crankcases

Hi Colin,

   What year is your engine, the later ones are easiest.

Hi Colin,

   I don't think this will be worth the effort. If it was a 1948 onwards type it would be fairly straight forward as there are more common parts. Are you swapping your own cases for 16H ones or are you trying to build another engine ?

This is a 1936 WD16H bottom end with an earlier top half...Tha basic castings for any given era are identical but sv tappet drillings don't line up with OHV pushrods etc. It's not a bolt-on conversion.

Hi Colin,

   The flywheels, main-shafts and big-end are the same on both but the 16H con-rod is 8" centres, while the ES2 and Model 18 rod is 7". I have never checked it, but the flywheel balance factor may be different to compensate for the longer rod and the heavier piston on the 16H.

Edgar Franks writing in 1948 says "The crankcase layout is identical in each case and by the substitution of large unions to accommodate the push-rod cover-tubes, the S.V. crankcase becomes suitable for the O.H.V. engine. This necessitates special machining and it is not intended to suggest that a conversion from one type to the other is a simple proposition."

So is the case on the left of the photo a SV case with the large unions you mention for use as a OHV, as i`ve been wondering why I haven`t seen another quite the same?