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Non return valve between oil pump and big end feed jet.

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Non return valve between oil pump and big end feed jet.

Posted by Pete McDermott at February 13. 2018

Can anybody please help by clarifying how the small non return valve that sits in the orifice adjacent to the oil pump feed bush is meant to be retained.  Photo below shows it in a 19S timing cover but it is such a loose fit that it simply falls out if the cover is inverted.  I recall seeing one in another cover and it seemed firmly embedded as part of the cover. I would prefer not to have to strip that engine down to examine.  I can't see any mention of this item in the parts book so presume it's part of the timing cover. The only reference I have found is a brief mention in the Mike Pemberton engine video of one being there.

 

The orifice in which it sits is about 1mm wider, that's why it falls out and without any sealing around it can't function as a non-return valve.  I could sleeve it to fit or even epoxy it in place but the positioning must be critical as it could block the tunnel to the big end feed if too far back.

 

The valve consists of about 1/4" brass body incorporating what seems a 1/8" ball and tiny spring, these don't look as though they are meant to come apart. Composite photo showing aspects of the loose valve also attached.

 

Any advice and/or useful reference would be appreciated.

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Re: Non return valve between oil pump and big end feed jet.

Posted by michael_sullivan at February 13. 2018

Are these the part numbers for the items you are looking for?

Illus #     Part #   desc.

B97         13792   Oil feed jet, timing cover to mainshaft

B98         13791   Bush for oil feed jet

B99         10617   Spring, for oil feed jet

B100       17706   Presure release ball 3/8" in timing cover

B101       10260  Spring for pressure release ball

B102       Plug (retaining??) for timing cover pressure release

These items are shown in the singles parts list on Illus. plate B

Hope this helps

Mike

Re: Non return valve between oil pump and big end feed jet.

Posted by Barry Carson at February 13. 2018

i have just looked at my 56 19s timing cover cant see a valve or any evidence there has been one there just the oilway up to the crank.  dont know if there should be one there or not to be honest.

 

Barry

Re: Non return valve between oil pump and big end feed jet.

Posted by Pete McDermott at February 14. 2018

Michael, thanks for copying the oil feed jet and relief valve parts from the manual. However these aren't what I seek and I think are all apparent in the photo of my timing cover that I attached.  The non-return valve arrowed in red does not seem to be listed, hence my query.  Your input appreciated anyway.

Barry, you are probably right in that this non-return valve is missing in many timing covers.  I have another 19S and an ES2 in which it is firmly pressed into the oil pump orifice. However on a previous M50 I don't recall one, likewise a spare autojumble cover that I have is missing it.  No sign either in my WD or pre-war 16Hs.  In the present can of worms that I am working on it's just floating around in the hole ready to fall out when inverted.

I can find no mention of it in the Haycraft, Franks or Garratt manuals, just the briefest mention of it being there in the NOC Singles Engine Video.

Just what its function is, or the effect of it not being there, I am not sure.  Its presence would ensure that a supply of oil remains in the tunneling from oil pump to big end bearings should the engine be left unrun for any length of time.  The same thing would however occur anyway if it were not there as the drain-through / wet sumping properties of the oil pump would  ensure a supply of oil along the same route, eventually filling the sump.  Most likely explanation therefore would seem to be that it is intended to be a built-in anti wet sumping valve as it would only open with pressure from a working pump. Given the volumes that have been written on wet sumping and oil taps it seems surprising that no mention of this.

The above my inexpert guess, any more informed opinion appreciated.

 

Re: Non return valve between oil pump and big end feed jet.

Posted by ian_soady at February 14. 2018

Are you sure it's an original fitment? I'd expect it to appear in the parts books. It's not mentioned in Edgar Franks's book which is my bible (although my copy only goes up to 1949).

 

Re: Non return valve between oil pump and big end feed jet.

Posted by michael_sullivan at February 14. 2018

Pete:

What year is your 19S?

My parts list is for 1961/62 Models ES2, 50, 88, 99, and 650

Perhaps there was an engineering change in the later year models?

Mike

Re: Non return valve between oil pump and big end feed jet.

Posted by paul_nicholls at February 14. 2018

Hi

See attached photos of a late timing cover with the original "anti-sumping valve" 😉

Also from the 61-62 parts manual with the valve listed.

I think you have a home made valve or a later cover. I'm not convinced they work as my 1961 ES2 still wet sumps a bit. I haven't attempted to remove the valve as I think it would damage the retaining cup. Maybe I'll try one day.

Hope this helps.

Paul

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Re: Non return valve between oil pump and big end feed jet.

Posted by Pete McDermott at February 14. 2018

Many thanks indeed Paul and congratulations on solving this conundrum.  The embedded ball valve shown in the photo of your timing case cover is exactly as I recall seeing in my 1957 19S engine and my 1959 ES2, it was clearly a standard fitting in later ohv models.  I see now that the part numbers you list are indeed included, although not illustrated, in all Parts Lists from 1957 until the end of singles production.  The 1957 list shows the same numbers, total costing then just 14 old pennies !

The 19S engine I am presently working on is 1955 and wouldn't therefore have been fitted with this valve, the little brass widget that I found is likely a DIY item that shouldn't be there and will be discarded as I fit a Mick Hemmings anti-drain valve to all my post-war Nortons.

Mystery solved, well done !  What a useful technical forum if you hang on long enough !

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