. The timing is fixed
on 3 degrees before TDC. As the piston is driven down the expanding steam is exhausted out
the bottom of the cylinder, much the same as a two-stroke engine. The process is known as
a total loss cycle, as the exhausted steam is discharged directly to atmosphere and is not
reused. A simple ball valve in the supply line is used to throttle the engine. Proper
lubrication of the engine is critical after running on the wet steam, so screw plugs in
the cylinder tops allow oil to be squirted into the barrels. The original camshaft is also
retained to drive the oil pump.
The engine was set up on a test stand with a gutted split-case gearbox used as a
mounting point for the starter. A temporary steam line was run from the Stanley's boiler
and the starter battery connected. The engine fired into life with a roar typical of a
Volkswagen and revved out quite sweetly, issuing massive clouds of steam from the zoomie
exhausts. Without a tachometer it was hard to tell how much it was revving but it sounded
great. The engine was fitted with an alternator and a 3 piston compressor for a water
pump, but this was not required.
Many thanks to Bill and John for a
fantastic day
Simon Matthews
Home
Bill's extraordinary engine came to my attention through Bob
Hickman, who asked me if I was interested in seeing a VW motor that was a bit different.
The offer was too good to refuse! We met Bill at John Pride's residence in beautiful
Picnic Point. John is a friend of Bob Hickman and is also an avid car nut. He owns not
only a Model A Ford but a 1921 Stanley steam car in perfect working order. As an appetiser
we were treated to a spin around the block in the Steamer and after riding in the car, it
was obvious why this method of power was so popular in early part of this century. The
smoothness of the power delivery had to be experienced to be believed. It was quite eerie
accelerating away from a standstill in a car with no clutch or gearbox and an entire lack
of vibration.
