The Good Oil ?

[pete376403]

Another point to consider is that no car that I am aware of uses a roller bearing crankshaft - but plenty of bikes do (eg both of mine)
I don't know if there are any restrictions or limitations on oil for a roller crank but it could be a point. I know Ducati used to specify a monograde 50 for the old bevel motors

[bungbung]

Another point to consider is that no car that I am aware of uses a roller bearing crankshaft - but plenty of bikes do (eg both of mine)
I don't know if there are any restrictions or limitations on oil for a roller crank but it could be a point. I know Ducati used to specify a monograde 50 for the old bevel motors

Would that be due to the roller bearings surviving on less lubrication than a plain bearing requires? e.g. two stroke oil injection systems, or wet sump four strokes with small oil capacities. I would think plain bearings would require higher quality lubrication.

[pete376403]

Dunno about higher quality - certainly higher pressure and volume. I have seen a two stroke with a plain big end bearing - an old Tecumseh lawn mower engine - and they seemed to work ok on premix. The rod end and bearing had a slot to let the oil in.

[Motu]

A roller bearing bottom end can take a lot of lubrication abuse,the oil is mainly for cooling purposes,there is stuff all pressure and usualy only rudimentry guaze filters,a plain bearing bottom end takes a lot more looking after.

Those old 2 strokes with bushes for bearings always ran engine oil at heavy ratios,like Seagulls had SAE30 at 10:1,easy to see why they smoked and fouled plugs.They may survive on modern oil at 25:1,but any less oil is going to kill the bearings.

[Cary]

A friend has had Mobil 1 4T Racing oil in his 1990 ZZR1100 for a couple of years with no problems. I'm going to use it in mine at the next oil change. By all accounts it has come out tops, and it's cheaper.

Would say it is expensive overkill for a VFR

[Bonez]

I use cheap oils. Change it and the filters on a regular basis - 3000-4000kms. Yeah I know I'm a cheap bastard but two of my cickles have over 120,000kms clocked up so it must be doing the job..................

[Pixie]

I used mobile S thats semi synthetic in my Bike once and it made no difference to the clutch but I can get Motal 5100 for the same price so why risk it? its more to do with the detergents in the oil and the anti foaming agents. If my bike had a dry clutch like the BMW I dont think I would even bother to change the oil! ever!
but If I did I would use Mobile 1. but then If I had a BMW I would'nt be bothered about the cost of oil only about my telecom shares

The clutch slippage issue is due to the friction modifiers in the additive package of oils rated later than SH .Bike oils are rated SG or SH and car oils with these ratings are ok to use but will probably drop in viscosity faster than the bike oils.
The additive package in diesel oils is of a higher standard,is more durable and more expensive and the oil will retain it's viscosity longer than a car oil when used in a bike.
This viscosity loss is only a problem in bike engines as they use the same oil to lubricate the gearbox as well.

[Motu]

The clutch slippage issue is due to the friction modifiers in the additive package of oils rated later than SH ..

And viscosities 10-30 and lower,they are made for US economy standards...10-40,15-40 etc are usualy not friction modified,but it pays to check.Castrol Magnetec uses esters for the magic,nothing wrong with that.

[scumdog]

There are two things wrong with using car oils in a bike of unit construction. Firstly the friction modifyers can induce clutch slip. This is terminal as the fibre plates absorb these slippery bits. Secondly, and more importantly, car engine oils are not designed for the high shear forces produced by gearboxes and will break down quickly, resultuing in a high rate of engine wear. Motorcycle-specific oils are much better in this regard, being more shear resistant, though they do still suffersignificant degradation. This is why you are advised to change your bike's oil more often that you would your car.
:

I am prepared to stand corrected but haven't several front-wheel drive cars used their engine oil to lubricate their gearboxes as well?

[What?]

I am prepared to stand corrected but haven't several front-wheel drive cars used their engine oil to lubricate their gearboxes as well?

I'll stand beside you, SD, but I don't know of any cars like that.
Maybe Motu does???

[Motu]

Only 40yrs worth of Mini's,1100s,1300s,1800s,Maxi's,Tasman's and Kimberlies....and a few other clones.Still plenty of those on the roads today.

[Kickaha]

Only 40yrs worth of Mini's,1100s,1300s,1800s,Maxi's,Tasman's and Kimberlies....and a few other clones.Still plenty of those on the roads today.

Drove an 1100 last week,for the first time in about 20 years I'd be quite happy not to drive another one for another 20

[vifferman]

I'll have to see if I can find it again, but I was reading a post on the US VFR forum, and "The Oil Guy" said he was talking to a fellow motorcyclist who happened to work for Mobil USA, and this guy said he ran a mixture of mineral oil and Mobil 4T in his bike. When questioned, he said that the while the synthetic had excellent lubrication properties, it wasn't so good at holding the contaminants in suspension, whereas the mineral oil was. So even though synthetics have superior properties in most respects, you're better off using a synthetic-fortified oil, rahter than a full synthetic.

[Motu]

Drove an 1100 last week,for the first time in about 20 years I'd be quite happy not to drive another one for another 20

Heh,heh,hard to beleive they were the standard small car for years and there were thousands on the road.I've done a shit load of work on them and these days a young mechanic wouldn't know what the hell to do with one let alone want to get his hands very dirty touching it.We still get the odd Mini in,like the one yesterday for a radiator,but they are long gone.

They said Sir Alec Isognosis was crazy to fit the gearbox under the engine and use the same oil in 1959,but he was a true genius and it's a pity only half his ideas were put into production.

[Lou Girardin]

Heh,heh,hard to beleive they were the standard small car for years and there were thousands on the road.I've done a shit load of work on them and these days a young mechanic wouldn't know what the hell to do with one let alone want to get his hands very dirty touching it.We still get the odd Mini in,like the one yesterday for a radiator,but they are long gone.

They said Sir Alec Isognosis was crazy to fit the gearbox under the engine and use the same oil in 1959,but he was a true genius and it's a pity only half his ideas were put into production.

And half their problems wouldn't have arisen if they had modern oils back then.
Idler bearings for one.