Sunday Discussion - Oil.

[SteveC#222]

Just done an oil & filter change on the XBR. Had to get some more oil from the garage as I didn't have quite enough. What a variety of prices for 5 litres of 10W40 semi synth oil! All known names, the most expensive was twice the price of the 'cheapest' for the same SAE spec.

So here's the question how much do you NEED to spend on oil?

To clarify, If I was running a 160bhp 200mph performance bike with 10,000 mile oil changes then I would happily spend money on an high performance oil, BUT as I run a 35bhp 100mph bike that has 12-1500 mile oil changes do I need to? As long as it's a recognised name to the correct SAE spec, does it really make any difference if I get 5ltr of Comma at £14 or spend over £30 on 5ltr of Castrol?

A friend of mine once worked as fleet manager for a firm using big industrial & mining vehicles where you only changed oil after Lab analysis and he reckoned that most of the 'names' use the same basic base oil and just put in their own additives.

What do we think?

[themoudie]

Aye Steve,

Concur with your fleet manager friend.

I buy 25l drum of Morris 10W/40W semi-synthetic motorcycle oil for £99-00 delivered, from a supplier in Ipswich via Ebay (£4-00 per litre).

Change the oil and filter at the manufacturers recommended mileage and before any winter layup; if you have sufficient bikes or don't take them out in the inclement weather/salt on roads period.

BROS 4,000 miles (paper element)
SRX 2,000 miles (paper element)
Morini single 1,000 miles (wash gauze)
Ducati single 1,000 miles (wash gauze) have monograde 40W to use up!

Full synthetic, fine for warp factor bikes designed for it.
Oil, fine if that is what the beast was designed for, and you haven't rebuilt the motor; but may not keep the inside of a motor as clean as the modern semi-synthetic, which may cause thrombosis if it shifts some 'big lumps' when first used!   And, having had problems from using car type additive oil, with my 'wet clutch'    will only use 'motorcycle designated oils without those additives to save the grief and expense of a slipping clutch/rectify/replacement! Shall say nae mair as I've already harrumphed enough on this forum about oil and a slippery clutch! 

Toodle pip, Bill

[timbo]

Buy in bulk is the secret. I currently use a 20 litre drum of Motul 10/40 semi. 10/40 semi is all we need for any of our Jap stuff. Do not use fully synth   
My RE uses the cheapest 20/50 car oil. Older stuff, I'm still  learning, will cheap   20/50  do instead of straight 40 or 50?
(Yes, I know oil is discussed on here every few months, but let's face it, its important) 

[Andy M]

I apply the same logic to oil I know to be the case with brake pads. The "brands" test to the spec and meet it. If Castrol 10W40 was mostly used chip fat they'd be as busted as VW the day the story broke. Wun Hung Lo Lubricants can go bust and set up up again a Pu Pong Oils and you'd never know. They photocopy the test certs. Wilco's , Halfords etc. Could be buying either, but its probably certifiable. Claims of added unobtanium crystals for added protection and a fresh lemony smell I view as sales b$/^*$s.

For the amount I use (3.5 litres a year on the NC) I buy a brand I know. If I was running a fleet or on 2000 service intervals I may make more effort.

The service intervals are debatable too. Triumph upped the Bonneville from 4000 to 6000 the day Harley did. No physical changes, a pure commercial decision not to lose sales. One of the yanks had his Weestrom oil tested at the specified interval and found it fine to double the interval. Writers of manuals who sell oil may not be the best people to set a number.

Andy

[SteveC#222]

I would never use a really cheap oil I'd never heard of, but for our type of bikes I'm sure the expensive oils are probably not worth the extra cost.  The oil I drained today (Comma I seem to remember) although dirty, the viscosity was still good as you would expect after only 1200 or so miles. By contrast the Castrol GTX that I used to use  in my BMW 1000 was like black water after 5000 miles with almost no 'body' left in it!

[johnr]

i last changed the oil in my m21 in 2008, not a problem.

[SteveC#222]

i last changed the oil in my m21 in 2008, not a problem.

Is that because it uses so much you do a rolling oil change every time you top up? I  had a GN250 like that! 

[timbo]

What oil do you lot reckon I should use in a 1950s Matchless. It has just had a rebore and new rings. Should I use straight 40 or 50? As the bike hasn't run in years, what about running in? Should I change the oil after the first 100 mile, ie. to flush the engine, then after 500 miles, then after 1000? I havnt much experience of old Brit stuff 

[themoudie]

Aye Tim,

I used to run a 1953 AJS 18S doing up to 1,000 mile a month at times. My advice would be to use a 20W/50W mineral oil. Maybe an own brand (Halfords) for the first 20 - 50 miles, which then comes out all sparkly and gets dumped, wash the felt filter thoroughly. Refill with the same oil and again keep the engine spinning, never lug it, for a further 250 - 500 miles. Dump this lot, then having washed the felt filter thoroughly, refill with Duckhams Q 20W/50W or GTX 20W/50W mineral oil and change the oil at the manufacturers recomended intervals, cleaning the felt filter every time and start giving it a bit of a load. Should be nicely run in by the 1,000 mile mark and happy to chuff along. 

Another thing, don't forget to check the torques of the cylinder head bolts after the first run, once the motor is cold and again after 250 miles, when the motor is cold. Tolerances were not the same as CNC manufacturing techniques of today, but worn out machinery that had been installed prior to WWII and then been run into the ground for decades. 

This article from 'Real Classic' gives some good background: 'Real_Classic'_"The_Oil_Truth"

Hope all goes well, Bill

[timbo]

Will give that article a read, but not sure I'd risk 20w50, as I was always told you should only use it if the engine has been completely stripped and rebuilt, as otherwise it may disturb old debris inside the engine and possibly cause a blocked oilway. Too risky, I fear, so I'll stick with 40 or 50 I think 

[themoudie]

Aye Tim,

Go for the 40W, but be aware that the modern 40W mineral oil may contain the same detergent additives that a 20W/50W mineral oil contains, even though it is a monograde and will not contain the same long molecular additives that improve the lubricity range of the multigrade mineral oil. It is those detergent additives that may cause you grief.

Did you not flush the bottom end through and give it a blast with compressed air afore rebuilding the top end? Having seen what is about these days and the contents of supposedly "part restored" or an "unfinished project, all the expensive bits done", I would be even more inclined to dismantle, inspect and reassemble EVERYTHING, afore putting oil, and fuel into the beast and lighting the blue spark.

A friend recently acquired a wee Duke single, of previously known ownership and maintenance routine (owner deceased), but been standing a while (10 years). Changed the oil, cleaned the gauze and ran it for 100 mile afore dropping the oil again and re-cleaning the gauze. Within another 250 miles the death rattle from the big end occurred! So now it may need a £500 + rod and big end bearing kit plus the cost of having the work done as you need a press with a capacity of at least 30 tonne to take them apart and put them together again. Shame, nice wee bike! 

Fingers crossed  Bill

[timbo]

Using Comma Classic 40w, at £20 for five litres. Will change after first 100, and see what come out