Oil Pressure

[cypriot_boy_2k7]

How much pressure is in the sump when the cars started?

For an M40

[BenHar]

One bar.

Ben

[ross2009]

you on about crank casing pressure or actual oil pressure ?

[cypriot_boy_2k7]

you on about crank casing pressure or actual oil pressure ?

actual oil pressure in the sump only, had a lil mess up with my oil return on the sump, drilled a bit of a big hole on the sump, all sealed with copper washers and tested by filling it up with water no leaks but I don't know if it will hold under pressure.

[ross2009]

there shoudnt really be hardly any pressure on the return its just s drain

[cypriot_boy_2k7]

Is Ben's info wrong?

[ross2009]

look at it this way when you undo the oil filler cap is it pressurised ??????

[cypriot_boy_2k7]

look at it this way when you undo the oil filler cap is it pressurised ??????

Very good point

[Brianmoooore]

Pressure in the sump is negative with respect to atmosphere. That's why the engine idles rough when you take the oil filler cap off.

[BenHar]

The pressure may be lower than atmospheric when it is running but one bar (one atmosphere) is the max it will go to. That will be when it is not running.

Ben