The diesel engine had been around for some time in various forms, indeed
its application in heavy goods vehicles and PSVs was becoming almost universal
by 1945. Various attempts had been made to launch diesel tractors onto the
UK market, but most of these had fallen by the wayside. Strange to say there
was not one totally new multi cylindered diesel on the British Tractor Scene
pre-war. The AGE tractors using Blackstone and Aveling engines were basically
Internationa122/36 frames with diesel engines fitted. A few International
Petrol Start Diesels as fitted to their WD40 and TD35/40 Crawlers were imported,
but like the domestic conversions they did not amount to much. Mainstay of
the Compression Ignition picture was the Marshall, but even there production
in total hardly got into four figures. As the majority of UK tractors were
in any case multi cylinder units with automotive type engine and transmission
layout, it was obvious that any manufacturer setting out to build tractor
engines would adopt the multi-cylinder concept.
One of the immediate problems, which arose in producing a diesel engine,
was its cost, not only in development terms, but in production also. Much
finer tolerances were necessary and stronger components desirable to withstand
the much greater compression pressures of such engines. Barford & Perkins
of Peterborough became part of Agricultural and General Engineers (AGE).
Their main product line was motor road rolling equipment. The Peterborough
works was closed by AGE when they took over in 1928/29 and their road-roller
business was merged with that of Aveling & Porter to form Aveling-Barford.
Mr Frank Perkins moved to Aveling's works at Strood as Works Manager. It
was while he was there that the Vixen engine was designed, the drawings being
done by a Short Bros. (Seaplanes) draughts- man working at weekends in the
cellar of Mr Perkins' house. One or two engines were built at Aveling's before
the big decision was made to form a Company to produce them.
Frank Perkins Ltd. was formed and premises at Queen Street, Peterborough,
formerly occupied by Barford & Perkins, were rented. This was a case
of 'coming home'; Frank Perkins obviously knew that the works were standing
empty, and an approach to the owners, Milton Estates, secured a lease. Indeed,
quite a lot of equipment, such as the benches, were still there. Here the
application of medium sized diesels for industrial and marine work in the
nineteen thirties, was pioneered. The Leopard, Wolf and Lynx engines were
basically intended for multi use applications, covering vehicle, industrial
and marine installations. However the use of the Leopard engine in tractors
was instigated in the mid thirties. A Fordson N Land Utility tractor on Firestone
wheels and tyres was supplied to F. Perkins Ltd. on 11th February 1937 by
Willenhall, Staffs, Fordson dealer Reginald Tildesley. This was serial number
808499 and it was delivered to Peterborough without engine.
A Perkins Leopard engine serial number 7343, built on 16th June 1937 was
fitted. This was a Leopard II engine with cast iron pistons and was rated
at 34bhp at 1100 rpm, it being derated from the usual industrial rating of
46bhp @ 1500rpm to prevent damage to the rear axle.
The prototype tractor was tried out at Tettenhall near Wolverhampton in July
1937, prior to its exhibition at the Royal Show, which in 1937 was
at Wrottesley Park nearby.
In October and November 1937 a further 11 tractors without engines were supplied
to Perkins ex Tildesley, and in 1938/9 a further 17 were supplied, making
29 in all. Incidentally, the TVO engines were used to provide a 'float' for
Tildesleys' exchange engine scheme on the Fordson. The first Leopard conversion
to go into full time farm service was bought by Mr T.R.C. Blofeld of Hoverton
Fruit Farms, Wroxham, Norfolk. It had the reputation of being a bad starter,
but the early models had no self-starter and were started on the handle using
a decompressor. It would appear that most of the others were exported, and
there is at least one extant in Australia and one in New Zealand. The latter
example has a self-starter. Another engine was also installed in a Muir Hill
3 cu yd. twin wheel dumper that appeared at the Public Works Exhibition at
Olympia in 1938 - this also had electric start.
With the advent of the war, conversion of tractors ceased, but in the meantime
the development of a new range of engines was under way at Peterborough.
The result was the P series of engines that came onto the market in the early
war years. By taking the design from the outset to produce three, four and
six-cylindered units using common parts saved much in development and production
costs. Incidentally, one and two cylinder prototypes were built but never
produced in any quantity, and it took some time before the three-cylinder
variant appeared. In fact, one P3 prototype was built in 1939, and fitted
in a London Taxi, but it was to be 1951/2 before the engine was developed.
The P series originally had names as had the other pre-war engines -the P6
was the Panther, the P4 the Puma, and the P3 the Python. In fact, the P4
was introduced November 1937 and the P6 in February 1938. There were of course
two versions of the P series. That for use in applications where engine speeds
of over 1500RPM were required had aluminium alloy pistons, and that for use
where engine speeds of below 1500RPM were required had cast iron pistons.
The calibration of the fuel injection pump produced engines with very different
torque characteristics. There were common parts amongst al1 3, 4 and 6 cylinder
variants, all of which shared the same bore and stroke of 3.5"x5". The swept
volumes were P3 -2.36 litres, P4 -3.14 litres, and P6 -4.73 litres.
The design of the engines was such that different sumps, flywheel housings,
front and side mounting plates, and exhaust/inlet manifolds allowed a diversity
of use, whether with a wet clutch application such as the Fordson Major,
or a dry one such as the Massey Harris 744D. For vehicle use of course mountings
were different, but the sump used with Industrial applications had sufficient
strength, when necessary, to include the engines in 'unit' applications.
There was even a petrol version of the P6, developed in conjunction with
Dennis Brothers of Guildford, to replace their equivalent petrol engine;
two were built, and were only experimental.
The P series had not been used widely in tractors until Frank Perkins converted
a Fordson Major for his own use. The result was that Ford Motor Co. sent
two Majors for conversion, one with a P4, and the other a P6. Both had fabricated
sumps and flywheel housings. Whilst both gave a satisfactory performance,
the P6 was chosen due to its lower maximum speed which suited the E27N gearbox
better, and in adopting the engine as a production option it also must be
remembered that the Ford dealer network were already geared up for Perkins
spares and service as the engine in its vehicle (V) form was fitted in the
So it came to pass that the P6(TA) engine was born and graced a good few
thousand E27Ns, either straight off the production line or as conversion
packs which Perkins sold themselves.
Morris Motors were also looking for a diesel to fit in their new Nuffield
Universal tractor. They chose the P4(TA) that fitted the Nuffield chassis
in more comfortable form than the P6 fitted the E27N. In the case of the
Fordson a special sump had to be cast to support both front axle and connect
this with the flywheel housing. Whilst most P series engines were made for
dry clutches, the E27N's wet clutch also required a special flywheel housing
and suitable oil seal for the starter motor.
As we shall see in due course, other manufacturers made use of the Perkins
engines in their (TA) Tractor adapted form.
One feature of the adoption of Perkins units in some applications was the
fact that the power output of the engine was much more than the equivalent
Petrol or TVO models. Also the initial cost of the diesel-engined version
was much more than the equivalent spark ignition one.
With Ford and Nuffield offering Perkins engined variants, and David Brown
their own engine, it was not long before Ferguson's sales force were calling
for a diesel version of the TE-20. Now as Harry Ferguson himself was not
a diesel fan, it took some considerable persuasion to get him to agree to
a diesel-engined tractor at all.
The Perkins P3 was looked at, but the cost of installation and the modifications
needed would not suit, so a Standard engine was fitted instead. This engine
was designed by Freeman-Sanders specifically for Ferguson, and was built
for them by the Standard Motor Co., who later developed the same unit for
use in their 'Vanguard' car.
There was one thing which opened the way for a conversion pack from Perkins
for the Fergie 20 and that was the fact that the diesel engine supplied by
Ferguson could not be fitted to existing tractors. The first tractor converted
by Perkins was actually a Ford-Ferguson 9NAN for his own use, but the principles
of the conversion were the same for the TE-20. The 9NAN was acquired by Frank
Perkins during the War and the engine fitted in this case was a P4, there
being no P3's at that time. It was cut up in the mid 1970s under Customs
supervision, along with an MF85 imported as a test tractor for the A4-300
engine, as no import duty had been paid on them!
Massey Harris were looking at building tractors in the UK, as there was great
export potential, and the government were supporting the 'ground nut' scheme
in Africa. A few type 44 frames were taken and fitted with the P6(TA) engine.
Tractor assembly had commenced at Manchester in 1948. Due to shortage of
space, the 744 as it became was then assembled at Kilmarnock from 1949.
Thus, not only were Perkins engines now being fitted in production by leading
manufacturers, they were also available to convert s.i. engined units to
diesel. By the late forties 'conversion packs' were available to convert
the lions share of popular models.
The promotion of Diesel conversion packs was just as well, as new engine
business fell off considerably with Ford fitting their own diesel to the
New Fordson Major, and Nuffield fitting the BMC engine to the Universal by
the early fifties.
The P series was not "without its problems in agricultural service. Unlike
many road haulers and others who used the (V) "vehicle" version, farmers
were not renowned for their care and attention to machinery, and a diesel
engine requires more of this to maintain peak performance. The chain driven
timing could, if not properly adjusted, cause starting problems, and early
tractor applications had engine breather problems later cured by modification.
The tendency to over-rev. the P series (TA) units with their cast iron pistons
often caused bent con-rods, little end failures, and cylinder head gasket
failures. Indeed later P6 engines all had alloy pistons that alleviated many
of the problems, and many rebuilds received these also. This is why a lot
of P6(TA) engines still extant appear to the unknowing to be "V" or vehicle
ones! The main problem with the P6(TA) was the farmer's habit of leaving
the engine running when not working, as they were in the habit of doing with
paraffin engines. This caused the exhaust ports to choke with carbon and
Dereck Lambe tells me that he has taken off manifolds to see ports with holes
not large enough to push a pencil through. Of all the tractors fitted with
the P6(TA) the Fordson Major E27N was the most successful. Early models had
the habit of breaking half-shafts; however a new design with suitable heat
treatment cured this, and the E27N back end was really the only one which
could stand the full power of the P6, and indeed this was the tractor which
has endeared the P6(TA) to present day collectors and enthusiasts above all
other. Of course more were built than any other diesel engined tractor of
1953 saw the introduction of a completely new engine for industrial use -the
L4. This unit was designed expressly for low speeds up to 2000rpm. It had
a bore and stroke of 4.25 x 4.75", a swept volume of 4.42 litres, and could
be set to give up to 59bhp @ 2000rpm. A gear driven timing arrangement was
fitted and the camshaft, unlike the P series, was in the normal position
with push rod operation of the valves. The cylinder liners were, however,
of the wet type.
The new engine was adopted by various manufacturers for use in tractors.
The Massey Harris 745 used the L4(TA) from 1953, and M-H also adopted it
for their combines. Just to confuse the issue the development tractors were
744 with the new L4 engine fitted! It was also available as a conversion
pack for Old Fordson Major, New Fordson Major, Nuffield, and International
Farmall M tractors. Later it was adopted as the power behind the new Track
Perkins dealers were keen to seize any opportunity to convert tractors to
diesel, and indeed a few 'one offs' were built to satisfy customer requirements.
Where a popular model was involved it was possible to supply the complete
'conversion pack' to suit. The approved and popular conversions were:
- P3(TA): Ford 9N/8N. Ferguson TE-20. Farmall H. Allis
- P4(TA) Nuffield Universal.
- P6(TA) Fordson Major E27N.
- L4(TA) Fordson Major E27N. New Fordson Major. Farmall
M. International T6. Minneapolis Moline UT. Nuffield Universal.
It is believed that the most popular International L4 conversion was for
the T6 crawler.
Perkins engines were also fitted into limited numbers of International W4,
W6, and W9 tractors, A few Oliver 80s and 90s, a few Massey Harris 203 and
55 models, and a few Case D series. There was no approved conversion of the
Fordson 'N'. It was naturally possible to fit either a P6 or a L4 to the
standard Fordson, but as part of the agreement with Ford Motor Company which
allowed Perkins to sell conversion packs to Ford dealers, it was agreed that
conversion of the 'N' would not be encouraged. In any case the rear axle
was considered not to be capable of taking the increased torque of the diesel.
The agreement also allowed for supply of certain parts for the conversion
packs from Ford's parts operation. Ford did not want the life of the thousands
of 'N' models to be extended by dieselisation.
For the next chapter in the story we move back to the events taking place
at the Ford Motor Company at Dagenham. Fords had long wished to build a model
in the UK to compete with the "grey menace" or Fergie 20. It was quite possible
to do this, but the cost of developing an engine for such at tractor, which
by the mid fifties had to be a diesel, was prohibitive.
The Ford boys knew of the original Perkins conversion of the Ford 9NAN, and
as the new tractor was very much an updated 8N Ford's took some P3 engines
for evaluation during development of the Dexta. These were however a development
version that had a simple gear driven train and a small Holburn-Eaton type
oil pump driven from underneath the crankshaft timing gear. This allowed
the CAV in-line injection pump to be flange mounted directly onto the back
of the timing case. All external oil and water pipes were eliminated. It
was called the P3.144 and eliminated the expensive features of the P3, the
skew driven oil pump, and the chain driven timing. A four cylinder (P4.192)
variant was also built. Although the P6-288 had a DPA rotary fuel pump it
retained the chain timing. The gear-timed version was built in France as
the 6PF, and was for Industrial use only (no vehicle version) and was never
available in the U.K.
At Ford's request, Perkins fitted their 3 cylinder engines with Simms Pneumatically
governed fuel injection pumps and injectors and also removed the company's
name and trademarks from all parts. Perkins also designed the dress items
such as exhaust manifold, water outlet housing, and gearbox adaptor plate.
The engine went into production as the F3 in August 1957 and all were built
In the early 'sixties the cylinder bores of the P3/ 144 were opened up to
3.6" diameter in common with other engines in the P series. A CAV. DPA fuel
injection pump was fitted and the engine became the 3.152. The F3 was also
up rated and a mechanically governed 'Minimec' version of the Simms in-line
fuel injection pump fitted -this was known as the F.3/152 and was supplied
for the Super Dexta from February 1962. Again all were built at Peterborough.
The engines supplied to Ford had all the blocks and heads cast at the Dagenham
foundry of FMC, the rough castings being supplied to Perkins on a 'free issue'
basis. The logistics of this operation were remarkable. No large stocks of
engines were held, each day Perkins built just enough engines to cover the
Dagenham assembly tracks requirement for the next day. These engines were
delivered by Perkins' own lorries overnight. A small buffer stock of one
day's supply of engines was kept in a special building at Peterborough to
cover for any breakdown on Perkins' assembly line, and a similar number was
held at Dagenham in case of breakdown or accident to any of the lorries on
the delivery run. These lorries brought back the rough block and head castings
as a return load, and the whole system seems to have worked remarkably well
for the seven years that the contract lasted. This system is known today
as just in time'. The Japanese fondly believe they were the first to introduce
Some 153,322 F3, and 64,496 F3.152 engines were supplied to Ford, a grand
total of 217,818 engines between August 1957 and October 1964.
Perkins became part of Massey Ferguson Limited in 1959, and this consolidated
the use of Perkins products in MF tractors. In fact from 31st August 1959
Massey Ferguson had taken over the Banner Lane Coventry plant of the Standard
Motor Co. This did not involve any engine manufacture, and M-F was keen to
move to a stage where their new subsidiary would provide all the engines
for the tractor plant. The Standard 23C engine had a reputation as a bad
starter, especially in cold weather.
The first Perkins engines used in a Massey Ferguson (as opposed to a Massey
Harris) tractor were fitted in the new M-F 65 tractor introduced in 1958.
The Perkins 4.192 engine was chosen to power this tractor and this gave the
UK market a 50HP plus tractor with the Ferguson System that put the competition
in the shade somewhat. It is interesting to note that the forerunner of this
tractor, Frank Perkins' own 9NAN with P4 fitted existed some ten years earlier.
Also, one of Harry Ferguson's LTX prototypes was fitted with an L4 engine.
It took M-F that long to shake off the 'light tractor' ideals of Harry Ferguson,
who was not in favour of high powered tractors, but believed in the lowest
powered engine that would do the job with his draft control system.
Shortly after the M-F control of Banner Lane took effect, the M-F 35 was
given a three cylinder Perkins 3.152 engine.
In 1961, a direct injection version of the 4.192 engine, which in its bored
out form to 3.6" was the 4.203, came into production, and this was known
as the AD-4.203. This was used from its inception, in the M-F 65.
With the Fordson Super Dexta on the market, ironically with engines from
Perkins, the 35 was given the A3.152 engine from 1962. Perkins also supplied
A3.152 engines for Ferguson's Detroit plant that were fitted to MF35s there,
and also MF50 tractors. The Dieselmatic 65 used the 4A.203 engine in the
USA, and later the AD4.203, whilst the Super 90, only built in the Western
Hemisphere used the A4.300. This engine was a bit more than just a bored
out 4-270. It had a dedicated tractor block, with cast-in tractor fittings,
dry type cylinder liners, a 5 bearing crankshaft, and a harmonic balancer
The 4.270 was an update on the old L4 engine, and brought direct injection
to this engine, plus the use of a distributor type fuel injection pump. Conversion
packs for the older tractors now used this engine instead of the L4, and
other manufacturers such as Marshall took the newer engine instead.
Allis Chalmers had fitted Perkins P3 engines in their model B at the Totton
Southampton plant, and continued to use Perkins engines -the P3.144 in their
D270 and D272 models once assembly had moved to Essendine. The ED40 tractor
used a Standard Motor Co. 23c engine however. This was a tactic used by Standard
to annoy Perkins and M-F by selling engines at lower prices to take up the
loss of production encountered with the loss of M-F business. They also got
in to Fords by supplying a limited number of Petrol 87mm engines for Dextas
sold in Denmark and elsewhere. These latter were, however, of special build
to suit the Dexta gearbox housing.
Small numbers of engines were supplied to other manufacturers both at home
and abroad, and examples of some of these are shown in the book. Notable
crawlers that used Perkins engines were the Howard Platypus, the Bristol,
and the French built Continental.
There we leave Perkins for the moment. As the sixties progressed and the
seventies dawned an even greater variety of products came out of Peterborough,
and a new factory was built. But that is another story!
Allan T Condie
Perkins Diesel Conversion & Factory Fitted Units