PANTHER PROBLEMS

Thanks to all for another magazine, it is quite a nice change to major on the practical side. I’d like to make a hopefully helpful suggestion regarding Nick Adams’s problem with oil blowing out from the crankcase and primary drive housing of his Panther 120.

The very clear picture of what he calls a ‘flappy valve’ is, I believe, a ‘clack valve’ in good old Yorkshire / Lancashire parlance. It shows the split pin which forms a key part of the mechanism to be of an unsuitable type and furthermore to be incorrectly fitted.

The split pin should be long enough to pass through both opposing holes, and to leave enough to be bent over outwards in its two parts after passing through the second hole. The really crucial point is that said overall length must also allow for the length of split pin spanning the centre hole to be able to have its two sides parted in the middle and bent symmetrically outwards. This is to result in a sort of vertical diamond figure being assumed by the two halves of the opened-out pin in the centre hole.

This way, when the little disc is blown outwards by positive crankcase pressure, hitting the split pin with some force, said disc is supported from tilting and thereby jamming open. Conversely, it will be seen that a straight centre portion of the pin, as shown in the page 50 picture, will not reliably resist such tilting and subsequent jamming open of the disc.

Nigel Stennett-cox , member 1182

Ah. Clack valve. I’ve not heard that for a while! Thanks, Nigel. Frank W