MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MG Y Type - Oil Pressure Valve

Hi,

Please see the attached pic of a Peter Edney oil pressure adjusting valve.

Has any one fitted one of these?

Any constructive comments favorable or otherwise?

Rob

Rob King

Failing oil pressure is a sign that something is not right so 'faking it up' isnt something that I would say is a good thing to do. I would say look into why you are getting failing pressure. Are you using the correct viscosity oil? Do you have the correct volume in the system? Is your pump in good condition? Is your original oil pressure relief valve OK ... or is the ball bearing grooved? Is the spring in the oil pressure relief valve OK or worn out? Is there a blockage in the pipes? Is your pipe to the gauge leaking where it comes through the fire wall where the rubber joiner pipe is? Are the bearings on your crank worn? etc.

My 2 cents worth anyway.

Paul
Paul Barrow

In my experience, all British engine designs I have known from circa1930 - 1970 are marginal on oil cooling. The designers expected a lot of the oil in taking away heat from the crank and dissipating it before the oil was drawn back into the block again.

I read once (somewhere ?) that 40% of the engine cooling in an XPAG is done by the oil, and only 60% by the water/radiator.

When the TC was developed, they needed to fin the sump to help keep the oil cool, so it would not lose it's viscosity & thence protection to the moving parts.

So if you are getting a little more power from your Y-Type (with an un-finned sump), and therefore generating a bit more heat in the crank & block, you need to look after your oil.

Change it frequently, especially if you see less than 10psi/1,000 rpm. Don't be afraid to overfill a little - even an extra half litre of oil will help dissipate that heat & maintain oil pressure on the highway (you need a minimum of 40psi at 4,000rpm).

You should also keep the outside of the sump clean, and remove any build up of road grime/mud. Ensure you have good airflow around the sump too !.

Don't worry about the oil pressure at idle - as long as you have 10psi, that will be enough.

And talk to the specialist oil suppliers like Penrite - take their advice on the oil to use. I find multigrades not as good as single grade.
A L SLATTERY

When an oil pressure adjusting valve is used to lower the pressure, I'm fine with it. High oil pressure costs power.

When the valve is used the get higher pressure then I would have agree with the comments from Paul.
Willem van der Veer

AS I understand it the relief valve in the oil pump is designed to lift at around 60 psi, if the engine is badly worn and you have low oil pressure increasing the pressure applied to the relief valve by the adjuster shown will not increase the pressure reading on the gauge, as the oil will still quickly dissipate through the excessive clearances in the engine.

However if the relief valve is passing at low pressure due to a poor seat or grooved ball applying extra pressure will stop the valve lifting and will increase the engine oil pressure on the gauge.

I know this through experience, on my newly rebuilt engine, I was getting 25 psi on tickover but the pressure never increased when the revs were increased. Although the relief valve ball and spring looked ok I replaced them with a new set unfortunately this made no difference.

After fitting a couple of washers behind the spring the pressure increased a little when the engine reved. So I fitted the adjustable valve from peter edney and I now get 30psi on tickover increasing to 60 psi at 4000 revs.

Obviously over time the relief valve seat has worn and the ball needs extra pressure to stop it passing below 60psi. I could therefore remove the pump and have the seat remachined but the engine needs lifting to remove the pump so for now I am happy with the adjustable valve its doing its job.

Cheers Chris
C A Pick

Chris,

I hadn't looked at it that way and in the way you explain it, the use of this valve is certainly a good thing. Thanks for the comment.
Willem van der Veer

Thanks for your contributions guys...

Tony...thanks for you advice regarding cooling.

Chris...exactly my thoughts and observations.

Paul...I would like to think that my newly rebuilt engine does not suffer any of the issues you list and I was really looking at providing 'adjustment' rather than 'faking it up'

I guess, on balance, if there is no detrimental effect, a bit of adjustment cant hurt....

Rob
Rob King

No offense meant by my use of the term 'faking it up' Rob - I just didnt want you to be masking a problem. Hope you understand - some unscrupulous rebuilders might use such a device for this purpose.

Paul
Paul Barrow

This thread was discussed between 06/04/2014 and 09/04/2014

MG MG Y Type index

This thread is from the archives. Join the live MG MG Y Type BBS now