The engine runs on air (when piped up as a HP twin), but I have some doubts about the timing of the valve events. The "book" from Camden and the Model Engineer description is somewhat vague, and so I am trying to augment the descriptions with those contained in the SBA "Steamboating Guide".
A few questions emerge.
1) The words for the engine state that the "Lap" is 3/16" and the "lead" is 1/32". Are we to assume that these are the steam lap and lead, as the SBA also make reference to "exhaust lap"....?
2) the Piston Valve (inside admission) is drawn as being exactly the same length as the distance between the outer edges of the exhaust ports on the HP side... this would imply that there is no "exhaust Lap", which I suppose might tie up with Question 1.... Is this an OK situation?
3) in my notes on the blog I commented that the height of the ports in the LP valve chest (an outside admission balanced slide valve) is dimensioned as being two different sizes on the drawings (5/16" or 3/8") resulting in a distance between the top and bottom edges of the two ports being 1.25" or 1.375" Interestingly the height of the slide valve is not dimensioned at all!!! Would I be correct in thinking this needs to be the dimension of the ports plus the lap (3/16") (e.g. 1.4375" or 1.5625" depending on the port dimensions)??
4) Also does anyone know what happened to "figure 9" in the Valve Setting section of the SBA's book? - I can't see it anywhere
5) Are there any good on-line "setting Stephenson valve gear" guides for Piston and Slide valves - the SBA one runs to 10 pages and has me baffled (even allowing for the apparently "missing" figure) ?
5) Lastly Mr Leak advocates using "Araldite" as a jointing compound between the 4 parts of the cylinder block and also to seal the HP liner into the block - looking at Araldite's specs it seems not to have any high temperature strength, does anyone have any better suggestions? (I'm asking as in both situations it seems to leak
)...as usual, thank you all in advance!