310.—Improvements to the Peerless Fan.
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In Hint. No. 268 a contributor made some suggestions regarding the various troubles experienced with the -Peerless .fan. Another correspondent thinks that he did not go quite far enough in this respect, for,as a user of this type of vehicle for some years, he has found that the fan is the weakest point in the design of an otherwise good and serviceable machine.
The trouble is that the fan, running at a speed in the neighbourhood of 2,000 r.p.m. when the lorry is in low gear, si,ts up a considerable vibration, and
-even if the key holding the central spindle is a good fit, sooner or later the locking-nuts work loose, the fan spindle turns round slightly, and the fan touches the radiator, probably knocking a corner off one or more of the blades or loosening the retaining ring which keeps the blades in one plane. If the fan is again tightened, the loss of the blade corner throws the fan out of balance, and the trouble recurs even sooner than before, and this time the spindle probably breaks off just above the top locking-nut, to say nothing of the damage which may be caused to the radiator tubes.
As this happened on several occasions, our correspondent made an effort to rectify the trouble, and did so with success in the following manner:—
A new bucket was made from a piece of scrap steel plate is in. thick, this being cut out to shape and drilled to aecommociate the usual holding-down setscrews, and the other holes drilled and tapped Ein. gas thread. Two uprights, made from diameter mild steel, 6 ins, long, were then screwed into the plate and locked above and below it by 1336 means of thin nuts, the ends of the rods being riveted over. The top portions of the uprights were also screwed tin. gas thread and nuts and spring washers fitted.
A broken fan spindle was utilized to form the top portion of the bracket, it being securely riveted into a specially formed piece of mild steel, as shown at A in the illustration, the sides being carefully caulked round after riveting up the spindle. With this bracket it is practically impossible for the fan spindle to work loose. It would be as well to mention that a new fan was made at the same time, using in. mild steel plate for the centre stars and is in. thick plate for the blades, the outside retaining rigbeing discarded, as it is really unnecessary if the blades are fairly stiff.
311.—Lubrication of F2 Type Fiat Engine.
The circulation of the lubricating oil in the engine of-the F2 type Fiatis effected by a small gear pump fitted at the rear end of the crank chamber base and driven direct from the camshaft.
The oil in the sump is drawn threnigha suction tube fitted with a detachable filter. Before it leaves the puistp it passes through a second filter, also detachable, and is forced into the collector tube lying inside the base and connected to the bottom by means of an outside tube. From the collector tube, the oil passes down through a number of, small pipes to the bearings of the crankshaft, and thence to the big-end bearings through a, duct bored in the crank,shaft.
Inside the pump there is a small valve in communication with the filter chamber. This serves to release excessive pressure, and the oil, escaping through this valve, returns to the sump.
Oil is poured into the crankcase through an orifice in. the upper part of the base chamber ; it can he released by unscrewing a plug in the bottom of the sump, which is provided witha further hole with a cover for the purpose of inspecting the oil level. This level 'should be kept l ins, below the edge of the inspection hole.
So soon as the engine has been started, examine the pressure gauge. If there is little or no pressure, make certain: (1) That there is sufficient oil in the sump ; (2) that the filters are clean ; (3) that the pimp does not drew air from a looSe union or from the cover ; (4) that the release valve spring is not broken ; (5) that the pressure gauge is not broken.
If the pump has not been in operation for some time, it is possible that it is empty and will not draw oil from the sump, in which case it will need priming. Do this-by filling with oil the vertical filter chamber, after removing the screwed top. If the gauge still shows insufficient pressure, see that the release valve is properly regulated and that the oil is not too fluid. If the pressure shown is excessive, even when the engine is hot, it is possible that the release valve is Eitue,k on its seat.
In winter it •is preferable to let the engine run slowly for some few minutes• in order to warm the oil mid to ensure that it is circulating properly. To
expedite this'heating, the radiator may partially be covered or the fan belt removed. It is advisable to add fresh oil after every 10 hours' running, and the " sump should be washed out and clean oil put into it
about every 1,00 miles, according to cylinder wear. To lubricate the :valve tappets it will be sufficient to take off the aluminium cover and to put a few drops of oil on the eight rods every now and again.