1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180 
POWER UNITS an
Page 110
Page 111
If you've noticed an error in this article please click here to report it so we can fix it.
FRANSMISSIONS
Proprietary Power Units, Gearboxes and Rear Axles Suitable for Employment in Commercial Vehicles of Many Types
ALARGE number of successful commercial motors has, in the past, employed engines and transmission sets made by specialist concerns; to-day the tendency is on the increase. In certain instances a complete range of vehicles may be produced incorporating proprietary units of various makes. In other cases one or more chassis of a range may embody such units, because a more reliable and practical product is available than could be turned out by utilizing plant better suited to other sizes of work. The policy of employing proprietary assemblies is not one to be regarded as the last resource ; its pursuance results in
obtaining the highest efficiency coupled with financial economy.
Dealing first with petrol engines made by specialist concerns, we have the Coventry Climax range, units of which are adopted by several vehicle makers as standard. Probably the best known is the L6 six-cylinder engine of 353 cubic ins. capacity, 3i-in. bore and 5-in. stroke. The R.A.C. rating is 36 h.p. It is of the side-valve type with a separate block and crankcase, the upper half of the latter being in cast iron.
c52 The Dorman range of 18 engines— exclusive of marine motors—includes 17 petrol engines and one two-cylinderedDiesel type. The last-named is made under Acro licence and is sold for purposes other than road work. The petrol engines range from two-cylindered models to six-cylindered designs,. the smallest having an output of 8.5 b.h.p. at 1,000 r.p.m., whilst the largest has an output of 100 b.h.p. in similar. conditions. Two of the most popular are the 4RT_I and the 4RTIL ; they are similar in design and both have a stroke of 140 tom. The former has a bore of 100 mm. and the latter of 105 mm. The valve covers and all the auxiliaries are grouped on the near side, making the unit particularly well suited to forward-control chassis.
Among the five "fours" and three "sixes" of Meadows make, that best known by commercial-motor men is the 6EX, designed for duty in large coach and bus chassis or high-speed goodscarrying machines. It has six cylinders and a volumetric capacity of 7,983 c.c., developing 115 b.h.p. at 2,200 r.p.m. The crankshaft is carried in seven main bearings; on the near side are all the auxiliaries except the starter and the sparking plugs.
An engine of repute is the Tylor Tiger ; it is of the medium-speed variety, intended for heavy-duty work. The four cylinders are cast in pairs; the bore is 5 ins, and the stroke 6 ins. Drive from the three-bearing crankshaft to the camshaft is by silent chain with an external adjustment.
A recently introduced range of power units is handled in this country by Automotive Products Co. It is the -Hercules, emanating from Ohio. In addition to four-cylindered types there are "sixes" of 260 cubic ins., 298 cubic ins., 339 cubic ins., and 360.8 cubic ins. The valves are located side by side, and the auxiliaries are grouped on both sides.
Including the recently introduced Hivelo series, the number of Buda-built engines is 25. They are of the sidevalve type ; the four-cylindered patterns range from 36 b.h.p. to 90 b.h.p., whilst six-cylindered power units peak at 56 b.h.p. in the case of the smallest and 155 b.h.p. in the case of the largest.
A Promising 011 Engine.
A compression-ignition engine which is making great headway at the present time is the Gardner, a Manchester-built motor, which can be obtained in one, two, three, four, five or six-cylindered types, according to the horse-power re' quired. The fuel pump is partly of Bosch design ; starting is by hand, control of the compression in the cylinders being arranged to permit swinging to obtain momentum, followed by normal firing in a certain number of cylinders. After this all cylinders are brought into action and the engine is ready for running.
Another interesting engine is the llesselman; although it employs Diesel oil as fuel, electric ignition is adopted, and the compression ratio is comparable to that of a petrol power unit.
The Lister range adopts as standard a bore of 41 ins, and a stroke of 51 ins.; the number of cylinders varies from one to four, according to the output demended by the customer. These engines are of the cold .starting type, the compression ratio being capable of a temporary increase for this purpose.
Built under the Acro licence is the Aveling and Porter Invicta ; it has four cylinders and develops 62.5 b.b.p. at 1,800 r.p.m. The compression ratio is 14.52 to 1; injection of the fuel is by a Bosch pump.
To provide power for small industrial trucks and for auxiliary appliances, horizontally opposed twin-cylinder engines are marketed by Coventry' Victor and Douglas. Single-cylindered and V-twin engines are produced under the names of Blackburne, J.A.P. and Sturmey-Archer, whilst one of the bestknown range of two-stroke-cycle units is the Villiers.
Turning now to the next step in the line of power we come to gearboxes. Both the Dorman and Meadows concerns supply suitable types to mate with power units of their design.
Proprietary Gearboxes.
Among the range of Moss gearboxes is the G4,000/2; this gives four forward speeds and reverse and is designed for vehicles up to 50 cwt. and 4,000 c.c. The casing is in east iron and incorporates a clutch housing. Another design is intended for use with 16-20 h.p. engines, and cast iron is again employed for the body of the box.
Fuller gearboxes, handled by Automotive Products Co., are a specialized product from America. The drive is through a multi-plate clutch to the constant-mesh pinions, thence, on the indirect gears, through wide gearwheels on the layshaft and niainshaft. Types are made to meet most transport needs, and auxiliary two-speed boxes are listed.
One of the largest concerns supplying rear axles to the commercial-motor industry is Kirkstall Forge, Ltd. The main load-carrying member is a onepiece drop forging ; the worm gear may be arranged for overhead or underslung mounting.; particular care has been paid to the rigid location of the worm and wheel. Bus-type axles incorporate a dip-stick for checking the oil level. Brake sets can be included in the layout. Complete bogies can be provided, including three-differential types.
M.092 rear axles are marketed with spiral-bevel drive or the Guest full-encircling worm. In these pages we illustrate a bevel-drive type for vehicles up to two tons. The easing is a one-piece steel pressing.
The well-known and comprehensive range of Timken axles, marketed by Automotive Products Co., includes beveland worm-driven models for chassis of every pay-load capacity. For the benefit of those who are interested or may be interested in proprietary engines, both petrol and oil, gearboxes and rear axles, we append a list of makers' names and addresses:—
Automotive Products, Ltd., Brock Ilcuse, Longhorn Street, London, W.1. Aseling and Porter, Ltd., Rochester, Kent.
British Mercedes-Benz, Ltd., 111, Grosvenor Road, London, &W.1. The Buda Co. (England), Harvey Works. Wembley, Middlesex. (Blackburne) Burney and Blankhurne, Ltd., Atlas Works, Bookham,
Coventry Climax Engines, Ltd., Friar's Road, Coventry. Coventry Victor Motor Co., Ltd., Cox Street, 4,0ventry.
(Gardner) Frank H. Dutson (Leeds), Ltd.. 75, Hunslet Low Road, Leeds. W. H. Dorman. and Co., Ltd-, Staliord. Douglas Motors. Ltd., Kingswood, Bristol.
Kirkstall Forge, Ltd.., Kirkstall Forge, Leeds. R. A. Lister and Co., Ltd., Dursley, Gloucestershire.
Henry Meadows, Ltd., Railings Park, Waiverhampton. The Moss Gear Cc., Ltd., Crowa Works, Tyburn. Birmingham.
(Hesselman) oil Motors, Ltd., 56, Kingswa..7, London, W.C.2.
(J.A.p.) J. A. Prestwich and Co., Northumberland Park, London, N.17.
Sturmey,Areher Gears, Ltd. faraday Rood, I.enton, Notts.
Tylors (.1134), Ltd., 134, King Street, London, W.6
A liiterS gnglimarillij t,;0„ Malatioc Road. Wolverhampton.