The Moteur Japy Frères
Serié R, type B, Serial No. 2746, 3hp.(cv)at 1300tpm.

An unusual stationary engine


The finished engine resplendent in French Blue

One Sunday afternoon in about 1980, I was hurrying through the village when I spotted a small lorry parked outside the public house. On the back of the lorry was the unmistakeable shape of some unrecognisable stationary engine. As I couldn't determine the make of engine, I stopped the car and climbed out to investigate.
The castings bore the name 'Moteur Japy', under all the dirt and rust! Most of the remainder of the engine was liberally splattered with whitewash and oily mud. All the hoses were perished and rotten, one of the two tanks was dented, the magneto points were missing and there appeared to be a crack in the cylinder casting. As I was in a bit of a hurry I continued with my brief but urgent errand, only to return and find the lorry had departed. On my arrival home, feeling a bit cheated, I was somewhat cheered to find the lorry driver at my front door! He had heard I collected engines, and was actually asking where I lived, while I had been looking at the engine. So we struck a deal, a very favourable one as far as I was concerned, and I spent the rest of the day investigating what I had just bought.
The lorry driver told me that he had made a delivery to Saumar in the Loire Valley, where he had discovered the engine in a vineyard. Apparently it had been in use there all its life, pumping water. He bargained for it and brought it back. However he had been unable to sell it although, strangely enough, someone had stolen the magneto contacts since the engine's arrival in the UK.

The Moteur Japy is a vertical engine, rather larger than a Lister D-type and very much more complicated. It is water-cooled, assisted by a fan cast onto the rear of the large disc flywheel.
The cooling water is contained in a horizontal tank from whence it feeds a small belt-driven water pump which circulates the water through a radiator formed from a series of 8 mm copper tubes. This radiator is concentric with vanes on the flywheel. The water also circulates in the normal manner around the cylinder and head. Above it is another tank containing the petrol. Each tank has a push-on brass cap marked 'Eau' and 'Essence' respectively, both tanks are extremely heavily galvanised.
The horizontal carburettor is brass and made by Japy-Griffon. It was cracked and the float damaged beyond repair. It carries the serial number RB6589. The magneto is by Lavalette, 175 Avenue de Choisy, Paris, and has the number 281 .D. 7364. A very well cast brass nameplate bears the information Japy Frères et Cie., Beaucourt, France. Its s/n is 2746, the engine being a type B, series R. It produced 'puissance' or power, of 3 cv (hp) at 1300 rpm. The lubricating oil has a sight glass level with an instruction plate alongside stating (in French), "Before starting the engine, the oil level must be halfway up the glass. Refill with fresh oil if the oil completely disappears out of sight of the glass." The glass itself had long since disappeared in favour of a couple of corks!
The exhaust silencer was a mass of rusty iron. It comprised two cast-iron end pieces set vertically, sandwiching between them the cylindrical part of the muffler. Inside I found a very mangled plastic container, which, with the aid of my French dictionary, I discovered had once held suede shoecleaner! In common with other French engines, the starting handle is fixed permanently to the engine. The driving pulley being attached to the large flywheel. I was curious as to the engine's internals as it was seized solid. On removing the cast-iron rocker cover, I found, not only that it was overhead valve using one rocker and one pushrod thus 'toe-heeling' the tappets, but that it contained a nest of some sort of solitary wasp! A similar nest, housing what appeared to be a different species, was found in the water pump! The sump contained about 2 litres of water, a handful of chicken feathers and an awful lot of  indescribable oily slime.

The whole engine came apart very well considering its neglected state; it had obviously been assembled with great care and skill. I was very pleased to find its date of manufacture stamped on every major casting - 17/11/27, a nice touch even though, in every case, it had been stamped upside down! The cylinder bore appeared to be only slightly ridged but with marks of corrosion below the piston line..
Restoration was soon underway. A bit of judicious honing soon rectified the bore. New rings were supplied by Mr. Jenkins, a regular advertiser in Stationary Engine Magazine. Here, I must add, I have never had such swift and helpful service. The cylinder head is located in a relief turned in the top of the cylinder, and pulls down to grip on a 1.5 mm thick gasket, during reassembly. A piece of sixteenth of an inch thick "Hallite" was just right. Under all the whitelime etc., the engine appeared to have been painted blue. The water tank, which was badly dented, was straightened and received a new brass cap which was spun up to match the other one. The radiator tubes were replaced and soldered back into their brass manifolds. Care was needed to maintain the correct diameter when all was assembled.
The rubber hoses were all replaced, as were the hose-clips which originally were those gruesome thin tin things which are tightened by turning a sort of split-pin. A new shaft and bearings were made for the water pump, the former from stainless steel to prevent a recurrence of the corrosion. Woodruff keyways were cut and the pulley fitted to new keys; the glands were repacked with suitable graphite packing. A new round section drive belt was made from leather. During reassembly, each part was primed and painted blue, the final colour being some coach paint surplus to requirements on the local Boys Brigade bus! The colour seemed to suit the elegant Gallic contours of the Japy Frères very well.
The cracked carburettor was sealed by soldering and I designed and made a pattern for a new float from hard wood just to see if the engine would run. Subsequently a local coppersmith made me a replica from brass sheet and tube. The missing oil level sight indicator caused problems as I had no idea what the original looked like. All I had to go on was the circular recess where it fitted on the crank-case wall to which it was retained by an 8 mm stud and domed nut. My scrap box revealed a clear perspex Norgren water-trap from a compressed air line. It was just too large, so I cut off most of its cylindrical section, then skimmed up the domed end in the lathe to just fit the recess and drilled out the water drain tap at the centre of the dome to clear 8 mm. This certainly works well, looks like glass and is in keeping with the style of engine.

The finished engine was found to be quite difficult to time. On the flywheel rim was stamped PMH, which was decoded as 'Piston maximum hauteur' or TDC. At intervals around the rim was OE, FE, FA. Once again, with the aid of my dictionary, I translated this to the positions of opening and closing of the valves, and set the tappets on the single rocker to achieve this. However, where to actually time the spark was quite a different matter. I had fitted a set of points (I think I used Lucas) to replace those missing from the magneto, at the same time I had to make a new cam-ring to suit them. Had my empirical theory and calculation let me down? Eventually, by more trial than error, I managed to achieve a firing point relative to TDC, so with both valves 'on the rock', I duly marked the flywheel at this point. When the time came to start the engine, nothing happened. Eventually it gently began to try to fire .
I tried weighting the float to increase the height of the fuel. This brought a better response because the Japy burst into life with a bang and a blue flame shot from the air-intake, narrowly missing singeing my eyebrows. Two days, and many more adjustments later, the engine was running quite well. Certainly well enough to put it on a trolley and take it to its first event - The Second Great Gathering of Stationary Engines at Longleat, where it aroused much interest. After having a good run I managed to reduce the speed by several stages to a nice steady 700 rpm.

Many years and a few rallies passed and one day I tried to start the engine but it lacked compression and refused to fire. I decided that it would be best to get the cylinder rebored and stripped the engine carefully so as not to damage the paintwork. The cylinder barrel is a separate item so once it was off it was a simple matter to take it to a local engineers to have it bored and a sleeve fitted. The piston rings looked as good as when I fitted them so I took along the piston as well for them to gauge sizes.  Eventually Beales of Bath located a long sleeve and did a good job, charging me slightly more than I had paid for the engine in the first place sixteen years or so before. The engine now runs really well and is a nice thing to have around.

During 1999 I had seen another such engine on a postcard of a museum in France, this was a larger one of about 6hp. I subsequently found a webpage for a Japy Frères enthusiast in Belgium who actually keeps a register of Japy engines so I contacted him and he has added mine to the impressive list.

This engine is certainly very different and could be unique in this country, unless someone has recently imported another one? If so, I would be delighted to hear about it.

email - <EdotGdotBrain@bath.ac.uk> (anti-spam - replace the "dot")

This is an updated version of that which appeared in Stationary Engine Magazine, Issue 160,  June 1987
©Revised September 2000  and Updated January 2002



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