Oil change on 1957 50/350

Dave, Never heard of this before, especially at this time of year. All I can think of is that you started with a very low oil level. What colour is the spark plug? Running lean is another issue. Also long periods at standstill when alreadyhot. Then there is partialoil starvation but only to a minor degree. I wonder what grade of oil you are using? I use SAE 40 all year round in my singles but top up with SAE 30 during the winter. These days we generally don't get weather warm enough to warrant SEA 50 that much, though if no other problem found it sounds like you may need it?

Not sure about flushing but would be interested to know why she overheated? I'd look for the cause before going any further.

Maybe it is time to forget about using these obsolete monograde oils which have no guarantee of performance quality and change to a modern 15W40 or 15W50 multigrade oil?

By ' burnt the oil' do you mean that it has disappeared with a fog of smoke or that the oil is horribly black?

I would be a bit wary of going for a thin multigrade oil for a low oil pressure roller big end. I stick to SAE 40 for my singles, multigrade for twins with plain big ends. If the oil has gone filthy black very quickly, it could be the engine is running much too rich.

With your description of your initial running before setting off and with the use of SAE 50 oil, you certainly could not overheat the oil as you say. All oil becomes very black with use and it will probably be still okay.

I use Castrol 20W/50 in my 1961 Model 50 and have never had any trouble whatsoever. When it is hot weather it will take on the consistency of SAE 50 and when it is cold it will flow better than SAE 50. On long runs the machine will turn in almost 100 mpg running at speeds of up to 55 mph.

I must point out that I do have a tap fitted on the oil feed line to stop wet sumping when the bike is not run for long periods.

Regards,

Previously Gordon Johnston wrote:

I would be a bit wary of going for a thin multigrade oil for a low oil pressure roller big end. I stick to SAE 40 for my singles, multigrade for twins with plain big ends. If the oil has gone filthy black very quickly, it could be the engine is running much too rich.

My response is:-

When you compare the amount of oil that a two stroke roller bearing big end receives in say 80 miles, it is negligible to the amount of oil that passes through the big end bearing on our Model 50's.

My BSA bantam uses a total of 200 cc of oil in 80 miles whereas the Model 50 has about 16 gallons of oil pass through in 80 miles.

I think that you will agree that the Model 50 big end is very adequately lubricated and note that all Japanese singles with roller bearings specify at least the use 10W/40 multigrade oil.

I think the idea that the British single cylinder roller bearing big ends somehow cut up the molecules in multigrade oil and soon render it useless is simply untrue.

Regards,

The oil industry lied about its new and unproven multigrades in the 1960s and 1970s and many of us have not trusted them since. This has been compounded by their continual changes to viscosity and specification whilst retaining the same brand names. It's no wonder that so many prefer a product from a small producer that isn't changed every few years.

How many engines were ruined by Duckhams Q turning into emulsified snot and Castrol's decison to change Castrolite from a monograde 30 to a multigrade which turned into paraffin after a few hundred fast miles ?

Good point Richard and I used to be a big fan of Colin Chapman's Q

But what I'm at odds with is that SAE 50 oil should not have burnt, we are not talking about a Summer ride through Death Valley! Rich running does help to make the oil go black early but an over lean mixture would cause hot running.

Still need to know the colour of the plug. Shouldn't overheat that quick, even on a red hot day with SEA 30 and Ethanol in the tank !!!

Previously richard_payne wrote:

The oil industry lied about its new and unproven multigrades in the 1960s and 1970s and many of us have not trusted them since. This has been compounded by their continual changes to viscosity and specification whilst retaining the same brand names. It's no wonder that so many prefer a product from a small producer that isn't changed every few years.

How many engines were ruined by Duckhams Q turning into emulsified snot and Castrol's decison to change Castrolite from a monograde 30 to a multigrade which turned into paraffin after a few hundred fast miles ?

Dear Richard, your assertion that the oil industry lied about multigrade oils in the 19660's and 170's is frankly rubbish . All multigrade oils must pass a shear stability test which exceeds by far,in severity, anything that we can do to it.The introduction of more viscosity grades is a response to improvements in additive technology and changing demands of engine manufacturers.

By all means put your faith in a small supplier, he will be dependent on a large additive supplier for components and you have no idea of the performance quality of the product.

Some of the publicity put out by some 'Classic Oil' suppliers seems to me to be a little economical with the actuality.

Duckhams Q has never ruined any of my engines because I have never used it - I did not like its dark green colour.

When I started off motorcycling in 1960, a work colleague advised me to use Castrol because they were the only major manufacturer who just produced oil ,all the others were petroleum producers as well.

I have stuck to Castrol faithfully to this day without the slightest bit of trouble. The Castrol Edge 5W/30 in my VW Golf TDI can last for 18k miles depending on type of use the engine gets and certainly lasts for 10k with stop/start motoring.

I have just poured my three years old Castrol 20W/50 back into my Jubilee (I take it out in November to stop wet sumping) and it is already in the Model 50 as it has a tap on the oil feed pipe to stop wet sumping. I may do a change on the Model 50 this year as the oil has done 2k miles but it will probably be okay for another season.

I think it is fair to say that these days all oils are vastly superior to those produced when our machines were fresh out of the factory.

Regards,

Agreed John, even the straight oils of today are better than they were in the 50's and 60's. I did use Q for many years in the 70's without any issues butI don't think that this was long enough to draw any conclusions?

But Charles, while there is nothing wrong with Castrol, they are not the only agents of decent oil. I use a lot of Miller's these days but ran on Silkolene through the 90's. I always use castrol gear oil but don't tell Anna. Has anyone had an issue because the oil was sub standard. (Assuming the correct grade for the application)

As long as the oil is doing its job is all that matters. Some high mileage reports are what we need.

Dear Neil,

I did not mention Castrol or any other supplier. When I started motorcycling in the 1950's Castrol was the oil of choice because of its involvement in motorsport on both 2 and 4 wheels.

In my professional life, I worked closely with Castrol and most other major lubricant supplies on the development of their products.

Castrol are now part of BP as Duckhams also became.

I too use Castrol gear oil in my 1955 dominator. Modern gear oils contain additives which inhibit corrosive attack on copper containing alloys.

If I had a really high performance bike and did high mileage at high speeds ,I would probably use Mobil 1 15W50. I remember talking to one well known lubricant supplier about their involvement with a certain F1 team, I was told, ' Oh we are only sponsors, the engine manufacturer says , you can put anything you like on the outside as long as you only put Mobil 1 on the inside'.

So Charles - what oil would you use in my 1956 single and 1969 Triumph. I am using expensive SAE40 but lean towards a cheap and cheerful 20/40! The rumour is that the aggressive detergents in these oils are dangerous in an old bike without modern filters.

Dear Stuart,

With regard to the supposedly bad effects of modern level detergent oils, there seems be be a lot of disinformation about.

Many of the advocates of Low detergentcy oils seem to confuse detergency with dispersancy. Detergents are in the oil in order to keep hot surfaces clean and neutralize acidic combustion products.They protect against piston ring sticking and the build up of hard carbon deposits on the crown land of the piston. These deposits and ring stick leads to enhanced wear, increased blow-by and reduced performance. So oils with modern detergents do this better than low detergency classic oils.

Dispersants are there to deal with sludge and soot. Sludge is generated by unburnt fuel fragments and water produced in combustion. Sludge blocks filters, oil ways and can form hard deposits which ruin your engine. Dispersants also stop soot, formed by combustion, from forming large particles which cause oil thickening and increase valve train and piston ring wear. So good dispersancy is a good idea.

With regard to oils for your bikes, I notice that 20W50 oils are becoming rarer, I believe that HD agents do stock this viscosity grade, and some on line suppliers offer them as well, Valvoline, Silkoline and Miller seem available from these sources. A good 15W40 is a good substitute in most cases and Halfords list a range of these including Mobil Super 1000X1 which has a good specification. Look for oils which have ACEA on antique on the container, Mobil is this +API SL.

If you have been running on antique oil , then it is probably a good idea to drain hot, clean the tank and strainers and then use some flushing oil to get rid of the worst of the muck which may still be inside your engines. Morris offer what looks to be a good flushing oil,

Good Luck.

Previously charles_bovington wrote:

Dear Stuart,

With regard to the supposedly bad effects of modern level detergent oils, there seems be be a lot of disinformation about.

Many of the advocates of Low detergentcy oils seem to confuse detergency with dispersancy. Detergents are in the oil in order to keep hot surfaces clean and neutralize acidic combustion products.They protect against piston ring sticking and the build up of hard carbon deposits on the crown land of the piston. These deposits and ring stick leads to enhanced wear, increased blow-by and reduced performance. So oils with modern detergents do this better than low detergency classic oils.

Dispersants are there to deal with sludge and soot. Sludge is generated by unburnt fuel fragments and water produced in combustion. Sludge blocks filters, oil ways and can form hard deposits which ruin your engine. Dispersants also stop soot, formed by combustion, from forming large particles which cause oil thickening and increase valve train and piston ring wear. So good dispersancy is a good idea.

With regard to oils for your bikes, I notice that 20W50 oils are becoming rarer, I believe that HD agents do stock this viscosity grade, and some on line suppliers offer them as well, Valvoline, Silkoline and Miller seem available from these sources. A good 15W40 is a good substitute in most cases and Halfords list a range of these including Mobil Super 1000X1 which has a good specification. Look for oils which have ACEA on antique on the container, Mobil is this +API SL.

If you have been running on antique oil , then it is probably a good idea to drain hot, clean the tank and strainers and then use some flushing oil to get rid of the worst of the muck which may still be inside your engines. Morris offer what looks to be a good flushing oil,

Good Luck.

Please ignore ' on antique', after ACEA, typo!

Sorry

Thanks Charles,

All sensible stuff well put.

There's still loads of options for obtaining 20w50 motor oil, I've been running Matchless and Norton on Valvoline and Comma products [Comma: Part of the Exxon,Esso,Mobil goup] for many years now.

There's even decent oils/delivery deals of the above on Ebay for those not near any local stockists! Try search "Motor Oil 20W50"

As to the original thread of this post started by Dave I'm at a bit of a loss. As long as the timing and carburation arre within acceptable bounds the oil shouldn't "burn". Dave does not say that it actually gets really hot, during the current weather my ES2 for example hardly gets the oil much more than luke warm [tested technically by holding hand on oil tank in pub car park!] even after a 45 mile run at speeds 9/10ths of what she'll do.

The Norton oil pump is a positive gusher compared to the G3 Matchless! AMC singles have an interesting oil plunger/pump as others will know, resulting in very feeble oil circulation and ditto above regarding temperatures, but even circulating the lube that slowly has never burnt the oil or given any trouble with a diet of 20W50.

Rob.

A bike that is running a bit rich on the needle jet will dirty up the oil in no time.THe additives inPremium grade fuel has the same effect on my bikes.

Stuart:

Is the Triumph a twin? If so, you are talking apples and oranges in regard to the oil requirements. The Norton single has a roller bearing conrod and the Triumph will have plain bearings. The Norton single will be much more tolerant about oils. Just pick whatever meets your temperature requirements where you live. Here in sunny California I run straight 50w all year, but it never goes below 40-50 deg F.

For the Triumph a good quality 20-40 or 20-50W should do nicely depending on temps.

Mike

I would be a bit wary of going for a thin multigrade oil for a low oil pressure roller big end. I stick to SAE 40 for my singles, multigrade for twins with plain big ends. If the oil has gone filthy black very quickly, it could be the engine is running much too rich.

Well Gordon, I am with Charles on this one two stroke engines have all roller bearing bottom ends and they use a thin oil, so I will keep saying this is the misconception with these mono grade oils, So Gordon think of it this way you would not what thick blood in your veins as this is the cause of heart trouble ,your doctor would give you something to thin out your blood , So its the same with a Norton engine thin oil get around and though the oil-ways that much better with thin oil than thick oil, And geared oil pumps like nothing better than a thin oil to build up pressure, and Norton single oil pump built up a pressure of 50/60lb per square inch to lubricate the large end roller of the bottom end then this is dripped out to splash feed the rest of the inside of your engine the only other pressurized parts are the rockers arms from the returning feed pipe ,So your more better of with a 10/40w or a 15/50w synthetic or semi-synthetic oils but the trick is to stick to one brand of oil and use the same grade every time around, and black oil is caused by a blow by the piston rings when the engine running hot is all a indication of weak mixture in the carburettor .do check your jet settings , some time after a long standing period ethanol can gum up the jets making for weak running , so have fun in sun Yours Anna J Dixon

With your description of your initial running before setting off and with the use of SAE 50 oil, you certainly could not overheat the oil as you say. All oil becomes very black with use and it will probably be still okay.

I use Castrol 20W/50 in my 1961 Model 50 and have never had any trouble whatsoever. When it is hot weather it will take on the consistency of SAE 50 and when it is cold it will flow better than SAE 50. On long runs the machine will turn in almost 100 mpg running at speeds of up to 55 mph.

I must point out that I do have a tap fitted on the oil feed line to stop wet sumping when the bike is not run for long periods.

Regards,

well my advise too you is your only masking up the real problem of a worn oil pump so by fitting these taps and other devises your not doing your engine any favorers what so ever. as when starting the machine it take over 30 seconds for the oil to circulate the engine, in- affect your engine is running dry for that 30second period of time. in turn your only causing extra wear and tear on your engine. so the best answer too this is too fix the problem the worn oil pump , and take out the tap . as you would not what a tap in your veins too your blood supply would you , well its same with a engine oil is the life blood of that engine. Yours Anna J Dixon

Thanks for the advice Anna, but I am sticking to a straight 40 for my single cylinder bikes with roller big ends. Call me a dinosaur, but I am definitely not putting a 15W-50 multigrade in them. I know 40+ years of ignorant living in the past is no match for modern science and technology, but it works for me. Quite happy to use a multigrade in my Norton and BSA twins with plain big ends though. I have distinct memories of bevel drive Ducatis having expensive bottom end failures when using thin oils. Silkolene produced a high detergent straight oil specifically for them which sorted the problem. Could be co-incidence of course.

Our old bikes are not particularly highly stressed so it probably doesn't really matter what oil you put in them as long as it's clean. It is all down to personal preference, the bike really doesn't care.