The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: rowan.bradley on 17.11. 2017 12:51

Title: SRM Replacement Oil Pump
Post by: rowan.bradley on 17.11. 2017 12:51
Does anyone have any experience of replacing an A10 oil pump with the SRM "A7 A10 Oil pump SRM Billet high delivery Improved"? Is this a worthwhile project? Are there any problems in fitting the pump? Are there any cheaper alternatives that I should consider?

Thanks - Rowan
Title: Re: SRM Replacement Oil Pump
Post by: cyclobutch on 17.11. 2017 13:24
I was once told that they were too efficient and because they circulated the oil so quickly it had less chance to cool down.

I think there are folks here who use them and rate them and will discount the above as BS. They'll be along shortly I'm sure.
Title: Re: SRM Replacement Oil Pump
Post by: ellis on 17.11. 2017 13:48
HI rowan.Bradley,
 I fitted one of these pumps to my 1960 A10 last year with no fitting or running problems. You will have to remove the original studs and also the small round spacing washer on the front stud as well as the main pump gasket. You will receive new Allen bolts in place of the studs along with an installation sheet.
I cut down an Allen key so as to use a socket onto a Torque wrench to tighten the screws. I do recommend using a small smear of Wellseal on the timing cover gasket to eliminate oil leaks. The pumps are expensive but well worth the money.

Regards
ELLIS   
Title: Re: SRM Replacement Oil Pump
Post by: scotty on 17.11. 2017 14:22
I installed one on my Golden Flash.

My experience is that it's good quality, easy to install,no fitment issues and it performs very well.

IMHO a worthwhile modification.

S
Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 17.11. 2017 16:06
First class high delivery and scavenge pump well worth fitting especially as the originals tend to warp. Have used one since 2009 and done over 30000 miles with it.
Title: Re: SRM Replacement Oil Pump
Post by: A10 JWO on 17.11. 2017 16:08
Top quality pump, the oil gushed round. Easy fit. No issues, get one for Christmas. Nice colour as well : )
Title: Re: SRM Replacement Oil Pump
Post by: rowan.bradley on 17.11. 2017 18:12
Thanks for those recommendations. I will consider fitting one if my pump looks in any way worn or damaged. I have not actually found the old pump yet (still sorting through many boxes of bits).  And maybe when I've found it I'll ask SRM to test the old pump as someone else suggested.

Thanks - Rowan
Title: Re: SRM Replacement Oil Pump
Post by: rowan.bradley on 17.11. 2017 18:20
I was once told that they were too efficient and because they circulated the oil so quickly it had less chance to cool down.
I think that suggestion violates the laws of physics. Things cool down at a rate proportional to the temperature difference between the hot object and the environment. Therefore the rate at which the oil cools will be dependent on the temperature of the oil. By moving the oil faster that can only make it hotter. Therefore it can only make to cool down faster.

Or put in more common sense terms, if the oil moves faster, each circuit the oil makes around the system may lose less heat. But it makes more circuits. And this latter effect outweighs the former, resulting in more cooling.

It's the same argument that says no to the often stated view that turning on and off the central heating uses more energy than just leaving it on. Again the heat loss is directly proportional to the temperature difference between the inside and the outside of the house. Therefore the more time you can manage with the house cooler, the less fuel you will use.

Thanks - Rowan
Title: Re: SRM Replacement Oil Pump
Post by: Billybream on 17.11. 2017 19:20
Please see listing on EBay for pump repair etc. Listed under BSA A10 Oil Pump.
Cannot vouch for or recommend but might be worth a try.


Listing description:-

Starting with a new 'A' or 'B' series oil pump gasket for the price of £1 up to a complete refurbished pump.

This listing is for a new gasket only but please contact me for more information on service exchange and rebuilt pumps, I will strip & check your pump free of charge and only charge you for the return postage if no work is carried out (tracked , insured & signed for postage)

Service exchange and new parts for oil pumps for A10 & A7 twins, Gold Flash, Rocket Gold Star, A50 & A65 BSA C10 to DBD34...

I will refurbish your old pump (depending on condition) or part exchange your pump for a refurbished one depending on stock. I keep a limited stock of refurbished pumps

The pumps are stripped & cleaned, all working surfaces are checked & cleaned & all sealing faces are lightly refaced,  the pump gears checked for wear and replaced if necessary, then reassembled with a new thrust washer & retaining spring clip The steel end plate is either re-machined or replaced with a new one depending on condition  (the scores in the end plate caused by use can cause the pump to lose efficiency and underperform)

'C & B'  pumps are also fitted with a new non return ball & retaining circlip.

Free gasket (and spacer washer for 'A' series pumps) included depending on stock & availability.

The pumps are run for 10 minutes to check for ease of movement and a good flow rate.

Please check my feedback for other satisfied buyers of these pumps.

Please remember that these pumps are all at least 50 years old and the Mazak alloy is prone to 'creep' and cracking so I examine all pumps very carefully before deciding if it's suitable for refurbishment, I do not charge for the examining or quotation but will charge postage if you want it returned untouched.

I have a limited number of Aluminium and Cast Iron pump bodies and will quote for these on request.

For an additional cost I can supply the A10/A7 pumps fitted with a brand new Rocket Gold Star type drive worm which has a slotted drive for a Tachometer, please ask for details.

My criteria is 'would I run this in my own bike?' if the answer is no then I won't sell it...

I send these by tracked signed for & insured delivery.

Any questions please email, or call 07721 022444







 
Title: Re: SRM Replacement Oil Pump
Post by: KiwiGF on 17.11. 2017 20:01
Does anyone have any experience of replacing an A10 oil pump with the SRM "A7 A10 Oil pump SRM Billet high delivery Improved"? Is this a worthwhile project? Are there any problems in fitting the pump? Are there any cheaper alternatives that I should consider?

Thanks - Rowan

A cheaper alternative is to upgrade to a used A65 pump, the A10 drive end has to swapped onto the A65 pump. The A65 pump has wider gears and gives more flow, same as the SRM one I’ve been (reliably) told. I’ve done this mod.
Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 17.11. 2017 20:44
Only the 1971/72 Oil in frame pump gears are higher capacity to the A10 - less teeth and wider scavenge gears.

The 1962-1970 gears are same dimensions as the 1956 on A10 gears, some gear part numbers being the same 1956 - 1970.
Title: Re: SRM Replacement Oil Pump
Post by: Greybeard on 17.11. 2017 23:00

Bantam John Phelan was doing high capacity new pumps made of steel and about half the price of SRM ones. Me and Dutch bought his pump. Working fine after four years. I don't know if he is still trading.
Possible phone number :01246290021



http://www.sumpmagazine.com/bsamotorcycles/bantam-john.htm (http://www.sumpmagazine.com/bsamotorcycles/bantam-john.htm)


And


https://www.pressreader.com/uk/classic-bike-uk/20160224/281685433907237 (https://www.pressreader.com/uk/classic-bike-uk/20160224/281685433907237)
Title: Re: SRM Replacement Oil Pump
Post by: chaterlea25 on 17.11. 2017 23:09
Hi Rowan,
I have fitted at least 4 SRM pumps to different A10 bikes
No problems,
I probably have 25,000 + miles on my own SR,
No wet sumping is a bonus

John
Title: Re: SRM Replacement Oil Pump
Post by: Tomcat on 18.11. 2017 06:10
I have one in my Super Rocket, they are 'fit and forget'.  *smile*
Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 18.11. 2017 08:19
Photo shows the gears used in the late A65, SRM and SDD oil pump. Scavenge gear much wider. All gears have 11 teeth compared with 14 on the 1956 on A10 pump so move more oil.

The SRM pump is a proven product from a well known, reputable and easily cotactable dealer.
Title: Re: SRM Replacement Oil Pump
Post by: duTch on 18.11. 2017 09:03

  I don't have an SRM pump, but as GB said .
 

 ........................ You will receive new Allen bolts in place of the studs along with an installation sheet. .....................
Regards
ELLIS
      *conf2*

 ....I stuck socket cap screws in for convenience, but have learned better and ( when I get some), want to replace them with original studs for better torque-down / anti-loosen / thread protection effect

Title: Re: SRM Replacement Oil Pump
Post by: rowan.bradley on 18.11. 2017 10:18
want to replace [socket cap scews] with original studs for better torque-down / anti-loosen / thread protection effect
Why are studs better in these respects? If they are, why do SRM supply socket screws?

Thanks - Rowan
Title: Re: SRM Replacement Oil Pump
Post by: KiwiGF on 18.11. 2017 10:31
Photo shows the gears used in the late A65, SRM and SDD oil pump. Scavenge gear much wider. All gears have 11 teeth compared with 14 on the 1956 on A10 pump so move more oil.

The SRM pump is a proven product from a well known, reputable and easily cotactable dealer.

Hi Julian, on request, I gave a couple of pumps I intended using to my engineer guy to assess (local brit bike expert) and who did a lot of work on on my 56 engine, he told me to use the one that had new A65 gears and the same flow as an SRM pump, I did not question him on this further, but to me both the pumps looked identical from the outside. I assumed, possibly incorrectly, that it was the tooth size (not necessarily width) that provided a higher flow rate.

Am I wrong in thinking this? Is the A65 pump different in other ways than just the gears and drive end? (I’ve not seen an A65 drive end, but I’ve read it’s different because the pump rotates the other direction to an A10).
Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 18.11. 2017 10:35
It is much easier to remove and replace the pump using socket cap screws.

It is not usually possible to remove a pump held with studs and nuts without removing the pump drive worm from the crankshaft at the same time as withdrawing the pump.

But as always it is a matter of personal preference.
Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 18.11. 2017 10:55
The A65 pump was subject to a number of changes over the years.

The first ones used the A10 main body, 67 1382, (but nut drive end) and the same set of gear - feed gear 67 1403 and 67 1404 - scavenge gears 67 1405 and 67 1406.

By 1968 it had gained an o ring at the drive end and a different body but kept the same gears.

The shaft closest the crankcase joint was extended into the drive end.

Then the bodies were changed and dowled together for better alignment.

By 1970 it still had one A10 feed gear 67 1404 and one A10 scavenge gear 67 1404. But the same tooth form and nuber would have been used by the replacement or it woild not have fitted together.

So to this point the gears were the same although some improvements were made to the body which no doubt made a better pump.

Then came the cast iron oil in frame pump, a much better pump altogether with wider gears and fewer teeth and no chance of distortion by age or bad fitting or over tightening.

The SRM pump is a quality item and I am very glad not to be running a zinc alloy bodied pump.

On this pump as said earlier the gears have 11 teeth rather than the 1956 pump with 14, the feed gears on the SRM are about 0.34 inches wide compared to 0.31 on the A10, and the scavenge gears on SRM pump 0.58 inch wide compared to 0.44 on the A10.

I first used a high delivery pump on the A10 in 1994 when SDD produce a super cast iron bodied one and have never looked back being confident that the engine was getting the best oil circulation and pressure possible.





Title: Re: SRM Replacement Oil Pump
Post by: a10gf on 18.11. 2017 11:11
It is much easier to remove and replace the pump using socket cap screws.

It is not usually possible to remove a pump held with studs and nuts without removing the pump drive worm

Unscrewing studs is possible, see removing it (https://www.a7a10.net/BSA/Oilpump.htm) and pump goes right out, at least works on my engine, studs not overtightened + good threads.

want to replace [socket cap scews] with original studs for better torque-down / anti-loosen / thread protection effect
Why are studs better in these respects? If they are, why do SRM supply socket screws?

imo...

Socket screws very practical vs studs very safe for threads (usually goes longer in, & thread strip over time will be located on nut side, not 'inside' the engine).

That said, if threads are excellent and it's parts that are not going to be removed \ refit for very long intervals, socket screws should work fine, probably why it's in the SRM kit. For removeable \ service parts like oil sump, I'd definitely stick to studs...
Title: Re: SRM Replacement Oil Pump
Post by: Rex on 18.11. 2017 12:16
Yep....poor engineering practice to replace studs and nuts with screws/bolts.... ;)
Title: Re: SRM Replacement Oil Pump
Post by: rowan.bradley on 18.11. 2017 12:50
Am I right that the argument against using screws/bolts is that you will be repetitively screwing a steel screw into an alloy tapping in the crankcase casting, whereas with a stud you will be screwing a steel nut onto a steel stud? And that if the nut or stud gets damaged or the thread strips, you can remove the stud and fit a new one, whereas with the screw you would be into helicoils etc.

Sounds reasonable to me. But I hope that once I've changed the oil pump I will very rarely need to remove it, and this seems to be confirmed by the people who have used the SRM pump and say that it is "fit and forget". So I don't think this is a big issue for me...

Thanks for all the advice - Rowan
Title: Re: SRM Replacement Oil Pump
Post by: bsa-bill on 18.11. 2017 16:18
Quote
So I don't think this is a big issue for me...

no - sometimes very very best practice is just not as practical as easy practice (been talking to Confucius )
Title: Re: SRM Replacement Oil Pump
Post by: Greybeard on 18.11. 2017 16:44
Am I right that the argument against using screws/bolts is that you will be repetitively screwing a steel screw into an alloy tapping in the crankcase casting, whereas with a stud you will be screwing a steel nut onto a steel stud? And that if the nut or stud gets damaged or the thread strips, you can remove the stud and fit a new one, whereas with the screw you would be into helicoils etc.

In the case of an oil pump it's not going to be disturbed very often so I can see an advantage of socket head screws in that they would make removing the pump easier. In other situations though, particularly the super-dooper drainable sump plate sold by SRM and others, socket head screws are supplied. This doesn't seem very sensible to me; the sump plate is likely to be removed fairly often and the socket screws can so easily be overtightened into your precious crankcases.

A tip if fitting one of these thicker sump plates that also have two gaskets with gauze between is to use the studs designed for the rocker covers. They are Whit one end and BSC the other and are a bit longer.
Title: Re: SRM Replacement Oil Pump
Post by: RichardL on 18.11. 2017 19:37
When I was first rebuilding my A10 (OMG! 13 years ago, now) I was not aware of a lot of best or smart practices. When I checked the threads for my sump plate, three were bad and one was good. I fixed the bad ones with the most available solution, that is, metric Helicoils, and left the one remaining original Whitworth. I use socket-head screws and, to this day, have to keep track of which hole gets the Whitworth. I tighten that one with less enthusiasm.

Richard L.
Title: Re: SRM Replacement Oil Pump
Post by: Sluggo on 18.11. 2017 20:47
The part about too fast oil flow is TRUE,, tons of engineering papers on this. (SAE)  Oil is a coolant and a lubricant.  If it flows too fast it does not pick up the heat or do the whole heat transfer thing it is supposed to be doing.  In addition, too fast is more friction.  Basic physics that shows the whole energy thing for every action there is a reaction.  Forcing a liquid requires force and energy, forcing it faster requires more.
But when you over pump lubes then you break down all the additives as well as Aerate the oil which is never good.  Oils ALSO have an optimum temp range.  (That in itself is a complicated topic)
Oil is very much a goldilocks situation.  Engineers calculate all this out for a design.. We can argue this all day but its pretty self evident that the oils BSA had in mind back in the 1950s is an entirely DIFFERENT concoction today.

The SRM pump seems to be a nice piece of kit, but for many of us is painfully expensive.  I have been intrigued by the idea of alternate fittings and was planning to research the late model A65 pumps for retrofit.  I have a few late model cast iron A65 pumps as well as the crappy alloy early A65 pumps and thats a future project.  I can snap some photos if helpful, but I dont have any A10 pumps handy at the moment.

In researching the A65 pump I ran across this page, and found it very informative.. well worth a look,
See: https://www.classicbritishspares.com/blogs/news/the-bsa-a65-oil-pump-journal-1962-1972

Pix, diagrams and text on the 3 types of A65 pumps on that page,,, here is what they say about the castiron pump.

" The BSA cast iron oil pump. Also known as the best oil pump and the rarest of them all. What makes the cast iron oil pump so sought after is the material in which it is made from. The earlier oil pumps before mid 1971 where made from a "pot-metal" alloy type material which is prone to wear and tear. I am not sure why it took BSA so long to develop a better quality oil pump. For those who own BSA unit singles, you will also notice that the 1971-1972 models had cast iron oil pumps installed. The problem with the cast iron oil pumps are, is that they are rare and expensive! The only alternative to the cast iron oil pump is going with a SRM oil pump. The cast iron oil pump can be fitted to all BSA A50 and A65 models from 1962-1972 and is the best upgrade in my opinion."
Title: Re: SRM Replacement Oil Pump
Post by: Colsbeeza on 18.11. 2017 22:16
Hi Sluggo,
Something does not ring true to me about heat transfer *????*. As flow increases, the heat transfer rate increases to a small power (roughly 0.23 if I remember correctly). That means that the fluid transfers heat more rapidly. So the temperature difference from inlet to outlet is lower.  Perhaps that is what you meant? The recirculating oil would average about the same temperature overall, as it is governed by the rate of heat transfer to the environment. eg. an original oil pump may see an increase of 50 C Degrees, but the SRM may see 35 C Degrees due to higher flowrate, and the oil tank temperature would be about the same as before or slightly higher due to the extra friction you mentioned.
Your other points eg, aeration etc. seem quite valid. *smiley4*
Do you have references to a couple of papers to clarify this.?
Seems from your argument that the main benefit from an SRM pump is better oil flow consistency and reliability, not increased oil flow.
From my readings, the presence of oil is more important than the oil pressure in plain bearings. Not sure if I can find a reference to that though.
Important to me, as I am contemplating purchasing an SRM pump or something reliable. However, if I win the lottery, I may be better getting a cast iron original. Do they fit the A10?
Yours was a great contribution to the subject.
Colin
 
Title: Re: SRM Replacement Oil Pump
Post by: Sluggo on 19.11. 2017 02:39
Hi Sluggo,
Something does not ring true to me about heat transfer *????*. As flow increases, the heat transfer rate increases to a small power (roughly 0.23 if I remember correctly). That means that the fluid transfers heat more rapidly. So the temperature difference from inlet to outlet is lower.  Perhaps that is what you meant? The recirculating oil would average about the same temperature overall, as it is governed by the rate of heat transfer to the environment. eg. an original oil pump may see an increase of 50 C Degrees, but the SRM may see 35 C Degrees due to higher flowrate, and the oil tank temperature would be about the same as before or slightly higher due to the extra friction you mentioned.
Your other points eg, aeration etc. seem quite valid. *smiley4*
Do you have references to a couple of papers to clarify this.?
Seems from your argument that the main benefit from an SRM pump is better oil flow consistency and reliability, not increased oil flow.
From my readings, the presence of oil is more important than the oil pressure in plain bearings. Not sure if I can find a reference to that though.
Important to me, as I am contemplating purchasing an SRM pump or something reliable. However, if I win the lottery, I may be better getting a cast iron original. Do they fit the A10?
Yours was a great contribution to the subject.
Colin

Oh good lord, sweet Jesus, Mary & the orphans thats a mine field right there,, (another oil debate...  *help*)
But I stepped into it.,.
So, what you are talking about has so many variables its possible to go in a lot of directions without strictly defining the exact conditions you wish to look at variables for,

Viscosity? Friction modifiers and additive content? Surface condition IE: Smooth or textured? Differentials in temp of the liquid vs surface? Those just come to mind, I am sure a full engineer could come up with a ton of other possibilities.  (I am only smart enough to be dangerous, dont claim to be a genius)

But this page might be a good start but you can read a LOT of articles just to get a nugget, but some are spot on.
See: http://topics.sae.org/heat-transfer/papers/

Fluid dynamics is a complicated topic,, but this looks fun!
See: http://papers.sae.org/2017-24-0041/

" During gasoline direct injection (GDI) in spark ignition engines, droplets may hit piston or liner surfaces and be rebounded or deposit in the liquid phase as wallfilm. This may determine slower secondary atomization and local enrichments of the mixture, hence be the reason of increased unburned hydrocarbons and particulate matter emissions at the exhaust.Complex phenomena indeed characterize the in-cylinder turbulent multi-phase system, where heat transfer involves the gaseous mixture (made of air and gasoline vapor), the liquid phase (droplets not yet evaporated and wallfilm) and the solid walls. A reliable 3D CFD modelling of the in-cylinder processes, therefore, necessarily requires also the correct simulation of the cooling effect due to the subtraction of the latent heat of vaporization of gasoline needed for secondary evaporation in the zone where droplets hit the wall. The related conductive heat transfer within the solid is to be taken into account.In this work, a preliminarily validated spray model is specifically implemented by solving the strongly coupled heat and mass transfer problem describing the liquid and vapor phases thermo-fluidynamics after impact and the wall change of temperature. The discussion is made considering a different boundary condition with respect to standard simulations. Sprays are assumed from to different injectors in order to verify the wallfilm simulation model: the impact over heated walls of the ECN “Spray G” is first discussed, by comparing numerical results with experimental measurements deriving from a combined use of the schlieren and Mie-scattering techniques, then the footprint on the wall of the spray delivered from a 6-hole Bosch injector is related with infrared thermography and LIF measurements taken from the literature."

This is another example,,,,
See: http://papers.sae.org/2016-01-0197/

" Prediction of Engine Thermal Behavior during Emission Cycle Using 1D Four Point Mass Model"

There are forums for specific engine design discussions and you can delve very deep into these topics,, Once you get into arguments with engineers things get very pedantic quickly....
Title: Re: SRM Replacement Oil Pump
Post by: muskrat on 19.11. 2017 02:52
 *???* *conf2* *doubt* *pull hair out* *countdown*
Title: Re: SRM Replacement Oil Pump
Post by: Sluggo on 19.11. 2017 07:31
Colin to be more specific regarding your question, I can directly say I have never owned a SRM pump, or seen one in person, more importantly have not reviewed the tech data related to flow, or volume.   But based on info I have heard and read, the 2 main benefits of the SRM is better quality of components, as well as ***I BELIEVE*** More volume.
The same can be said for the cast iron A65 pumps and both the blog I posted a link to, as well as reams of info I have read the Cast Iron A65 pump is the ideal BSA should have gone with to begin with, and same as what ***I BELIEVE***About the SRM pump is better materials, construction and more volume of oil.

As to fitting an A10, dont quote me on that but i saw references on this forum and others that it is possible to combine parts of the cast iron A65 pump with the A10 and make a A10 super pump.. but i have not confirmed that but something I am looking into.  But I would agree with you and my point is pressure is not that important, but volume is and consistent volume at that.

A good metaphor Is I enjoy building engines and American V8s commonly.  Depends on the application, but one constant I always strive for is optimizing the oil system and one product I always use is a Melling High Volume oil pump,. Take the Chevy V8 for example, Chebbys have stock an excellent oil pump and design right out of the box,  And while I dont build extreme race engines on the street anymore. (Not much fun to drive or own) I expect to flog the heck out of any engine.  So the Melling is a well engineered Oil pump and it appears to me, very similar to what the SRM pump offers.   The Melling is designed for a nice boost in volume but not too much, too fast, or too little.  (Goldilocks)   When installed I see a typical boost in pressure of 20-40% and Pressure was never the goal but it is a symptom and byproduct of the larger amount of oil volume.
In another topic I talked about interviewing the engine guys and crews for the IRL-CART race teams during their transition to synthetics.  In their case with the Chevy Illmore engines the synthetics ran with LESS pressure but more volume which was a big benefit due to the difference between a synth & Dino oil.  As well, those were multi million dollar motors and they had ZERO oil failures the previous season with the synthetics & if they had, The oil company promised to pay for the engine.

These old BSA engines dont need rocket science, but an interesting issue DOES exist.  I bet,, In fact I would wager if you COULD compile detailed data for Engines say... 1955 and take that same engine with a few upgrades and modern products such as superior synth multi grades oil, a return line filter and a high volume quality oil pump how would they compare under todays conditions???

I believe I know the answer.. I know a couple Hyper mileage guys with vintage Iron,, and they get obscenely high mileages out of these same clunky old engines.  Not only are they mechanically sympathetic, but the difference in materials means they can get extreme mileages between major overhauls or service that was never possible back with the same engine in the 1950s.

In Aviation school one of my instructors said the dumbest thing shops do is have a new guy doing engine tear downs.  Instead you should have one of the most skilled and knowledgeable do it.  Forensic engine analysis.  A worn engine will tell you vast reams of data if you look carefully and can interpret the info.

Besides the SAE papers,, of which there are thousands and thousands it appears, there is a number of forums that argue over this stuff. I used to Seagull a few of them but its exhausting.    One of the biggest debates I ever saw blow up was a discussion of oil shear under gear tooth changes in Gerotor style oil pumps (Which BSA have)  Some of the discussion got quite heated. 

This forum is one of those... See: https://www.engineersedge.com/engineering-forum/forum.php

You get interesting exchanges like this:

"Do a you have a geometric mathematical proof for "the explosion at the base of the closed cylinder doesn't just blow past the cylinders, but pushes them apart. "?

You need to expand on the physics explanation and evidence to move forward..
---------------------------
In the phase, or phase space, of the evolution of the combustion, it looks like beneath the cylinder at combustion a cross section of a torus, but what is actually a nonlinear oscillation that looks like this: https://www.google.com/search?q=osci...qgtdkG79s11qM:
So it is a nonlinear oscillation that produces the flame pattern.

I went to the link and it mentions a double well structure. The flame itself produced between the two hemispheres looks like a double cone, that looks like this: https://www.google.com/search?safe=s...QDgFxUKFLSFqM:
------------------------------------
This is not a mathematical proof of the concept. You need to model the physics and associated math... I don't think you're conceptually understanding the acting pressures correctly...
____________________________________
See? Flame trolls and articulated debate.. sheesh..  *fight*

But there is some really interesting ideas that have come out in the last 10 years challenging past beliefs..

See: http://papers.sae.org/2013-01-1643/

" Study of Motor Oil Cooling at Low Reynolds Number in Multi-Port Narrow Channels"

But perhaps this is all for nothing,, after all, The UK is probably going to ban these old clunkers anyway..

See: https://www.marketwatch.com/story/uk-to-ban-new-diesel-gasoline-cars-by-2040-2017-07-26?utm_source=fark&utm_medium=website&utm_content=link&ICID=ref_fark

The internal combustion engine was dealt another blow on Wednesday when the U.K. pledged to ban the sale of new gasoline and diesel cars by 2040, following a similar move three weeks ago by France.

While far from a knockout, the decisions by the U.K. and France--which together account for about a third of new cars sold in the European Union--are among the most aggressive moves by governments recently to legislate away the traditional gasoline- or diesel-burning engine, which has been for more than 100 years been the preferred method of powering passenger vehicles.

For decades, governments have struggled to rein in the pollutants the engines caused but with few alternatives have balked at banning them outright.

Volvo's recent announcement that it would only sell fully electric or hybrid cars starting in 2019 and the arrival of Tesla Inc.'s $35,000 Model 3 have put further pressure on gasoline and diesel engines.

"We can't carry on with diesel and petrol cars, not just because of the health problems, but also because the emissions they cause will accelerate climate change," U.K. Environment Secretary Michael Gove said in an interview with the British Broadcasting Corp.

More on that page.........



Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 19.11. 2017 08:53
The drive ends are completely different between A10 and A65 pumps. To use the A65 iron body you would need an A10 drive end.

There was a very nice cast iron A10 pump made in the mid 1990s by Stuart Digby Developements, used the late A65 gears and had the o ring seal and shaft which extended into the drive end.

A real quality item but I dont think many were made.

I bought one in 1994 - cost new then almost £200.

Good parts seldom come cheap.
Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 19.11. 2017 09:14
Worth reading this thread includes side by side photo of A10 and A65 pumps.

https://www.a7a10.net/forum/index.php?topic=5829.0


To clarify - both pumps rotate in the same direction - different worm drives needed to maintain the direction due to the different position the drives go into the pumps.
Title: Re: SRM Replacement Oil Pump
Post by: Triton Thrasher on 19.11. 2017 09:24
I was once told that they were too efficient and because they circulated the oil so quickly it had less chance to cool down.

I think there are folks here who use them and rate them and will discount the above as BS. They'll be along shortly I'm sure.

The bigger or better pump maintains oil pressure when the oil is hot and thin and clearances may have opened up with expansion.  When full pressure is reached, excess pumped oil passes through the relief valve to the sump and is scavenged back to the tank.

If that fills you with overheating terror, stay away from the bigger or better oil pumps.

I can’t say Sluggo’s quote about bouncing petrol droplets convinces me of anything except that he likes to type.
Title: Re: SRM Replacement Oil Pump
Post by: mikeb on 19.11. 2017 09:44
Quote
Are there any problems in fitting the pump?
i was very sad when fitting a srm pump to my a10 as i could no longer look at it and marvel at the beautiful blue colour. almost as sad as enclosing my new thunder rods from view. crazy money but after a $$++ rebuild I thought of it as cheap insurance. would do it again
Title: Re: SRM Replacement Oil Pump
Post by: Greybeard on 19.11. 2017 09:53
i was very sad when fitting a srm pump to my a10 as i could no longer look at it and marvel at the beautiful blue colour.

Great marketing. It certainly looks like it might be made of magic!
Title: Re: SRM Replacement Oil Pump
Post by: mikeb on 19.11. 2017 10:00
Quote
It certainly looks like it might be made of magic!
anything that keeps my a10 running smoothly IS magic!
Title: Re: SRM Replacement Oil Pump
Post by: KiwiGF on 19.11. 2017 10:52
I was once told that they were too efficient and because they circulated the oil so quickly it had less chance to cool down.

I think there are folks here who use them and rate them and will discount the above as BS. They'll be along shortly I'm sure.

The bigger or better pump maintains oil pressure when the oil is hot and thin and clearances may have opened up with expansion.  When full pressure is reached, excess pumped oil passes through the relief valve to the sump and is scavenged back to the tank.

If that fills you with overheating terror, stay away from the bigger or better oil pumps.

I can’t say Sluggo’s quote about bouncing petrol droplets convinces me of anything except that he likes to type.

Yep, sluggo needs to spend more time in the shed, less on the keyboard  *whistle*
Title: Re: SRM Replacement Oil Pump
Post by: BSA_54A10 on 19.11. 2017 11:08
once again, Sluggo, has produced some really interestig reading, which is why I like a lot of his postings.
But again I would scream "Relevance Your Honour".
There are so many engineering shortfalls in our engines , arguing obscure points of physics is some what a moot point.
The original A7-10 oil pump was up to the job right up to highest performance variation made.
Now like everything else it wears out and new ones have not been made for decades.
If you are going to tool up to remake an obsolete product it makes good sense to upgrade that product particularly if the upgrade does not cost any more than remaking an exact copy of the original item.
Thus the SRM oil pump is a sound item in both engineering terms and in marketing terms.

As for oil pressure being irrelevant , there are of course limits.
Too little pressure and the oil will not be able to float the bearings.
Too much and the flow of the oil itself will erode the surfaces that it flow across.

Title: Re: SRM Replacement Oil Pump
Post by: duTch on 19.11. 2017 22:36

 
Quote
Why are studs better in these respects? If they are, why do SRM supply socket screws?


As stated above, threads can wear with constant use, but moreso (mostly) under tension in or out.
 The finer BSC thread gives a better purchase for less effort, and in theory (my mind) will withstand vibration-loosening better.
 My plan (When necessary) is to use a locknut pair to undo the screws after slackening the holding nut.
  To those who say "fit and forget",  I say **** *eek***  (not really a good idea to forget stuff like that- *Note to self; the Gutzzi pump is buried a bit deeper).
 Do you ( 'second & third persons' ) never open the cover to check your dynamo hum (drive-chain/belt), or drain the ~70ml of oil when doing an oil change, or even check the magneto nut is tight?

 So GB, where does that put us?
 Before installing my Cast-body pump, I think I may have run kero or petrol through to make sure it  was clean and prime with fresh oil to ensure function, but didn't do what I usually do with a new toy and pull it apart to see how/why it works (so I know what did do when it doesn't work when I put it back together).... now I really wanna know what's in there...

 In addition, I read a mention on another site while searching for replacement filter heads, that; ".. the only part of an engine that receives unfiltered oil is the Oil pump..." ....
Have a nice day
 
Title: Re: SRM Replacement Oil Pump
Post by: Colsbeeza on 20.11. 2017 02:57
Thanks Sluggo and others,
I am sure that when I "fixed" my pump 25 years ago, I was unaware of all these issues (having no internet). The motor was undamaged, but bearings worn beyond acceptable limits. I dismantled the oil pump and used 1200 Wet & Dry emery paper on a sheet of glass to work the end plate until most of the grooves and wear was removed.  If memory serves me correctly, I think I also did the same to the end of the pump which mates with the end plate, to make allowance for the wear behind the gears. When assembled, it was a little firm, but not too alarming. And I did remember the little fibre washer spacer under the end of the pump.!
As I am sure it was the original pump from the bike, I wasn't too concerned about other issues and certainly not alignment of components. Anyway, it is in the bike and pumping a treat.
However, the outcome of all this theory on this Forum is that I may have contracted "Oil Pump Paranoia" - one who watches the oil pressure gauge constantly until I run it off the road, or at the very least rob me of all riding enjoyment.
So if I go down the SRM route in the absence of other alternatives, I will rely on the experiences recorded in the Forum -
In summary - Most owners with SRM pumps have not experienced any problems, nobody has said that the increased oil flow has worn out the bushes, nobody has reported that bubbles have destroyed their motor. Most have relaxed their concerns after a time. Perhaps all have been very satisfied with the outcome. So who am I to argue with that.?
And one doesn't have to get too theoretical to understand that the increased flow potential should improve bearing float/support when motor is hot and under load and thus reduce wear much more than extra friction may increase wear.??
I accept that the pressure relief valve setting then becomes quite important, so I will be watching that. 60 psi you say.??
In the meantime, I have just re-joined my local Vintage Motorcycle Club after an absence of 11 years, but belatedly realised that for all new members I must attend 3 monthly meetings before members vote to accept my application. The first was 4th November. Then - the machine examiner will pass or fail my bike before I get to ride it and sort out any issues. So all going well, I may be able to report progress about the end of January. I suppose I can fill in time with a few outstanding jobs - like replacing the "new" but 25-year-old Cheng Shin tyres I stuck on it then - just ordered Avons.!
One issue though - I read but cannot find the reference to oils on the Forum, where Richard "Orabanda" mentioned that he used Penrite 25W-70 oil. It sounded perfect to me, so I have filled my bike with it, assuming that it's 25W rating was less viscous that a straight 30 monograde - but just read it's Data Sheet that it's viscosity is 290 CSt at 40 DegC whereas other oils generally are only about 100 CSt. That now seems way too high, although it pumps OK - plenty coming back via the Return. Something isn't hanging together there, and I don't want to run it until I can sort it out *dunno*. I knew I should have done more research.!! Can any one tell me where that reference is? or can Richard comment.? I am sure he would have done the research.!! I have 10 litres spare at A$50 per 5 litres, so don't want to waste it. Happy to pursue that on an appropriate Oil forum. Second thoughts - I will post this bit on an appropriate Oil subject on the Forum.
Cheers
Col

Title: Re: SRM Replacement Oil Pump
Post by: orabanda on 20.11. 2017 06:07
Hi Colsbeeza,
Penrite used to call this oil "Enduro".

I have attached a data sheet. As they spell out, it has high zinc content (excellent for our pushrod bikes), and is designed for Hardly Davidsbums and BSA twins.

I have been using it for 20 years; no engine rebuilds yet!

Re the SRM pump, good kit; superior (lower wearing) materials to the 70 year old BSA pumps. If they produce more flow, that is to the advantage of the engine, in both the bearing delivery (pressure), and scavenge stages.

The parasitic power loss is insignificant, but greater flow rate to the crankshaft will result in higher oil pressure when the engine is hot, and greater flow return is likely to aid cooling.

Richard
Title: Re: SRM Replacement Oil Pump
Post by: Colsbeeza on 24.11. 2017 11:49
Thanks Richard,
Enduro has the same specs, so must be just a name change.
I have had some advice that for running in, a mineral oil with no additives except high Zinc is ideal. I might lash out for some Penrite Running-In oil, which has high Zinc. It is 15W-40, so I imagine putting up with wet-sumping until run-in is complete. I have a new camshaft and cam followers, so a bit wary of running without Zinc.
Colin
Title: Re: SRM Replacement Oil Pump
Post by: peter small on 30.12. 2017 18:58
Fitted SRM pump on my 1954 Road Rocket
Great delivery much better than original although it still wet sumps.
Did ask SRM about wet sumping they said it still would the pump would not correct it,
They told me the truth impressed,
Title: Re: SRM Replacement Oil Pump
Post by: cableguide on 01.01. 2018 17:23
And as I always say to anyone spending big bucks on these superb pumps....spend time cleaning out the hard gritty gunk in the oil tank nooks and crannies....I always take mine to the garage after a poke about and lengthy soaking and blast the insides with the power wash....
Nothing worse than doing all that work only to find those little bits of crud have broken free and scored up the pump chambers.
Title: Re: SRM Replacement Oil Pump
Post by: A10 JWO on 01.01. 2018 18:08
My 1954 still wet sumped after fitting the new pump from SRM, BUT I am pleased I bought it; quality : )
Title: Re: SRM Replacement Oil Pump
Post by: chaterlea25 on 01.01. 2018 20:00
Hi All,
There are several leakage paths that cause wet sumping on A10's

Quote
Did ask SRM about wet sumping they said it still would the pump would not correct it,
They told me the truth impressed,

A new pump will only solve some of the leakage path's
1, through the pump drive spindle and porosity /leakage between the pump parts,
2, through the pump gears and into the oil feed system when the anti sumping anti drain ball does not seal as it should
No 2  can be resolved by either an engine strip or modifying to the A65 position of placing the ball against the rear delivery port of the pump

It takes some extra work and £$€'s to reduce the wet sumping to minimal levels  *sad*
But worthwhile in my opinion *wink2* *good3*

John
Title: Re: SRM Replacement Oil Pump
Post by: RichardL on 01.01. 2018 21:35

2, through the pump gears and into the oil feed system when the anti sumping anti drain ball does not seal as it should
No 2  can be resolved by either an engine strip or modifying to the A65 position of placing the ball against the rear delivery port of the pump

It takes some extra work and £$€'s to reduce the wet sumping to minimal levels  *sad*
But worthwhile in my opinion *wink2* *good3*

John

John,

Is it fair to say that changing to the A65 ball.arrangement doesn't automatically solve wet sumping due to ball seat, but makes it easier to create and maintain a good seat? Last time my cases were apart I created a tool with a ball glued to the end of an aluminum tube and used that with valve lapping compound to create a good seat for a new ball. Has held well, so far. Ahh, just realized I am going to get heat for introducing grit to the oilways, but I am pretty certain my tediuos washout efforts were successful.

Richard L.

Richard L.
Title: Re: SRM Replacement Oil Pump
Post by: muskrat on 01.01. 2018 22:07
G'day Richard.
My thoughts on your method. Even with your impeccable cleaning there is a chance of lapping compound particles being embedded in the aluminum seat. This would wear the ball and create minute high spots in the seat.
My method is to buy two balls and use one to repair the seat. Pop it in the hole and give it a light tap with a pin punch and hammer. Throw that ball away and use the other. 7 years since I did the cafe, she might wet sump about 1/4 cup in a month (not that she goes unused that long). I did rebuild my original pump at the same time.
Cheers   
Title: Re: SRM Replacement Oil Pump
Post by: chaterlea25 on 01.01. 2018 22:47
Hi Richard
Quote
Is it fair to say that changing to the A65 ball.arrangement doesn't automatically solve wet sumping due to ball seat, but makes it easier to create and maintain a good seat

Probably

Lapping or tapping the ball into the seat widens the contact area, so the spring pressure per sq mm. drops in proportion

The issue with the A65 arrangement is preventing the gasket from interfering with  the ball seating
It took m a couple of attempts and a home cut gasket to sort it

John

Title: Re: SRM Replacement Oil Pump
Post by: JulianS on 02.01. 2018 09:49
For alloy bodied A65 pumps BSA recommended tapping the ball onto the seat  to get a good seal. For A65 ball/spring assembly.

I did not need to do that with my SRM pump.

Best pump gasket to use is the SRM type which has the holes in the right places and holes the correct size and which extends to the front mounting stud. Avoid the gaskets with tiny holes.

Photo shows the SRM gasket left, a new old stock A10 one at top right and a nasty cheap pattern one at the bottom right.
Title: Re: SRM Replacement Oil Pump
Post by: chaterlea25 on 02.01. 2018 22:12
Hi Julian and All,
The SRM gasket was not available when I built my SR and other A10's so I cut my own,
I make sure they are a tight fit on the stud holes so they cannot move in relation to the the oil delivery hole (especially)
I have another A10 engine to do soon so I may try the SRM gasket

John
Title: Re: SRM Replacement Oil Pump
Post by: worntorn on 02.01. 2018 23:00
Is there a specification for pump outputs, for example  return flow rate at idle or some other Rpm with a new stock pump and also the SRM pump?

Glen