Thread: The Ultimate FC

B81 Petrol will handle 3750rpm all day.( will do 4000rpm for a short time)
K60 Rolls Royce Diesel will do 3750 rpm max governed speed.
K60 replaced the B81 in early Abbot and FV435 ???? tracked vehicles.
The K60 is a designed power pack replacement for the B81.
The K60 profile is similar to the B81.
B81 diesels were never fitted to the stalwart as the british army was the main user and they were happy with the petrol motor.


The K60 is a common piston two crank design that has intermediate gearing between cranks and therefore could give the needed output speed.
The K60 is a interesting motor as it was a stolen German WW2 design and civie versions of this motor had outputs and power to weight only now beening matched by modern turbo/intercooled diesel designs.

K60 motor fitted in Stalwart by a private owner.

I understand these two pics are from one of two factory converted phaser Perkin diesels.
Many other Perkins were fitted in private hands.

Note due to the location of the water jets, vee type motors do not fit well unless its a narrowish, big block American V8 petrol.

This is the standard air compressor and power steering pump fitted on some sort of diesel in a stalwart........I cannot remember the diesel type.


K60 power packs can be picked up in UK as new very cheaply.

Interesting use of plastic drain pipe there, I'm assuming for the air intake?

I can also say I've learned something about Rolls engines, combined with the usual amusement that even with 70-80 years of technology advancing and designs developing the old stuff is still at very least a viable, if not a better option.

In a similar vein I have a mate who owns a small haulage company over here, they run a pair of (I think) MAN Rigids, and recently restored one of their old (70's vintage) ERF's with a Gardner engine.
They ended up running the ERF alongside the MAN's through a busy period and found the oldun was better on fuel, whilst the emissions test found that the engine was as clean, if not better than the Euro4 lumps with ****loads of emission control kit in the MAN's.

Progress...