oil pressure relief valve

[glaughton]

Does anyone know if there is a way to remove/replace the oil pressure relief valve without removing the starter motor. The nut seems difficult to get at. I may need to do this several times and do not want to have to remove the starter motor each time.

[les]

Can't say I've taken much notice of that but give it a go, if no luck, you will have to remove the motor, although I would have thought it was possible.

[bmcecosse]

You certainly don't have to remove the starter - or the dizzy! Why would you?? Why do you want in to the valve anyway?

[glaughton]

You certainly don't have to remove the starter - or the dizzy! Why would you??

Because the top mount & bolt of the starter get in the way.I can't get a socket on it (even with a universal joint) and it's not accessible with a normal spanner from above or below. Perhaps I haven't got the right tools ..?

Why do you want in to the valve anyway?

To shorten the spring.

[alexmcguffie]

Other than to reduce the oil pressure, why do you want to shorten the spring?

Couldn't you take the starter off (its only 2 bolts and a wire after all) and hand crank it until you are happy with the oil pressure

Alex

[philthehill]

It suggests to me that you are going to fit the 9/16" (edit) ball bearing which requires the shorter 66mm spring . If you do fit the ball bearing and shorten the spring make sure that you fit the shortened end into the cap and not against the ball bearing. The spring usually comes as part of the kit and is available from Mini Spares Pt No: AEA536KIT. I have to say that shortening the standard spring Pt No 6K853 is really of no benefit. The main benefit in fitting the ball bearing is that it has less tendency to jam either in the open or closed position than the cup type valve.
Oil pressure relief valve springs come in different strengths as well as lengths so I would advise you to fit the spring that goes with the ball bearing if that is your intention. The Cooper S oil pressure relief spring is Pt No: AEA536 and is well known for being used to increasing oil pressure on the 'A' series providing you have a good oil pressure system to start with.
The only other reason for shortening the spring is to fit an adjustable cap to the oil pressure release valve. Having the means of adjusting the oil pressure does not necessarily mean you can improve the oil pressure because if you need to do it for that reason it indicates to me that your oil pressure system is worn and should be overhauled. Do you have an oil pressure gauge fitted and if you have what are the readings when the engine is warm?

I have both the ball bearing kit AEA536KIT and the adjustable kit HPS4 on the shelf so am able to give you precise details of the spring used.

[glaughton]

Many thanks and it's an interesting subject but this is going off topic. Oil pressure, spring lengths, strengths, bullets and ball bearings have been extensively covered in another thread and thanks to the information given there I have all the necessary bits & pieces and know what I want to do (for good or ill!)

I would just like to know if it's possible to get the valve out without having to remove the starter motor. If so, how? I know it's not really a big deal to undo the 2 bolts and disconnect the wire, but if there's an easier way ...

You certainly don't have to remove the starter - or the dizzy!

perhaps you can help bmc?

[alexmcguffie]

I am genuinely interested to know why you want to do this.

[philthehill]

I am puzzled & interested at the same time as you have clearly stated above that you want to remove the cap and shorten the spring WHY?

[Trickydicky]

Never actually removed the valve but according to the Haynes manual (cue mocking ), the description of removing and replacing the Oil Pressure Relief Valve makes no mention to removing the starter motor or distributor.
The decription reads a straight forward removal and replacement sequence. Rather than using a socket do you not have a ring spanner to fit?

[glaughton]

I am puzzled & interested at the same time as you have clearly stated above that you want to remove the cap and shorten the spring WHY?

FYI
I recently had some work done on my A+ engine. The company that did the work installed a 9/16" ball bearing. My oil pressure is now a bit too high (70lbs at idle at normal running temperature). I want to check what spring is in there and if it's the original 72.64mm spring (part # 6K853), I am either going to replace it with the shorter 66mm 'S' spring (part # AEA536) or shorten the standard spring. I suspect that even the shorter stronger 'S' spring will still be too strong so shortening the standard spring may be the best option. My oil pressure gauge also now occasionally flickers wildly especially after the engine has warmed up. This could be caused by the valve twitching so I hope to resolve this problem at the same time. If not I may need a new gauge although it worked fine before the work (albeit at lower average pressures). It has not been pushed off the scale (which I know would damage it). It goes up to 120 lbs sq".

Now back to the original question:

Rather than using a socket do you not have a ring spanner to fit?

Thanks Tricky Dicky.
I'll try again but my 15/16" ring spanner can't reach the nut as the oil filter gets in the way.

[philthehill]

Thank you for enlarging on your problem.
I have checked my A+ engine and it would be near impossible for me to loosen the oil pressure relief valve cover without removing the starter motor retaining bolts and turning the starter body to give clearance. Also the relief valve cover is so close to the engine back plate (flats of relief valve cover are 3.5mm max from back plate when parallel with engine back plate when checked with a drill bit; so points of relief valve cover will be even less when turned) that any ring spanner of the correct size I have would not fit. It would have to be either an open ended spanner or a very thin walled socket and really there is just not enough room even for the open ended spanner to work satisfactorily. Therefore I would suggest that the starter motor bolts are removed and the starter motor body turned to allow access for a thin walled socket.

Having checked the size of the ball bearing in the Mini Spares kit you have the correct size 9/16" ball bearing fitted.
My mistake at quoting 5/8" without first checking.
You can pack out the cover with fibre washers which also helps to reduce the pressure. I have checked the depth of the recess in several covers and found a variation of several mm between them which does not help. The spring sometimes catches on the wall of the release valve housing which could cause flutter.
I hope that the above is of help and please let us know what you find and any conclusions made.
Phil

[glaughton]

Many thanks Phil - that is helpful info.

Yes I think a thin wall-socket is needed and I found a short Stahlwille 3/8" drive 15/16" thin wall socket on the net which might just fit in without having to move the starter motor. If not, then removing the two bolts is not difficult - just a bit of a pain if I have to repeat the exercise! Last time I did it was to get at the oil pressure switch / gauge take-off many moons ago ...
Graham

[philthehill]

A 15/16" AF socket is NO good it has to be 1" AF. I have just tried a 15/16" spanner on a spare cover and it will not fit!!!!!!!
If you can get a crows foot socket so much the better.

[glaughton]

OK - I haven't bought the socket! I read on the mini spares site that the domed nuts are 15/16". I guess this is only for the Mini.

[bmcecosse]

I have taken out many an oil pressure relief valve - and never had to remove the starter to do so... maybe you have a starter with an extra thick flange - or extra big headed bolts? Or perhaps the A+ 'in line' engine with the high mounted filter has the relief valve in a slightly different location to 'normal' A series I've always been able to slip my 1" (yes - not 15/16") socket on - and undo with an extension and ratchet. I urge you to REMOVE the ball bearing - it's a competition engine modification (which I did use in my comp engines) - the standard bucket is fine for a road car. 9/16" sounds a bit big to me - I don't think mine were larger than 1/2" - may be why you have extra high pressure??

[philthehill]

Everything is tight in that area on the A+ engine.
When fitted with normal starter flanges and bolts with normal sized heads the A+ when fully assembled still needs the starter motor bolts to be removed and the starter body turned to gain access to the oil relief valve with a socket. Whilst no doubt someone will pop their head up and say they have done it without undoing the bolts I would not even contemplate trying. I want my knuckles to remain in one piece.
Quote from Vizard page 395 "You may find that that using a ball instead of a plunger, causes the oil pressure to go too high, in which case progressively shorten the spring until the desired oil pressure is achieved under hot running conditions"
Also on the same page he states that the size of ball bearing to be used in place of the piston is 9/16".

Now to confuse even more some of the spare covers I have are 9/16" Whitworth.
The 9/16" Whitworth is a slightly looser fit on the cover than the 1" A/F so I would go for the 9/16" Whitworth if you are having to buy new.

[glaughton]

I have AF & Whitworth sockets but not those sizes! I'll try and measure the nut before buying but after some research on the net it seems 1" AF is the norm.

I have a 'bullet' type valve which I can use if necessary.

[philthehill]

Measure twice buy once!

[bmcecosse]

My engine work was all done long before Mr Vizard came on the scene.... Clive Trickey was our guiding light! And I suspect Mr Vizard learned a lot from him too....... I have one of these high filter blocks somewhere - If I can get at it I will compare the location of the relief valve. Why did they boost the pressure so high? 70 psi (at decent revs) when hot is ample pressure - and is generally provided by the standard bucket and spring if everything is in good condition.