Oil pressure question 1000 Jota

Peter T.

Peter T.

Junior member
Location
Zurich, Switzerland
Hi all
Has anyone of you ever measured the oil pressure? After rebuilding my engine and fitting the larger oilpump I have the pressure going up over 15 bar / 218 psi at higher revs (6000 rpm).
What should be the correct pressure?
Thanks for any advice.
 
I am no expert but that never stopped me before, try taking the cam cover off and see if the oil is arriving at the cam, that is a crazy high pressure from what I have heard. What oil are you running? How did you measure the pressure? Now I have gone and done it, an oil thread the day before Christmas.
 
Is that with the engine cold, or at full operating temperature?
Where are you taking the pressure reading from?
Has the gauge been calibrated?
15 bar would almost certainly blow the O rings out of the headgasket.
 
Peter T. said:
Hi all
Has anyone of you ever measured the oil pressure? After rebuilding my engine and fitting the larger oilpump I have the pressure going up over 15 bar / 218 psi at higher revs (6000 rpm).
What should be the correct pressure?
Thanks for any advice.
Click to expand...
Why do you want to measure oil pressure.
It's a high flow pump, not a high pressure pump.


Paul
 
Sorry for bothering before Xmas day.
Engine is leaking oil at primary chain cover and cylinder base.
Measuring was done with engine warmed up at crankcase / oil cooler output port.
Will now read posts referred by Andy above.
Wish you all merry Xmas.
 
ALL OF THE PUMPED OIL GOES THROUGH THE COOLER, the only pumped parts are the six cam bearings and the centre main bearing on the crank, the remainder is fed by splash, and gravity drainage, that includes the outer main bearings. There is a "flooded" oil gallery at the base of the cylinder block (closed by the base gasket) which is fed by a single very small feed hole directly from the pump/oil cooler.A leaking gasket in this area is not at all common, there is only one way in for the oil to this gallery, but eight ways out, which are the four external cylinder stud bores and two more for the centre cam blocks, all these six stud bores carry oil up to the cam bearings where they spray bleed and puddle oil to the head, the other two are internal direct drillings from the gallery to the centre mains, where oil is splashed everywhere by centrifugal force (after trapping cack in the slingers) this includes pistons, rods (both ends) and the outer mains.
block this "flow" at your peril, EG the oil cooler or the external lines.

Unlikley, but is is possible that a base gasket made without the feed hole to the oil gallery has been fitted, only, happened a few times many years ago, but you never know.

I doubt that the pump would be capable of 15 bar pressure under any circumstances, its not April first is it? the normal,pressure is so low it is very difficult to measure, maybe 5 or 7 PSI but the flow is many litres per whatever.
CLEM
 
Perhaps Peter T it may be a "weep" in the area you describe, happens with some builds, the correct o ring needs to be fitted on motor assembly. Material for this Oring is also a key parameter, Oring compression set is an underlying point of possible failure when substituting alternate Oring size. Photograph of the actual area will be of use in, making clear what is being discussed.

Did measure oil pump take off side pressure at around 10-12psi decades ago, used a special low pressure fluid gauge. There is a significant anomaly in what you are measuring, best estimate, test equipment part of that anomaly. HTH j.
 
Peter T. said:
Hi all
Has anyone of you ever measured the oil pressure? After rebuilding my engine and fitting the larger oilpump I have the pressure going up over 15 bar / 218 psi at higher revs (6000 rpm).
What should be the correct pressure?
Thanks for any advice.
Click to expand...
Do you really think 15 bar is to much? My idea is that a normal water pressure is about 6 bar. I also made te experiance that a oul cooler tube bursted when the cooler was blocked as the cooler was stuffed by material of a blown engine.
I think the pump will generate 15 bar, it is not so much- äh Clem??
 
andre g said:
Do you really think 15 bar is to much? My idea is that a normal water pressure is about 6 bar. I also made te experiance that a oul cooler tube bursted when the cooler was blocked as the cooler was stuffed by material of a blown engine.
I think the pump will generate 15 bar, it is not so much- äh Clem??
Click to expand...

Most packaging machines I’ve delt with use 6 bar of air pressure. 15 bar is huge!
 
what has houshold water pressure and machine air pressure got to do with the lubrication system in a Lav triple? my own houshold has a water pressure incoming at 10 PSI or if you prefferr 0.6bar. Most car engine runs at about 2 bar up to (maybe) 4 bar, obviously there are exceptions, they all have a lot of plain bearings, the triple Lav's only have the cam bearings and small ends as plain.
if you block (totally) the output of a gear driven pump it will raise a certain pressure, at a certain RPM (of the pump) but any increase in rpm over that max output will not add extra pressure, internal leakage being the main factor, and once "hydraulicked" there is no further pickup, 15 bar is around 220 psi, that would get past many places in a laverda triple engine, the weak points being the oil cooler hoses (depending on type, those with jubillee clips are the worst, the late RGS/Corsa or SFC1000 big nut type the best) and the cooler itself, plus the primary chain bleed (if fitted, most not, or later sealed) the squashed O ring between the crankcase halves, the oil gallery at the cylinder base etc, etc.
CLEM

Piet,were those two silicone horrors the same engine, I will bet the head gasket didnt leak!
 
Last edited:
chrisk said:
Most packaging machines I’ve delt with use 6 bar of air pressure. 15 bar is huge!
Click to expand...
Hi Chris,
yes, you are right. Usual oil pressure at engines for cars are up to 8 bar and with hot oil and low revs a bit more than 1 bar. Laverda engines with roller bearings need less.
 
As Andre says the secret is in the bearings. Ducati bevel engines dont use plain bearings and so the pumps run at very very low psi, maybe 10psi or maybe 0.5 bar.
Its plain bearings that rely on a pressure feed film off oil.
i would expect a normal engine to be between 2 and 4 bar. or 30/60psi
 
andre g said:
Hi Chris,
yes, you are right. Usual oil pressure at engines for cars are up to 8 bar and with hot oil and low revs a bit more than 1 bar. Laverda engines with roller bearings need less.
Click to expand...
Not only do they need less, the system should restrict the pumps' ability to deliver much more! If pressure rises far above normal, there is an obstruction, somewhere, simple.

The stock pump in good condition and with cold oil is perfectly able to burst the cooler hoses and blow up the cooler itself if need be... been there, seen it, got the fucken t-shirt. :rolleyes:

piet
 
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