Oil pump cover

[Captain flint]

Hi all,
I am almost ready to fit my 1275 Midget engine.
I have a new modified backplate,and a awaiting a new modified flywheel from David Manners,an exceptionally
helpful company.
My question is this,the oil pump aperture in the new backplate is 93mm and the minor backplate is 89.2mm.
The oil pump covers that fit into the respective back plates are slightly different sizes and have different part
numbers,each to fit their corresponding sizes.
The smaller Morris cover seems to fit O,K when all bolted up,a bit of clearance but tight when bolted up.
Can anyone see any unforeseen problems if I use the smaller cover
I only have the one cover.
Many thanks,
Martin.

[philthehill]

Use the correct oil pump cover otherwise you will increase the risk of oil leaking from the oil pump cover.
http://www.moss-europe.co.uk/cover-oil- ... soc=417394
In the photo below the one embossed with MOWOG is from a 1098cc engine and the one with the raised centre is a 1275cc engine.
The oil pump cover on a 803cc/948cc engine is usually to be found soldered into the rear engine plate.
Phil[frame][/frame]

[Captain flint]

Yes Phil,makes sense,many thanks!

[bmcecosse]

It still beats me why they felt the need to move and enlarge the oil pump cover - the oil pump is in exactly the same place on a 1275 as it is on all the other engines. Using the correct/best 'steel backed' oil pump works perfectly well with the earlier cover in an earlier backplate. Of course it needs to be slightly enlarged around the main bearing hole -a 5 minute job with an angle grinder, I'm not sure where you will find the larger cover now - does anyone make them new? You may have to 'make' one yourself. I would use an earlier 1098 backplate.. It works.

[philthehill]

bmc
see link above - in stock at MOSS.
The cover was produced as it was/is because the oil pump before the steel backed one was deeper and had the raised centre which fitted into the boss of the 1275cc oil pump cover.
I suspect that BMC/BL considered it cheaper to continue the same design even after the steel backed pump became available.
The oil pump below is a pin drive 1275cc Cooper S one (with the central boss much reduced in height) which I had to modify by mixing and matching parts and altering the securing method to fit the 948cc/998cc engine many years ago; and well before the steel backed pump became available. I also had to slightly dome the oil pump cover of the 1098cc rear engine plate to fit over the pump central boss.
Phil[frame][/frame]

[bmcecosse]

Oh yes - i've been there in the past with the Concentric pump too....