www.boxertrix.com

Late answer again.
I'm not sure if i understood you correctly. I understand the head thing, though.
The addition of pressure head in between a low oil level and a good level is quite measly.
What can the difference in height between low and good be? 2 cm?
This gives us (assuming oil density: 700, too lazy to check):
ro*g*h=700*9.81*0.02=140 Pa
what's the oil pressure? 4 bar? Again, too lazy to check.
4 bar= 4 000 Pa
the addition of 140 Pa to 4 000 Pa doesn't make much difference.

I have a mysterious anecdote to this:
many years ago, i worked at Volvo Bus. We had a double-decker bus that had an inline-6 engine laying down flat (as on the K 100). Oil had a tendency to fill up the valve cover, instead of draining back to the oil tray. So oil level was a critical issue.
So we did a test on the skid pad at the Volvo proving ground. We drove it round and round with lower and lower oil levels to see what it did to oil pressure.
I hacked into the oil pressure signal on the bus, and i also had a DC accelerometer, to read G-force.
Both hooked to a data logger.
It turns out that there was a perfect correlation between G-force and oil pressure!
The higher the G-force, the lower the oil pressure!
You'd think that either you have full pressure, or no pressure, but no!
If i'd wanted to, i could have calculated a conversion factor and read oil pressure by reading G-force!

There's thousands of these buses run everyday around the world, without any problems with oil starvation, but i'm still wondering...

sorry about the off topic.

//T

What pressure would the r1100 generate at tick over?

I'm sure your figures for the oil (and gravity!) are fine. I'm not sure how a change in suction lift affects a pump though. What about risk of cavitation? As I see it, only a change (drop) in pressure can make the chain rattle. I wonder if the oil has to go through a valve first, before it is allowed into the tensioner circuit. As way of protecting the engine bearings in the event of a pressure problem?

Don't apologise for the off topic. The bus story is great. Sounds like damn good fun. How do pumps go on out in space? Or in a very high altitude orbit?

Edit: I was surprised to see that the figure for motor oil density can be as high as 900 kg/m^3 although that will be at room temperature and not the 80 Celsius we could expect in practice. In old imperial terms it would probably generate 0.4 psi head for every foot! Ish!


Edit 2: ...... Which converts to 165 pascals. So, given the amended density figure and the fact I chose 25mm (an inch), checks out ok to your calculation. Although whether your calculation applies to the situation in the way you suggest, is another question.