Sherman M4A2 diesel engine designation

Originally posted by Larry Hayward
Some references I have seen, say that the M4A2 which the British & Canadians used in Italy had twin General Motors 6-71 diesel engines while others say they had General Motors 6046 diesel engines!

Where these the same and if so why have the different designations? Was this anything to do with early and late model variations.? Which is correct?

Ah, Hanno is the man for this, but as I see it the 6046 was a civvy truck engine and the 6-71 is just a modification of this.

It seems this unit is some 420 cu.in or 6.883 litres and rated for 187hp in the Sherman, looking at various websites they seem to rate it as 180 (nominal hp) which is close enough.

Its not bad at all for a diesel of that era at some 27hp/litre, being a scavenged two-stroke does give it a head start though.

Quite apart from the M4A2, the USN used them by the thousand in landing craft and generators.

R.