I have two RM's with the 2.5L engine (RMD and an RMF). I am looking for the spin on filter conversion as the RMF cannister loosen while driving, lost oil pressure and a main bearing is now in pieces. I have been unable to find a conversion for the 2.5L engine though 1.5L conversions are readily available. I would appreciate any information on where I can obtain the conversion or perhaps drawings so I can have one made here. Purchasing a kit would be preferred.
I have been looking for a conversion kit for my Pathfinder and have found a company called Flexolite, based near Salisbury, Wiltshire. They list RMB and RMF in the list of models for which they can supply a kit. I have not contacted them yet, so can't comment on how god they are. Rob
I have an RMC, and, fed up with getting oil up my sleeve during oil changes, I prchased a Flexolite conversion. Having fitted it according to the instructions, following start up, the oil pressure burst three filter canisters in turn! Fed up with scooping oil off the workshop floor, I reverted to standard.
I sent the filter head, and the flexolite to a very knowledgable guru and it appears that A. the filter canister should not be fitted with a by-pass valve as the Riley filter head already has one built in. B. That built in by-pass valve can stick closed, it does not make a noticable difference when running the original filter arrangement, but if it is stuck closed when running a spin-on, results are liable to be very messy.
In 50 years of RMC ownership I have never known an oil filter canister to work itself loose, as such. There are two things I have known which will have the same effect, dumping oil on road. A. It is very easy to over tighten the central bolt which secures the canister to the filter housing, this will have the effect over time of deforming the bottom of the canister upwards, into a dimple shape, to the point at which the bolt is tight and the canister appears well seated, in fact the canister is not wholly seated and, because the bottom of the canister is deformed and of reduced strength, oil presure can blow the canister downwards, depositing oil ..... I have personal experience of this happening, believe me. I got over this by restoring the canister to its correct pointed shape and welding a series of small webs on the bottom, radiating out from the bolt hole, and providing a bit of additional stiffness. Mine 'blew' in about 1975, and the repair is still in use.
O.K. Obviously no takers for that question, so, the next one.
I have spoken to the manufacturer of the spin on filters which I have been blowing apart in an effort to determine the maximun operating pressure of the filter canister. I did not get a straight answer as each canister is built, apparently, to conform to a vehicle/engine manufacturers specifications. I can accept that.
It was suggested to me that I examine the possibility of fitting a canister from the 'Off Road' range or the 'Industrial' range. That is OK, but the canisters are rated by 'Flow Rate', as a primary rating.
Question: what might be the flow rate put out by the RMB oil pump in good condition?
I am sorry that you have still got a problem with the filter, I faced a similar issue on a lea Francis engine some years ago my engine blew its filter conversion normally with 5 minutes of the engine start up when the oil is at its thickest and after trying three different filters I decided that the filters were not the fault and adjusted the oil pressure relief valve with a copper washer to see what difference it made ie oil press when hot at 2500 rpm or if the filter burst add another washer it was very much trial and error but as the filter normally let go at home so I was prepared and the whole set up took no longer than a day with no damage to the engine the vehicle is still running to this day and the engine remains original. I do not have an RM but the Leaf engine is similar hope this is of some help?
It does seem odd that the engine oil pressure is enough to blow the filter apart. I have an XJ6 with a spin-on filter and the engine has been rebuilt, giving much higher oil pressure than on the Riley. The Pathfinder oil filter is a nightmare to change, so anything to make that job easier would be welcome. I know that there is a conversion kit for the RMA and RME to take a modern filter and don't remember any reports of these failing. There must be a weakness somewhere in the 2 1/2 litre engine kit. Rob
It is good to get a response which lets me know that I am not alone. Various people have suggested that the issue cannot be the canisters, but must be a blockage in the system. As the canister now fitted (MAHLE) is working perfectly, as far as I am able to run the car, and the only thing I changed was the filter canister, I think the culprit is the construction of the canisters which have blown, which were all manufactured by MANN-HUMELL.
The significant thing about the M-H catalogue is that it lists filters according to 'Flow Rate', hence my question.
Clearly my rebuilt and carefully run in engine, with a suitably lapped and measured oil pump, is capable of pushing out a goodly pressure, also measured on a separate gauge.
My reasoning is as follows: The volume of oil circulating through the pipes and galeries must be a constant. The pressure is variable, primarily due to temperature, but also RPM. The only other factor will be the ability of the filter medium to accomodate the necessary flow of oil.
If a filter medium is unable to pass sufficient oil, and the pump continues to pump oil the same pressure, he excess oil has to go somewhere, surely, and in my case it has gone all over the road and the workshop floor, via 4 burst filter canisters.
A brief update. I think I have a solution to my problem. After four filter failures I have fitted filter No. 5, or is it No. 6, I have lost count. I've almost lost the will to live too.
I have purchased a MAHLE spin on filter and fitted it. I have also wound out the OPRV as fer as it will go without falling out of the block. I have done several short journeys, up to 14 miles, and have not shed a drop of oil, or a filter canister! I still get OP of around 80 psi cold, and around 35 psi hot and running, which i better than many RMs, I know.
I have also cut open all the failed MANN filter canisters I had, together with a brand new MAHLE canister, and there are significant differences in construction which, I feel, have an effect on the flow of oil through the filter, and the resistance of the filter to flexure under presure.
Based on my examinations to date, I do not believe there is any problem at all with the Flexolite conversion. Its effectiveness depends, however on the By-Pass Valve contained within the Tecalamit Filter Head being free and operative, and on any filter canister having NO anti-drain back valve and, preferably, NO By-pass valve fitted into the canister.
There is more work t be done, when I finish redecorating bedrooms. When that happy day arrives I shall be able to report further.