Morris Car Engines - Used Cowley engine, Isis, Mini Minor and more available
The Morris Motor Company, a
British car engines manufacturing
company. After the incorporation of the company into larger corporations, the Morris
name remained in use as a marque until 1984. Morris produced an amazing car
engine which are readily available as used, reconditioned or secondhand today.
Morris from the Anzani Engine
Factory had been given the task of improving a rather poor update of a
Morris sidevalve new engines. This update had been converting a 1292cc 10hp Morris
sidevalve into an overhead valve unit. The 'MPJM' ohv engine was fitted to the Series
3 Morris Ten/4, and only used for one year. A virtually identical 'MPJW' engine
had been fitted to the 1936 Wolseley Ten/40, and the MG 'TA' Midget as the 'MPJG',
again both of 1292cc. Claude was to take this Morris engine, and without too much
fuss improve it in detail, to be fitted to the new chassisless Morris 10hp saloon,
the 'M' Series.
The MPJM/MPJG series engine
had prooved to not be of the best, as it still used details dating back to the early
Morris Bull Nose cars, mainly in its 102mm stroke. Like many companies Morris had
tried a short-cut to ohv engines, by simply modifying an existing side-valve unit.
Claude was given the task of sorting this all out. He reduced the stroke to 90mm,
and Morris employees then dubbed the engine the ' Short-stroke Morris Ten 'M' Engine'.
This was because the 1140cc ''XPJM' engine went into the new monocoque 10hp car,
the 1939 Morris Ten Series 'M'. The 90mm stroke was not new to Morris, it was in
use in the current 918cc Morris Eight and 1378cc Morris Ten/Six, both side valve
engines. Claude had strengthend the internals, improved the ports and the breathing,
and had quietly produced the foundation of an engine that would become world famous
later. The 1140cc engine naturally also found itself in the 1939 Wolseley Ten/40
Series 3 version of the Morris Ten Series 'M'. Morris Motors named the engines from
this range the 'X' series, and they were to last from 1938 through to 1956. After
designing Anzani and Morris engines, Claude went on to be involved in another 'X'
series of engines, as after the war he helped design and develop Jaguars 'XK' six
cylinder masterpiece. He worked for William Lyons along with great names like William
Heynes and Walter Hassan. Claude was very involved in the now famous Jaguar V12
engine at Browns Lane, as chief designer for the company eventually, so his experience
on the little XPAG prooved very useful to the UK motor industry.
The Morris 'X' series of engines
was indeed becoming a success. MG had tried the Morris 10/4 Series 2 converted 1292cc
side-valve engine in the 1936 MG TA Midget, having been forced to do so by the new
management, now that their free-reign had been drastically shortened. When the 1140cc
XPJM engine was seen by MG, they saw it obviously had development potential. The
engine was stiffened up more, connecting rods and big ends strengthened, stronger
pistons, cylinders bored out to give 1250cc, and given bigger valves and ports.
This went into an updated TA to be called the 1938 TB Midget. A long association
of the XPAG engine as it was named with MG had begun. A modified Morris Series Ten
'M' gearbox with remote gearchange added was part of the mechanical package, and
together the engine and gearbox produced a very pleasant and driveable sports car.
One of the attractions of the XPAG engine was its ability to rev freely, and its
excellent bhp/torque figures for its size.
MG were more than pleased with
the XPAG engine, and it was only WW2 that stopped the TB roaring away to
more success, and the introduction of a MG Ten/4 six light saloon. This saloon was
later called the 'YA', ( after the YB's introduction,) which used a single SU carburetter
version of the TB unit, and a gearbox without the remote gear change. This coincided
with the start of the climb to success of our little 1140cc and 1250cc 'X' series
engine. In the post-war Morris ten Series 'M' and the Wolseley Ten/40, ( same car,
differing grill, badging and interiors,) the 1140cc unit was pouring out of Morris
Motors by the thousands. The engine had not really been out of production, as it
was being made all through the hostilities as a utility unit fitted to power water
pumps, petrol/electric sets, hydraulic pumps, and the like for the armed services,
( named the 1939-45 MPJM/U.) Oddly, Morris went back to its side-valve engine in
the car that replaced the Series 'M' Ten, as the 1948 'MO' Oxford. The Wolseley
4/50 used the same body and chassis, ( again, ) but with a four cylinder single
ohc engine. Wolseley's had always been up-market Morris's since Bill Morris had
brought Wolseley Motors back in 1927 for their excellent engines.
The 'X' series was
getting good press reviews in the motoring world. In Morris, Wolseley and MG form
it was renowned for its quiet running and freedom from vibration, both products
of a properly counterbalanced forged crankshaft with accurately fitting replaceable
shell bearings, and good breathing. The ability to rev freely was noticed as well,
as this was one of the first 'modern' high-revving engine fitted to a family car.
In the 1938 Morris Ten Series 'M' the 1140cc 'X' series engine propelled the car
to a maximum speed of 66mph. In the 1947 MG YA the 1250cc version propelled this
larger saloon to 69mph. In both saloons only a single SU carburetter was used. Fitted
with twin SU's into the 1945 MG TC top speed was recorded as 77mph. The 1952 Wolseley
4/44 made 70mph mainly because of its good air-flowing shape, and the 1953 1466cc
MG TF 1500 reached 85mph, which is not bad when you consider all the 'T' types have
the coefficient of drag ( CD,) of a brick! Today we consider the XPAG to be a very
'tappety' engine when compared to modern and silent ohc engines, that sound more
like hair-dryers than cars.
The 1250cc 'XPAG' version
of the small but lively Morris engine was also in huge demand. In the MG it had
been improved further with a timing chain tensioner soon after being fitted into
the TB. The 1938 'TB' had become the 'TC' Midget in 1945 with a few chassis modifications.
By 1949 some ten thousand XPAG engines had been fitted to TC Midgets, by 1952 another
6,158 to the YA saloon, 877 to the YT tourer, and by 1953 another 1,301 to the YB
saloon. The MG model that really used the XPAG, and the one for which many remember
it, is the immortal TD Midget. Between 1949 and 1953 28,643 XPAG fitted TD's were
sold, and add to that another 1,022 TD Mk2 Midgets. The XPAG MG engine was in its
hey-day. It was being tuned to terrific power levels of over 100bhp per litre with
superchargers in motor-racing. Specialist car makers liked the engine, and the XPAG
found its way onto many racing tracks. The high speed runs of Goldie Gardner in
September 1951 for USA class 'F' cars in EX135 no doubt helped the image of the
engine. Producing 92bhp normally, fitted with a supercharger it could be boosted
to 210bhp at 7,000rpm for short periods, then the little 1250cc engine managed 139.3mph.
The smaller Morris and Wolseley
1140cc engines had been built in large numbers, totalling some 90,000 cars.
The engine was modified as it went along in production, and in MG form seems to
be in three separate series. The Wolseley 4/44, was looking like a high built MG
Magnette ZA with a Wolseley radiator grill. The 4/44 was the last car to use the
engine up into mid-1956, almost a year after MG had stopped using it in the TF.
The Wolseley XPAW version had a very different sump and oil pick-up, and the dip
stick on the opposite side to the MG installation. 30,000 Wolseley 4/44's used their
version of the 'X' series between 1952 and 1956. For the enthusiast, the 4/44's
engine was virtually identical to the YB 'SC/2' engine with its humble 46bhp.
The design of the 'X' series
was very advanced for its day. Morris were in the forefront of technology as far
as motor car engines go. The cooling of the engine was carefully thought out, to
keep the block hot and the
exhaust valves cool. Virtually all the water flow is through the engine cylinder
head, fed in from the back, exiting from the front through a temperature controlling
thermostat. It was pump assisted, and did not rely on thermo-syphon alone. Later,
in the TF and 4/44 the cooling system became pressurised at 4psi. A counterbalanced
crankshaft with strong connecting rods, shell bearings, renewable oil filter of
the full-flow type, and valves angled towards their ports, were all good design.
An oil pressurised timing chain tensioner was soon introduced, and later a modern
sine-wave designed camshaft lobe, ( on the .012" version.) As well as the cooling
system being up to the minute, the lubrication was excellent, the type of oil pump
fitted being easily able to cope with engine wear. Virtually all the time it was
running the pump relief valve was letting excess oil back to the sump. This was
not missed by the unscrupulous, who added washers behind the relief valve spring
to boost a flagging oil pressure in a worn engine. The whole engine and gearbox
unit was a rigid design, with a cast iron block bolting to a cast aluminium sump,
and both bolting to a cast iron gearbox at a strong bell-housing. All this was rubber
mounted for insulation at three points, and there was even a torque rod to limit
engine movement. Excellent quality materials were used in the construction, and
long life was guaranteed if serviced properly. Today in 1999 there are old MG's
with original XPAG engines still fitted and running well. To cope with 2000 and
unleaded fuel, they will all require hardend exhaust valve seats fitting eventually.
The engine that replaced the
XPAG in MG cars, was the Austin based 'B' series. This was initially quite
a retrograde step, as it had split little ends using a pinch-bolt, split skirt pistons,
diagonal big-ends, felt oil seals, a terrible manifold system and an ancient by-pass
oil system that meant unfiltered oil fed all the bearings. The first car to use
it was the 1489cc MG Magnette ZA in 1953. With MG as the test-bench, the engine
quickly gained a full-flow oil system, solid piston skirts, thinner piston rings,
and much better oil control rings. With a bit of tuning the 'B' 1489cc series soon
produced more bhp than the 1466cc of the TF 1500, ( 68 to 64.) Politics inside the
new organisation of BMC, formed in 1953, meant Morris engines were to be dropped,
and Austin engines to rule. However, a production run from 1938 to 1956 is not a
bad record giving eighteen years of Morris 'X' Series.
Some Car Models that became
Morris Oxford (Bullnose), Cowley, Morris Oxford, Major, Isis, Twenty-One /
Twenty-Five, Twelve, Fourteen, Eight, Ten, Oxford, Six MS, Cowley, Isis, Mini Minor,
1100, 1300, 1800, Marina, Ital.