The plans for the Bolton No.7 engine were drawn by O.B. Bolton in 1946. The kit is available from E. & J. Winter models. A set of constructors notes were written in 1992 by Ernest Winter.
It is capable of providing 3/4 horsepower at 100 psi boiler pressure.
This model is air driven at 30 psi. The cylinder bore is 1 1/2" and the stroke is 2 1/4".
This is a classic , slow running horizontal slide valve engine of merit.