Author Topic: A10 oil filtering  (Read 8189 times)

Offline dpaddock

  • NC, USA
  • Valued Contributor
  • ****
  • Join Date: Jul 2006
  • Posts: 429
  • Karma: 5
Re: A10 oil filtering
« Reply #15 on: 24.05. 2008 23:03 »
I, too, am an engineer, retired now for some three years, with four grandchildren, a lovely wife, and a '57 Spitfire plus a '60 Goldie. With bikes like these, I want every bit of protection I can get, including engine oil.

I recently fitted a Ducati engine oil filter system to the Spit, and got quite a bit of wet sump. I attribute this to filter housing siphoning (at this time); I'll study this and get back to you.
David
'57 Spitfire


Offline Dynamo Regulators Mike

  • A's Best Friend
  • ***
  • Join Date: Apr 2008
  • Posts: 165
  • Karma: 6
  • Fareham, UK, 1960 A10
    • Dynamo Regulators Ltd
Re: A10 oil filtering
« Reply #16 on: 25.05. 2008 11:24 »
Laurence, indeed I also go by the soubriquet 'Blue Flash' elsewhere. Obviously from the bike, (now appearing left  ????), but also with an electrical connotation. Pleased to know the wheel hub is back in use after 20 plus years and is giving improved braking (,safety and enjoyment).

The suspicion of slight back pressure in the return line causing problems is truly puzzling. 20W50 at working temperature should have similar viscosity to straight 50. However when cold the 50 will see much larger resistance which does not normally cause any issue with sump build up. With long return line and filter might expect cooling effect to increase back pressure, but again less of a problem with multigrade.

Another faint possibility is that the filter changes the aeration of the oil significantly. Not the proportion of air to oil, but the size of the bubbles. Then assuming larger bubbles with filter these will leave the oil in the tank more rapidly. Then the feed pump is supplied with less aerated oil increasing oil flow rate compared with no filter. Then the scavenge side has to do more work and runs out of capacity under some conditions. Clutching at straws maybe.

Bill or I should say Groily, the oil level in the tank does not appear consistently lower with filter, and I have been keeping a close watch on this. Also the times I have drained the sump I have not measured more than 5 fl oz, but this is always after slow couple of miles running back through residential roads. Now a level sensor in the tank logging against engine speed and perhaps oil temperature would be very interesting. But beyond  me at present.

Glad to see another engineer entering the discussion with a similar problem with a filter. Look forward to your input dpaddock. I should add at this stage that I am an electronics engineer, but the same sort of enquiring mindset still applies.
Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL www.dynamoregulators.com

Offline bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5415
  • Karma: 61
Re: A10 oil filtering
« Reply #17 on: 25.05. 2008 13:00 »
before I fitted my filter I wondered about back pressure but after trying the thing by fitting the filter up ( Citreon element ) and blowing through it I was amazed at the lack of any resistance really, all right blowing through it is not the same as forcing liquid through it on the other hand the pump feed side should develop 60 plus lb/in so the scavenge side should do the same at least if it had to.
I tend to think the problem lies elsewhere, be nice to know for sure though.

All the best - Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5002
  • Karma: 48
Re: A10 oil filtering
« Reply #18 on: 25.05. 2008 15:05 »
Mike,

Interesting concept, that of larger bubbles dissipating faster, thus causing the pump to deliver more actual oil. I'm not sure I understand why the filter would make the bubbles larger. It seems the intuitive opposite, but, I suspect you have considered this more than I and have a good explanation.

Regarding the scavenge side sucking up the same amount as the feed side delivers, ultimately, this is trying to happen, but the circumstances by which this happens are different for the two functions. The feed side has the benefit of constant atmospheric pressure in the tank and gravity sending oil toward the pump. The scavenge side must depend on siphon created by the pump, as allowed by air pressure in the crankcase, which, in turn,  is dependent on pressure allowed in and out by the breather. As we know, the breather is infrequently open. Is it not possible that the inefficiecy of siphoning versus gravity (as helped by atmospheric pressure) makes the back pressure of the lines and filter more critical, particularly if the action of siphoning, itself, is normally contributing to reducing crankcase air pressure? Though I have no confirmation  from previous discussion in this forum, I am convinced that the main purpose of the breather is to create near-normal atmospheric pressure in the crankcase so that oil can be pumped in and drawn out.

Another aspect that has received little comment here is valve guides.  Bill suggested this as a possibiliity, believing they had not been mentioned. Going back, we see that you had the head rebuilt, including guides. For my understanding, guides would have been a more obvious and direct source of oil loss than excess oil on the backside of the oil scraper ring. Having new guides does not guarantee that they fit properly. However, I suppose that if it were guides, smoke would be more continuous. 

I trust that I have only ventured into things I understand while attempting to make it sound like I understand that of which I speak. Nevertheless, I always appreciate being set straight when I've strayed from the path.

Richard

P.S. As an electronics engineer (I believe in the UK), perhaps you can help me on another issue completely. My work requires me to understand a bit about 3-phase electrical power in the UK/EU. So, my question is: should I refer to UK 3-phase as 240/415 VAC, 230/400 VAC or somethng else completely. Anyone else knowing the answer, please feel free to jump in. Sorry, if this strays too far from our prime directive of exploring the exotic world of A7/10's. 

P.P.S. I modified my P.S., after-the-fact, to more closely resemble how we in the U.S. might rever to 3-phase, as in "120/208" (phase-to-neutral/phase-to-phase). Now I really have tortured the reader's patience for miles-off-topic.   

Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Offline Dynamo Regulators Mike

  • A's Best Friend
  • ***
  • Join Date: Apr 2008
  • Posts: 165
  • Karma: 6
  • Fareham, UK, 1960 A10
    • Dynamo Regulators Ltd
Re: A10 oil filtering
« Reply #19 on: 26.05. 2008 12:45 »
Hello again Richard a.k.a. manosound and sorry I spelled the name wrong last time. Only guessing that the filter would increase bubble size. No evidence but I just feel that a low aerated oil flow passing through a large area membrane would provide a good surface for the air to coalesce.

Whatever the subtleties with regard to oil pumping on either side of the pump, it clearly only takes a little change to make a good difference, i.e. fitting an oil filter providing minimal back pressure. I too am sure that the breather is contrived to maintain atmospheric or a slight vacuum in the cases. This in turn reduces oil leakage and reduces power loss. Surprises me how well it seems to work given that the air passage is such a low diameter and fairly torturous.

The valve ? guide fit in my engine was indeed within limits at the rebuild. Worn guides will puff smoke particularly on the overrun I am led to believe, as any excess oil is forced into the lower pressure in the cylinder. Also difficult to see how this would be affected by filter. If anything oil feed to the head would be less, due to pressure drop.

One little addition to this oil thread from me. I have 2 spare oil pumps in the garage which I thought were the same. However the gear tooth profiles are different. Wondering which one is the earlier and when and why the change was made. Could be performance but may equally have been for cost reasons.

P.S. with regard to your 3 phase question I am afraid this is not a familiar are to me, but is it not the phase to phase voltage that is normally used?
Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL www.dynamoregulators.com

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5002
  • Karma: 48
Re: A10 oil filtering
« Reply #20 on: 26.05. 2008 14:23 »
Mike, et al,

This is all so interesting and, perhaps, not that important if removing the filter solves the problem and you are riding happy. Nevertheless, "inquiring minds want to know."  I don't know if you are old enough to remember the Groucho Marx Show, or if it was even shown in the United Kingdom. Nevertheless, I suppose it is enough in the popular culture that you may understand my reference when I say "'Coalesce' is the secret word, you've one a hundred dollars!  O.K., get rid of the duck!" Yes, I can envision how the bubbles would coalesce on the input side of the filter. Now that I'm thinking about it, it seems that that would not lead to larger bubbles on the output side. Instead, only those small enough to permeate the pore size of the filter would get through, meaning, nearly no bubbles. What jumps out in this, at least to me, is that coalescing of bubbles on the input side of the filter may lead to really big bubbles in the return line, upstream of the filter, the affects of which I am not certain.

The change in pump gear profile is very interesting. I am off to the shed to open up my pumps to see which I have.

Richard

P.S.  I have seen where phase-to-phase is listed for UK/EU 3-phahse connectors. I suppose this is a way of rating the plastic or identifying the pin/socket shape or arrangement.



 
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

G/F DAVE

  • Guest
Re: A10 oil filtering
« Reply #21 on: 26.05. 2008 21:19 »
I have run a cartridge type filter & used 20/50 multigrade on my A10 plunger with no problems concerning oil usage.The scavenge side of the A7/A10 oil pump is of greater capacity than the feed, this is why you can see froth (bubbles) on return side if you peer into oil tank. Personally I think your problem with oil lies elsewhere.I would not run a plain bearing motor without a suitable filter & dont see the reason why such "experts" as SRM dont recommend them on the return to the tank .I also use this type of filter on my pre-unit TRIUMPH motor with plunger type oil pump also with no problems. I use a alloy sump plate with magnetic plug ,now this is always free of particles between oil changes .You take your chances when using the standard tea strainer filters as fitted by BSA which in turn must clog sludge trap quicker hence reduced oil pressure feed to big ends. BANG!!!!!   *doh* *doh*.ALL THE BEST G/F DAVE...

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5002
  • Karma: 48
Re: A10 oil filtering
« Reply #22 on: 26.05. 2008 23:29 »
Dave,

Can you tell us who made your cartridge filter and how you adapted from the armored lines to whatever thread is on the filter?

Richard

Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

G/F DAVE

  • Guest
Re: A10 oil filtering
« Reply #23 on: 27.05. 2008 10:11 »
Hi, Richard filter housing is a cast alloy one made by RGM that takes a citreon/harley spin on cartridge(check out ebay site ). Plumbing into the system is simple enough as on plunger A10,s oil union is connected to oil tank by rubber pipes .I have made a bracket that bolts to frame under the oil tank to mount filter .Filter housing has push on fittings so no threads just hose clips. Just make up extra length of pipe work ..easy..I think these filters were originaly made for norton commandos. If you need to fit one of these on a A10 swing arm model you just need new unions & pipe work for return side leaving feed pipe alone.I really can,t see these kits causing any problems only improvements. Also I know people that use oil cooler kits fitted at front of their frames, now with all that extra pipe work these must make extra work for the oil pump.But again they say no problems,I,m going to fit one of these to my TRI-BSA as on hot days (when we get them) will help keep motor cool in traffic also will gain extra oil capacity. Regards G/F DAVE..

Offline Dynamo Regulators Mike

  • A's Best Friend
  • ***
  • Join Date: Apr 2008
  • Posts: 165
  • Karma: 6
  • Fareham, UK, 1960 A10
    • Dynamo Regulators Ltd
Re: A10 oil filtering
« Reply #24 on: 27.06. 2008 11:48 »
I now have more to add to this thread after further mulling over and experimentation regarding my problem of increased oil consumption and frequent smoking on my A10 with return line filter fitted. I have carried out various tests both on the bike and on the work bench to try to get to the bottom of this. The world is divided into those who have seen problems with an return line filter fitted and those who have not.

Firstly using a borrowed gauge I confirmed that the scavenge pump vacuum was adequate and that there were no leaks to compromise oil pick up. A 0.9 Bar suck was seen. Then I borrowed a test block from local engineer, Bob Light, (of Hi-de-Hi filter fame) who used it in comparing performance of a series of A10 pumps, which work was presented in the BSAOC Star magazine. The block was set up to allow my small lathe to drive to the pump at an indicated speed, and provides convenient plumbing connections. The pump block becomes the heart of an investigative lubrication system employing a C15 oil tank and small plastic tray to represent the engine sump. A picture is attached with the pump partly obscured by a cover to catch much of the oil / grease flung from the worm drive. The pump I used for these tests was prepared by flatting the end plates and turned freely by thumb. Nothing special, just not brand new or completely shot, therefore hopefully representing a typical pump. The red plastic nozzle at the feed line outlet speeds the flow velocity giving a bit of a splash to include a little air, incidentally providing a small back pressure for the feed gears.

First the feed side pumping rate was measured as 4.3 cc per second @1000 rpm, and the return side 6.45 cc/s (from time to fill to a level mark in a jug). So this pump has 50% more return capacity than feed. Compare with a gear width ratio of 7/16? to 5/16?, suggesting a 40% higher capacity. Then I fitted a Vokes WDB40 filter in the return line. With the system running for a period of 10 minutes or so the overall aeration of oil in the loop increased, a very interesting finding. I then swapped the Vokes for the 2CV type formerly fitted to the bike. This filter again increased aeration after a good period of running, but not by as much as the smaller filter element.

The rocker feed flow proportion measured some 20% of the total flow in the return line (with open tube ? no rockers). With this returned to the plastic tray ?sump? as in the real system, the rate of clearance of extra oil poured into the tray fell markedly. This observation set me thinking. What if the rocker feed on my engine is too high? It has a silly old ?go faster? cast alloy finned rocker feed in place of the standard banjos. Is this less restrictive to oil flow? I fitted a piece of clear tube to the top end feed; there appeared to be no air inclusion and flow seems quite fast in the tube. If too much oil getting to top end then could be losing oil down valve guides (valves and guides replaced as necessary only 2k miles ago so not worn), and there would be a pronounced lag before the excess reached the sump to be scavenged. Maybe this could be part of why the exhaust more likely to smoke for a while after slowing down?

More questions than answers at this stage. Would like to see how the flow rates of the pump currently on my bike compares  with the one on the test rig. Where does change in aeration with filter fit into all this? My suspicion is that air inclusion has more effect that a couple of PSI backpressure on the scavenge pump. Different oils have different foaming characteristics. Anti-foaming is probably one of the additives skimped on with cheaper oil, and I am using cheap 20W50 for these tests. How typical is my rocker feed rate? It is easy to see a lot a variables here. Ratio of the tank stand pipe aperture compared with restricting holes in the rocker feed plumbing will affect proportion of oil to sump via rockers. Much of my testing was done at a convenient 1,500 rpm, a bit slow perhaps on reflection.

Hope this is still of some interest to forum members, it does all seem a long way away from the joys of pre-unit twin owning. But I just want to achieve the best reliability of the engine so I can ride it for thousand mile or more trips without concern or undue spannering. If anyone has details of standard rocker feed restrictions and dimensions I would very interested. (That was a question that came up somewhere on a message board recently but I could not find it again.) Any other suggestions while I am at it?

Cheers
Mike

Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL www.dynamoregulators.com

Offline LJ.

  • Peterborough UK.
  • Wise & Enlightened
  • *
  • Join Date: Jun 2006
  • Posts: 1403
  • Karma: 15
  • The Red A10!
    • LJ's Website!
Re: A10 oil filtering
« Reply #25 on: 27.06. 2008 13:08 »
This is very interesting stuff Mike thanks for putting the time in and writing up this for members to see.

I wonder if you also intend to try out different oils to see what results are obtained from them?

Please do keep us further updated of your progress.
Cheers!
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline a10gf

  • Wise & Enlightened
  • *
  • Join Date: Sep 2006
  • Posts: 2771
  • Karma: 42
  • West Coast, Norway & Alpes Maritimes, France
    • A10 GF
Re: A10 oil filtering
« Reply #26 on: 27.06. 2008 19:03 »
Mike, impressive work ! And absolutely interesting.

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 5002
  • Karma: 48
Re: A10 oil filtering
« Reply #27 on: 27.06. 2008 21:01 »
Mike,

Your thorough writing is not in vain. It is very interesting reading. I was thinking of trying something similar to see what the pressure output of the pump is at various RPM, however, I have neither thr lathe facility, pump block or, right now, time. In thinking about pressure, it occurs to me that to find that out for a given bike, it must be tested on the running bike, as each engine presents its own back pressure. Perhaps the "suck" is even more out of proportion, considering the delivery must make it through the entire maze of passages (including the oh-so-tight route through the crank). If this were true it would opt against wet sumping while running.

Regarding 1000-mile trips on an A10, not that I ever expect to come close to that, but my experience thus far would say that it might wear out the kidneys before the engine.

Richard
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Offline england kev

  • A's Best Friend
  • ***
  • Join Date: Mar 2008
  • Posts: 56
  • Karma: 0
Re: A10 oil filtering
« Reply #28 on: 28.06. 2008 11:22 »
In principle having a filter, even on the return, has to be better than not

Why?

These engines were designed by engineers not to have a filter, so why do we assume they would be better now with one.

Offline Dynamo Regulators Mike

  • A's Best Friend
  • ***
  • Join Date: Apr 2008
  • Posts: 165
  • Karma: 6
  • Fareham, UK, 1960 A10
    • Dynamo Regulators Ltd
Re: A10 oil filtering
« Reply #29 on: 28.06. 2008 12:30 »
Hi all, thanks for the words of encouragement.
Kev, the reason to fit a filter is to prolong engine life. Much engine wear is caused by initial wear particles circulating time and time again through bearing clearances and doing more harm, creating more wear. Known as regenerative wear in the trade. Engineers have known this for a very long time, and filters have therefore been fitted in many oil systems for a long time. Bert Hopwood, a key designer of our twins, or at laest his developmewnt team knew the benefits in the '50's. To illustrate, the BSA Daytona race winning bikes were fitted with additional external filters. But the cost accountants would not see it the same way. Added production costs and a more durable product does not help sell new machines.
Of course our lower revving engines last pretty well anyway but seems to me that longer yet intervals between precious rebores can only be good. It also means that modern oils can be used to better effect and changed less often. But that leads into other complex areas with as many opinions as voices. *eek*
LJ, I would test with other oils but the cost of doing it puts me off. Donations of oil samples for test welcome, about 4 pints is enough. ;)
Richard, the maximum suck capacity does not come into play in normal conditions unless testing for leaks. The crankcase pressure should be near atmospheric (mine measued at 2 to 3 inches of mercury under atmospheric from idle to a big handful of revs). The pumps removes the sump oil /air at a rate determined by the volume swept by its gears, hopefully a good bit faster than the rate of oil drain to the sump under steady conditions. But internal leakage in the pump will play a part, as it does on the higher pressure feed side. Leakage should be much less, I guess, with minimal pressure difference.
Hoping to remove the oil pump from the bike and set it up on the rig this weekend.
Will continue to post findings with the all important numbers where possible.
Cheers
Mike
Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL www.dynamoregulators.com