Thanks for the welcome back!!
Jo...The two Sugdens and the two Vipers were my first engines. I actually started the Sugdens way before the Vipers, but during a hiatus getting the Sugden cranks hardened and ground, I got stuck into the Vipers. They all got finished at about the same time!
The only one to have run so far is the Sugden in the picture, it seems to be a very nice motor. The Viper has "burped" but there is a needle valve issue to be sorted.
The Photograher In Chief (PIC) has said that she will take a vid of them running. When it's available it will be shown here. Incidentally the Sugden turns an APC 9" x 4" prop at 10,500rpm, which is pretty good for a plain bearing motor!!
cheers
Bill