Appreciate the second-hand value of En first hand. Gordon Plant did!
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power at 2,100rpm whereas the ''L" version produces the same power but at 200rpm less. This brings an advantage in turbocharger matching because the wider the engine speed range, the more difficult it is to get the matching right.
Environmental pollution, or rather ways of controlling it, is high on every engineer's list of priorities. The emissions problem for instance. Brain thinks that the probable level for hydrocarbon and oxides of nitrogen will be set at 16gm/bhp/hr as this is a comparatively easy limit to meet. Any move to go as low as, say, 10 will bring with it a loss of efficiency and poorer fuel economy. Rolls-Royce anticipated a five per cent fuel consumption penalty if the legislators insisted on lowering the emission limit still further.
Fuel bonus
"Given time, I think we, could probably do
10gm/bhp/hr as OUT knowledge improves. The alternative is to stay at 16 and get a bonus in fuel consumption.
Ever-conscious of the performance of Rolls' competitors in the engine field, Brian admitted that Rolls-Royce needs to work on the part load efficiency of their engines. Gardner have us on that point."
He wants five per cent more efficiency from the engines in future, but more than that (10-15 per cent) at part load, where, he feels, there is moreto come.
Increasing coolant and lubricant temperatures has an effect on parasitic losses but, here, the engine manufacturers are in the hands of the chassis builders. As Brian said: "Engine manufacturers have always had a battle on their hands to get adequate radiators. But there is a much better climate now."
With regard to cutting back on the water flow, Brian Leverton thought that there was definitely something to be gained here as reducing the flow and, consequently, how hard the pump has to work, will save a bit of power. But he did not think this was necessarily applicable to the Shrewsbury products which have a relatively low flow rate anyway.
Tuned inlets
Rolls-Royce has been an advocate of tuned inlet systems for some time now. With this system, volumetric efficiencies in the region of 90 per cent have been achieved, although some of this has had to be sacrificed to promote increased swirl. Giving an interesting insight into the R-R approach to vehicle engineering, Brian Leverton said: "It is not necessarily the ideal manifold for the engine, but at least it's possible to fit it into the chassis. We are essentially practical people at Rolls-Royce."
Talking of chassis installations and all the associated problems of the engine being too wide, too long, too tall, too everything brought us on to the concept of charge-cooling. Brian thought we were going to see more and more chargecooling in the future. Although it increased the first cost of the engine, it brought benefits in improved durability because of the lower maximum cylinder • temperatures.
He did not think there was going to be a massive explosion in the sales of charge-cooled engines, merely a gradual but consistent increase. He stressed here the advantage that DAF
has in building the comple vehicle, not just the engine. this way, the same factory c eliminate most of the instal tion problems associated w the extra pipework and an ex radiator in the case of air-to-air layout. As to the actt method of cooling the inlet E R-R prefers the air/wa• method and already has a jacl charge-cooling system in p duction.
No Gardner?
Most of the lorry mai facturers who offer Cumm and Rolls-Royce engines a offer Gardner options. S'a v haven't I included Gardner might ask?
In fact, I contacted all th of the engine manufacturer: the same time with a view producing a more comp article. But Gardner decline( take part and said they foun surprising that we should them what they would be dc in the future.
Will the next Gardner enc be a turbocharged V8 or a r cylinder in-line? The reader have to guess!
eGraham Montgorne