Sir,

The Ford Escort Service Manual reads—”The oil should be topped up before the ‘Min’ mark is reached. Filling above the ‘Max’ mark will result in a high oil consumption and external oil leaks”—which is just what one would expect.

If an excess pint of oil can quickly ruin a set of bearings, as stated by Mr L. J. K. Setright, it seems quite extraordinary that Fords do not strongly emphasise this point in their manual, instead of which they do not even mention it. The truth is, of course, that it could not possibly have this effect, which is a very good and sufficient reason for NOT mentioning it.

I am also rather puzzled about the trouble with the early BL 1800s referred to by Mr. G. S. C. Smith in your April issue. Experiments with bore finish to try and overcome the trouble must surely indicate piston seizure, but if the crankshaft “dipped” to this extent the cylinder walls would undoubtedly be flooded with oil, and I would have expected serious complaints of excessive consumption and fouled plugs. The only possible explanation seems to be that the oil temperature was increased appreciably, which in turn affected piston temperature to a point where on any cylinder with piston/bore clearance on the extreme bottom limit, seizure could occur. Piston clearance is usually kept as low as possible to avoid complaints of piston slap, but there is always some tolerance, and once a piston “tightens up” even slightly the temperature increases, which causes further expansion and further tightening, and final seizure is inevitable.

A. C. Savile.

[I read it as meaning that BL were puzzled by the engine seizures and coupled them automatically with piston problems instead of faulty dipsticks.—Ed.]