Dan, the bored out crankpin was a feature of the original and seems to help with smooth running a seven at high speeds the engine does not move about very much unlike the Husky I did recently which is all over the place even at slow speed.
Chris I just went with two small oil grooves in the aluminium piston as I have with all these pond boat engines which seem to work OK
Jo yes the Trojan is quite similar both Westbury's original which is more like the early ones with it's rod guides and Bertinat's Mk2 with it's tubular trunk guide closer to teh "New" one though I do personally find his trunk guide looks a bit chunky.
As I said a CNC is not required and infact it would be possible to do it all manually but one slight change to the finished look of the base would make it easier and one other additional change would make it very simple.
Not easy to spot the change as you can see from this.
The other thing that would simplify it even more is if the raised round bosses were done by cutting shallow counterbores and JBWelding in some short lengths of round stock otherwise it's just a bit more work and a few repositions on the rotary table to mill each round boss from the solid block.
I've already had a few people interested in drawings so will likely make a set available to those who want to build it and they will have both options shown.
Being fairly simple it will also appeal to beginners so that is another reason I have updated it to metric as there are many who prefer that to imperial and BA fixings or if you go with Reeves' Mk 1 small whitworth fixings
Plus being cut from solid there are none of those hard or misshapen casting issues and at about 1/4 of the price you would have enough pocket money to buy the materials for the other three of these that I have done.
