Oil

[grainger]

hey willie - back off - you got it WRONG - now you are on about something else entirely

the low number on a multigrade is the THINNEST the oil gets - the high number is the THICKEST it gets

sae 20/50 DOES get chopped to sae 20 in your gearbox and pretty quickly according to PC.

monograde oil doesnt get any THINNER than its SAE rating

cheers
gr

[Willie]

Sort yourself out.. In your earlier post you stated
that "20-50 is only 50 when cold"..This is totally wrong
it is 50 when HOT

[grainger]

im sorry ... you dont make sense

you think you are so clever ... i know im pretty thick but i know where to find out what i need to know and i tell you something i wont be listening to what you have to say anymore - bye

anyone else tell me im wrong and i will apologize to willie

cheers
grainger

[grainger]

hi doc

.... glad to bring a little happiness into your life

its what its all about intit ?

cheers
grrrrrrainger

[Cam]

Fight!!! Fight!!!

ha ha, that's great!! and it's what it's all about eh??

however the 'PRACTICAL classics' quote was a bit worrying!!!

Let's use SAE 20W50 as an example.

the 20 rating is the viscosity rating of the oil at 0 degrees centigrade (that's that the W tells you). the 50 is the viscosity rating at 100 degrees centigrade.

The higher the number, the more viscous (thicker) the oil is.

So 20W50 starts off at 20 when cold and changes to 50 when hot.

This sounds crazy, as how can an oil get thicker when hot??? a mono-grade oil can't, but a multi-grade can!

This is done by adding a polymer to a light base oil. The polymer chains are coiled up when cold and straighten out when heated up, thus making the oil thicker (more viscous - more resistive to a rapid change in movement).

But there is another complication, and that is that the oil does not change from 20 rating to 50 rating, but it changes from a 20 rating to whatever a 50 rating oil would be when it got hot (less than 50). So it's like putting a 20 rating oil in when it's cold, and a 50 rating oil when it's hot.

I hope this overcomplicates things and helps to confuse issues!!!

[grainger]

oh dear, i dont think i understand you cam but i think i owe willie that apology now please willie forgive me, im right out of me depth here ....

so it really gets thicker when its hot ? flipping heck i dont get that, so how come to change the oil and make it flow out easier you have to warm the engine up first ?

sorry willie i hope you dont expect me to lick both your boots

cheers cam - just off to watch Bo Selecta on welsh channel 4 - back later

grainger

[Chris Morley]

Oh dear.... I hate to jump into this private argument, but Willie's explanation matches what can be found on Castrol's website. I think PC have got it totally wrong. No surprise there: the recent article about Minors was full of incorrect 'facts' such as the 0-60 time and top speeds.

20w/50 multigrade oil is thinner at low temperatures (rated 20 at Zero Farenheit), reaching a rating of 50 at high temperatures. Even so at low temperatures it is a lot thicker than the oils in most modern cars (ie:10w/40) which probably explains why my car 'chugs' initially during cold weather.
Viscosity: this is the measure of a liquids resistance to flow. Put in another way, viscosity equals thickness. The thicker the liquid, the higher its viscosity. Monograde oils will get thinner as they heat up.

Multi-grade oils work like this: Polymers (large molecule chains) are added to a light base(5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. 20w/50 oil has less polymers than modern oils and is designed to work from -10F to +30F (ie: the UK).

Before multi grades were invented SAE30 oil was recommended for Minor gearboxes. However it was noted that Artic conditions would need SAE20 oil and tropical conditions might require SAE40 or even SAE50.

Shearing action can damage or destroy lubricating molecules within oil: however I doubt that a Minor's gearbox is a harsh environment compared to a high revving modern engine where shearing is a problem. I also note that Minor specialists and the MMOC's technical advisor all state that 20w/50 is suitable for Minor 1000 gearboxes. I would personally have to see scientific proof from a reputable oil company before changing to an oil dating from an earlier age.

[Chris Morley]

I see it's busy on here tonight - both Cam & Grainger replied while I was composing my oil thesis!

When you get back Grainger, I suggest you start editing your posts and think of a suitably grovelling reply for casting doubt on Willie's correct explanation .....

Willie - He's proper Bo, I tell thee !

[Cam]

Chris,

th'ey ostner tackeen mick owt 'ere northern accents are th'ey???

I think that Bo (and League) may be funnier if you live up here, as that's what the folks ARE actually like!!!

Although, in Stoke, we are a bit too south (not by much though!!) for the proper folks, but it's a close call!!

Back to the oil.................. although we wrote at the same time, it's nice to see that we agree!!!!

[grainger]

oh chris you are very welcome, thanks a lot for that, between you and cam i think its beginning to sink in

i bought that copy of practical classics because of the minor feature, and when i saw the article on lubrication i thought i should study it carefully as it is a very difficult concept to grasp but it seems like THEY had it all a**e about t*t ... i had noticed what willie said was on the back of the halfords oil i bought but i presumed that PC would know what they were on about .... but thats what the 'w' stands for next to the smaller number isnt it ? 'winter' ? ie when its very cold

damn damn damn, never mind, i had already edited my posts to remove any real insults otherwise i think willie would be looking to kick me head in now, anyway i'll leave it all now as its taught me a lesson anyway - just dont open me gob unless i really know what im on about

im off to the PC site to give them some stick

PS did you see that impression of graham norton this week, i think avid or whatever his name is, is a genius

bo selecta

grainger

[Cam]

Nah, missed it, but I'll look out for it, as it is bound to be very funny, as pretty much all his stuff is, especially the little bear!!! I nearly laughed till I cried the first time I saw that!!!! Brilliant!!!

[Chris Morley]

Grainger - I wonder who he is? I assume he's British because of the way the bear speaks. I think his posh'n'becks and Michael Jackson are the best characters. I love the oinking noise posh makes . As for scary spice, I'm sure that's 90% based on Jim Bowen.....

Shamone !!! eeee-heee

Cam - Is Stoke 'oop North'? I would have thought it was, although I've always considered Derby and Stafford to be in the Midlands.

PS - what's happened to Jane? Has Papa Lazarou got her?

[grainger]

yeah the scary spice is excellent and though the little bear ALWAYS gets 'excited' and he ALWAYS shouts obscenities at the squirrel i could watch it over and over, brilliant character ... did you see the one the other week where michael jackson got his own back on his dad !!!!

stoke is really the heart of the country, i think its great cos its been voted the worst place in the country to live, and the most unhealthy but that just keeps the snotty southerners away (i dont mean you chris ... flipping heck i keep putting my foot right in me gob dont i)

i love the stoke accent, i didnt think id got one but even though ive been in wales for about ten years i still have to pronounce my words carefully cos rind ere thay conner understand me otherways.

anyway ive sent off an email to Practical Classics complaining about their lubrication misinformation, if i get a reply i'll let you know

thanks for the help both of you

grainger

[Willie]

Well,thank goodness we got that sorted, no problems
Grainger, I was up half the night worrying that I have
been wrong about multigrade all these years!!
'Gets thicker as it warms up'....isn't science wonderful.

[Kevin]

'Gets thicker as he warms up'....isn't science wonderful.

I think that applies to me at times Willie

[grainger]

hi willie

yes i woke up this morning still trying to figure it out - so its not quite that it gets thicker as it warms up but it changes to a thicker sort of oil which still maybe thinner than it is when cold but not as thin as it would have been if it hadnt changed !!!!

thanks for not taking me seriously

cheers
grainger

[Kevin]

Grainger what I think is hard to get to grips with is the fact that as the oil gets hotter it physically becomes thinner but mechanically gets stronger which is the opposite to most things we are used to, but this is only up to a set temperature when it starts to go the other way. Have you ever had a car that has developed a water leak as you are going along (no temp guage) that you did not notice until the engine starts to become a lot noiser with interesting rattles and after stopping to cool down you find all the water has gone.
That is why modern oils with their additives are a very complex subject .

[Cam]

Cam - Is Stoke 'oop North'? I would have thought it was, although I've always considered Derby and Stafford to be in the Midlands.

It is Midlands really, but it's north midlands, about 50 miles (ish) north of the brummies. Derby is technically south of us (just) and so is Stafford.

PS - what's happened to Jane? Has Papa Lazarou got her?

Jane is OK, I saw her last Friday and spoke to her last Sunday. She tends to mither me now, instead of you lot!! But she has had problems with her computer lately, but I think it's sorted now.

Grainger,
I did not know that you were from Stoke originally?? where abouts?? Oh and not to nit pick, but I love the POTTERIES accent, but I hate the STOKE accent, they are totally different. I am from Smallthorne (voted 3rd worst place in Stoke-on-Trent to live!!) and we have a potteries accent round here (north Stoke), but Stoke itself and places like Meir and Longton (south Stoke) - (sorry Jane!!), have the Stoke accent.

OK, got it! good.

[grainger]

hi cam,

yes im a longton lad, born at the city general - i thought i said my parents still live at the top of anchor road. my mrs comes from weston coyney, we moved here when she became ill, she has trouble breathing so it made sense to get out of smoke, i mean stoke. ... this place is so pretty but im telling you i really really miss stoke, and if it wasnt for her health we would have come back years ago. stoke isnt like any other big city, its rate primitive intit ?

thats why we are back and forward to stoke all the time, in fact ive got to come over a lot during these school holidays, if theres anything going on with the stoke posse let me know and we'll meet up

no, i have nearly lost my accent, when i meet my family it all comes back, but round here you have to pronounce your 'R' s and 'H's and make sure each word is distinct from the others or they cant tell what youre saying.

cheers
grainger