Sandstone Heritage Trust - News
8th June 2006
David and I have been having some fun and games with a French engine we discovered in a scrap yard in Petit. It is a TRAIN JT 175 2 stroke all aluminium alloy engine made by E Train et Cie Constructeurs, Paris. Dated probably about mid 50s as the bolts are both BSF [ 3/16 " BSF can you believe it!! ] and metric.
|
Trains are known for motorcycle engines but it seems that they also built a range of stationary/industrial internal combustion engines too.
We can find very little information on the engine on the internet and have put an enquiry to SEM to see if there is someone in Europe who knows these engines outside the motorcycle fraternity. The device had us beat for nearly 3 weeks because we couldn't figure out the engine timing marks !!! All that was functionally wrong with the engine was a broken earth lead on the magneto. |
 |
Above is a picture of the engine as we found it. The lever in the front is a starting lever. We finally got the damn thing to run , at first very erratically , but then I realised that the plug kept oiling up and putting some load on the drive end improved things. I used Villiers 2 stroke timing data from Phil Taylor in Cape town to get it going--that was a good tip he gave me. We are using a 25:1 2 stroke mix as we don ' t want to seize the piston. After the initial run to reassemble the governor, I had to tap some new M6 threads into the magneto flywheel as the French decided to use 3/16 BSF in the 1950s which is definitely "not in stock" in 2006 and a non preferred bolt size [like the M7 they like to use on Peugeot and Renault cars], so I had to strip the magneto flywheel off the crankshaft again and when I was reassembling the engine, I found the actual timing marks. Oh and to add to complications all the crankshaft bolts are LH rotation threads. The drive end flywheel TDC mark is not at TDC but lines up with a bolt about 40 degrees before TDC. Then the real subtle stinger is that I couldn't understand why the magneto flywheel had a timing mark on the inside of the spoked area until I realised that the white line above the SEV logo on the magneto coil was in fact the magneto timing mark!!!!!! The suggested timing advance, a la Villiers, was but a degree or so out from this mark and in fact the engine is timed at just before TDC!!! So having deciphered the secrets of the magneto timing I set it all up correctly, fitted the flywheel governor which also is a cover over the magneto [ amazingly it is machined from solid leaded bronze , I assume to remove the need to oil it as the oil would foul the points] , connected up the linkages to the carb and the engine started on the second pull of the starting lever . The plug gap is also illogical because a gap of 0.6mm gives a good cold start but the plug starts misfiring as soon as the engine is warm. If I take the gap down to 0.4mm, the engine runs sweetly and the plus does not misfire. The only logical thing I can think of is that the plug gets too hot with the larger gap and the insulator starts to short. The only plug I can get of the correct reach is an NGK BP6 ES that is specified for a VW Beetle engine, maybe the heat range is wrong for this engine. Plugs were obviously a problem back then because the plug thread is a bronze insert in the all aluminium head. Now the next subtlety- the carb floods until the engine starts and the air correction jet comes in and leans off the mix!!! So to start it one chokes it for no more than 1 pull or the engine floods catastrophically!!! To stop the engine, there is a tickler valve UNDERNEATH the carb. This little valve shuts OFF the fuel when you press it!!!! Now that took some guess work because we couldn't figure out why the main jet needed a tickler and not the carb float. The tickler valve also seems to be an "antiflood valve"as closing it off when cranking the engine certainly stops excess fuel and allows the engine to clear itself once it fires. [It floods at the drop of a hat]. I made a new diaphragm for the tickler valve from the diaphragm of an old AC mechanical fuel pump. The rest of the Solex carburettor was not only complete but in good condition after I had removed the extinct wasps nest from the venturi. The engine is not particularly high revving and sounds comfortable at about 1500r/min and will go to 2500. It is not well balanced and idles about 1000r/min . This engine is certainly not for the average farmer who grew up with Lister Ds and Ford tractors. It defeated us for 3 weeks because of the timing !!! Cheers for now--- JOHN |