Breather Oil Trap

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ampwhu
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Re: Breather Oil Trap

Post by ampwhu »

i was sort of aiming it at those who are unaware of the importance of that part. I didn't know the 1st time and even fitted it without a gasket at first. Not again. easier to leave it bolted to the block.
pgp001
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Re: Breather Oil Trap

Post by pgp001 »

Phil

Just for reference, is there a specified clearance between the crank and the caps ?

I have another spare block with the seal cap missing and I would like to fit one to that if I can find one. No one is going to want the block without it I suppose.

Thanks
Phil
philthehill
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Re: Breather Oil Trap

Post by philthehill »

There is no specific reference to the clearance in BMC Minor 1000 Wksp Man Section AA.34 or that I can find in the general data section. It suggests using engineers blue to ensure that the oil thrower is not touching any part of the housing.

Declan_Burns
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Re: Breather Oil Trap

Post by Declan_Burns »

Phil,
Have a read through this article, you will find it interesting. It is about the XPAG engine which has more or less the same scroll arrangement as the Morris. They strive for a concentric clearance of 0.002".
https://ttypes.org/crankshaft-rear-oil-seal/

Regards
Declan


Regards
Declan
philthehill
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Re: Breather Oil Trap

Post by philthehill »

Declan
Many thanks for the link.

I have found a definitive quote re the clearance in the BL Marina workshop manual relating to the 1098cc & 1275cc engines & it states:-

'Check that there is a clearance 0f 0.004" between the oil return thread on the crankshaft and the oil thrower on the rear main bearing and the crankcase rear cover. Note: No wear should take place at this point as there is no contact between the surfaces, but running with excessively worn bearings can produce wear which will lead to oil leakage into the clutch'.

There is also a illustration on where and how to measure the clearance.

Phil

timberman2004
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Re: Breather Oil Trap

Post by timberman2004 »

I have a 1971 Traveller.
I can concur with Pgp, Canister completely blocked with nasty metallic crud. No passage of air, and producing oil leaks

on removal, I poked and prodded through the top tube using a stiff wire with a right angle bend to scour the inside best as possible, Then thorough wash with petrol sloshing inside and several nuts & washers in there, rattling about to further scour...like mixing a Martini

I love Pgp's shiny Ali insert solution, but dont know where to get that part from

My alternative to use 2 long-ish lengths slim wire bent into a 'U'. One around the bottom of the the pan scourer ball, to pull it up into the canister through the narrow top tube, via the wider base tube, and the other around the top of the scourer ball to extract at a later date when needed
pgp001
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Re: Breather Oil Trap

Post by pgp001 »

Re the "shiny ali insert" I made that myself.

You will not be able to pull a pan scourer or anything else into the can as there are some spring wire clips in there to prevent the filler material being sucked into the engine, those will prevent anything passing through.

The only way is to open it up and get it properly clean, then reassemble it with a new filler material.
I could modify yours so it is exactly the same as mine for £25 plus any postage costs incurred.

Phil P
pgp001
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Re: Breather Oil Trap

Post by pgp001 »

Well Timberman decided to send me his breather canister for modification and it arrived today.
It had a heady smell of petrol when I unpacked it so from that I guessed that Timberman had given it a good rinse out.
To all intents and purposes it looked to be in decent condition, and I reckon most folks would have fitted it to their engine without hesitation.

Anyway I had half an hour to spare this evening so decided to have a look inside before I make the parts to modify it, here is what I found.

Image

Image

After a bit of a scrape around this is what I removed, there was no filter material whatsoever in there, and the spring wire retainers had disintegrated into small bits.

Image

There is actually a small hole appeared in the canister where the damp rusty crusty deposit has eaten its way through.
I will be able to cover this up internally with my adapter sleeve now I know about it.

Image

I would imagine after fifty years use with no maintenance, there will be many more horror stories like this running round undetected.

Phil P
les
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Re: Breather Oil Trap

Post by les »

Phil, I have a canister dismantled, ready to think up a suitable joining device. After reading your kind offer to Timberman, would you consider extending that offer to myself ? If you would, then I will happily pay the cost plus what you deem appropriate for postage, in advance. It looks a great solution. My canister is clean, and I have the internal metal clip.

philthehill
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Re: Breather Oil Trap

Post by philthehill »

Not only do the canisters rot out in the side but also in the bottom.
The pipe from the cam follower chamber is above the bottom of the canister so any moisture is trapped in the well of the canister and cannot get out.
To me a badly designed item.

pgp001
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Re: Breather Oil Trap

Post by pgp001 »

This one was surprisingly good in the bottom, it had a layer of oily sludge which had kept the steel clean and shiny, the upper part was a different story though.

Phil P
JOWETTJAVELIN
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Re: Breather Oil Trap

Post by JOWETTJAVELIN »

You can't justifiably say it was a badly designed item. None of the engineers planned these things to last for decades and to criticise a long obsolete part well into the 21st century is unfair.
les
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Re: Breather Oil Trap

Post by les »

Phil ——-
77A9F0B2-25E0-44B5-8619-D121CA786521.jpeg
77A9F0B2-25E0-44B5-8619-D121CA786521.jpeg (1.68 MiB) Viewed 1576 times

pgp001
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Re: Breather Oil Trap

Post by pgp001 »

Les

I have replied via PM.

Phil
philthehill
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Re: Breather Oil Trap

Post by philthehill »

It was a bad design right from the start.
It should not have been designed/produced with a sump in its bottom which trapped moisture.
There should have been a service manual instruction re its servicing and cleaning. BL may have been a service schedule for the canister but so far I have been unable to find any reference to servicing the canister in any of the BMC/BL manuals I have.
Replacing the canister normally means replacing the timing cover or front engine cam follower cover unless you are prepared to un-braze the canister from the timing chain cover or engine cam follower cover and re-braze a new canister in its place.
New timing chain covers with the canister attached are not cheap that is if you can find one.
Other pressed steel parts of the 'A' Series have survived 50 years plus so why not the oil separator canister?
Having the ability to split and clean the canister is a very worthwhile mod and should have been done by the factory right from the start.
Phil

kingsley
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Re: Breather Oil Trap

Post by kingsley »

As Phil points out, the original oil traps are expensive to buy new and are relatively scarce used.
For those not too concerned about originality, they are bulky, particularly if you want to use three.
For those wanting to use a PCV system, is it practical to use 1 oil trap and feed the 2 or 3 breather pipes into that 1?
Also, can anyone recommend an alternative oil trap, either new aftermarket or used compatible?
timberman2004
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Re: Breather Oil Trap

Post by timberman2004 »

gosh ...a bit of a shock horror revelation. :o

quite surprising seeing that amount of rust in such an oil fume rich environment...i guess condensation from alternating hot & cold, and getting worse as the blockage grew.

This is off a 1971 Traveller, so one of the 'newest' out there. There must be 100s of engines with the same problem, being unable to 'breathe'
This will doubtless underline all the prior comments regarding the rear crank oil 'seal' leaks from earlier posters, and the need to relieve crankcase pressures.

wonder why it wasn't just an angled / bent pipe to the canister originally, rather than that more costly braised elbow with it's own little 'sump'... then excess would just roll back into the engine ?

look like Phil has an income stream for life now :D
timberman2004
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Re: Breather Oil Trap

Post by timberman2004 »

Quite grateful to Phil for ..ummm.. 'exposing' this issue. it's not like its a part one would usually check or service
Last edited by timberman2004 on Wed Jan 27, 2021 7:13 pm, edited 1 time in total.
philthehill
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Re: Breather Oil Trap

Post by philthehill »

Buy one of these:-
https://www.ebay.co.uk/itm/Classic-Mini ... SwX2pfrnae
Get it modified so as to able to clean and mount on the mechanical fuel pump aperture (if you have one). You may need an adapter plate (easily made).
Take the canister outlet pipe to either the PCV valve or carb.

kingsley
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Re: Breather Oil Trap

Post by kingsley »

Thanks for the info Phil.
I am still interested to know if anyone knows of any cost / labour / size effective, off the shelf alternatives?
I have been looking for quite a long time now and I am gobsmacked that I can't find one that has access for servicing and is a reasonable size, shape and cost.
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