Adventures
of Dr. Arthur Pistonock-Henderson
and the Rev. Pat McNutty
This remarkable story has just been discovered and
although the manuscript was in terrible condition, the
CLICK ON
THUMB NAIL TO SEE THE VARSITY TEAM OF 1926
Pistonock-Henderson
on left and McNutty in the centre; others are unidentified: does any surfer
know who they are?
Mr. John Pistonock, worked in
Arthur
Lansdowne Pistonock-Henderson went to
The description
commences at the inlet………..
Using a series of eight Binks 'Rat Trap' carburettors,
mounted on a rotating 'carb-wheel' which was driven off the drive side
crankshaft main shaft by a series of sequential thrunging sprockets and
incorporating a central axial fuel delivery pipe, this unusual set up allowed a
direct relationship between the engine speed and the volume of the inlet
charge.
At rest
(before the starting procedure was commenced) only one Rat Trap is lined up
with the inlet port of the pre-combustion expansion chamber, whose outlet is
the double venture shaped inlet tract system which ingeniously incorporates a
series of concentrically arranged ports which convey both the inlet combustion
mixture and the exhaust gases. Control of the port openings is by a series of
floating shafts which operate 2 'flapper' valves each. The whole mechanism is
regulated by the use of an extension governor which is also driven by the
thronging sprockets via a set of bevel gears and Oldham couplings.
After
the engine is first fired up (according to the theory) and as engine speed
increases, the sequential series of thronging sprockets cause the carburetor
wheel to rotate faster allowing each rat trap to momentarily spin by the inlet
tract and a fresh charge of the secret fuel mixture (another
story here!) to enter the pre-combustion
expansion chamber. This chamber has a series of 24 pressure-release valves
adjusted to open at 10 psi, 20 psi, 30 psi and so on in jumps of 10 psi upto a
potentially dangerous upper limit of 240 psi. Each one of the pressure-release
valves is connected to a whistle, expertly tuned by the musical McNutt to give
a slightly differing note, so that when the 23rd valve is fully
open, and just one short of the maximum at 24, the rider can just hear above
the exhaust note, the 'Charge of the Light Brigade' and consequently be warned
that Armageddon is perilously close!
These
valves can also be linked up, by the reed valve movement in the whistles to a
second expansion chamber which is used as a damping unit to compensate the
massive forces developed in the concentric multi-port inlet tract, which houses
the single valve. The valve is made from Jessops grade G2 high Chrome-Manganese
Austenitic steel. It is massive, the stem length is almost 8 inches, the stem
diameter is 21/32 inch and the head diameter measures 3 17/64 inch! It weighs
6lbs. The forces generated are very great and the inertia Newton Rating
Poundage Scale dictates the use of desmodromic opening and closing.
As
the engine speed increase and hence the pre-combustion chamber pressure also
rises, the incoming charge to the inlet tract enters all 5 of the
concentrically arranged ports, set within the massive aluminium-magnesium
composite inlet manifold. A con rod-direction-monitoring-lever, which operates
a convoluted linkage to one end of the ring of shafts that are located in the
walls of the concentrically arranged ports, hence when the conrod is on the
down stroke, the inlet tracts are opened to the pre-combustion chamber.
Conversely, when the conrod is going up, the flapper valves are closed for
compression or open for exhaust gases to exit via the single, but very big
'Brooklands Can'. The shafts open and close the flapper valves which then determines
the direction of the gas flow in the inlet tract and thus allowing the inlet
and exhaust gases to be kept apart.
The timing set up is crucial to ensure maximum
efficiency; the primary thronging sprocket incorporates a sensor which
synchronises:
·1
The rotating speed of the carburetor wheel
·2
The fuel flow rate to the central axial delivery pipe
·3
The throttle openings of all 8 rat traps
·4
The amount of transverse movement in the floating inlet shafts and hence
the opening and closing sequence of the flapper valves
·5
The relative pressures in the pre-combustion and damping chambers
·6
The extension governor
·7
Thronging sprocket RPM
·8
Desmodromic operating mechanism
There is no magneto to 'spark' the engine,
because after incorporation of the single valve ( 3 17/64 inch)into the
cylinder head there was no room left to put a spark plug! Consequently the fuel
mixture was developed to ignite under compression; the C.R. being a staggering
65 to 1. the squish band clearances were always a guarded secret and
unfortunately no figures are available. Rumour had it that they were some where
near 0.0005 of an inch!
The
thinking behind the One-Valve engine stems from the philosophy of all
engineering fundamentalists of reduction theory:
"Why use two when one will do"
Jas
L Norton, himself used the reduction principle to a lesser degree than
Pistonock-Henderson, in that he stayed with single CYLINDER engines.
Pistonock-Henderson, following his studies at Cambridge, learnt about the 'maximists'
and hence took the reduction theory to its extreme; he discarded the exhaust
valve.
So why
were 8 carbs used and dozens of thronging sprockets? Pistonock-Henderson had
wanted to use his own design of carburettor which infact was the original 'flat
slide' unit, pre-dating the controversial Gardener by many years. Using a 1st
W.W. 300mm 'Big Bertha' shell case and his Uncles garden spade he ingeniously
fabricated a huge and very simple carb'. Although tests showed the carb' to
have excellent 'full bore' properties, the frequent explosions and flame damage
within the pre-combustion expansion chamber when starting up the engine, meant
that the P-H Flat-Side had to be side-lined and an alternative system
developed. Enter the Reverand Pat McNutty; and known as 'RPM' or 'Flat Out' by
his close friends.
NcNutty
was an Ulsterman, of fiery temperament, but brilliant mind. While at Cambridge
he had combined the mechanical theories of his Engineering studies to the
esoteric pursuits of his Theology lectures to establish the school of
'Mechanical Experimental Semantic Sophistication' thinking, known in learned
circles as 'Messy thinking' or 'Mess' for short.
Whereas,
Pistonock-Henderson was a fundalmentalist reductionist, his old University
friend was precisely the opposite. McNutty was a believer in 'Sophistication'
and attempted to make everything more complicated. This contrast between the
two men, a classical dichotomy of reason, provided the ideal opportunity for
creative discussion. Faced with a problem, such as the carburettor issue on the
'Single valve' engine, they could never agree, no compromise would ever take
place and resolution was determined by a game of 'French Cricket' (subject of
another story), the result of the 'Carb Cricket Match was in the Reverands
favour and subsequently his other hobby of Nocturnal Rodent Watching could be
incorporated into the design. McNutty had bought a 'job lot' of Rat Trap carbs
by mistake, thinking they would help in his studies of rodents by catching them
alive. He had fixed 8 of them onto a small bicycle wheel and had mounted the
whole assembly on the floor of his Church. He would then position himself
behind the altar to watch the wandering rodents climb into the open bore of the
rat trap and when all eight were full, the wheel would spin at such a speed
that the rats were subjected to high centripetal forces to put them into a
hypnotic state. He could then stop the wheel, let out the rats , which were
fully hypnotised and McNutty could then have them at his mercy! One evening he
invited Pistonock-Henderson to join him in a rodent session, but that’s another
story!
Mcnutty's
carb wheel setup was exactly the sort of complicated device which appalled
Pistonock-Henderson's basic philosophy of reductionism and frequently his
distress was manifested by catatonic stupor. He would be so upset by the
protracted procedures, long winded and unsound logic of his friend that his
response was akin to total engine failure. Totally motionless, he would sit
upon his beloved 1926 model 19 Norton and take up the pose of the great Joe
Craig would adopt while hurtling along the 8 mile Clady straight at the Ulster
GP. In a racing crouch, ‘chin under the tank top paint’ and hands tightly
gripped to the handlebars and with a manic grin, P-H stayed like this for days.
Ignoring all basic instincts regarding biological functioning he would be found
in a pool of Castrol ‘R’ and his own bodily fluids; disorientated and
repeatedly jabbering some rubbish about only having one flywheel, one main bearing,
one wheel or some other quasi delusional belief pertaining to motorcycle
reductionism. Pistonock-Henderson’s, house Keeper, ‘Jugs’, was the only person
able to rouse her master; by cleverly using a large oil suction gun in
combination with a rack and pinion totally adjustable motorcycle workshop
lifting bench, she was able to bring Pistonock-Henderson to his senses.
Pistonock-Henderson
and Jugs, his Housekeeper, post catatonic stupor!
The two
friends differed in other aspects beside their respective engineering
philosophies. P-H was married and had insatiable sexual appetite (according to
Jugs), whereas McNutty, was a virgin, married to the church and his multi-head
universal milling machine. They had formed a solid relationship based on their
love of Norton motorcycles, French cricket and total mistrust.
Both
rode Model 19 Nortons and there was little to choose between them in local
speed trials; they would frequently tie for first place, despite differing
riding techniques. It is interesting to learn of how these two pioneer
motorcycle engineers differed in their approach to obtaining maximum speed and
efficiency.
P-H, a
reductionist, removed the gearbox from his machine and reverted to the earlier
belt drive set-up as found on ‘Brooklands Single Speeders’. He would also
remove both mudguards and the saddle; strangely, P-H would never sit on the
saddle when he was riding, unlike his catatonic position. He would cut off the
left hand side of the handlebars, and since there was no clutch, there would be
no requirement for a clutch lever. The valve lifter, magneto lever and throttle
lever were all incorporated into a single toggling switch which through its
three dimensional axis controlled everything! It also meant that no other
person could ride his machine because they could not master the remarkable
spatial dexterity of P-H’s right thumb, which had been triple jointed since his
teenage years. In side the engine, the inlet cam wheel was removed and an
extension fitted to the follower which allowed it to run off a modified exhaust
cam. Both valves were retained, but the valve springs inner and outers (4 in
all) were replaced by a single double hairpin valve spring, made by Trenco
under special licence, who also made the extraordinary ‘piston return spring’
which was used on later versions of the Desmodromic Single Valve Pot Engine.
McNutty
used a differing approach to engineering principles, which incorporated his
‘messy’ thinking ideas; he was a master at complicating systems, many of his
fundamental beliefs stemming from his religious background, he claimed his
ideas were messages from God, who had spent time with the late Jas.L. Norton.
His Model 19 Norton incorporated TWO engines, linked together by a central
crankcase fabricated from a flat sheet of steel; the left engine was connected
by its right sided T/S mainshaft, via a series of thrunging sprockets to the
D/S mainshaft of the right engine. Two top ends were used and the four cams
retained so that valve timing could be varied between the left and right
cylinders of, what was now, a 1200 cc vertical twin engine. Abandoning the
total loss oil system, he modified 4 pilgrim pumps using a complex
multi-chamber weir sump system to work alternately between feed and scavenge,
and added additional oil feed pipes to both ends of the four rocker posts, all
4 cam follower/cam interfaces, and to each of the 8 main bearings (2 on each of
the outer ends of the crank and 4 in the central supporting mount where the
thronging sprockets lay. There were copper oil pipes everywhere!
Two
Sturmey Archer gearboxes were used to make a six speeder, but this device was
only used at certain circuits where McNutty was able to successfully bribe the
scrutineers, other wise he had to retain the standard three speeder. With the
extra power developed from the big twin all chains were replaced by triplex
chain and a multi-plate clutch incorporating a ‘slipper’ centripetal twin
satellite shaft to reduce rear wheel spin on take off! Double sided brakes at
both front and rear and linked by a rod and cable linking system; two sets of
handlebars (one for racing, t’other for testing) and many other totally useless
pieces of metal were added to his mount. It weighed in at 586 lbs, where as
P-H’s machine was less than half that at just 201 lbs.
The
power to weight ratios were remarkably similar, although the shape of the power
curve differed.
Although
both rode Norton’s, their styles were different. P-H used the ‘doggie’ riding
position technique, stripped to his under garments with shaven head enclosed in
a pair of streamlined goggles and McNutty the ‘straddling’ method, wearing a
set of 6mm thick Donkey hide, 6 piece leathers (another story) and on top a
full length trench coat. His crash helmet was huge, adorned with ornamental crowns
and plummells of many colours, so heavy that it had to be strapped in place by
a series of leather straps to the front and rear mudguard stays, which were
infinitely adjustable by small duplex thronging clips.
They
looked magnificent…………. Pictures to follow
Dear Dr. Cohen,
I was fascinated to read your archive material
about those old blighters, Pistonock Henderson and McNutty; I was in the
Varsity Motorcycle team of ’26, that’s me in the picture, between my two old
chums. We had some super times, I particularly remember the day we stuffed the
I recall the early
trials of the desmodromic single valve pot engine at Spagthorpe
aerodrome when 'Slasher' McGrath had both legs amputated just below the
knee by eight whirling Binks Rat Trap Carburettors. Investigations
proved beyond doubt that 'Stumpy' (his nickname was subsequently changed after
this tragic accident) was at fault for foolishly trying to adjust the oil flow
to the thrunging sprocket secondary coupling which caused the momentary lapse
of concentration. This near fatal mistake would lead to
'stumpy' spending the rest of his days strapped into a Ner-a-Car as a pathetic
shadow of his former self. I remember that there was no immediate
damage to the engine or its components and 'Stumpy' was able to control the
twin foot brake Nock-Nutty Manxman model despite the tremendous handicap of
watching his legs being minced up by McNutty’s ridiculous Rat-trap device and
safely back to the pits. He was a brave lad!
Yours most sincerely,
Fabian ‘Foxy’
Faggot-Thorpe
Dear Doc,
I thought you would be interested in a quite
amazing discovery. My great Uncle Archie J. Butterworth was a just a young lad
when he first met those two motorcycle lunatics, Pistonock-Henderson and
McNutty. He used to tell me about the sessions spent in the workshops testing
the latest configuration of the internal combustion engine. Apparently there
were many total disasters with regular visits from the local fire brigade to
put out blazing sheds after an engine would disintegrate on the test bed.
Uncle
Archie obviously learnt a lot from those ‘pioneers of the unusual’ and he
patented a swing valve motor in September 1949 in which the inlet valve swings
completely away from the inlet port and thus allowing the inlet tract to be
free from obstruction, (unlike the more conventional ‘poppet’ valve) and
consequently improving the quantity of inlet charge. I have managed to get hold
of his prototype engine and the original drawings and patents.
The
first dyno test showed that the engine developed 50 BHP! Not bad eh! Archie
then abandoned the single cylinder engine and built a horizontally opposed four
cylinder which produced 220 BHP. The single cylinder motor is being put in a
featherbed frame and with some development we hope to be able to blow off the
short stroke Manxes and G50s!
Yours faithfully,
Aero Mileo de Raceo.
Picture of, Butterworth’s Swing Valve motor
click on image for a whopper!! (250kBs)
and now being installed in a featherbed frame.
The original drawing for Butterworth’s Swing Valve motor.
The exhaust valve is conventional and the swing inlet
(shaded)
Just swings
out of the way! WOW! There are many
advantages to this design.
See how many
you can work out. Answers next month!
click on image for a whopper!! (250kBs)
