The Expeditious
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Repair of Engine Parts
The Activities of a Midland Concern Manufacturing Andrews Resistwear Cylinder Liners
A RECENT visit to the new worts of the Andrews Crankshaft and Cylinder Co., Ltd., in Montague Street, Birmingham, made it clear that this concern is not only well equipped for its work, but is also organized and conducted in a manner which explains the satisfactory results of its labours. From first to last, all work is carried Out under careful supervision.
On receiving a part such as a cylinder block, crankcase or crankshaft, it is carried on an overhead runway to a 000-gallon paraffin tank, where it is washed with the aid of a pressure spray, care being taken to flush out the various oil ways as well as the surface of the job. At various later stages during its passage through the well-equipped machine shop, it is again cleaned in a similar manner.
Specializing in Cylinder Liners.
To deal with worn cylinder bores the company specializes in thel fitting of liners, of which two types have been standardized. These are the Sheepbridge-Stokes Centricast and the Andrews Resistwear air-hardened centri
fugally cast liners. In the past the latter have been rather expensive, but, due to the introduction of new plant and improved methods, the cost is now only some 10 per cent. greater than that of plain grey-iron liners. We understand that, after 80,000 miles' use by a local bus company, a set of these liners had worn only 6-1,000 in. in the bore. After reboring the block is cleaned and is heated by immersion in boiling
water. The liners are then pressed hydraulically into the hot block in order to ensure that at normal running temperatures the bores shall be truly circular. Another interesting point is that, before insertion, the liners are smeared with a special graphite preparation which prevents corrosion and thus ensures uniform heat conductivity
from the liner to the block. Incidentally, we were shown the remains of old liners which had been removed by boring, and these had not broken until the thickness was reduced to about 3-1,000 in.
After grinding, the cylinder bores are finished off on an Archdale honing machine with an hydraulically operated rising and falling table. An even finer finish is obtained on the Hardalloy pistons by the use of a diamond cutting tool mounted in a special, nicely adjustable holder. These pistons, which, we understand, are becoming increasingly popular, particularly for heavy commercial vehicles, are cast under pressure, and each stage of manufacture, from the mixing of the alloy onwards, is carefully controlled At the time of our visit a batch of 100 5-in, pistons for a well-known make of lorry was going through the works. Whether they be made of aluminium alloy or cast iron, all the pistons used are normalized after the rough machining, and, as is the ease with all the other components, they are carefully inspected after each
operation. As a result of these methods the Andrews company is able and willing to guarantee in writing that an engine .reground and fitted by it with new pistons will have an oil consumption as good AS when new.
Besides attention to the upper half of the engine—which, incidentally, includes the fitting of new valve seats, if required—the works is equipped to regrind crankshafts of all types and sizes. Main bearings can be rebored in line with great accuracy, which is an important point in that the crankshaft and the bearings themselves are freed from unnecessary and detrimental loads. Remetalling is carried out at controlled temperatures with a metal containing 95 per cent, of pure tin.
Time-saving Organization.
To commercial-vehicle operators it is essential that no time should be wasted when repairs or overhauls are undertaken. This is a matter which depends as much upon the office as on the workshops, and in this direction, too, the Andrews organization is thorough.
Apart from the fact that time can .frequently be saved for old customers by reference to the detailed records which are kept of each job which goes through the works, every effort is made to avoid waste of time.
To this end each piece of work is followed up, and—a useful point— should the unexpected happen and progress be delayed, the customer is at once informed of the delay so that he may make early allowance for it in his arrangements. •