The Lech Zakrzewski Oil Filter Converter for an MG TA

29 Sep

In 2001 Lech Zakrzewski published a drawing of an oil filter converter for an MPJG engine which has a Tecalemit bracket between the block and the filter housing.

Much has been written about oil filter converters using custom made parts and parts from much later engines. The advantage of Lech’s conversion is that no extra pipe work or additional metalwork is necessary. I decided to make this from aluminium as a bar of suitable diameter was available. This needed a threaded steel sleeve for the screw-on filter for wear reasons. The complete original working drawing is shown opposite.

The oil flow for the original felt type filter was from the centre of the filter to its outside. This converter causes the oil to flow from the outside of the filter to its centre as is usual for modern filters.

There are two types of oil filter bracket for the MPJG engine. For early blocks the bracket is mounted below the oil gallery and two oil pipes are used, one from the oil pump to the bracket and one from the bracket to the block oil gallery. This bracket was changed for later blocks to the type which is bolted to the block at the oil gallery.

The later bracket has a bypass valve which should be blocked similarly to that shown. In the photographs, both sides of the converter are shown with the later Tecalemit filter to block bracket. This type of bracket is used on MPJG Engine no.1025 which came with my TA no.0844. As it was in very good condition this converter was ideal.

The upper photo of the two above shows the top of the converter and the Tecalemit bracket as fitted to the block. The lower photo shows the filter screw on the side of the converter and the bracket by-pass hole filled with a grub screw. There should be an annealed copper washer under the screw which holds the converter to the bracket. A suitable washer is a top bearing washer from an SU ‘H’ type carburettor, part number AUC 2122. This will need a slight increase in its internal diameter.

At the final assembly (photo, right) the converter is positioned between the oil pump and the breather pipe with the thread on the converter fixing screw secured with Locktite 243 Threadlock. Between the converter and the Tecalemit bracket I used a flat rubber ring, this was from my spares box, its origin is unknown. Its dimensions are 50mm inside diameter 59mm outside and about 1.5mm thick. As an alternative I think that a thick paper gasket and suitable gasket cement can be used.

Suitable filters are: Fram PH966, Unipart GFE 443, Champion C 103, Motoquip VFL 101, Crossland CRO 642, Cooper Z25, Wix WL7098, Hof 203, Delphi FX0004.

Many thanks to Lech Zakrzewski for the drawing (above) and details.

Bob Butson
September 2010


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6 Responses to “The Lech Zakrzewski Oil Filter Converter for an MG TA”

  1. Brian Rainbow 29. Sep, 2010 at 7:38 pm #

    Bob,
    the Tecalemit bracket that you show in your pictures must NOT be used for an oil filter. The filter head you show is for a fuel filter, with a low pressure (about 15psi) bypass valve in the port. In the original writeup that Lech produced in July2001 he states:
    A note of caution, there are two types of Tecalemit housings that will fit the MPJG engine (actually there are 3 types. BR), the original type and a version fitted with a by-pass valve in the aluminium housing. I have been reliably informed that the latter type was intended for a fuel filter and the bypass valve operates at about 15 psi. Obviously this type should not be fitted onto the MPJG engine unless the valve has been permanently blocked off.

    If you look at the article I wrote in TTT Issue 29 September 2008 on page 22 you will see a photo of the two acceptable Tecalemit filter heads that can be used on an MPJG engine depending on whether it is an early or late block.

    You must NOT use the Tecalemit filter head that you have. I have several of the correct ones for the later block if you don’t have one.
    Best wishes, Brian Rainbow TA2551 Leamington Spa, U.K.

  2. Bob Butson. 30. Sep, 2010 at 6:31 pm #

    This original bracket is clearly marked Tecalemit Oil Filter,it has nothing to do with fuel. In the photos the bypass is clearly shown as being sealed with a grubscrew. I willcontinue to use it.

  3. Bob Butson 02. Oct, 2010 at 10:31 pm #

    This bracket is clearly shown in The original MG T Series by Anders Ditlev Clausager (photo opposite page 25), and again inthe MG T Series Restoration Guide by Malcolm Green page 67.

  4. Brian Rainbow 03. Oct, 2010 at 9:47 am #

    Bob,
    the Tecalemit filter head is identical externally on both oil and fuel filters. The differences are internal are are as follows:

    OIL FILTER has a return hole from the internal outer section of the filter, this hole is 0.318 inches diameter and lines up with the same size hole in the main oilway on the MPJG block.

    FUEL FILTER has a direct return port from the input port to the output hole (which is much larger at 0.689 in dia) which contains a low pressure bypass valve. Now you have removed the bypass valve and blocked the output port from the input with a grub screw. The alloy wall that you have screwed your grubscrew into is only 0.090 ins thick (90 thou) so the grub screw is held by 2 threads at most. With hot engine oil passing through the inlet port at 40 to 70 psi and different expansion rates of alloy casting and steel screw this is very risky. If the grub screw were to come loose and get forced into the main oil gallery it would have a disastrous consequences to your rare and valuable engine.
    For that reason I sent you an e-mail several days ago ooffering to send you free of chage a proper Tecalemit oil filter head for your engine. It is up to you to decide on sticking with your modified fuel filter head or using a correct oil filter head.
    Best wishes, Brian

  5. Bob Butson 04. Oct, 2010 at 9:54 pm #

    I have carefully measured the depth of the bypass valve hole and it takes 3.5 turns of an M8x1 thread. The grubscrew used is secured with JB Weld. The pressure difference across the screw is the difference between the oil pressure on the inlet side of the filter and that of the outlet side.

  6. John James 18. Nov, 2010 at 7:05 pm #

    Bob Butson has provided an update to his article as follows:

    Brian Rainbow has sent me an alternative Tecalemit filter bracket. It is identical in external appearance to the one in my article. This one was also removed from an MPJG engine but it has no drilling for a relief valve. I had no idea when I wrote the article that such a bracket existed. As Brian has pointed out, using this version will be much safer……….Bob Butson

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