Morris 4X4

[Mike K]

Originally Posted by Richard Farrant

Mike,
The 25 HP did not represent the actual engine power, this was what was known in Britain as the RAC Rating and done for taxation purposes. It was a formula decided by the bore diameter and the number of cylinders. This meant that engine manufacturers designed engines to fall in the lower taxation rate in order to get sales, hence long stroke engines. It really hampered engine design.
These MCC 4 cyl 3.77 litre engines actually had a Brake Horse Power rating of 80bhp @ 3000 rpm.

Another example is the Bedford 28hp engine with an actual power rating of 72 brake horse power.

regards, Richard

Yes, the RAC rating of the Morris 6 engine was also 25 HP . The Morris 25 saloon of the 1930's and some pre-war models of the MCC commercial truck range , CS8 and CDSW all had these 6 engines. The CS8 engine was rated at 60 bhp , think this was due to the carby which has a inbuilt rev. limiter device.