Thunderace oil thicknesses?

[Wideboy]

I've got three different oil types said for the thunderace

10w30, 10w40 and 20w40 all semi synthetic

if im burning oil i would want to use the thicker oil which is 20w40 (i think) but do the oil codes mean that the oil is at different viscosities when at temperature?

It used to be how long it took to drain through a measured container, obviously the thinner, the quicker.

This was explained in MCN a few weeks ago.

All modern oils are a combination of different oil types. The first number followed by the "W" is the "Winter" (or cold) viscosity, so, when the bike is cold the oil will have the viacosity of 10 weight oil, but it is 10W40 for example the oil will flow like 40 weight oil when hot, the higher the numbers of either means greater viscosity (thicker) oil.

The reason for the mixed oil types is because a 10 weight oil wouldn't be able to help the engine much when hot and a 40 weight oil would be like treacle on start up, so, mixed oil is the best of both

[Wideboy]

Originally Posted by Cymraeg_Atodeg

This was explained in MCN a few weeks ago.

i read no further than this bit

Originally Posted by Wideboy

i read no further than this bit

You tool

[timwilky]

We do have oil experts on here, But I have not seen well oiled post for some while.

Viscosity is a funny thing, it is a measure of the shear forces required to allow movement of the fluid.

The method we used was to time the decent of a ball within a measuring tube. and I seem to recall the unit of measurement was the stoke or centistoke

[Bibio]

if its burning a lot of oil there is something not quite right.

stem seals, worn bore, sticky rings. give it a good flush out with engine oil flush and take it from there. there are also additives you can use to lessen the effect.

i think you'll find that the thunderace and the earlier xups are well known for useing oil,(from new)and if you use a oil flush when you change the oil it will most likely make it smoke like a twostroke.so i'm guessing if its useing less than a 1 ml a mile then its not worth worrying about(1litre per 1000 miles)and 2ml a mile is getting a bit smokey,but if its burning 3 or 4 ml a mile then a strip may be on the cards

[Wideboy]

no work is necessary, there's loads of theory's flying about such as the bore wasnt machined perfectly circular ect

Over on the Thunderace forum they discuss using mineral oil if it's burning a bit. Food for thought

I used bog standard semi synthetic Rock Oil guardian (10w40) and it was fine