New Meadows 80 b.h.p.
Page 49
If you've noticed an error in this article please click here to report it so we can fix it.
Oil Engine
AN important newcomer to the Meadows range will be exhibited for the first time at the commercial motor show this year. The engine is a direct-injection four-cylindered 5.43litre unit developing 80 b.h.p. at 2,200 r.p.m. and has been designed for quantity production. Known as the "330," the engine follows the Meadows practise of employing a square stroke to bore ratio and the maximum output is obtained at the low piston speed of 1.735 ft. per mm. Both the bore and stroke are 120 mm. The maximum torque is 230 lb.-ft. at 1,200 r.p.m., the corresponding b.m.e.p. being 105 lb. per sq. in.
The hardened crankshaft is carried in five bearings with the underslung caps secured by 4-in.-diameter studs, and the main and big-end bearings are of the steel-backed precision type lined with indium-treated copper-lead alloy.
An unusual feature of the new unit is that out-of-balance secondary forces are counter-balanced by contra rotating weights driven at double-engine speed by two shafts mounted below the crankshaft. These shafts are geared to the auxiliary train and transmit the drive to the we;ghts below the centre main bearing.
The auxiliary gears are alternately steel and cast iron, the drive being taken from the flywheel end of the engine. The " high" camshaft is located on the off side of the engine and runs in fivepressure-fed bearings.
Of integral design, the crankcase and cylinder block is of cast iron and wettype centrifugally cast iron-alloy liners are used. Two cast-iron cylinder heads are employed and renewable valve seats are provided for both the inlet and exhaust valves.
The toroidal-cavity pistons are of aluminium alloy and are fitted with three 4-in, compression rings and two oil-control rings. The fully floating gudgeon pins are lubricated through a 'drilling in the connecting rod.
• Of particular interest is the HobournEaton gear pump in the lubrication system, which essentially comprises a five-star inner operating in an eccentrically mounted six-star outer. The pumping action is a function of varying clear-. ances between the teeth at the two "seal points" and oil trapping is obviated. The output of the pump is particularly , good for the space occupied.
The wet • sump has a detachable pannier, which may be at either end of the sump to suit installation arrangements. It has a fullflow filter.
The fan and centrifugal water pump are belt-andpulley driven from the front of the engine, and belt drive is also used for the compressor or exhauster. A feature of the cooling system is the directional cooling of the injec tors. Circulation is controlled by a tliermostat.
The gear case, at the rear of the engine, is closed by the flywheel housing, which carries the engine support faces and is designed with an S.A.E. flange. The fuel-injection-pump drive, speed-governor centrifugal head and the pump-operating levers are contained in a sub-assembly in the gear case and operate in pressure-lubricated bearings.
The weight of the unit with the flywheel is approximately 900 lb., and it has an overall width. of 21 ins. The length from the fan to the flywheel fact is 354 ins,