Future C.A.V . Equipment
Page 43
If you've noticed an error in this article please click here to report it so we can fix it.
nETAILS of alterations to the range of vehicle electrical equipment made by C.A.V. Ltd. were given in a paper read by Mr. J. A. Cook, product controller (electrical) of the company, at its Southern Areas Agents Conference held at Eastbourne last week.
Starter and dynamo production has been rationalized by the replacement of many types used on vehicle engines; all starters up to and including 5-in, diameter are being replaced by the CA45 co-axial type and an improved, high-powered version of the BS5 starter—the SL5—is 'Icing introduced to replace units in the SP5, 8S6 and U6 ranges.
There are two starters, the SP6 and S7 for large engines so that engines up to 70-litre capacity are covered by only four basic starters.
Regarding generators, Mr. Cook said that it had been decided to replace all 4.5-in. and 5-in. machines by the 0L45 dynamo. The only other d.c. generator still to be made is the 1155, a.c. units making up the rest of the range.
The C.A.V. AC7 alternator which replaces the G7, DO7X and D8C dynamos now has silicon diodes built into the slip-ring end-shield to provide rectification to d.c. and is a 7-in.-diameter machine producing 60A. It weighs only 40 lb. and Mr. Cook said that in terms of cost per useful amp. the AC7 alternator is already cheaper than its d.c. counterpart.
For the future, he said that there is plenty of scope to reduce the cost of the a.c. machine so that ultimately it should be cheaper than a d.c. unit of equivalent physical size. The reliability and life of the a.c. machine is inherently superior to an equivalent d.c. unit said Mr. Cook and the AC7 should have a life of up to 250,000 miles between major overhauls.
C.A.V.'s generator range is completed by two large alternators—the AC8 and AC14 and summarizing the range Mr. Cook said that the GL45 and H55 d.c. machines must obviously be replaced by a small alternator in due course so that the company's range would consist of four basic machines—all alternators--each designed to have a life at least equal to the period between major engine overhauls.
Not referred to by Mr. Cook, but displayed at the conference and attracting much attention from operators, were prototypes of side and front corner lamps (for the new trailer regulations) which are to be available from C.A.V. These had the designation L740 and a feature of them is the use of " capless " bulbs. These are of all-glass and do not have the conventional metal cap. Instead, the glass below the actual bulb is formed into a tongue with wires to the ends of the filament located on the outside. The base of the L740 lamp is of moulded rubber in which the generally rectangular blister lens clips and the bulb fits in a slit in a thickened portion which has electric connectors. No details of price or availability were given.
In a second paper read at the conference Mr. S. F. Barber, product controller (diesel) of C.A.V., dealt with the technical aspects of matching fuel injection equipment with engine requirements. There were; he said, two basic problems; ensuring the equipment is tuned to the particular engine, and producing a range of equipment to meet the requirements of the whole engine market in the most economical way. Mr. Barber dealt mainly with requirements for the automobile market—engines with capacities of up to 2.5 litres per cylinder—and fully explained design considerations of fuel delivery, tuning adjustment and injection rate.
Speaking of fuel pump design, Mr. Barber said that C.A.V. expects the DPA distributor-type injection pump to replace A and AA pumps and also the N and NN units on engines up to 1.5 litres per cylinder capacity in naturally aspirated form. The latest pump in the in-line range is the BB type and this will take over from the NN on engines of 2 litres per cylinder capacity with ratings in excess of 140 b.m.e.p.
Before introducing the BB, C.A.V. considered whether the range of engines above the capacity of the DPA should be met by a larger version of the distributor pump. This was not considered practicable because of the number of engines involved which were made in five-cylinder form which resulted in uneven firing orders not able to be met by a distributor-type pump. It was therefore not possible, Mr. Barber said, to eliminate all the in-line pumps for vehicle engines, although the DPA covered by far the greatest quantity, of engines made at the present time.