Morris Minor Owners Club

According to the manual it should give 20 psi at running idle, but my oil indicator switches on when running idle (indicating less than 8 psi?).[frame][/frame]
Planning to exchange the oil pump and fit a oil gauge.

MarkyB already commented:

The reason for low oil pressure is not usually the pump but wear in the bearings, main and big end.
Just replacing the pump wont fix it.

bmcecosse:

Exactly! It's not the pump (which is a later 'good' one...) It IS worn bearings... Drop the sump and let's see the centre main - and a big-end.... Oil pressure gauge is certainly a GOOD idea..

I'll drop the sump and check the bearings, will post the pictures here. BUT before I start, are there any do's and dont's I should be aware of? Can I do this alone or do I need 4 hands at a certain stage? Would it be a problem to put the engine on its side getting the bearings out?

Thanks for the help.

Just lay it over and pop the sump off. Remove the inlet oil filter mesh assembly (two tiny bolts and one large union nut) and then undo the centre main cap - two bolts - and show us the shell - and the shaft bearing. Note which way the cap fits before removing (take a picture to remind yourself). Also undo one of the big-end caps -and again note which way - and again show us the shell - and the shaft. If you don't have the Workshop Manual then Google for 'Morris Minor Workshop Manual' - it's there as a FREE download.

Below he pictures of the bearings.

Big end bearings seems OK, hardly any 'copper'. The main bearings however show a lot of copper. Are these worn out?

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Are these worn out?

In a word - yes!

The centre main journal appears to have some ridges, but could be just the light. Are all the main bearing journals really flat across the width?

If they are, then new pump, new shells (big ends and mains), new filter element (check that the bottom plate and spring are in place) and good quality 20W/50 oil (some will disagree) and you should be good to go for many more miles in the future.

If the journals are in anyway suspect, you will need to measure the journals and potentially a crankshaft regrind (assuming there is material to do so).

As above - the big-end shell is showing some distress - some crazing of base metal which in that case appears to be Al/Sn -which suggests to me they have been renewed at some point. The main shells are worn out - and are the much stronger bronze material. I think you have probably caught it in the nick of time - but as above - you need to investigate the ridges on the main bearings. The big-end you show looks pretty good! Make sure you don't mix up the big-end caps - they must be kept with the same con-rod. And again when the time comes - refitted right way round.

Probably going to be shouted down by the salvage everything brigade ,But since you are at the stage of a complete stripdown and rebuild,If it was me I would automatically get the block rebored(The scoring looks bad to me) with new pistons and rings( I have never in 40 odd years of engine rebuilding ,every had 100% satisfaction from fitting rings only, they have always come back to bite me sooner than later)
I would have the crank out and down to an engineers for proper measuring and regrinding with new shells and mains,Having done that I would know that the engine was almost as good as new,good for another 20 years or more.
But it comes at a cost.You may consider another engine,if you can find one that has a good history but then you still take a chance on it.
Whatever you do good luck with it,one thing you are doing is learning a lot about engines and credit to you for having a go,many would'nt even try to take the engine out in the first place. You are at the start of a rapid and enjoyable journey.

I tend to agree, wish I'd gone for a rebore and new pistons rather than new rings and a hone.
Time and money were a bit lacking at the time, Ho hum.

It's all down to cost and the intended use of the car. If it's only a 1000 mile summer week-end car, then the cost of rebore/new pistons and crank grind may not be justified. I do think the crank will be ok here - I can't see the bores well enough to judge, but the piston we have been shown is certainly poor and doubtful if it can be salvaged. A refresh with glaze bust/new rings (and that piston replaced with a 'better' one) and new shells all round - may give this engine 10,000 miles of useful service - which could be 5 to 10 years use for the owner! However if all the pistons are similarly damaged - I agree a rebore should be seriously considered. It might be more attractive to consider a complete reconditioned engine on exchange from Bull Motif.... which works out at ~ £800 including vat after the exchange (assuming can collect/deliver - otherwise add carriage both ways.)... http://www.morrisminorspares.net/checkout.php

Brought the engine block and head to a refurbishing company here in NL. They will measure all and come up with some advise this Saturday. Will probably fit all necessary new parts. New bearings, pistons with piston rings are not that expensive. I will go for the max solution, want to enjoy the car for the next 50 years, being close to early retirement .

Will post the findings soon.

Probably a wise choice - but get a firm quote for exactly what they will do - and how much it will cost...