Hi Hutch,
Does the R.A.N have a one or two piece timing gear cover?
The lack of the raised “button” on the Star certainly ties it in with the RAN style cover. That raised bit on the 1913 and 1915 covers is even found on the later 1920’s casings that no longer use it for the chain guard screw.
Hi Ian,
Yes the R.A.N. generator has (well this one does...) a two piece timing cover as shown in this picture of an incomplete one shown on this forum;
https://www.douglasmotorcycles.net/index.php?topic=2218.0Two piece timing covers were used by Douglas up to 1914 on the 2 3/4 hp. In 1915 Douglas introduced the single piece timing cover. This doesn't necessarily date the "Star" flywheel side crankcase half to pre 1914 design tho', only the timing side half. Note the bulge in the R.A.N timing cover where the end of the crank shaft would be. I presume this would possibly in relation to the starting handle but without seeing inside it is pure speculation on my part. Might be for an extra support bearing....not sure.
The R.A.N. engine may have a different oiling system to the standard motorcycle engine, something I still have to investigate. looks like an oil filler on the top "half" of the timing cover, or maybe a breather? I will have to hunt down the instruction book on the R.A.N. generator that Alan hinted about earlier in this thread.
I had a quick look at my conrod collection and have one or two similar in design to the big end of your "Star" one, but with a much larger and squarer section around the little end. If you put them in a lathe and machined the little end down they would look just like your "Star" rod.
I had always assumed these conrods were "early" veteran 2 3/4hp ones as they are heavier in design than the normal conrod you would find in a vintage 2 3/4hp. The pictures from the 1912 -1915 Douglas literature don't appear at first glance to tell us much - except the 1912 ones are different again. So are these heavier ones I have Douglas or not?. Don't know, but one has the marking "T89" stamped into it, I gather that this would have matched the numbers stamped in the crankcase halves of the original engine? If this is Douglas, I don't know over what period they did this. I did find a "vintage" or later "veteran" style rod with the number N124 stamped into it, so possibly Douglas did stamp the matching crankcase numbers on the rods up to a certain time, say WW1? Don't know, but maybe someone on the forum does?
I will get some pictures of the rods I have when I get a chance and will clean up the rods I have and have a closer look also.
cheers
Hutch