Thank you all for your answers the topic seams to be interesting.

Grenvelge

The classic oils from Castrol are fine I am only concerned about the warming up time that they should be too viscous for the 216.

Jerry

In theory the 20W50 oil sounds right but I am not sure about its ability for fine atomization when cold that is needed for the splash lubrication of the conrod bearings for the 216.

Tiny

I see your concern about the braking down of multigrades but the average classic car should not make too many cycles between oil changes unless it’s a daily driver I am also thinking of using a modern 15W40 after cleaning the oil pan and passages (if I ever come so far).I also posted this question in the vcca forums and Gene recommended….10W30.

Floyd.

The Netherlands should have lower temperatures as Washington state so normaly I should use a W20 or sae 20 but they are hard to get here.

Green

Normaly I also should not use a modern oil unless I was 100% sure that my oilways and pan was clean and change oil very often or modify the 216 to a fool filtration system.
Panic
That is right for modern cars
In my daily driver I change oil every 19000 miles that’s about 1500 cycles and oil comes out as clean as it goes in.
I think the 216 should only make 2500 miles and the oil should be completely black and useless when it comes out.

Hoyt

My question was more philosophical as practical.
I am more or less aware of what goes on with oils. My main question is what is the long term effect of different oils on the conrod bearings of the 216 the first few minutes of operations before the oil comes to the right temperature.
In practice I am taking a big risc using modern 10W30 oil without knowing if my oil pan and oil ways are clean.
It’s a different Castrol product that is made in England here is the link: http://www.castrol.com/castrol/sect...Id=9014107&contentId=7027099#7094382

Jianis