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Sq 4 oil pressure

Posted: Sun Jan 26, 2014 4:28 pm
by Brian.Challinor
I've just started my 52 square 4 after a complete rebuild. My worry is I am not getting any reading on the oil pressure gauge. I have only run it for less than 30 seconds and the oil is retuning to the oil tank , but I do not want to run it any longer until I get pressure at the gauge. I have the original pump fitted with new springs and balls. What should I be doing next?

Posted: Sun Jan 26, 2014 5:50 pm
by Brian.Challinor
Panic over , I just stripped down the timing case side, and found that I'd put the drilled stud in the wrong way round.(The stud that the banjo goes on to.) Good job I didn't run it for long. Doh . Schoolboy error.

Posted: Sun Jan 26, 2014 6:07 pm
by Steven.Carter
Well done, I call it cold sweat time. Its horrible.

Steve

Posted: Sun Jan 26, 2014 7:13 pm
by simon.holyfield
You beat me to it Brian. Well done!
Where did you get that rocker feed stud from? I can't find one anywhere.

Re: Sq 4 oil pressure

Posted: Sun Jan 26, 2014 8:49 pm
by Brian.Challinor
Simon
It was in one of the boxes that the bike came in, I'm still not happy with the oil pressure, when I started it after turning the stud round I was getting 50psi , dead chuffed, then I left it for half a hour and started it again 25psi dropping down to 0 . I've left it alone for now but I'm wondering if its air locked or I haven't put enough oil in.

Posted: Sun Jan 26, 2014 10:26 pm
by brenton.roy
Brian, you could check the spring tension on the relief valve at the end of the crank. I think it gets weak.
Brenton

Re: Sq 4 oil pressure

Posted: Sun Jan 26, 2014 10:30 pm
by Bob.Murphy
Way back when I rebuilt a four-pipe Square Four, I used to get 52 psi when cold which dropped to around 5 psi on the road when hot. The problem turned out to be the pressure release ball valve in the front crankshaft.

A new spring and properly seated ball cured it - 52 psi when hot at road speed.

I guess yours is a two-pipe with a plunger pump (mine had a gear pump) ?? So you may not get that pressure when hot (just guessing).

I used Castrol Grand Prix (straight 50), what oil are you using ??

Bob.

Re: Sq 4 oil pressure

Posted: Sun Jan 26, 2014 10:31 pm
by Bob.Murphy
DOH :!: :!:

Beaten to it :roll: .

Bob.

Re: Sq 4 oil pressure

Posted: Mon Jan 27, 2014 9:45 am
by Brian.Challinor
I have a new spring and ball in the relief valve, will check the seating of it. I 'm using Morris straight 50 oil.

Posted: Mon Jan 27, 2014 10:00 am
by simon.holyfield
I was planning to turn mine over with a power drill on the shock absorber, until I got oil pressure.