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 Posted: May 5, 2019 03:38PM
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I put more of the car back together today.  I even managed two test drives between rain showers.

For now I am using the standard plunger, the cut-down -S spring, and the adjustable cap.  I have the cold oil pressure set to a bit over 60 PSI.  Yesterday when I started the engine with the full length -S spring, plunger and regular cap the cold oil pressure was close to 100 PSI so the shorter spring does make a difference.

I'll use it as it is for the time being and make adjustments if and when necessary when summer heat arrives.

Thanks all.

Doug L.
 Posted: May 4, 2019 05:53PM
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Doug - I would go with the adjustable and the cut down Cooper 'S spring.  You could also think about removing the pressure relief valve and filling in the hole forcing the oil to go thru the oil filter instead of dumping at 60psi or whatever it is set at.  Years ago, say 25 or 30, I removed the pressure relief valve in the oil filter, filled the hole it made with a dime and JB weld.  

 Posted: May 4, 2019 05:17PM
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Sounds like a good pump choice.

 Posted: May 4, 2019 04:16PM
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Yes indeed.  Adding washers will lower the relief pressure.  It's odd that your adjustable leaked along the jam nut threads.  That side of the system is supposed to be (more or less) at atmospheric pressure.  It is the "dump" side of the valve.  I have never noticed leakage on mine.

The old hot-rodder rule of thumb was you wanted a minimum of 10 PSI at hot idle with an additional 10 PSI for every 1000 RPM up until the setpoint where the relief valve opens.  My engine runs with at least 30 PSI at hot idle but I find that very disappointing since it has never had better pressure even immediately after its engine rebuild.  

Doug L.
 Posted: May 4, 2019 03:50PM
 Edited:  May 4, 2019 04:00PM
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I use a slightly cut down Cooper S spring with the standard plunger with a standard oil pump.  My cold start pressure is 80 PSI and will drop to 65-70 for cruise, usually about 50 at idle using 20W50 oil.  I tried the adjustable oil pressure fitting and didn't like it, the damn thing leaked around the jamnut threads and seemed that I was always chasing the correct oil pressure setting (could have been caused by the ball bearing that I was using in place of the plunger).  When I replaced the plunger, I made sure that the exterior was smooth and free of any manufacturing burrs.  Don't know what your pressure is at idle, but in an email conversation with Calver, he said that 25 at idle and 55 PSI running is fine.  Rather than cutting springs, you can always try reducing oil pressure a bit by placing a washer or two under the dome nut, right??

 Posted: May 4, 2019 03:44PM
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I believe the turbo oil pump was developed for the metro turbo and it delivers about 50% more oil flow than a standard Mini pump.  According to the link below, 9 GPM (turbo ) vs 6 GPM (standard ). 
https://www.minimania.com/part/CAM6614MS/Austin-Mini-Turbo-Oil-Pump-Reproduction

The argument against turbo pumps is that an engine without a turbo cannot use the extra oil and its associated pressure.  The relief valve will direct the excess back into the sump when the relief valve opens.  Basically, with the turbo pump you are spending horsepower where it is not needed.  That said, I want higher oil pressure than my engine has and this is a way to get it.  I won't notice a loss of HP driving around town on a hot day but I will notice low oil pressure when at a stoplight in the depth of summer.

Doug L.
 Posted: May 4, 2019 03:17PM
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I have not, could you explain what a turbo pump is? High volume or other?

 Posted: May 4, 2019 03:05PM
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The engine and gearbox went back in the Mini today.  I still have to finish connecting the front hubs and fit the bonnet.  One of the other things I have to work on is the oil pressure.

During this engine-out work I chose to install a turbo oil pump since I was never happy with my car's hot idle oil pressure... not even after the engine was freshly rebuilt.  Along with fitting the new turbo oil pump I removed the ball bearing oil pressure relief conversion and re-fitted the traditional plunger.  Now the question turns to relief springs.

I have several springs:  a cut-down (for the ball conversion) Cooper-S relief spring, an uncut Cooper-S relief spring, and a later standard Mini relief spring.  I also have at my disposal one of the adjustable relief valve nuts to set the pressure.  My question is which spring should I use and should I go with the adjustable setup (which is my gut feeling).

I have only fired up the engine twice since reinstalling today.  When the engine got warm (not like a hot run) the pressure was still way up around 80 PSI with the full length Cooper-S spring.  My thought is to use the cut down spring with the adjustable nut or possibly to use the new standard Mini spring (cut down a little) with the adjustable nut.  Have any of you used the turbo pump as an option and if so what relief spring configuration did you settle on?

Doug L.