we are all well aware of the rotary oil pumps morgo make for triumphs so i asked the question when are they going to do them for nortons the reply i got back was "its in the early stages of development now " so hopefully there is some light at the end of the tunnel for those of us that wet sump .
oil pumps
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Fast Eddie
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phippsy said:
Why would one rotary pump be less susceptible to wet sumping than another?
Improved tolerances is one way. But the stock pumps from AN are improved tolerance anyway.
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Saved from other forums many years ago...
There are four possible wet sump leakage paths in a Norton oil pump and
lapping the ends only address one.... shaft o-rings address the second.
3rd= gear to gear wear 4th=gear tip to pump body wear
3 o-rings....
2 on the rotating main shaft,
one between the feed and scavenge side gears
and one between the scavenge gear and the drive gear.
The shaft is ground with grooves to sliding o-ring fit tolerances.
1 on the idler shaft between the feed and scavenge side.
This shaft is stationary and the gears turn, therefore, this
shafts is ground with a groove to stationary o-ring fit tolerances.
These groove tolerances are easy enough to find, sorry I don't
have the numbers readily at hand.
There are four possible wet sump leakage paths in a Norton oil pump and
lapping the ends only address one.... shaft o-rings address the second.
3rd= gear to gear wear 4th=gear tip to pump body wear
3 o-rings....
2 on the rotating main shaft,
one between the feed and scavenge side gears
and one between the scavenge gear and the drive gear.
The shaft is ground with grooves to sliding o-ring fit tolerances.
1 on the idler shaft between the feed and scavenge side.
This shaft is stationary and the gears turn, therefore, this
shafts is ground with a groove to stationary o-ring fit tolerances.
These groove tolerances are easy enough to find, sorry I don't
have the numbers readily at hand.
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acotrel said:
This only stops one path to the sump, the delivery path. The other path is thru and around the gears to the inlet or suction (suction is not a good description for the inlet side of a rotary gear pump, but that word may be more meaningful to many readers) side and thence to the sump.
The AMR modification puts the spring loaded ball in the timing case, and modifies the pump with O rings to lessen oil seepage thru the other path. I used the word lessen because not all the seepage paths (as Hobot has pointed out) thru the pump are closed by this mod.
Slick
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Fast Eddie said"
"Improved tolerances is one way. But the stock pumps from AN are improved tolerance anyway."
Do you have any proof? Or are you infering that a new pump has better clearances over an old piece of crap, which I would strongly agree with.....
I bought a brand NEW AN pump and tested it against about a 2 dozen NHT pumps. The brand NEW AN pump did good as I hoped (considering the money....wow). However A few used pumps were very very close.
I will be writing an article for the INOA Norton News about NHT pumps. I built two test rigs 4-5 years ago and have been casually taking data and formulating test procedures to insure good data. I have demonstrated them at the 2011 and 2012 INOA national rally as well as other venues.
I have discovered (measured) used pumps can ''blow thru" or wet sump 5 times more than new. I've also tested pumps for nationally known norton shops. In reality there is no money in it, so I don't really offer it as a standard service.
Hobot may have requoted my ancient wet sump passage..... and I see no reason with the AMR double oring cross chamber sealing plus the output check ball will not totally stop wet sumping .....if done correctly. Curious to know why do you think it does not address all the wet sump sources?
"Improved tolerances is one way. But the stock pumps from AN are improved tolerance anyway."
Do you have any proof? Or are you infering that a new pump has better clearances over an old piece of crap, which I would strongly agree with.....
I bought a brand NEW AN pump and tested it against about a 2 dozen NHT pumps. The brand NEW AN pump did good as I hoped (considering the money....wow). However A few used pumps were very very close.
I will be writing an article for the INOA Norton News about NHT pumps. I built two test rigs 4-5 years ago and have been casually taking data and formulating test procedures to insure good data. I have demonstrated them at the 2011 and 2012 INOA national rally as well as other venues.
I have discovered (measured) used pumps can ''blow thru" or wet sump 5 times more than new. I've also tested pumps for nationally known norton shops. In reality there is no money in it, so I don't really offer it as a standard service.
texasSlick said:
Hobot may have requoted my ancient wet sump passage..... and I see no reason with the AMR double oring cross chamber sealing plus the output check ball will not totally stop wet sumping .....if done correctly. Curious to know why do you think it does not address all the wet sump sources?
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oH man Bernard I'm sorry to know you learned these extra oil paths in our oil pumps. Will add to growing list. I can add one more, too tight a cam chain can pop through the oil pump snout. My email files got crashed so don't have who I grabbed it from but it wasn't not DynoDave or I'd remembered that but likely ole Eagle Eye Dave was where he got it. Dave may have the best powers of close observation of anyone I know.
I ask the guys at SRM who make upgraded pumps for BSA & Triumph why they haven't made one for our Nortons which to me are more prone to wet sumping then any Beezer or a Triumphs that I've owned,, all they said was that there wasn't enough demand.. Seems like time we inandated them with requests!! I could be wrong but it seems like they could make one that would solve this issue.. What do you more all knowing folk think?? I would spend the $$ for one.. Glenn T.S.
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The thing is the norton pump is a pretty good pump the triumph etc pilgrim pumps are not! they are notorious for going wrong just a small amount of dirt in the ball valve will stop these pumps from working the norton gear pump will just carry on ,,,,,,,,,,,,,bazgtsun said:
Fast Eddie
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dynodave said:
No 'proof' as such, Im just resiting their claim. I fitted one though and mine doesn't wet sump noticably (not yet anyhow)!
Excuse my ingorance here, but what is a NHT pump ?
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L.A.B. said:
LAB... quite correct
Many are barely aware of the commando origins and unfortunately many parts of the world are flooded with all the models of early norton twins. Here in the US, it seems that BSA and especially Triumph beat norton to the marketing /sales punch. So early nortons are scarce.
As such I've learned there is so much bad information out there that I have very often had to try and discover what is the real mechanical history of these bikes for my self by direct examination of the hardware.
I have a file cabinet drawer full of data and information, and the research continues whenever I have some spare time. My contribution to the INOA Tech Digest and my website are only a tiny sliver of what I have.
The biggest lies and misrepresentations do seem to get more of my attention. Oil pumps and wet sumping are one of these areas.
For club members and friends, I discovered two very dead pumps that were going to be reinstalled in engine rebuilds. One club member is coming this saturday to our Boston North shore (local NENO group) tech session and ...you guessed it, a 20M3S commando pump will be tested in preparation for a rebuild...for which I get another data point for my test results and up coming article.
My norton obsession started with this bike here, new 70 roadster, in the late fall of 1970.
Gidday all.
these oil pumps, must have been quite a bit on this now. they are not trochoid or other types with complex rotors and stuff. they are gear pumps. the cooking variety. last a long time on clean oil.
I have not seen the o ring mod so a picture would enlighten me please. they must be very tiny o rings if they go on the shafts. that may lead to issues in itself.
the pump was not faced in my rebuild. it was OK. it has sat for a bit now and the tank level just dropped about 1/8th inch if that over a 4 week period.
the old factory pumps were not done to hand built tolerances. they were production items. if refaced correctly and this is the important bit, for a standard streeter you will notice a big difference. I have never seen serious wear on the shafts and gear bores and outside diameters. not to say it does not happen, but if it has , contamination is the cause. if the gears are contacting their bores the pump is ready for the bin because the shafts are badly worn. another myth to explode, backlash has no bearing on pump effiency, None.
I reckon that most of the oil pump trouble is caused by contaminated oil causing premature wear. the gear to body width clearences needs to be only a tenth or two. take the trouble to get this, and there will be a big difference.
the forthcoming paper by Dyno Dave should be revealing. ya cant argue with good valid and reliable research. in the meantime, ensure the oil is filtered and changed regular. face the body's and plates as per book or other proven methods, and ride with peace of mind for a long time. the issue of oil draining into the sump can be remedied easy. if pump is in the bike functioning OK, but leaking quickly, get the end float to a couple of tenths and you will notice a difference. a couple of tenths though requires attention and concentration to get right. Remember the original pumps were a production item made to a price.
Contrary tales and advice welcomed Bradley
these oil pumps, must have been quite a bit on this now. they are not trochoid or other types with complex rotors and stuff. they are gear pumps. the cooking variety. last a long time on clean oil.
I have not seen the o ring mod so a picture would enlighten me please. they must be very tiny o rings if they go on the shafts. that may lead to issues in itself.
the pump was not faced in my rebuild. it was OK. it has sat for a bit now and the tank level just dropped about 1/8th inch if that over a 4 week period.
the old factory pumps were not done to hand built tolerances. they were production items. if refaced correctly and this is the important bit, for a standard streeter you will notice a big difference. I have never seen serious wear on the shafts and gear bores and outside diameters. not to say it does not happen, but if it has , contamination is the cause. if the gears are contacting their bores the pump is ready for the bin because the shafts are badly worn. another myth to explode, backlash has no bearing on pump effiency, None.
I reckon that most of the oil pump trouble is caused by contaminated oil causing premature wear. the gear to body width clearences needs to be only a tenth or two. take the trouble to get this, and there will be a big difference.
the forthcoming paper by Dyno Dave should be revealing. ya cant argue with good valid and reliable research. in the meantime, ensure the oil is filtered and changed regular. face the body's and plates as per book or other proven methods, and ride with peace of mind for a long time. the issue of oil draining into the sump can be remedied easy. if pump is in the bike functioning OK, but leaking quickly, get the end float to a couple of tenths and you will notice a difference. a couple of tenths though requires attention and concentration to get right. Remember the original pumps were a production item made to a price.
Contrary tales and advice welcomed Bradley
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My norton obsession started with this bike here, new 70 roadster, in the late fall of 1970.
that bike looks like mine. Even the helmet is the same colour as mine was in the 70,s. the houses look different from those in NZ though.
Dereck
I agree with the quality of the Norton oil pumps. My 750 which has done only `13,000 miles takes about 4 months to leak down a litre. My 850 takas about a week to do the same and the ball valve has been a good investment to stop that.
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Do note that most the grit in oil comes off rings and bores and bearings which then go straight through the sump side cogs so filtering is a bit too late for that, including Combat cam washer tabs. Is there a way to tell if low oil pressure at hi way heat is from a bad pump or bad bottom end clearances?
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Hi Hobot, the only way to know is to strip the engine and measure everything. First check out the pump, and if it is worn, fix it and then go for a ride. You will then know what your problem is. Good bearings on a bad pump will end up with very low oil pressure at idle. Mind you, worn B E bearings will rattle at no load free running.
Dereck.
Dereck.
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