Oil Filters

[P3Steve]

I must admit that I havn't changed the oil filter on my P3 for about three to four years now. but I do less than a thousand miles a year and the old girls got a good oil pressure of between 35 to 40 pounds when hot when running about mid revs dropping to about 20/25 on tick over, I change the oil every year and while doing this check and clean in petrol the gause filter round the oil pump pick up (Which always comes out clean) I use the Halfods 20w50 classic oil and it always comes out almost as clean as it goes in having only done a 1000 miles or less (Its slightly darker but still clear) and looking through the hole for the gause plug which as you know is quite a lg hole there apears to be no sludge in the sump. So what do you guys think about leaving the oil filter on for a few years between changing knowing how hard they are to come by also one cant forget the cost, do you think its going to do any harm, most older cars from the 1940s/50s would normaly go between 5 and 6 thousand miles normaly between oil and filter changes when they were new so do you think its ok leaving it for 3 to 4 or even 5 years knowing that in real terms its done less that 5000 miles total and has had new oil every year. Also has any body got an idiots way of converting to a modern spin off filter bearing in mind that my engineering skills and access to machining tools is very limited or dose any one do a kit that fixes with out to much trouble, Im good with hammers and spanners having done some time in the trade but always farm out engineering jobs as most are beyound my skills level and way out side my comfort zone.

[Rubythursday]

The P3 filter is a bypass filter, not a full flow so it is not as effective. I would leave it as it only filters a small quantity of oil anyway.

[lakesrally]

Hi Steve, like you I change the oil in my P3 75 every year and changed my last filter after about 8,000 miles but that took quite a few years. The originals are getting hard to find and are not cheap but I prefer to keep the car the way Rover intended so as long a I can find the correct filters and can still afford them then I intend to carry on using this system.

[davedt20]

This may be of interest to all P3 60 / 75 and Land Rover series 1 owners, I make an oil filter adaptor kit for all of these models using a modern spin on filter. It bolts on in place of the old canister type filter and it only takes a minute to change the spin on filter, and no more bruised knuckles !!!!. I also do an adaptor kit for early P4 75 Wipac type cylinder head mounted filters, again using a spin on filter.

I also offer fully reconditioned P3 and P4 steering boxes and idlers in RHD or LHD, and P3 and P4 fully reconditioned exhaust manifolds, all on an exchange basis.

Please ring me on 07966 136 890 or email dave.dt@frankdudley.com

[Freewheel]

The P3 by-pass filter continuously filters part of the oil stream - but to a finer particle size.
- Whereas a full flow filter tends to filter to larger particle size: and later shell bearings don't have the ability to 'absorb' circulating hard pieces of swarf like white metal...

The issue with modern full-flow filters on a by-pass system is that they they are better than no filter - or an ineffective original: but aren't what the system was designed for [unless the filtration size is matched]. Issues around pressure drop may also need to be adjusted out, which the P3 system does allow for.

About 20 years ago when I worked in analytical labs I actually performed the particle size measurements comparing on sump oil drawn from my P3 and P4: and ought to publish the results in Freewheel when I next dig them out.

Since the P3 by-pass filter only filters a trickle - I would change at the stipulated mileage IIRC the service is about 10,000 miles? - certainly if it's getting fresh oil every year.

If taking over a car after a long period in storage - it's not such a difficult job to drop the sump and clean out the congealed carbon slurry: there are stories of the sludge coming adrift and causing the gauze oil pump input filter to implode with the suction in extreme cases.

[davedt20]

I think there is some confusion re my oil filter adaptor kit for the P3 and Land Rover series 1. Chris, you are right that the system is a by-pass type, but, the spin on filters I use are a modern paper type with far more effective filtration than the old wire mesh type that was originally used. I know that suppliers like John Craddock etc are selling old stock original type for £112.80 each inc VAT plus carriage, but, the problem is that these filters have been on the shelf for decades and being a mesh type core, they will have badly deteriorated internally turning to rust and will probably do more damage being fitted to an engine than leaving an old filter on. My kits cost £111.50 delivered to the UK, and once fitted make filter changes very, very easy. The principal of a by-pass filter is that if the filter becomes blocked, the oil supply to the filter is re-directed into the oil gallery, and not filtered. There is no oil pressure drop with my system, but, as you know, the system is fully adjustable anyway. I recommend that if one of my kits is fitted, that the oil filter is changed annually, this costs approx £5.00 and takes less than 2 minutes, and the spin on filter can be bought off the shelf from any Motor Factors Worldwide, far, far cheaper than trying to find the old type filters.

Some years ago I fitted an early P4 75 engine to my P3 Graber DHC, I modified the block to incorporate a P3 oil filter system, but, also kept the cylinder head screw on filter. It was then that I designed and made my adaptor kits for both P3s and P4s because I didnt want to fit very old stock and suspect filters to my engine, so now I have a double filter system that is very, very effective and keeps my oil extremly clean, as the old saying goes, the proof of the pudding.

If any members have questions about my kits, please ring me on 07966 136 890 or email dave.dt@frankdudley.com


Dave Dudley-Toole