hien directs
Page 18
If you've noticed an error in this article please click here to report it so we can fix it.
IVECO has nosed ahead in the race to develop the first small, high-speed, direct injection diesel engine with its 8140.21 which is on display in Geneva this week.
But the new direct injection 2,445cc lveco engine will not become available until later this year, by which time Ford is expected to have unveiled its engine of this type. The Perkins/Austin Rover equivalent is unlikely to make its debut before 1985.
lveco's engine will be fitted in Daily vans and chassis cabs in turbocharged form and will be on offer to other vehicle manufacturers. It is being built at the Sofim, Foggia factory in Italy and is a development of the 8140.61 naturally aspirated 2,445cc indirect injection four cylinder unit which currently powers the Daily and which will continue to be available when the di engine comes on stream.
Like the indirect injection Sofm diesel, the direct injection version has a two-piece, castiron cylinder block with dry cylinder liners, a five bearing crankshaft, and ribbed belt driven overhead camshaft.
Bore and stroke on both types is 93x90mm (3.66x3.54in). The Bosch VE rotary injection pump with all-speed mechanical governor is driven by the camshaft belt via a geared shaft which is also geared to drive a layshaft for the oil pump and tachometer drive.
The turbocharged engine on display at Geneva has a gross maximum power rating (to the DIN 70020 standard) of 68kW (91hp) at 3,800rpm. Maximum torque of 216Nm (159Ib ft) is achieved at 2,200rpm. The engine's maximum no-load governed speed is 4,630rpm, and its compression ratio 18:1.
At full load at the engine's rated speed, the turbocharger (which may be either KKK or Garrett and is fitted with a waste gate valve) is set to give a boost pressure of 0,88kg/sq cm (12.8psi).
Development of direct injection small diesels has been spurred on by the demand for better fuel economy, which is typically better by about 15 per cent from a di engine than a similarly rated idi engine.
lveco claims an 18 per cent improvement with its latest turbocharged Sofim diesel and the engine's performance curves show that minimum full load specific fuel consumption is a little over 220 g/kWh (0.362Ib/hph) and never rises above 252 g/kWh (0.414 lb/hph). By comparison, the 8140.61's minimum sfc is above 260g/kwh.
One of the inherent disadvantages of the di design is its higher noise level. The lveco engine has highly flexible gaskets between the two sections of the cylinder block and these help to damp high frequency vibrations while the plastic valve cover with its sound absorbent lining is another noise reducing feature.
Heat loss to coolant is significantly lower in a direct injection engine than an indirect injection equivalent and this has led to Iveco using a smaller radiator on the latest Daily engine. This should help to overcome any potential slow-warm-up problems but there is unlikely to be any cold starting problems. The 8140.21 does not require preheater plugs.