Common oil for these 3 engines?

[vyv_cox]

The viscosity provides an oil film that prevents metal-to-metal contact. Insufficient oil film thickness = bearing failure. Is corrected in many engines and compressors by increasing oil viscosity.

No significant amount of oil remains in a plain bearing when the engine stops - a hydrodynamic film is generated when the oil pump supplies oil and not before.

A cold diesel engine typically knocks when first started. This provides the highest load that the bearing will see.

Cheers,

 

[lw395]

We run a boat (BMC 1.5 diesel), 2 diesel cars, 1 petrol car, 5 motorbikes and a lawnmower and after some research I found that Shell Helix Plus 10/40 is the right spec for all of them. I buy it in 20l drums from Emo Oil and it's about £3 per litre.

Depending on what the bikes are, I would be cautious about this. Most motorbikes have the clutch and gearbox running in the engine oil. So the oil is a little different to cope with the shearing and pressure from gear teeth.
Or so the makers claim.
One of my bikes, a BMW, has separate gear and rear axle oil, just a narrow car really. The other, a Ducati, has a dry clutch but gearbox in the engine oil. Given the high price of engine parts for it, I'm (relatively) happy to pay OTT prices for fully synth bike oil. So far, the low wear rate on the valve train is keeping me positive about it.
There are some BMW bike forums where opinions about oil are much stronger than on here, but it would be easier to persaude all the rag'n'stick merchants on here to buy stinkboats than to get some people to accept that synthetic lubricants are any good!

 

[vyv_cox]

but it would be easier to persaude all the rag'n'stick merchants on here to buy stinkboats than to get some people to accept that synthetic lubricants are any good!

Horses for courses, my friend. I have two modern vehicles with turbo-charged diesel engines, and use high-spec synthetic lubricants in both of them. I use API CD in my Yanmar. Match the lubricant to the duty.

After nearly thirty years in Shell, the last five or so as a rotating equipment lubricant advisor, I have picked up a little knowledge on the subject.

 

[lw395]

Be interested to know your thoughts on the influence of gears in motorbike oil, and what are the additives/changes that oil suppliers use, compared to car oil?

Putting a bike label on things sometimes seems to up the price more than a marine label.
I only try to balance out the 'straight sae 30' BSA M33 enthusiasts.... and to point out that opinions differ on this complex subject.
Cheers,

 

[Kawasaki]

Which motorcycle or cycles are you trying to sort out gearbox oils for?

 

[vyv_cox]

Sorry, I'm the wrong person to answer this. I know nothing about motorcycles and not an enormous amount about gear oils.

Gear oils are specified according to the predicted surface temperature of the gear contacts, or maybe only the critical ones in a multi-gear box. At the high loads and sliding speeds of modern gears hydrodynamic lubrication breaks down, so gear oils need to be able to provide boundary lubrication. As with all oils nowadays there is a cocktail of additives but the main ones are boundary lubricants, usually sulphur based such as ZDTP. The effectiveness of gear oil's carrying capacity is assessed by FZG test. You may find this interesting http://www.fzg.mw.tum.de/forschung/zahnraeder_stirnraeder_en.php4

 

[lw395]

Which motorcycle or cycles are you trying to sort out gearbox oils for?

Don't know if you were replying to me specifically, but I don't think I have much choice with the Ducati, I can only stick with synthetic motorcycle oil.
The BMW gets treated as a car, more or less.

I am just interested in what the real differences between bike and car oil are. If I was running a low value machine I might want to save a few quid by using car oil, but I'm not. I'm interested in sources of info that might be relevant later or to friends. Just something that interests me!

 

[Kawasaki]

Don't know if you were replying to me specifically, but I don't think I have much choice with the Ducati, I can only stick with synthetic motorcycle oil.
The BMW gets treated as a car, more or less.

Sorry lw, yes I was!

I am just interested in what the real differences between bike and car oil are. If I was running a low value machine I might want to save a few quid by using car oil, but I'm not. I'm interested in sources of info that might be relevant later or to friends. Just something that interests me!

Yep, stick to what type and grades are relevant to your paticular Ducati.
It does not have to be 'ducati' oil as you probably know.

Check what has been used in the past.
What I mean is.
If you have an 'empty' that you can read the spec off.
Any make will do as long as it is the same spec.

The BMW (presume it is an 'older' model) obviously soungs like less of a perfomance machine and yes you can basically treat it as a car.
Except oil changes will be more frequent
You probably know that too!

Considering gearbox oils for motorcycles.
In most cases , compared to cars a 'lighter' oil is used.
Bikes generally don't have a sychromesh type box.
Plus some run the same oil for the clutch and gearbox
Again as you know, gearchanging is rather swift on a bike compared to a car.
Lighter built too
More 'finely' enginered as well, if that's the correct terminology?!

Some machines may be constructed whereby the engine , gearbox and clutch all use the same lube.
In that one fill up hole and one drain plug and the one oil does the lot!

Take for instance the common or garden Honda C90
The oil is this engine (and others of the type) has to lube the 3 bits mentioned before

So normally a 10/40 is lobbed in.

Oil changes therefore have to be done at shorter intervals.
The oil will contaminate more quickly in this set up.

Back to gearbox oil

Oh and shaft drives
Presume the BMW is a shaft?

More traditional types of Hypoid or 'ep's are used in the drive system.
Anyway, back to gearboxes! (got me going on motorcycles you have)

Flip, I might go on all day!

So
Here is a good link for you
www.rockoil.co.uk

I used to be a Distributor for them on the motorcycle side many many moons ago
I have no commercial interest now.
However I do speak to them occasionally for old times sake and advice etc
They do marine stuff too.

Nice family firm
Who major in motorcycle oils.
Always willing to take a call and discuss and give advice.

What are you putting in the BMW Eng/Box etc at the Mo?
Cheers
K