Which Engine Oil should I use ?

[paul G]

The oil thread gravitational pull is starting.....

There is a standard for oil for wet clutches so clutch slip is easily avoided http://www.oilspecifications.org/articles/JASO_MA_JASO_MB.php

Gearboxes should also have EP additives to reduce wear, but you rarely see that bit debated, it's always about the clutch because that's where you can feel the difference.

Personally for road bikes I just buy any known brand bike specific oil, yes the prices are a rip off, but it saves having to understand all the oil threads. (for trials where the clutch feel is more important I use Motul 300v)

That is the reason to go for the Diesel one as it has additive’s for the turbo.
There has been many, many discussions on here about it and the people who are in the know recommend Diesel not petrol oil.

[Trigger]

Paul is correct, you need the right spec which is found in diesel oils for the gear box and clutch. Car gear box's and clutch are separate to the workings of the engine. Make sure the spec recommended in you Manuel fits the spec on the oil you wish to buy.   

[K2-K6]

As any aside,  welcome to the forum kew. I'm assuming you're running that motor in an outfit, is that for road racing?

It's something I think that ends up just hanging as no ultimate conclusions are really informative enough to define what the mythical (well they appear mythical to me) friction modifiers are in any observable or verifiable facts.

If I were to pay for and build up an engine I would consider the oil performance in protecting that as a primary aim and then try to see how that could perform for the conditions the clutch is in. I'm not niave enough to dismiss the clutch as being essential that it operates properly and is able to transmit the torque asked of it but it becomes purely speculative if the engine lunches itself when used fully.

I've been looking at many aspects of oil in various engines and can see many parts of those specifications which are published but when you get to the "friction modifiers" that shouldn't be used in wet clutches,  nothing appears available. How can logical decisions be made when this area almost resembles the magic circle?

I'm aware that molybdenum disulfide is considered accumulative in soft clutch materials, and looks detrimental. It's seems as if this is used then in the short term if it made the clutch slip then it wouldn't be removed by changing the oil back to non moly type. So I would try to avoid oils with that ingredient.

Most of the oils specified for use after about 2004 have things like ZDDP removed to avoid contamination of exhaust after treatment devices and reduce the effectiveness of the cats or dpf kit used on cars. I think it's worthwhile avoiding these as the replacement seems to be moly although there is nowhere I can see that will really nail this component down. It's also considered in emissions driven decisions that the removal of ZDDP (primarily used to protect cams in older engines) will result in shorter life of these components. They dismiss this on the basis that they will last long enough and anyway a significant failure after the end of warranty will ultimately lead to a newer and more efficient vehicle being bought. It takes no account of the field we are talking about as they really couldn't care about old engines.

It's hard to get any real hard data about some of the things that concern us, but useful if we can unearth things that would give improved protection.

[Greebo]

K2-K6

What bikes do you run [is the clue in your user name ?] also what oil do you use ?

[K2-K6]

My name here is from those two 750 models but they are not currently running. I've been looking after things like this since the 1970s when there was much less choice of decent oils when now there are loads.

Right now I have a 1984 cbx750 on the road which I've been running on Mobil 2000 semi synthetic which is a 10w40 oil. This motor has hydraulic valve adjusters, incorporates an oil cooler as standard and also (I think it's maybe the first general production bike with one)  a slipper clutch. That is a car oil but the clutch has no signs of slipping under load and it's a pretty banzai powerband for the age of bike. It takes off about 7000rpm and if you're not quick enough to change up you'll hit the rev limiter at about 11200rpm it first and second. It's output is about 94bhp.

Are you after a recommendation for something or to discuss further?

I do think it's fascinating area to discuss,  but it is coloured by many aspects of oil marketing speak rather than engineering principles.

Just the statement of "friction modifiers" amuses me as the oil in it's entirety is a friction modifier, which is exactly why we use it in engines!

[Greebo]

As you can see from my avatar I have a fully restored /rebuilt K6 café racer style.

I am using Motul 5100 semi synth' 15w50.but it is quite expensive which is not really an issue,
But after seeing this very cheap oil on the forum I was just wondering [without getting into too much technical jargen] if it its good enough as some members are saying

http://www.ebay.co.uk/itm/Engine-Oil-Triple-QX-Premium-SAE-10W40-Part-Semi-Synthetic-5L-A3-B3-B4-5-Litre-/400698136407?hash=item5d4b785757:g:YpIAAMXQyY1TVkaX 

[Chris400F]

Interesting how the pack states that it is for Petrol and Diesel vehicles given the earlier comments about the additives in oil for diesel vehicles.

Personally I have been using this stuff:
http://www.millersoils.co.uk/automotive/tds-automotive.asp?prodsegmentID=209&sector=Motorbike
It is a motorcycle-specific oil; you can pick it up for a bit over £20 for 4 litres which is fine by me.

[K2-K6]

I was certainly thinking along the lines of modified engines in my answers as I believe you are taking it toward considering how to look after something that could have elevated torque and heat loadings. In that case it's relevant to look into what you could do.

For standard engines that don't deviate from normal running the demands are really not that great.
Bryanj offers some really good advice on oil which I wouldn't argue with or his reasoning as you don't need to spend alot of money to look after them.

I'd view them like this,; I don't believe any of these 4cyl Hondas have an intrinsic problem regarding lubrication. They seem to have got their R And D bang on if you consider the bearing sizes, cam lobes, gear design etc and how long they have lasted, as a result they don't need anything special in the way of oil spec to look after them.

BUT categorically they need clean oil above any other criteria, so whatever you use you need to make sure it's kept up to scratch to avoid wear.
Common with any carburettored engine with very basic choke to get them going. If you have a high proportion of cold starts relative to proper warmed up hot running, then you'll prematurely contaminate any oil you choose with unburnt fuel, condensation and various byproducts of combustion, principly acids as I understand it, making any starting specification of oil fairly academic. It will, when contaminated sufficiently fail to do what you are asking of it.

The Motul you are using is a very good oil but you're probably going to have to discard it way before you've got any value back from it so you might as well spend less and change it more often.

Bit of an odd habit is smelling the oil (Yeh I know I should probably belong to oil sniffers anonymous)  but if you go and smell the new oil in the bottle to calibrate your nose, then take the dipstick out of the bike and smell it........ Usually you'll get varying degree of petrol.

Many of these bikes unless used more extensively will be the same, and it doesn't do them any good.

It all depends on personal attitude to synthetics (now there's another whole area of discussion) and if they are appropriate, but you can get 5ltrs of VW 505.01 spec oil (in gold coloured container from asda) for £13 currently that I think is a really good oil which I've used in many of the engine's I'm looking after. With low bike usage you'll probably be changing it in less the a thousand miles anyway as it'll reek of petrol.

[Trigger]

Oil is a bit like some people recon Nike trainers are the best, a trainer is a trainer to me. Just think about the trade, mine comes in big containers with TRADE on the side, as long as it is to the right spec, I am happy. Change your oil often, as most engine damage is because the oil breaks down.

[Greebo]

Good shout Trigger

Same as the Grub in Sainsburys & their "Taste The Difference" products that are almost double the price of the standard Sainsbury Brand...the prices & the packaging are the only "Real Difference".   

Thanks also to K2-K6 !

Greebo

[Chris400F]

.... as long as it is to the right spec, I am happy.

Trigger, I think you could have unwittingly struck the metallic pin squarely on the cranium here.
What is the right spec? Oils have changed vastly since the bikes were new 40+ years ago.
The original specifications for my 400/4 call for an SAE 10W-40 oil of Service SE Grade. Nowadays this is referred to as the API specification; in 1977 SE was the highest specification available. My understanding is that within reason the later higher specifications supersede the earlier ones.
The Millers oil I referred to has a 'Performance Profile' of API: SG, SH, SJ and JASO: MA / MA2. The JASO classifications seem to be for motorcycle-specific oils. The Millers oil is suitable for off-road, on-road and track motorbikes, and is for use in motorbikes fitted with oil immersed 'wet' clutches. I am happy it is right for my bike.
If I look at the Triple QX oil in Greebo's link I see it is classified A3 B3 B4. These specifications are for car and light van petrol and diesel engines. They may be perfectly suitable for use in bike engines but I can't link between the different sets of standards.
So my choice is to stick with a motorcycle-specific oil. It doesn't cost me a great deal more, and as I only run the one bike the difference isn't multiplied several times. as it would be for others on here.
So, bottom line (literally), what standard/specification would you be looking for in your 'Trade' oil?

[Bryanj]

Considering the service change of 1500 miles, when i also think the filter should be changed, there is no need for the extra expense of the "modern" motorcycle" oils which even the manufacturers like Fuchs admit to being standard oils in a more expensive can

[MrDavo]

Nowt wrong with Nike trainers, Trigger. I have got through 2 pairs of black Nike Air trainers, wearing them almost every day, in nearly 20 years.

The first pair went round the world, up Vesuvius and Sydney Harbour bridge, inside the Great Pyramid at Giza, and are now the 'garage' pair though one of the soles is hanging off a bit, nothing Evostick wouldn't fix.

The second pair the wife got me for Xmas a couple of years ago, she quailed at the price, but admits no present she has ever bought me before or since gets used almost every day. I do (almost always) wear boots on the bike, though, seen a few shredded feet over the years.

As for oil, in the CB750 I use the straight forward 20/50 dinosaur oil the bike was designed for, as others have said it's not in long enough for modern witchcraft to make a difference. However why are the intervals so short? Heat in an aircooled engine, or design?

My 911 is air cooled, and that gets 12,000 miles per oil change according to my handbook (though I do it a damn sight more often than that). Apparently if you use modern fully synthetic oil it will pour out of oil seals that weren't designed to contain anything so slippery.

I thought I was saving money on the Harley by ignoring the bullcrap marketing ads that tell you only to use the expensive Genuine H-D oil and nothing else (oddly, it says in the manual to use oil designed for a diesel at a pinch, maybe it's a detergent thing) I used any old multigrade, but did change it at regular intervals. Then at 23k miles the ground and hardened bearing surface of the crankpin turned to glitter. It gets the real thing again now, I have other cranks to change.

 A wise man told me many years ago 'oil is cheaper than bearings'.

[Trigger]

Considering the service change of 1500 miles, when i also think the filter should be changed, there is no need for the extra expense of the "modern" motorcycle" oils which even the manufacturers like Fuchs admit to being standard oils in a more expensive can

Are you telling me Bryan, that those 1 ltr bottles you see in dealerships on the top self at £12 is the same grade that comes in those 205 ltr blue drums is the same stuff. Well I never   

Now it looks like the Great oil debate has moved on to the Great foot wear debate 

[K2-K6]

That expensive stuff in lovely bottles isn't up there on the top shelf for nothing, pure oil porn, the luscious golden little beauty.