HINTS ON MAINTENANCE.
Page 28
If you've noticed an error in this article please click here to report it so we can fix it.
How to Get the Best Out of a Vehicle, to Secure Reliability, and to Avoid Trouble. _
439.--Improving the Exhaust Nozzles on the Yorkshire Steam Wagon. It sometimes happens that, through constantly removing and replacing the small exhaust nozzles in the smokebox doors of the Yorkshire boiler, the threads become worn, and if, after this, they become at all choked with oil, etc., they are sometimes forced out.. If these nozzles, which act as blowers, he lost, the production of steam is considerably diminished.
To save this trouble the holes in the smokebox doors can be opened up from .1 in. gas to in gas and fitted with reducing nipples to take the g-in. nozzles. The last-named should then be rethreaded to allow for the length of the nipples.
This modification has not only prevented much of the trouble which had previously occurred, but has 'permitted old nozzles on which the original threads were badly worn to be utilized ; also, instead of removing the nozzles by means of the footprints, the nipples can be unscrewed with a spanner.
440—Shortening the Stems of Overhead Valves.
It is often found on engines with overhead valves, especially when new ones have been fitted, that the sternsare too long and the adjusting screw unscrewed so far that, when the valve is closed, the head of the screw touches the cover enclosing the valve gear, or else the valve stem touches the end of the rocker arm and no clearance can be obtained without shortening the push rod, which is not advisable.
Owing to the valve gear being in a trough, it is practically impossible to reduce a valve stem with a file, the, alternative being to remove the valve cage, often a difficult matter ; in fact, in some cases, the whole cylinder block may have to be. lifted off. This difficulty can easily be overcome in the manner illustrated by our sketch. First remove the rocker arm to expose the valve stem, and then slip a short piece of tube, or anything of suitable size and with• a hole approximately the same as the diameter of the valve stem, over the end. Then obtain Si twist drill which will fit the tube, and B46 grind the end flat as if it were to-be used for bottoming a blind hole. Then, by means, of a brace, reduce the end of the stem as required, using the tube as a guide. Cutting may be facilitated by first drilling a small hole in the centre of the stem. This method of reducing valve stems may also be applied to other purposes, such as shortening studs, dowel pegs, etc. •
441.—Taking up Play in the Crossheads of Steam Wagons.
In order to take up play between the crosshead pin and the bush in the engine of a steam wagon without renewing the bush, remove both the bush. and pin, cut the bush along one side with a hacksaw, and insert between the crosshead and the bush suitable liners made of thin tin or brass foil of sufficient thickness to compress the bush on to the pin without making it too tight. If thought necessarya parallel reamer can be run through the bush to relieve the hard spots. If this job be carried out carefully a good bearing can be obtained.