how much Oil pressure do I want?

[Quart Meg Miles]

Alternatively the replacement pump is not machined correctly.

I fitted a (high pressure) replacement pump from Burtons as I believed my original was worn out and it was fine though the 60 psi frightened me! After a few weeks the pressure started dropping (my partner was driving it 50 miles a day) and was eventually around 5 psi. I suspected the valve but it was the gasket that had failed where the machining overlapped the high pressure area of the pump with a sump or inlet area on the block.

I had it replaced with a standard pump and the irony is that it doesn't give any better pressure than the original though the screw-in filter is more convenient.

[RogerFrench]

Methinks I'll remove the pump and investigate. Thanks everyone.

[GHill]

Hi All

In my car it idles when warm at about 30psi however as soon as I put my foot on the accelerator/gas it stays at 60psi, is this normal? Are there any issues with running high PSI?

Regards
Gareth

[rgh0]

It sounds like you have a high pressure pump installed. The only difference is they have the relief valve set at 60 psi. The normal relief valve is set at 40 psi. it is normally not needed on a road car but I don't believe it does any harm either. The standard gauge only goes to 60 PSI so its always at the top end while driving which I don't personally like as I like gauges that normally read middle to 3/4 range in normal use. Perhaps a greater tendency for leaks to develop in the high pressure supply lines but if its all built right 60PSI should not be an issue

cheers
Rohan

[GHill]

Thanks Rohan

That gives me an excuse to buy some more bits

I do have a small oil leak on the right hand side of the engine so I will check the supply lines for leaks!

Thanks again
Gareth

[oldchieft]

It sounds like you have a high pressure pump installed. The only difference is they have the relief valve set at 60 psi. The normal relief valve is set at 40 psi. it is normally not needed on a road car but I don't believe it does any harm either. The standard gauge only goes to 60 PSI so its always at the top end while driving which I don't personally like as I like gauges that normally read middle to 3/4 range in normal use. Perhaps a greater tendency for leaks to develop in the high pressure supply lines but if its all built right 60PSI should not be an issue

cheers
Rohan

The down side of big oil flow pumps is you are dumping oil back to the sump and wasting power with pumping losses. The balance is you get better pressure at low speed.

The good part of high flow is you are passing via an oil cooler (if you have one fitted) before you dump back to the sump and supply the system.

Higher pressure relief valve protects bearings that are carrying high loads, so with high compression ratio or high MEP of a loaded performance engines that would be an advantage, it is a case of deciding what the engine will be called on to do and what you want to waste in way of power.

Serious race competitors will rebuild often with new parts and change oil even more often.

Back in the day before F1 cars were limited to the number of engines and the number of strip downs allowed the perfect engine was the one that won the race and fell apart as it pulled into the pits.

Most car owners go for big on flow and big on pressure to be on the safe side. I also run a big orange warning light smack in front of me.

Jon the Chief

[rgh0]

Hi Jon
I suspect he does not have a high capacity pump. based on his pressure description just one with a high pressure relief spring. If he had a high pressure / high capacity pump I would expect more than 30 PSI when cold at idle

cheers
Rohan

[john.p.clegg]

I think Rohan is right (have I ever doubted him?),I have a high capacity low pressure pump fitted giving me approx 40 psi at tickover/when thrashing it/when hot or cold....I fitted this as my tolerances are on the large side and was loosing pressure when hot and ticking over...

I think Colins thoughts on oil pumps were that it was the volume that you circulated that mattered...

John

[prezoom]

Assuming that the main difference between the standard and high pressure oil pumps is merely changing the oil pressure relief valve spring, is the high pressure spring readily available through the normal supply system? Also, looking at oil pump I removed the other day, are the pumps drive gear also available as a replacement part?

Rob Walker
26-4889

[types26/36]

Assuming that the main difference between the standard and high pressure oil pumps is merely changing the oil pressure relief valve spring, is the high pressure spring readily available through the normal supply system? 26-4889

Burtons sell an uprating kit (65lbs) and the used to sell an 80lbs but not sure if they still do.
http://www.burtonpower.com/uprating-kit ... fp202.html

[Mick6186]

I've always referred to my oil pressure guage as a 'worry guage' !!

[prezoom]

Thanks.

Rob Walker
26-4889