Oil pump rebuilding
- Thread starter Mofosheee
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Yes, every engine that i get to look at has the oil pumped stripped and the clearances closed up. The procedure is in the workshop manual but it misses an important point. It only outlines the flattening down of the brass end plate when the pump body should be addressed for wear as well. To do that you have to remove the oil pump bush (that the conical rubber seal sits on).
Strip the pump noting which way the gears sit. The hardest thing in fully stripping the pump is removing the drive gear woodruff key. This allows the drive shaft to be removed from the drive side casting. Measure with micrometers the depth of the scavenge side void in various places and the width of the scavenge gears. Correct any differences here by lapping the scavenge side body till the depth measurement equals the gear width.
Then lap the drive side casting flat (removing any gear marks from the face)
The oil pump bush can be removed by using a suitable pin punch working from the gasket face (that bolts up to the engine)
Repeat the measurement of the feed side void depth in various places and gear width. Correcting any differences by lapping the body till the depth measurement equals the feed side gear width. Be careful here to measure both feed gears widths, they can vary so only aim for the widest gears measurement. Now you can lap the brass end plate flat to remove any gear marks.
Wash very everything thoroughly and reassemble using clean oil. If you have done it all correctly the pump should be stiff to turn. I run rebuilt pumps in, by immersing the pump in a container of engine oil, and using a hand drill for a few minutes. If the pump is Very stiff, slightly loosen the through bolts, then using the drill and oil container run the pump in the oil for a minute or so, gradually tighten the through bolts, repeat the run in oil etc.
When finally happy with it all, lock the through bolts in place.
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Mofosheee
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Low pressure and wet sumping brought me here. Probably get a new prv as well.
Timing case removed............. will disassemble tomorrow. Hopefully the pump internals look good.
Found this as well.
Many thanks!
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I did mine (N15CS, same pump) and it stopped wet sumping immediately and thereafter for a few hundred miles. Now it's wet sumping again, not as badly as before the refurb, but the way things are going I expect it will get there given time. I didn't do the level of detail dobba99 outlines (wish I had that info before!) but I took a lot of care doing it.
I'm curious how long such a thorough refurb might keep the wet sumping at bay. But I don't want to be the instigator of another wet sumping thread - I guess it's too late perhaps.
I'm curious how long such a thorough refurb might keep the wet sumping at bay. But I don't want to be the instigator of another wet sumping thread - I guess it's too late perhaps.
I also did myoil pump and it stil wet sumped. But oil pressure did go up as I have a pressure gauge.
I then installed a Feked oil shut off valve that has also has electrical contacts and wired it so that when I shut off the oil, no power goes to the ignition circuit
Dennis
I then installed a Feked oil shut off valve that has also has electrical contacts and wired it so that when I shut off the oil, no power goes to the ignition circuit
Dennis
By the nature of it being gear pump it will pass oil - it's how it lubricates itself in use, some just pass more than others. I refurbish my own pumps and the most important thing is to make sure the face of the gear that mates with the face in the bottom of the body recess is fitted back in the same way. I also refurbish and run the pump on the engine for few hundred miles miles before I strip it, not as part of a build, This allows any tiny wear particles as the pump beds back in to be caught by the big end shells which will be swapped out after a few hundred miles and not thousands of miles. It's actually easy and satisfying to do.
ashman
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Most people on here don't use their Nortons for everyday riding in fact most would only take them out once in a while so when not being used a bit of wet sumping be good to keep the bottom nice and lubed as well the cam, but then mine only wet sumps when let sit for over 4 months and that is very rare I let any bike sit that long, in 49+ years I haven't touched my oil pump only refit a new rubber and gasket when it's been pulled out and reprime when put back on, oil pressure will always be high when cold and it also depends on the grade of oil, if your motor runs very hot it will lower the pressure lower than normal as well and running flat out some say the oil pressure drops low, so I haven't fitted my pressure gauge, I am too busy looking where I am going, very rare I look at my taco or speedo, just listening to my motor tells me a lot.
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I use the oil pressure gauge that Norton provided!
Seriously, how many motorcycles blew up engines due to lack of oil pressure back in the day when NO motorcycles came with oil pressure gauges (or temp gauges OR fuel gauges). The primary reason for installing an oil pressure gauge (or warning light) came about NOT because there was a problem with oil pumps/systems but because operators weren't checking the oil level and eventually - there wasn't any to pump.
I had an old beater car when I was very young and the way I knew I needed to add oil was that in an aggressive turn, the idiot light would illuminate. Sure, I could have checked the oil regularly with the dipstick like you were supposed to!
Check it "before every ride" is what motorcycle manuals typically state. Does anybody actually do that?
Seriously, how many motorcycles blew up engines due to lack of oil pressure back in the day when NO motorcycles came with oil pressure gauges (or temp gauges OR fuel gauges). The primary reason for installing an oil pressure gauge (or warning light) came about NOT because there was a problem with oil pumps/systems but because operators weren't checking the oil level and eventually - there wasn't any to pump.
I had an old beater car when I was very young and the way I knew I needed to add oil was that in an aggressive turn, the idiot light would illuminate. Sure, I could have checked the oil regularly with the dipstick like you were supposed to!
Check it "before every ride" is what motorcycle manuals typically state. Does anybody actually do that?
robs ss
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I'm a wierdo, but I check it weekly after a ride (to see the "real" oil level) and before a ride a week later (to check for sumping - quite good for now!)
ashman
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With my oil and STP mix my Norton don't use or drops any oil the only time I look in the oil tank is when it sits for a few weeks of not riding, I have no dip stick in my round oil tank but I knew where the level sit on the oil return pipe1/3 down from the top, if it's down to 1/2 way it has ran into the sump but that is usually after sitting for a few months so that is very rare, last year it sat for a few months while I was caring for the wife after her eye OPs and both bikes weren't getting out much, if the oil gets down to 2/3 that's when I pull the sump plug to drain before starting, only a few minutes to drain and re top the tank while I check everything else like tyre pressures before getting out.
baz
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I thought the early dommies came with an oil pressure gauge as standard but Norton deleted them due to owners getting scared of low oil pressure?I use the oil pressure gauge that Norton provided!
Seriously, how many motorcycles blew up engines due to lack of oil pressure back in the day when NO motorcycles came with oil pressure gauges (or temp gauges OR fuel gauges). The primary reason for installing an oil pressure gauge (or warning light) came about NOT because there was a problem with oil pumps/systems but because operators weren't checking the oil level and eventually - there wasn't any to pump.
I had an old beater car when I was very young and the way I knew I needed to add oil was that in an aggressive turn, the idiot light would illuminate. Sure, I could have checked the oil regularly with the dipstick like you were supposed to!
Check it "before every ride" is what motorcycle manuals typically state. Does anybody actually do that?
I have a pressure gauge on my rocket 3
It starts off at 110psi from cold
And when idling in heavy traffic drops to around 10 psi
baz
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Wasn't Bert Hopwood involved in designing both Triumph and Norton twin motors. Triumphs and BSA a usually have plunger oil pumps. My short stroke 500 cc Triumph motor used to rev to 10,500 RPM regularly, but after races when the oil was hot, the pressure indicator button was not usually out when the motor was running. I had the journals of the billet crank ground, hard chrome plated and reground. After that the indicator button used to stay out even when the motor is stopped. Matt Spencer on this forum says the top part of the Triumph pressure relief valve actually fits the Norton relief valve. However I suspect the wear rate in my Norton 850 motor is much lower than in my 500cc Triumph motor. So I have never worried about oil pressure in my 850 motor. When it arrives home after use, I disconnect the oil line to the pump, and stuff a bolt up the tube. Theoretically the oil pressure is probably intended to be sufficient to float the bearing shells clear of the big end journals, so the white metal does not pick-up, and cause the big bang.
robs ss
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So... which part of your post helped the OP in any way - or for that matter had any relevance to this thread?
Mofosheee
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Sorry for the delayed response. After disassembling & visually inspecting the 50 year old pump and prv I thought eff-it and ordered a new parts from Andover.So... which part of your post helped the OP in any way - or for that matter had any relevance to this thread?
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