Oil pressure reads max when Perkins 4.236 running

[JAYEN1]

This is not exactly on subject, but maybe helpful.
I have a 4236, circa mid'80's.
Broke an alternator/water pump belt at a most inconvenient time(of course). Fortunately I was looking at the ignition light at the exact moment it came on.
It took less than a minute to shut down engine, but nonetheless it was on the verge of boiling.
Luckily I had a spare V belt cable tied onto the front of engine, for just such an emergency. I have a few other devices driving off the front pto.
Since then I have put a very loud piezo alarm into the alternator circuit.
I also have a set of, 'murphy gauges', as a back-up.
I think it is called, 'cost v benefit'.
If the boat is new to you I would also recommend that you have a complete HP injector pump and injector service and change the 'O' ring seals in the heat exchangers.
good luck!