27 replies to this topic

[mini13]

actually, the kit usually comes with a spring that is still too long, it depends on the outlet, but often the kit used to come with the cooper S spring which although being shorter, was a higher rate so results in high oil pressure, Ive seen 90 psi at idle warm using the kit as is.

[Dusky]

actually, the kit usually comes with a spring that is still too long, it depends on the outlet, but often the kit used to come with the cooper S spring which although being shorter, was a higher rate so results in high oil pressure, Ive seen 90 psi at idle warm using the kit as is.

90 psi warm idle must have a hell of a tight clearance. Or running grease instead of oil.

[mini13]

Admittedly that was a lump running on R40, so not the normal, but the point is the springs still wrong.

[Dusky]

Admittedly that was a lump running on R40, so not the normal, but the point is the springs still wrong.

Stillweird. As its less viscous than a 20w50 oil. (14.7 @ 100°c)

[Lenhamracer]

sorry for the long delay, I took a break over christmas and than I started renovating my garage with all new electric, floor and so on. Now nearly done I will care for the mini again.

I am running a ball in the PRV. Instrument is Smiths mechanical. Cold pressure goes up to 80 and even when warm stays at 80 when revving up the engine.

Currently the streets are full of snow and salt and I can not really warm up the engine to find out if the problem will occur again. 

May be I change the ball for the cup? I still have e new one...

What about the adjustable valve from Minisport??

[mini13]

definalty sounds like the balls the problem, I'd swap for the cup as you have one.

 

 

the adjustable valves are handy, as you can set the pressure pretty quick once warm, saves messing around with cutting springs and adding washers.

[Spider]

There's some info here on the pit falls of using that set up on a road car in here;-

 

http://www.theminifo...huttle-vs-ball/

[carbon]

sorry for the long delay, I took a break over christmas and than I started renovating my garage with all new electric, floor and so on. Now nearly done I will care for the mini again.

I am running a ball in the PRV. Instrument is Smiths mechanical. Cold pressure goes up to 80 and even when warm stays at 80 when revving up the engine.

Currently the streets are full of snow and salt and I can not really warm up the engine to find out if the problem will occur again. 

May be I change the ball for the cup? I still have e new one...

What about the adjustable valve from Minisport??

Thanks for the update with details of your oil pressure. The numbers are not too excessive if you're using 20W50.

 

I'm running 20W50 and this gives almost 100psi on fast idle immediately after starting, will drop to maybe 60psi at idle when just warm after maybe 2-3 miles, and steadies out at about 40psi idle when engine hot.

 

Variation in oil pressure between engines could be a combination of bearing clearances and oil pump condition/capacity. There are differences in capacity between the different oil pumps available for A-Series. I have never measured them up but the steel-backed pumps look like they may have quite a bit more capacity than the alloy-bodied pumps.

[Lenhamracer]

Swaped the ball for the cup and tested the engine today. Cold 60 at 1800 min and 75 after 3000 , after heating the engine up ( driving) idle 1200min 25-30 and above 3000 min 65. looks good.
Problem was that out of the blue the pressure dropped on the last event to 40 at 5000min and 10 at idle. After a longer break pressure was fine again.
This Saturday I am at an event in Belgium - hope it is fine now.
I have received the adjustable valve seat from mini spares today but not fitted yet.
Will keep you updated

[Lenhamracer]

Been out on a 320km rally in Belgium yesterday, very small B and C roads fast and big fun and no more oil pressure problems. I swapped the ball for a cup and fitted the adjustable Valve. Works fine - hope it will last like that

Thank you all for your help and the very helpful information

[duffdub]

When replacing the relief valve, mini spares says to grind it in. What does that mean?

[Spider]

When replacing the relief valve, mini spares says to grind it in. What does that mean?

 

Put some fine Lapping Paste on to the Bucket, then put the Bucket on a Stick, put it in the Block and lap them together. It's probably good practice to do this, but I've never done it.

[weef]

If you had the same problem before you fully rebuilt the engine and you found no fault with the oil galleries, plugs etc then I would suspect the fault to be with the gauge. It would be quite unlikely for the rebuilt unit to show the same fault unless you missed something during the rebuild. The only common part is the gauge. Try another gauge and be sure to bleed it.