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)
