Pace Dry Sump Question

[PVFCpug 6]

May well be a daft question but here goes anyway.

 

I have a little bit of a concern in that when I initially start up my MI16 with a pace dry sump and slim Jim pump attached the pressure shoots around the whole scale and off the scale of the mechanical gauge and stays at probably 130PSI for about 30 seconds. Also shows far right on standard dash gauge (kept it in as a safety feature)

 

I dare not rev it other than enough to keep it running until I get some warmth on the oil.

 

Is this normal, because once the oil is hot I am looking at 25psi tickover and a steady 55-60psi when in the revs range. Which is exactly what I want.

 

Is there not some form of limiter on these devices or is it simpy a matter of carrying on doing what I am and nurse it a few minutes until the presure drops to a reasonable level.

 

Is it possible this will damage seals etc for the amount of time it is that high?

[Ryan 99]

I think the pace pumps have an adjustable pressure relief valve on the end farthest away from the pulley. It sounds like it's set too high.

[PVFCpug 6]

The only adjustment as far as I am aware is the pressure adjustment screw which is on the far end of the pump. I am not sure their is a relief at all TBH.

[Tom Fenton 1,542]

They are as far as I'm aware a fixed displacement pump, so usually would require some kind of relief valve. 130psi sounds very high and I am suprised you have not had problems with the oil filter blowing out its seal at this kind of pressure.

 

The pressure adjustment screw you talk about is the relief valve, I would try backing it off a little. Other than that it is a case of changing oil grade, what oil do you use in it?

[PVFCpug 6]

Crap, dont say the screw I thought was the pressure adjustment is actually the relief. Good job I dont use it much.

 

I use 10w40 oil and am about to change it completely for 5w40 Silkolene.

 

I used the guide as shown here which clearly says it is the Pressure adjustment. But thinking it through I suppose the pressure is totally reliant on revs as opposed to some screw adjustment.

 

Guide: http://www.canong3.co.uk/pug/mi16pacedrysump.pdf

[Tom Fenton 1,542]

Pressure is caused by the restriction to flow, the relief valve is spring loaded with the adjuster to allow excess oil back to sump, as otherwise oil pressure would be huge due to the small clearances is can pass through in the engine at the bearing shells etc.

 

Changing to 5w oil will lower your cold pressure, if you are doing this make the change and then see what you get.