Breather Oil Trap

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pgp001
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Breather Oil Trap

Postby pgp001 » Tue Jun 30, 2020 12:56 pm

I have just modified my breather can so it can be cleaned out occasionally.

Image

Image

It was in a right state inside when I cut it open, the new filler material is an aluminium pan scrub from Aldi.

Phil

philthehill
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Re: Breather Oil Trap

Postby philthehill » Tue Jun 30, 2020 2:32 pm

Well done - a very good and useful modification. 8)

If the oil separator is not cleaned on a regular basis the bottom of the canister rots out.

I use the stainless steel version of the Aldi pan scrub.


midget
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Re: Breather Oil Trap

Postby midget » Mon Jul 06, 2020 6:37 pm

Good Idea.
But on this subject, What happens if you empty the canister of its "gauze baffle" and run it empty?
Does this then allow too much oil mist to escape into induction system, causing high oil consumption?
I ask, as near completion of A+ rebuild and am keen to reduce oil leaks from usual sources. I have tried cleaning/repacking canister previously to no advantage.
John

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Re: Breather Oil Trap

Postby philthehill » Mon Jul 06, 2020 6:41 pm

The gauze is a must otherwise any oil mist will go straight to the inlet manifold and then engine.
The gauze catches the oil mist and the oil mist drains back to the sump.
Without the gauze the oil consumption may increase.
My advice is to keep the gauze inside the canister. The gauze is more effective on heavy breathing/worn engines.


midget
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Re: Breather Oil Trap

Postby midget » Mon Jul 06, 2020 7:34 pm

Phil, yes understood, but have you ever tried it in practice? I know that you have multiple breathing methods on your engines, but I do not have the option of fuel pump outlet due to this one destined for non Minor application
John

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Re: Breather Oil Trap

Postby philthehill » Mon Jul 06, 2020 8:58 pm

I have to admit that I have not run a oil separator canister without there being gauze inside the canister, but I have run engines without the benefit of an oil separator canister and they did tend to be prone to breath oil fumes leading to higher than normal oil consumption.


midget
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Re: Breather Oil Trap

Postby midget » Tue Jul 07, 2020 6:16 am

Thanks, I will re-stuff it.
John

pgp001
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Re: Breather Oil Trap

Postby pgp001 » Tue Jul 07, 2020 9:27 am

Mine was full of rusty dusty congeled steel wire wool when I opened it up, not a good mixture for sucking into an engine intake :(

Phil

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Re: Breather Oil Trap

Postby Rolomorris » Wed Jul 08, 2020 4:58 pm

My A+ 1275 (upgrade) engine was fitted by a Morris Minor specialist when I purchased the Morris and the breather system was I thought crude and it found to contain no gauze.
When I rebuilt the engine myself after it seized I replaced the timing chain cover so no outlet and just used the fuel pump outlet. I made up a breather that looked like the one in the Mini Spares site but was out of stock at the time however the inlet to the canister directs the fumes to the base. As the specialist had not included gauze neither did I, the breather hose to the carb is Mini Spares 12A1735 and the engine does not use oil. 2 attachments one
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after.JPG
after.JPG (43.71 KiB) Viewed 190 times

jagnut66
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Re: Breather Oil Trap

Postby jagnut66 » Wed Jul 08, 2020 6:27 pm

I have just modified my breather can so it can be cleaned out occasionally.
Hi,
This does seem like a good modification, where did you get the joining piece from?
Many thanks,
Mike.
1954 Series 2 on axle stands needing more welding......

philthehill
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Re: Breather Oil Trap

Postby philthehill » Wed Jul 08, 2020 6:50 pm

If you do not have the gauze inside the canister it absolutely negates the need to have the canister - you might as well have a pipe direct from the engine block/timing cover to the manifold or carb. The gauze is there for a purpose i.e. to separate the oil from the crankcase fumes. Whilst a recon/rebuilt engine may not be a heavy breather there are many out there that are.
The oil separator canister was fitted to address environmental concerns with engine piston ring blow past.
The inlet to the canister has to be at the base so that any oil caught by the gauze inside the canister can drain back to the sump.
I would suggest that just because the 'specialist' did not include a gauze inside the modified, flat faced canister does not mean that it is right.


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Re: Breather Oil Trap

Postby pgp001 » Wed Jul 08, 2020 10:17 pm

I have just made a surprising discovery this evening.

I am in the process of swapping the engine and gearbox in my Traveller for one that I have just totally rebuilt. This evening I hoisted the old one out and removed the gearbox from it.

Looking down the back of the flywheel I can see an aluminium housing which is obviously one of those new fangled crankshaft seal kits.

Prior to me fitting the breather canister system on that engine about a year ago, it was leaving a 4" diameter puddle of oil after every run, the breather stopped it doing it however.

So that makes me think the crankshaft seal kit has failed, I have not heard good reports on those, and this seems to bear that theory out.

Phil

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Re: Breather Oil Trap

Postby oliver90owner » Wed Jul 08, 2020 10:58 pm

So that makes me think the crankshaft seal kit has failed, I have not heard good reports on those, and this seems to bear that theory out.

Not necessarily so. It stopped leaking, so would appear to be doing its job after you relieved the possibly excessive crankcase pressure - oil seals are there to prevent oil passage/loss at low differential pressure, not to retain oil under pressure. Special seals are needed for that.

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Re: Breather Oil Trap

Postby philthehill » Thu Jul 09, 2020 8:35 am

The best thing you can do with the oil seal conversion kit is throw it in the bin.

The inline 'A' Series was not designed or intended to have a oil seal fitted to the rear of the crankshaft unlike the Maestro which has a purpose made crankshaft and oil seal housing.

Unless you fit a MED crankshaft oil seal conversion kit you will encounter problems with the lip seal.

The rim of the crankshaft flange was never machine finished to accept a lip seal. Unless the rim of the flange is absolutely smooth there is a good possibility that the seal will fail.

If the engine has good crankcase breathing facilities there is no need to fit the lip seal conversion.

I fitted a crankshaft oil seal kit to my 1400cc 'A' Series only to have it fail not long after fitment which was undertaken with the utmost care and precision. I went back to relying on the scroll return and all was well afterwards. Maximizing the ability for the crankcase to breath is the way forward.


pgp001
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Re: Breather Oil Trap

Postby pgp001 » Thu Jul 09, 2020 8:55 am

Hi Phil

I get what you are saying about binning the seal conversion, but that will leave me needing the upper half of the scroll seal cover which will have been removed. To try and obtain and fit one is not really something I want to start messing with just now.

This engine was running very well until I took it out and will now sit at the back of the garage as a known good condition spare should I ever need to use it again, hopefully the newly rebuilt one that I am about to fit will last me out and someone else will eventually get the spare.

Phil

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Re: Breather Oil Trap

Postby philthehill » Thu Jul 09, 2020 9:36 am

Fair enough.

For those not in the know this is the upper part of scroll seal cover mentioned above.
rear cover 1.jpg
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Rear cover 2.jpg
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Re: Breather Oil Trap

Postby ampwhu » Thu Jul 09, 2020 5:58 pm

I have left that in position on the engine I'm building because it didn't leak before and having moved one previous, I could never stop the leaking!

pgp001
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Re: Breather Oil Trap

Postby pgp001 » Thu Jul 09, 2020 10:20 pm

That's the one bit that you don't want to be moving if possible. Mine has the bolts wired to stop you inadvertently undoing them.

Phil

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Re: Breather Oil Trap

Postby ampwhu » Fri Jul 10, 2020 6:22 am

i agree. lining it up so it's doing its job is an art!

philthehill
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Re: Breather Oil Trap

Postby philthehill » Fri Jul 10, 2020 7:54 am

There is no great mystery or art to installing the top half of the scroll housing.

Fit the crankshaft & rear main bearing cap, then the top half of the scroll housing with the three securing bolts but do not fully tighten the bolts. The scroll top housing can only move horizontally on the rear main bearing cap, it cannot move up or down otherwise that would open up a gap between the main bearing cap and scroll top housing enabling the oil to weep through. Centralize the scroll housing about the crankshaft/crankshaft main bearing cap, tighten the bolts, wire the bolts (note; not all bolts have the hole drilled to enable the bolts to be wire secured, some are secured with spring washers) and the job is done.

An easy way without fitting the crankshaft is to use a short length of turned bar the same size as the diameter of the internal rim of the rear main cap scroll housing but making sure that the bar is not gripped sufficiently to prevent its removal, fit the rear main bearing cap, place the turned bar in the main cap scroll housing and fit the top half of the scroll housing to it and nip up the bolts. The top half of the scroll housing is then central about the crankshaft and main bearing cap. Remove turned bar and tighten/lock wire the three bolts.



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