Replying to Dave Croft's question on Villiers Mar-Vil and Century varients reminded me of the value of carrying out a 'forensic' investigation of spare parts lists to try and determine how an engine was changed during its production life.
I then remembered a piece I wrote for SEM a couple of years ago challenging the accepted version of the Fuller and Johnson Farm Pump Engine's production history.
The article was intended to stimulate debate but, unlike another piece twelve years earlier, it drew not a single comment - perhaps an indication of how the magazine has changed over that period.
As this NG seems to be populated by people who think there is more to engines than pretty pictures I wonder if I will get a better response here (Dave might also like to try on ATIS).
Well here it is, comments please:-
Some readers may remember the controversy which raged during 1988 and 1989 over the Fuller and Johnson Farm Pump Engine and the many variants thereof. This kind of good-natured argument actually does our hobby an enormous service by bringing to the pages of this magazine information which would otherwise remain in the hands, or heads, of a few individual experts. 12 years ago it was an Australian who stirred things up by daring to comment on this most American of engines. I hope that as a 'limey' I can do the same.
Conventional wisdom has it that there are basically two styles of F&J Farm Pump Engine- the early type; with plain flywheel, wooden base, spark plug in cylinder barrel, con rod lubrication by grease cup on big end, and a floor-standing battery box: and the later type; with makers name cast into the flywheel, spark plug in cylinder head, big end lubrication by external grease cup via drilled crankshaft, little end lubrication by oil via hollow piston pin, and a bracket cast onto the crankcase upon which the battery box is mounted. All these changes are supposed to have occurred in 1917 and Verne Kindschi's excellent history of F&J states that the company did not build engines from mixed components, the variations one sees now being entirely due to later repairs. Perhaps foolishly, I want to challenge this assertion.
My evidence comes from two copies of the Farm Pump Engine instruction book and spare parts list. One copy, supplied by Verne, is dated 1929 and as well as the expected spares for the later style engine, it also lists some of the earlier parts together with the engine serial number at which they were superseded. The part identification system used by F&J appears to add a letter suffix to the basic part number to denote a modification. Thus, the old style J-2 cylinder barrel became J-2A when the spark plug hole was deleted at engine number 102701 and the con rod advanced from J-97B to J-97C when the new lubrication system was introduced at engine number
102791. Presumably the latter part had been subject to two earlier mod's, though it was probably only with the removal of the big end grease cup that it became non-interchangeable. Prefixes were used to denote sub-assemblies. Thus XJ-2A was a new style cylinder barrel supplied complete with four J-11 head studs.Both the engine numbers referred to above were built in 1917, so no surprises so far.
The other parts list I have is undated but, as it makes no mention of the above mod's, it is presumably pre 1917. It does however cover the Multimotor, an unsuccessful development of the Farm Pump Engine introduced around 1916. The first thing to notice is that the only parts unique to the Multimotor (apart from the myriad different pulleys which gave it its name) are the base casting, the crankshaft and a gear shaft. All the other parts were presumably common to the Farm Pump Engine. This includes the crankcase and as all the pictures I have seen of the short-lived Multimotor show the engine mounted battery box, I believe that the bracket for this had already been incorporated into the crankcase casting before 1917. Another indication that this was so is that the battery box illustrated in the earlier booklet would be impossible to use standing on the ground as all the cable entry holes, not to mention the ignition switch, are underneath. This booklet also lists both wooden and steel bases, the tie rod for the latter being one of the few parts to carry a mod suffix, being J-141A as opposed to J-141 for the wooden base.
As a final piece of evidence to support my theory of evolution rather than revolution, may I cite my own engine. According to the serial number it was made in 1913 and indeed it has many of the early features; plain flywheel, spark plug in cylinder barrel, wooden base and big end grease cup. However, it also has a drilled crankshaft and an engine mounted battery box. Now, I am quite willing to believe that the crankshaft may have been replaced at some time during the engine's life. But the crankcase? Quite apart from wondering how such a sturdy lump of cast iron could wear out or be damaged sufficiently badly to warrant replacement, the engine is in beautiful unrestored condition and looks very much 'of a piece'. Such paint as remains on the various components matches well both in texture and colour, which by the way is black rather than green, apparently not unknown but unusual. Furthermore, unless the repair was carried out at the works, would anyone have bothered transferring the old serial number to a new crankcase? No, I reckon this is the crankcase the engine left the factory with in 1913.
All this then suggests a possible sequence of mods to transform the old style Farm Pump Engine into the new: -
Introduction of Farm Pump Engine 1909 Engine mounted battery box by 1913 Steel base by 1916 New lube system and relocated spark plug 1917 Maker's name on flywheel?