Xu9J4 Oil Pressure

[mollisk 2 1 Cars]

I have fitted an oil pump and drive sprocket / chain assembly from a 306 GTi engine to my MI16 engine. A new relief spring was also fitted.

With the engine at normal temperature the oil pressure reaches a maximum of 4.2 bar above 3500 rpm and 2 bar at 1250 rpm.

Has any one a similar spec. engine with which to compare pressures ?

( The oil pressure gauge has been recently cal. checked )

 

 

Thanks,

 

Kev M

[welshpug 1,662]

what does it give at 4k+?

[mollisk 2 1 Cars]

The maximum pressure is 4.2 bar above 3500 rpm, ie it sits at 4.2 bar from 3500 rpm to 7000rpm.

 

Kev M

[Tom Fenton 1,542]

Sounds fine to me.

[Miles 331 1 Cars]

Where are you getting the reading from? May sound silly but the OE gauge isn;t great

[mollisk 2 1 Cars]

The OE gauge has been replaced with an aftermarket one which has been calibration checked.

 

For information, the engine is used in competition and has completed approx 12 tarmac rallies. When I fitted the new pump I removed the big end cap farthest from the pump to check the bearings using plasti-gauge. The bearings were found to be in good condition.

The engine has always had an Accusump system fitted ( 1.5 litre ) with a pre-charge pressure of 2 bar. The accumulator is fitted in the co-drivers footwell and connected into the block via the low oil pressure switch tapping. The XU10 oil pump and sprocket / chain have been fitted for added insurance against oil surge.

 

 

Kev M

[Baz 421]

Sounds fine to me.

 

+1.

[unariciflocos 49 1 Cars]

The XU10 oil pump and sprocket / chain have been fitted for added insurance against oil surge.

 

Kev M

I don't think draining the sump faster using a higher flow pump will help with surge.

[sport1901966 8]

Again sounds fine to me, similar figures to my freshly rebuilt XU9J4

[welshpug 1,662]

I don't think draining the sump faster using a higher flow pump will help with surge.

 

 

exactly my thoughts too the only true solution is a dry sump.

[mollisk 2 1 Cars]

I agree that a dry sump system is the answer to the oil surge problems with the XU9J4 engine. Unfortunately my budget does not stretch that far. Having done some research, I decided to use the Accusump system combined with an external drain line from the cylinder head and a PTS baffle plate.

Although the XU10 oil pump will flow at a higher capacity at a given engine rpm compared to the standard pump ( due to the drive sprocket gearing turning the pump faster) , once the oil pressure has reached its working pressure and the relief valve lifts the excess oil will drain directly back into the sump from the pump. Therefore no extra oil will be circulated in the engine compared to a standard oil pump operating at the same pressure.

Ultimately, the idea is to keep the suction of the pump supplied with oil and if that fails hopefully (!!)the Accusump should give a few seconds until the oil drains from the head back into the sump.

 

Kev M

[petert 591]

The 26T sprocket only helps to keep the pressure up at idle, so your oil light doesn't keep coming on. If racing, you're better off keeping the smaller sprocket. You should also fit a windage tray to separate the oil in the sump from the spinning internals.