Which Oil?

[LynnLegend]

Thanks all for your very knowledgeable replies!

[Sluggo]

Peter I am not familiar with that brand, but You in Oz & me US, so, the issue is that many auto type filters use a flap or check valve

(most seem to be a nitrile or rubber like disc inside if you cut open a filter which is never a bad idea to see what each brand is made of)

On many cars this is intended to prevent wet sumping or at least all the top end oil draining back.
(is my guess, intuition, assumption)  Many only allow flow one direction, or limit flow to over a certain pressure.  I have not talked to any filter engineers or designers so I am speculating on motives here.  But I can say with experience is that when applied to a Brit bike with our creaky old oil systems Most RETURN side of the pumps tend to be overgeared compared to the inlet side.  (Theres ratios for people who care to look) But as a result at lower RPMS the pump is cavitating a bit on the return and lots of air and bubbles so pressure is actually quite sporadic and iffy at low RPMS.  At higher RPMS most pumps have a sizable stream squiriting into the tank, But at low RPMS you can see 2-5 PSI on a roller bearing bottom (IE Goldstar-B33-B34 etc)
or on many twins 5-7 psi then that might not be enough to move past the filter if restricted.
That means you are repeating the Norton Combat problem in reverse (oil puddles at high RPM on the Combat cases)    Fred does a good job explaining that at Old Britts,,, Worth a read
See: https://www.oldbritts.com/n_c_case.html
But on a old BSA you could have a sizable, albeit alarmingly high amount of your oil capacity backing up in the engine. (Some of these preunits have small oil tanks) Before your pump picks up enough and pressure to move that oil back to the tank.

So, dont know if you have access to a Norton Commando filter but if you do, you can move air freely thru the filter media in BOTH directs..THAT is what you want. Unimpeded flow. IF there is any restriction in any either direction I would strongly recommend you not use that type filter.
Nobody is restricting people to a Norton filter.  Theres cross references to suitable filters for a number of cars that will work. (Note *IF* using a Norton filter base, some use different threads than a std car.  Check threads. Dont load up shavings and metal fillings or worse have the filter fall off)

I have bought Harley filter bases from the dealership take off sale depts.  Some HD model uses a remote filter base.  But again check the filter you are installing. But they tend to be small bases, nice alloy finish or some textured black material.  And, filter availability tends to be good.

One other note. On some car applications they run a check valve in the housing itself, this tends to be a 10-12mm small spring loaded disc.  Those are a safety valve where if a forgetful owner runs a clogged filter it bypasses the filter entirely and floods the engine with unfiltered oil as a safety measure. (Dirty oil is better than NO oil).  These types of filter bases are not a great idea for a vintage Britt bike.

[Peter in Aus]

Thanks Sluggo, I can see I will have to do some looking around, it is obvious the filter I am using is not suitable
Cheers
Peter

[BSA_54A10]

Again for older engines I buy tractor and ag supply oil as it has the zinc we need.  Delo 400 is also used in many Diesel pickups as well and has been a reasonable choice.  Big Blue bottles
See: http://www.deloperformance.com/en-us/products.html    Multiple choices for weights...

No problems here, know lots of people who have diesel cars & used diesel oil in their bikes without problems


I have a frequent rant about filters but the short version is a return line filter is a must have item on any of my british bikes unless built for show only. I only have one bike I am considering not using one on. A full flow Norton commando type filter is what I use but sometimes use aftermarket mounts, but sometimes the norton ones. The key issue that some people have argued about, I still insist only one type filter is acceptable on these old bikes.
You must test the filter and many modern ones have a internal flap or check valve limiting flow. the idea is to prevent backflow or sumping but they only operate over a certain pressure.
BAD FOR OLD BRITT BIKES!   This results in the oil sumping until pressure is high enough for flow which can be a disaster.
The test can be embarrassing in public but you place your mouth over the opening and make sure air flow can move thru the filter.  Once you ID filters that are acceptable many places have a cross reference for similar filters.

Never hear of an automotive oil filter with a check valve so what car takes them ?
OTOH I have 28 different transmission oil filters that all have check valves in them but as they are 4 times the price of an auto filter I could not see any BSA owner buying one of these.
In fact they are all big filters with a substantially bigger thread to prevent idiots fitting them to their cars so I doubt that any would fit in the first place.
And if they did the filter grade 5-10 micron is so small that 30W oil would not flow through it in any case.


I will make a point about oil grades and thickness. While I agree that a thicker oil will leak less, and run quieter,  Its exactly what you DO NOT WANT.  I was taught by a old master in aviation school about oils and learned as well in multiple test labs  (POL=Petroleum, Oils & Lubricants)
from techs much smarter than me.  Oil FLOW and VOLUME is what you want.  Thickness (Viscosity) results in poor flow and actually friction in itself.  Thick oil resists flow and is hard on the pump, and components.  High pressures are an indication of friction and resistance to flow.
Much better to have low pressure and high volume than high pressure and low volume. 

However this while having some fact in there ( Viscosity is a measure of the friction of the oil ) what you are advocating might apply to aero engines but is utter crap in so far as an A 7 / A 10 engine.
The oil clearences on BSA's and engines DESIGNED BEFORE WWII are massive compared to modern engines.
No where in the engine is there a metered oil way and running high volume low pressure oil flows will result in extreme wear if not a thrown left rod.
The engines were designed to have a specific flow of oil traveling between the surfaces and this takes into account the viscosity of the oil creating enough back pressure to prevent all of the oil draining at the timing side bearing.
End fed cranks might get away with it but no BSA twin will.

We used to run very light oil in the race bikes, ( Good for an extra 2-3 Hp ) but they got pulled down after every meeting and we changed bearings on them more often than I change my undies

Of course a thinner oil will leak more but thats a seperate issue.  When your BSA is not marking its spot its probably out of oil.
There is a number of things you can do during a rebuild to optimize lubrication but thats a seperate topic.

I grilled one of the lead crew chiefs for Rahals team in the old indy car series when the synthetics were first coming out, and they were sponsored by Penzoil,  During the Chevy Illmore era.  They were alarmed at extremely low pressure readings during car testing. A call to Penzoil and their techs was a response of "No problem, run it!"  When they continued to express doubt
Penzoil said "If you can show any engine damage linked to lubrication we will buy/pay for your motors replacement"  These motors were a sizable chunk of money.  The engine and crew chief techs told me at the end of the season they did not have one engine failure related to lubrication.  That was pretty compelling to me.

[BSA_54A10]

Peter I am not familiar with that brand, but You in Oz & me US, so, the issue is that many auto type filters use a flap or check valve

(most seem to be a nitrile or rubber like disc inside if you cut open a filter which is never a bad idea to see what each brand is made of)

On many cars this is intended to prevent wet sumping or at least all the top end oil draining back.
(is my guess, intuition, assumption)  Many only allow flow one direction, or limit flow to over a certain pressure.  I have not talked to any filter engineers or designers so I am speculating on motives here.  But I can say with experience is that when applied to a Brit bike with our creaky old oil systems Most RETURN side of the pumps tend to be overgeared compared to the inlet side.  (Theres ratios for people who care to look) But as a result at lower RPMS the pump is cavitating a bit on the return and lots of air and bubbles so pressure is actually quite sporadic and iffy at low RPMS.  At higher RPMS most pumps have a sizable stream squiriting into the tank, But at low RPMS you can see 2-5 PSI on a roller bearing bottom (IE Goldstar-B33-B34 etc)
or on many twins 5-7 psi then that might not be enough to move past the filter if restricted.
That means you are repeating the Norton Combat problem in reverse (oil puddles at high RPM on the Combat cases)    Fred does a good job explaining that at Old Britts,,, Worth a read
See: https://www.oldbritts.com/n_c_case.html
But on a old BSA you could have a sizable, albeit alarmingly high amount of your oil capacity backing up in the engine. (Some of these preunits have small oil tanks) Before your pump picks up enough and pressure to move that oil back to the tank.

So, dont know if you have access to a Norton Commando filter but if you do, you can move air freely thru the filter media in BOTH directs..THAT is what you want. Unimpeded flow. IF there is any restriction in any either direction I would strongly recommend you not use that type filter.
Nobody is restricting people to a Norton filter.  Theres cross references to suitable filters for a number of cars that will work. (Note *IF* using a Norton filter base, some use different threads than a std car.  Check threads. Dont load up shavings and metal fillings or worse have the filter fall off)

I have bought Harley filter bases from the dealership take off sale depts.  Some HD model uses a remote filter base.  But again check the filter you are installing. But they tend to be small bases, nice alloy finish or some textured black material.  And, filter availability tends to be good.

One other note. On some car applications they run a check valve in the housing itself, this tends to be a 10-12mm small spring loaded disc.  Those are a safety valve where if a forgetful owner runs a clogged filter it bypasses the filter entirely and floods the engine with unfiltered oil as a safety measure. (Dirty oil is better than NO oil).  These types of filter bases are not a great idea for a vintage Britt bike.

Most oil filters have a bypass valve. usually set at around 5 to 14 lbs/Sq" .
This is no problem unless you fit the filter backwards where the tired old bad design BSA pump can in fact blow them apart.
Problems with Notruns are no problems with BSA's and applying the Notrun fix to BSA's is a fools errand.
A 7 engines with the std A 7 oil pump have been used very successfully in go carts for years till they got uncompetative with the Maco & Rotax engines.
These engines were running at speeds up to 7500 rpm & I know of one where clock springs were added to the rockers so the owner could get 8500 out of the engine ( braver man than me )
Now these ran special racing rods and a few other trick bits  but retained the std oil pump.
Mortons were running midget cars, some with A 7 engines in as well and again these ran std BSA oil pumps without problems, on dope pumping caster oil.

As for having al alarmingly high amount of oil in the sump , garbage.
We all know exactly what happens when you get better then 200cc of oil in the sump.
Instant smoke screen we have all been there at some time in our lives.

Commandos have a very long stroke and a very bad crankcase design because it started out as a 350 and go overblown to 860.
The A7 was designed as a 500 from the start and then the engine got squared off which drastically changed the charasterics of the pressure pulses.
Crankcase pressure forces oil into the return side of the pulp just the same as it does with every other possible escape path.
Very little of what goes on inside a Notrun is directly applicable to a BSA.

[JulianS]

My simple view;

Oil- I use Morris 20-50 Golden Film in my A10.

 Have used 20-50 multigrade since I bought it in 1973, staring with the then common green Duckhams Q20-50. Has done many many miles including commuting to shift work summer and winter. Never had a problem with multigrade.

Filters - Rocket 3 type in cannister - worked fine and no problems, difficult to mount to allow it to clear everything and be easy to change. (used 2 years)

Next tried commando type various different makers filters - worked fine and no problems but difficult to mount to allow it to clear everything and be easy to change  unless fixed in tool box. Did not like giving up tool box and thought the oil line a bit too long. (Used over 10 years)

Finally chose a Morgo compact type and have been using it the past 3 years. Easy to mount and change filter. Works fine no problems.

Not had any problems with oil backing up in the sump.

[chaterlea25]

Hi Sam,
Ask you Grandad what oil he used, being a farmer it was probably what he bought by the 5 gallon drum?
(At least that how it was when I grew up on a farm!!)
If the bike was ok on that oil I would continue with the same ??

I run my A10 on Castrol Classic 40, same brand of oil for the last 15 years
All the other A10's and otherbrit twins I build get the same medicine

John

[Black Sheep]

I used to run my Norton on Agricastrol 40. I did meet a guy (an industrial chemist) who ran his BMW on hydraulic oil, swearing it was very much better than any engine oil. Haven't tried that. Morris's 20-50 or Castrol XL 40, depending on the bike, work for me.

[RichardL]

Hi,

Can anyone give some advice on what kind of oil I should run in my A10?












 

Richard L.

[Zander]

Hi,

Can anyone give some advice on what kind of oil I should run in my A10?

Oily oil is best












 

Richard L.

[edboy]

of course, there is always the bsa manual when your options are exhausted. was it sae 40 in summer? and sae 30 in winter?

[Rgs-Bill]

of course, there is always the bsa manual when your options are exhausted. was it sae 40 in summer? and sae 30 in winter?

    VALVOLENE VR 1 (RACING OIL )  still has 14 ppm of the zinc we need it comes in mono grade, for 45 years in my 62 RGS I have used 40 weight mono grade , year around in Seattle Washington U S A , temps never get hot enough to use 50 weight. the bottom end has never had to come apart, top ends has had 3, in 45 years.  It is low detergent so the sludge trap will still work.  You do not want detergent oil unless you have an oil filter, which I do not. Change it whenever I drain the sump, (wet sumping ) and feel any grittiness in the oil when rubbing between my fingers.  45 years has to say something for the original engineers, and using mono weight, non detergent oils ! !   If you use multi weight detergent oils, 20/50 say, and do not have a filter, the metal particals are not getting taken out of the oil by the sludge trap, they just keep going through your bearing surfaces causing more and more wear.

[Sav]

Silkolene Chatsworth SAE 40 Classic & Vintage Monograde Mineral Engine Oil in my A10Sr and A7ss

[mikeb]

Lynnlegend - easy to overthink this one right? like who knew oil was so complicated? from my reading of 100  threads:

if you have a filter and clean sludge trap: a modern like penrite 20-60 (here in NZ/Aus, not sure if UK) which has extra zinc. zinc is good for our cam followers etc

if you don't have a filter then don't use a 'modern' detergent oil. use Morris 40 - they make it in your country.

if you are unsure use Morris 40. change it every 1000 miles or less.

and Richard:

Can anyone give some advice on what kind of oil I should run in my A10?

you are not entitled to ask that question

[Greybeard]

I use Morris SAE 40 with a clean sludge trap and a return line Norton type filter. Also, frequent oil changes, (I bought a 5 gallon drum to save money).  Also, I fitted an alleged high capacity oil pump from Bantam John Phelan. Belt-and-braces, me?