Engine Oil - Which Type?

[floydraser]

There comes a time in every man's life when he has to change the oil in his boat engine.

I am seeking advice on what oil to use. The engine is a Thornycroft/Leyland/Standard /Triumph/Fergy Tractor jobby. OE.160

Oil recommended by the original instruction book:

Mobil Delvac Special – Shell Rotella 20/20W – Esso HD20 – BP Energol SAE20 etc. Looking like SAE20 then?

The bottle of Morris's SAE 20 tucked in the engine would suggest that's what is already in the sump.

The oil pressure comes up quickly and looks healthy. So should I stick with SAE 20 or has oil technology moved on and produced a better alternative?

I won't be doing it until next year but someone round here was selling off excess stock the other day.

Thank you in advance for all the helpfull advice.

[Cheesey69]

the oil may have moved on but your engine has not. Modern stuff is just too thin, too clean and full of other magic not even thought of in the 70's. 

I don't know the exact oil you need but I use what was around at the time of production for my BMC 1.5 , I use Morris 20w50.

[Karizma]

What a minefield picking the right oil is now a days!

I've got a Nanni 4.19HE and after lots of research decided to put Morris Classic Marine 10W-40 in it - seems to be great.

[annv]

Hi Floyd I use Castrol 4T 15W-40 Marine engine oil This has additives to stop corrosion inside the engine i have used this for last thirty years or so very pleased with the results. John

[Smoggy]

As someone that builds engines for a living I had to take the handbook out of our van into the carshop next door and point in a "what the flip" manor to get oil for a top up the other day, a nice simple mineral/semi-synth/synth and grade was so easy.

We just use a straight 80 (aero grades seem to just double the number) mineral gloop in the stuff we run and hand mix an inhibitor with it or W80 for turbo'd engines.

[floydraser]

Thanks everybody. I was just being cautious and didn't want to discover there was a miracle boaty oil available after I had spent my money. I'll stick with SAE 20 with a decent brand name. I don't mind change but I know old engines are not always so broad minded. One sniff of a modern synthetic and they hit the self destruct button.