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[kiwimodeller]

Having just acquired a Sun off our local internet auction site I have a few questions that I am sure forum members will be able to help with. Of course it would be easier if there was a handbook/instructions that Stuart put out that I could obtain a copy of. Was there such a publication? Failing that can anybody tell me what the threads are likely to be in the valve cover for the steam inlet? Also is the exhaust system of a curved pipe with both internal and external threads original and if so what are these threads likely to be? There are two oilers with flip tops set in to the top of the crankcase which I presume are for lubricating the main bearings but how does one oil the big ends and little ends of the conrods or are these just splash lubricated? Also there is a small diameter plug in the lower side of the case just above one of the engine mount holes - is this for draining condensate and oil from the sump? The engine is fitted with a water pump system on the front of the crank and an interesting reversing gear system on the flywheel end which gives a drive across the engine which would be ideal for a paddler. I suspect that the engine (as advertised on the auction) has never been run except for demonstrations as the cross shaft has never been fitted with a drive pin. I have a 6'6" paddler and was thinking of swapping the Sun in to it and removing the Allan Rayman single as that does not have reverse but I have the impression that the Sun is a single acting fairly high revving engine more suitable for high speed use. Is this correct? On the one day list is a high speed steam launch, perhaps with a mono tube (flash) boiler. What do members think about which engine for which application. I have a 4" Raebosch variable pitch prop for the launch and I am sure the Rayman design 9" x 4" boiler would produce enough steam for either engine so that would not be a problem. Any info about the Sun engine and how they run would be most appreciated. Thanks, Ian. ps will have another go at pictures shortly.

[kiwimodeller]

Drive end photo

[kiwimodeller]

Pump end photo

[kiwimodeller]

Sun, side view

[ooyah/2]

All threads on Stuart models are M.E.  x 32 t.p.i. and the exhaust and inlets are 1/4 x 32 exept when you go to 3/16" and under which are 40 t.p.i. all studding is 7 ba that is if the builder has made the engine to Stuarts drawing.

I don't think that the Sun engine in your pics will be suitable to drive a paddler as the revers gear will turn each output shaft in different directions unless I am missing something.

Also as it's not self starting as the cranks are set at 180*.
It is a wet sump and all the bearings get lubricated via crank case pressure.

A.A. Raymans engine being single cylinder it's not self starting either and it will not stand up to Flashsteam pressure ( I have tried it and my coil melts  the Ali insert in the piston, ) this engine is designed for a straight runner and will not reverse, it will work however with the boiler that was designed for it and you could use your variable prop.

George.

[kiwimodeller]

Thanks for the info George, it seems like the Sun is not the thing to be swapping in to the paddler but I am not concerned, it is a nice engine to have on my window sill and one day I will get around to building something suitable to put it in, perhaps with the variable prop. At some time I will also find a twin  cylinder reversing engine for the paddler. The pump will come in useful and the reverse gear set up is interesting. I will pull it apart and put some pictures on Paddleducks as thats where it should be of most interest. It is not separate output shafts, one shaft goes right through. The bevel gear hub slides along the shaft and depending which bevel is engaged with the one on the flywheel determines the direction of rotation of the output. It needs a selector fork making to engage in the groove in the bevel gear hub and it also needs a roll pin across the shaft to connect the slot in the hub to the shaft so it has obviously never been run in a boat but running the engine slowly on air and shifting the hub by hand it does go in to gear easily and there is room for a neutral position when neither side pinion is touching the engine one. I think it will be more suitable for a relatively low power steam paddler. Again, thanks for sorting me out, I always come away from Mayhem inspired to go do some more work and retirement is coming SOON! Cheers, Ian.