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Oil pump and History

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This coming Spring I need to do something about wet sumping on my 99.

Servicing the oil pump and machining two new gears on the feed side to suit is one answer, this worked perfectly on my 88 Dommie racer.

Here is my issue: About 20 years ago I was given an oil pump by a retiring rider who said he would never need it.The pump came in a wooden box and well packed. It is covered in light machine oil and turns without resistance. A ready to use Dommie oil pump.

In the box is a hand written note about the work done, by John Hudson.

I feel this is a bit of history: My issue is; should I simply swap pumps with the John Hudson serviced pump or should I leave it and repair the pump causing the wet sumping.

What would you do?

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If you leave it in the shed it will likely end up in a skip one day . John was about making bikes better ,he would want it fitted. Put the note in your bikes folder . More chance of it surviving.

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When you come to sell your bike a 'John Hudson' serviced oil pump (with note) would be a bonus selling point.

Lateral thought.......is this boxed pump the correct model for your Norton?

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I would use the serviced pump, then overhaul the other at your convenience, you could always keep it in the same box, if you like.

It's an oil pump, not the Cuerdale Hoard.

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Whether you use it or not, dismantling it for a detailed measurements would help to demystify a god like legend and provide information of a real world engineered component. No disrespect to JH intended.

IIRC the early NHT pumps were narrow gear and when the 650+   1-3/4 journal cranks came out the gears became the "wide" variety. These narrow gear pumps are incredibly rare here (US) and the late wide gear pumps are almost universally used here with 3 start gears.

I do think the factory refurbishment process is WAY over sold. It only addresses 1 of the 4 wear modes. Yes it can help a bit if you are lucky.pump test rig

 

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Thats all well and good, but can you actually buy a new pump for a  Dommy ?  Does not appear  in  RGM or Andovers lists . From comments I have read  you are better off re-furbing  your old pump. Mine is now 63  years old and still works fine. When the time comes I will re-machine it to take a set of cleaned up  secondhand 650 gears .

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IIRC the early NHT pumps were narrow gear..........We all love a puzzle !!!

The pumps sold by Norvil and Andover Norton should fit any most of the Norton twins.  These will generally be the higher capacity type but when fitted with the  3 start gears will work fine on the smaller  journal engines. Excess oil pressure will just bleed out into the timing cover until the oil gets hot. The pre-1966 88, 99, 650 and 750 engines all had this arrangement.

 

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I figure the NOC brits know what an early NHT is,  1949 thru 1959 + a few more for the dying small journal 500 + 600. Early Nortons are almost unknown of here as almost all were private imports or purchased much later outside of the Berliner or norton west era.

Then the 1960 650 manxman plus the remaining 650, 750 & 850 are the 1-3/4 crankshafts. It seems fairly clear to me.

Yes today or at some decades ago the narrow gear oil pumps that fed the 1-1/2 cranks sold out and their fate is still unknown to the public. So at least here, (USA) we have to make do with wide gear pumps. for any and all NHT.

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I am a bit reluctant to go the way of additional oil supply as both my Nortons have suffered overoiling issues. The 99  when i fitted a 6 start gear suffered oiled  plugs,smoky exhaust and drowned ignition system. All it really needed was a bit of fine tuning to the rocker supply which it now has. What it benefitted most from was a change to a modern low ash high performance fully synth  multigrade  oil , Easy starts, no apparent wear, a clean engine. I'm sure that if oils of this quality had been around Noton would have specified them. I see that Mike Pemberton has come to the same conclusion for his 750. The Atlas also could not cope with the Uprated oil supply that AMC fitted. Smoky exhaust ,oiled plugs and mag. Now fitted with  valve seals.special rings and electronic ignition its much happier. It too may be switched to a Multigrade to make starting easier in our cold climate.

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hello, Neil

if it was me, i would recondition your original pump and save the John Hudson one with the info. 

 

Barry.

 


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