Morris Minor Owners Club

Hi All,

Can anyone please give me some hints on how to externally identify the USHM3 engine from the USHM2 and USHM1 engines.

I know that the USHM3 has the provision for a water pump and thus may be fitted with one. Are there any casting marks on the blocks.

As has been mentioned I am looking for a USHM3 engine and would like to be able to correctly identify it before attempting to purchase one. Also are there any problem areas that I should look out for?

Regards and thanks,
Stu

Hi Stu,
The USHM1 engine was used on the Morris Series 8E. It had no oil filter and oil filler was towards the front right side. The head was also different with a vertical top hose outlet.
The USHM2 engine was used on the early Series MM up till around 1950. Early versions had no oil filter. The engines also had no thermostat, no water pump and the dynamo was mounted on the cylinder head.
The USHM3 engine was used from 1950 on. It had an oil filter, thermostat in alloy housing, alloy water jacket with dynamo attached, blanking plate or water pump, block drain tap or bottom hose, redesigned cylinder head.
The points to look out for are corrosion in the alloy castings, although new castings are available.
Generally they are a robust, smooth running engine, capable of a reasonable performance if correctly tuned.
Also there was a military generator version of the engine which although useful will require a donor engine to supply the correct parts. Instructions for fitting this engine are on the Series MM website

Attached are Engine001 = USHM2 and Engine 002 = USHM3<br><br><br><br>