Oil Pressure relief valve

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DavidOliver
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Oil Pressure relief valve

Post by DavidOliver »

Has anyone increased oil pressure by installing a stronger spring to the relief valve, or by packing the spring with washer/s?
And while at it, what maximum pressure would be recommended when the relief valve opens?
Also are stronger springs available, I see no reference at SJS?

Dave the cog.

cthomp32
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Re: Oil Pressure relief valve

Post by cthomp32 »

DavidOliver wrote:
Sat Dec 12, 2020 13:24
Has anyone increased oil pressure by installing a stronger spring to the relief valve, or by packing the spring with washer/s?
And while at it, what maximum pressure would be recommended when the relief valve opens?
Also are stronger springs available, I see no reference at SJS?

Dave the cog.
Hi Dave

The relief valve spring design is based on pump flow rate, clearances in lubrication system and oil viscosity, so as long as these are all ‘factory’ it shouldn’t need to be adjusted.
As oil pressure is just the result of flow being restricted, I’d be inclined to leave it well alone.
If you’re seeing reduced oil pressure I’d just change it for a standard new spring first.

Cheers
Clive

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DavidOliver
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Re: Oil Pressure relief valve

Post by DavidOliver »

I have a hydraulic pressure guage, no electrics, and had noticed a sudden reduction in start up (cold) pressure.
I thought it could be a sticking pressure valve. On dismantling the oil pump I found the rotors fine but to fully
dismantle the pressure valve is a bit of a hassle and I have no spares here in Malaga.
I have done a full oil change including removing cam covers to get every last drop out, while re-sealing the cam cover gaskets.
I could not locate an oil filter here with a guaranteed non-return valve and I spent some time priming the reassembled pump
by force feeding oil into the oil gallery and then spinning the auxiliary drive with the timing belt disconnected.
I now have an SJS filter and pressure valve plunger on their way (before Brexit and Xmas holidays).
Hence the question about spring rates.
The pressure is not low on start up, just seems to sit at lower than previously up to 3000 revs then increases a tad.
As I need to change the filter for a guaranteed valved one I will dismantle the pressure valve and check the spring.

Dave the cog.

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