Thanks Martin.
I know they also call it a Ford 8 which means 8 tax horsepower and really nothing to do with real hp.
RAC means Royal Automobile Club
The RAC (British) formula for calculating tax horsepower:
D= cylinder diameter
n = number of cylinders
So (2.23" bore x 2.23 x 4) / 2.5 = 7.956 hp. How come they did that? The more hp you had the more it cost to register the car.