Engine oil breather

[phasesonix]

Please could someone tell me if my oil breather is connected correctly in the photo below(goes to the carb) Thanks

[svenedin]

Yes this is correct for a very late engine breathing arrangement (closed-circuit breathing with a breather inlet SU HS2 carburettor). This arrangement superseded the relatively brief (at least in a Minor) use of a Smiths PCV valve. If you want to know if that has always been the engine breathing system on your engine, have a look at your engine number. Engines that had closed-circuit breathing are designated "10ME" (rather than 10MA) although a very late engine may be 10V with an E later in the sequence.

The correct pipe from tappet chest oil separator to carburettor inlet is an unusual pipe with a different internal diameter at each end. The part number is 12A1735. This is available from e.g ESM or Minispares. It is important that the breather pipe is well secured with clips and is made of a material suitable to cope with hot oily fumes. Any leak will draw in air causing a weak fuel/air mixture which if it happens suddenly can cause the engine to refuse to run at all.

Stephen

[phasesonix]

Thanks very much, it is a 10V engine. It does use a bit of oil- will any problems with the breather system cause the engine to use oil? (it doesn't leak)

[phasesonix]

Yes this is correct for a very late engine breathing arrangement (closed-circuit breathing with a breather inlet SU HS2 carburettor). This arrangement superseded the relatively brief (at least in a Minor) use of a Smiths PCV valve. If you want to know if that has always been the engine breathing system on your engine, have a look at your engine number. Engines that had closed-circuit breathing are designated "10ME" (rather than 10MA) although a very late engine may be 10V with an E later in the sequence.

The correct pipe from tappet chest oil separator to carburettor inlet is an unusual pipe with a different internal diameter at each end. The part number is 12A1735. This is available from e.g ESM or Minispares. It is important that the breather pipe is well secured with clips and is made of a material suitable to cope with hot oily fumes. Any leak will draw in air causing a weak fuel/air mixture which if it happens suddenly can cause the engine to refuse to run at all.

Stephen

Thanks very much, it is a 10V engine. It does use a bit of oil- will any problems with the breather system cause the engine to use oil? (it doesn't leak

[svenedin]

Thanks very much, it is a 10V engine. It does use a bit of oil- will any problems with the breather system cause the engine to use oil? (it doesn't leak)

If the engine is worn (worn piston rings, worn bores or both) this increases the "blow-by" (gases getting past the piston rings and causing crankcase compression. The breather system then sucks these blow-by gases (which are oily) into the engine and burns them.

The oil separator is supposed to help to condense some of the oil back into the engine and it should contain a metal gauze. Usually this has either rusted and blocked the "chimney" or just rusted away to nothing or has been removed in the past. A suitable replacement is a stainless steel pot scourer (not the type with any soap of course).

I would suggest checking the oil separator chimney and doing a compression test. My engine is bit earlier and has a Smiths PCV valve, the principle being the same. Before the engine was rebuilt it did burn oil rather a lot. The compression test was good on a cold engine but I suspect when driven at speed there was a lot of blow-by. Since rebuild oil consumption is minimal.

But having just a blocked breather system can also increase oil consumption. The crankcase compression is not relieved and so the oil has to go somewhere. Usually it leaks out of anywhere it can but it can also find its way into the bores and get burnt, increasing oil consumption.

With this system you should have a long, vented oil filler cap. Actually this is not a vent but an inlet for fresh air. Part GFE6003


Stephen

[cswagon1]

Hopefully someone could enlighten me as to whether my engine is correct by not having any sign of a breather system please.
The engine number is 10D-U-H xxxxx and I have no idea yet what these numbers represent.

I also tried looking up the chassis and body numbers but failed miserably on that one too.
Chassis no. Z35127-34 XXXXXX
Body no. 275.777

Thank you

Graham.

23.JPG (1.22 MiB) Viewed 2550 times

[svenedin]

Hopefully someone could enlighten me as to whether my engine is correct by not having any sign of a breather system please.
The engine number is 10D-U-H xxxxx and I have no idea yet what these numbers represent.

I also tried looking up the chassis and body numbers but failed miserably on that one too.
Chassis no. Z35127-34 XXXXXX
Body no. 275.777

Thank you

Graham.

23.JPG

I think 10D came from an 1100 Austin A40 MarkII. U is central gear change, H is high compression

The trouble is, the A-series engines had multiple different breather systems and they were used in many different cars. Parts get swapped around because they are interchangeable e.g rocker covers, tappet chest covers, timing chain covers etc.

You should have a rocker cover with a breather outlet pipe that connects to the air filter and a "Swan neck" breather pipe on the tappet chest cover. Somebody has fitted a rocker cover without a breather pipe (which is for later engines with closed-circuit breathing) and swapped the original air filter for a pancake type replacement.

Is there a breather outlet on the timing chain cover?

Is your engine leaking or burning oil? If no I wouldn't worry about it.

If you want to go back to closer to original, get a rocker cover with breather outlet elbow and connect this to the air filter. I believe the K&N pancake air filters can be adapted to take a breather pipe or go back to the original air filter. Note that it is not as simple as drilling the rocker cover and fitting a pipe. The proper covers with breather pipe have an internal oil baffle to prevent excessive oil getting into the breather pipe. There should be a swan-neck breather pipe on the tappet chest cover connected to a longer pipe that anchors on the mechanical fuel pump aperture (which in your case will be blanked off as not used).


Stephen

[svenedin]

Breather outlet A-series rocker cover showing internal oil baffle to prevent excessive oil being drawn into the breather pipe.

Stephen

IMG_2535.jpeg (945.45 KiB) Viewed 2530 times

IMG_2536.jpeg (1.69 MiB) Viewed 2530 times

[cswagon1]

Thank you once again Stephen for your reply.
So I should look out for a rocker cover with breather pipe or weld a pipe onto the existing, and I was
going for a new air cleaner anyway, so I need one with an inlet pipe.
I only bought the van a few weeks ago and haven't had more than a few miles test drive so far so I'm
unsure of the oil consumption or anything really.
The exhaust was burning clean as I was watching that in the wing mirror when I went up an incline so
hopefully no worse than any old vehicle, in particular my other means of transport which is an old
diesel engined Land Rover.
Now to check out Ebay.

Graham.

Just seen your picture, many thanks for that also.

[svenedin]

Thank you once again Stephen for your reply.
So I should look out for a rocker cover with breather pipe or weld a pipe onto the existing, and I was
going for a new air cleaner anyway, so I need one with an inlet pipe.
I only bought the van a few weeks ago and haven't had more than a few miles test drive so far so I'm
unsure of the oil consumption or anything really.
The exhaust was burning clean as I was watching that in the wing mirror when I went up an incline so
hopefully no worse than any old vehicle, in particular my other means of transport which is an old
diesel engined Land Rover.
Now to check out Ebay.

Graham.

Just seen your picture, many thanks for that also.

You're welcome. Those K&N air filters are expensive and if you don't want it, you could easily sell it. I am pretty sure they can take a breather pipe with a small modification so there is no need to change it unless you want to. The original air filter has a stub pipe for the breather pipe.

https://www.minispares.com/56-9121-k-n- ... 25-central

See what I mean?

Stephen

[cswagon1]

Thank you Stephen, I'll see how the oil consumption is once it's on the road then, and make a decision from that.

Is there anywhere that I can look up what my chassis and body numbers translate to please?

Chassis no. Z35127-34 xxxxx

Car no. 275-777

Thanks again

Graham.

[svenedin]

This is the only reference that I know: https://potteries.mmoc.org.uk/Identify.htm

You can apply for a Heritage Certificate which should give you give you further information. https://www.britishmotormuseum.co.uk/ar ... rtificates


Stephen