G'day mini nerds,

I'm having an issue with the oil pressure on my 850 mk1 project, I've got a pressure gauge thet reads 50lb when the engine first starts up although as it gets a bit hotter and revs, it goes down to about 15-20lb. I have some air in the oil pressure line although I figure that if it starts high (50lb) this may not be the issue. Am I going to have to change my oil pump or is this just a matter of bleeding the oil pressure line.
I've attached photos.

Cheers mini maniacs.

The oil will always lose pressure as it heats up. My old engine had similar oil pressure readings at idle, it was just worn out and probably needed new bearings and oil pump.

It should increase the oil pressure with RPM, about 10psi per 1000rpm. Bleeding is not critical and will drive you bonkers

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Awesome. Thank you mate. I'll keep an eye on it and make sure it doesn't go to 0. I still haven't given it a good run yet so hopefully it goes back up.

Thanks again

What oil are you using? How long has it been in there?

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"Show me the Mini!"

I'm using a "gulf western" 20W-50 SN/CF and it's been in there for about 6 months but I've only turned it over about 5 times since putting it in

Try some HPR30 tends to hold its pressure once it heats up .

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That's why it's good to be.............ME

Pressure that low it needs a rebuild.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Awesome. I'll try the HPR30 before going the rebuild route. Hopefully that holds it all together. Thanks guys

or an oil pump...

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"Show me the Mini!"

or checked the accuracy of the oil pressure gauge.

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1970 Mk2 Cooper S under restoration

We had low oil pressure and a rebuild was recommended.
Pulled out the oil relief valve to find that it wasn’t seating properly.
Bought a new valve and spring , and bingo, all good.

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Find a job you love and you will never have to go to work !

This is all awesome stuff. Thank you guys. I changed the oil which helped a bit but it ended up back at 20 anyway. I will try all of this in the desperate attempt to avoid a rebuild.
You guys are the best.
Cheers again

Try the pressure relief valve.

I definitely will. I'll start looking at that tomorrow. This quarantine stuff is great for my mini

Mine lasted a couple of years with it that low. I changed to the 20/60 HPR and bumped up the idle to 1500rpm. Not recommend for long term health of the engine though

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