24 replies to this topic

[sledgehammer]

+1 on  spacing the spring & checking the seat - def true & works on some cars

 

if spring has weakened / seat worn , oil flow / pressure will be lost down the relief port , stronger spring force will close the port earlier , leaving more oil to flow around the engine

 

pretty logical when thought about & sad when some resort to insults

 

if the relief valve is closed anyway , then it won't improve flow going to bearings - but well worth a try - 10 mins work to clean , re-seat & space if required

 

it may be an idea to check the oil pressure gauge is correct

Edited by sledgehammer, 29 July 2018 - 05:56 PM.

[Dusky]

 

 

About 20 years ago when I started working on minis we used to put a Cooper S ball and spring into the oil pressure relief valve to increase the oil pressure on a worn engine.

Obviously not a long term solution but if you have more oil going around it can't be a bad thing especially at idle when pressue is at its lowest.

That doesn't even work.

Also, @OP, 5 psi at idle is very very low. Is that with a quality 20/50 oil?

Thats a very rude response and you are wrong, the Cooper S Ball and spring can increase engine oil pressure as below:

https://www.minimani...ring---Cooper-S

http://www.minispare...36.aspx|Back to

The pump in an engine is usually capable of far more oil pressure than required and the pressure relief valve dumps oil back into the sum to reduce the output pressure to the required level.

When the bearings start to wear the gaps around them get bigger, more oil is lost through them in the same amount of time and the overall system pressure is therefore lower which results in lower pressure and possibly low oil flow to other components like the cylinder head rockers.

By increasing the pressure you may get more oil around the system which will save other components in the engine from requiring replacement/reconditioning and as long as the running pressure isn't too high then this should be ok.

Whilst 5PSI at idle is very low it is the running pressure which is more important, of course if the pressure has suddenly just dropped the pressure relief valve may be sticking/damaged/have something stuck in it so its worth taking the old one out and cleaning and checking it.

 

Because, a pressure RELIEF valve opens at a certain Psi to RELIEVE the system of excess pressure.

Standard valves open at anything between 50 and 70 psi. Please entertain me, how will putting a 100 psi relief valve help you when your pressure is only 5 psi.
Please take all the time you need.

As you're so keen on mini spares: https://www.minispar...assic/HPS4.aspx

Edited by Moke Spider, 29 July 2018 - 08:59 PM.
Dusky - please play nice mate

[Homersimpson]

 

 

 

About 20 years ago when I started working on minis we used to put a Cooper S ball and spring into the oil pressure relief valve to increase the oil pressure on a worn engine.

Obviously not a long term solution but if you have more oil going around it can't be a bad thing especially at idle when pressue is at its lowest.

That's a lie and doesn't even work.

Also, @OP, 5 psi at idle is very very low. Is that with a quality 20/50 oil?

Thats a very rude response and you are wrong, the Cooper S Ball and spring can increase engine oil pressure as below:

https://www.minimani...ring---Cooper-S

http://www.minispare...36.aspx|Back to

The pump in an engine is usually capable of far more oil pressure than required and the pressure relief valve dumps oil back into the sum to reduce the output pressure to the required level.

When the bearings start to wear the gaps around them get bigger, more oil is lost through them in the same amount of time and the overall system pressure is therefore lower which results in lower pressure and possibly low oil flow to other components like the cylinder head rockers.

By increasing the pressure you may get more oil around the system which will save other components in the engine from requiring replacement/reconditioning and as long as the running pressure isn't too high then this should be ok.

Whilst 5PSI at idle is very low it is the running pressure which is more important, of course if the pressure has suddenly just dropped the pressure relief valve may be sticking/damaged/have something stuck in it so its worth taking the old one out and cleaning and checking it.

Because, a pressure RELIEF valve opens at a certain Psi to RELIEVE the system of excess pressure.
I hate it when people state blatant lies on online forums, giving people hope of quick fixes. What's rude about stating the facts, it's a lie and doesn't work?

Standard valves open at anything between 50 and 70 psi. Please entertain me, how will putting a 100 psi relief valve help you when your pressure is only 5 psi.
Please take all the time you need.

As you're so keen on mini spares: https://www.minispar...assic/HPS4.aspx

 

Sometimes the old the shuttle valves are worn/scored/don't seat properly or the spring is weak.  The S Ball and spring tends to seat much better and has a strong spring increasing pressure (although as you correctly say this at the higher end of the rev range) and we used to put them in cars years ago and it solved a lot of problems, either permanently or temporarily (the OP started with trying to get the engine to limp along a bit further).

 

Your response was unnecessarily rude, I am not lieing we use to do this years ago and it worked in many instances and many minis soldiered on until rust made them uneconomical to repair.

 

You could have just said my response was incorrect because I had not taken into account that the valve is closed at idle (its been a while since I had to do any indepth work on an engine oil system other than just replacing parts), instead you chose to call me a liar.

 

Please in future refrain from responding to my posts and do not call me a liar, I wouldn't be so discourteous as to say this to you.

[Homersimpson]

Back to the OP's problem, one thing I don't think anyone has mentioned is to check that the oil pressure gauge is accurate, may be worth putting a different mechanical gauge onto the engine to check.  Thinks might not be as bad as reported.

 

Apologies just noticed that Sledgehammer has mentioned this.

Edited by Homersimpson, 29 July 2018 - 06:48 PM.

[Dusky]

[quote name="Dusky" post="3551845" timestamp="1532887590"]

[quote name="Homersimpson" post="3551823" timestamp="1532873054"]
[quote name="Dusky" post="3551819" timestamp="1532868489"]
[quote name="Homersimpson" post="3551807" timestamp="1532861580"]

Sometimes the old the shuttle valves are worn/scored/don't seat properly or the spring is weak. The S Ball and spring tends to seat much better and has a strong spring increasing pressure (although as you correctly say this at the higher end of the rev range) and we used to put them in cars years ago and it solved a lot of problems, either permanently or temporarily (the OP started with trying to get the engine to limp along a bit further).



The conical seating area of the cup is a lot bigger than the contact circle of a ball.

[dotmatrix]

I would: check the gauge, if the pressure is low then buy a good used engine, have it refreshed to what ever standard you can afford and then swap Them when the new engine is ready.

[Bat]

Hi,

I think the main thing is to check that the relief piston is shutting fully and seated properly. If it is letting a lot of oil return to the sump pressure will suffer across the range.

Ball and spring or engine rebuild, I know which I'd try first!

Cheers 

Edited by Bat, 29 July 2018 - 08:57 PM.

[Spider]

Dusky May have been harsh, but he was also right.

Putting an S ball and spring in, which means the oil pressure RELIEF point is higher, is not going to make the pump create more pressure.
5psi is a far lower pressure than the std spring would allow the pressure relief valve to open, so increasing that spring pressure (which is what the S spring does) is not going to make any difference.

The S spring will only increase pressure if the pressure developed in the system is higher than the standard spring can control.

 

I'm away from the office until later in the week, however Dusky and Homersimpson, if this thread can remain friendly enough until then, I have a series of illustrations showing what's wrong with using the ball for a relief valve. They are not a good idea and I agree with Graeme here.

[Spider]

 

Dusky May have been harsh, but he was also right.

Putting an S ball and spring in, which means the oil pressure RELIEF point is higher, is not going to make the pump create more pressure.
5psi is a far lower pressure than the std spring would allow the pressure relief valve to open, so increasing that spring pressure (which is what the S spring does) is not going to make any difference.

The S spring will only increase pressure if the pressure developed in the system is higher than the standard spring can control.

 

I'm away from the office until later in the week, however Dusky and Homersimpson, if this thread can remain friendly enough until then, I have a series of illustrations showing what's wrong with using the ball for a relief valve. They are not a good idea and I agree with Graeme here.

 

 

I've added this to FAQ;-

 

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

[mini13]

very good write up!