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Halford 20w 50 on special

5K views 30 replies 9 participants last post by  Doug748 
#1 ·
Just noticed that Halfords (here in the UK) has a promotion on oils - 25% of -- so those who use it can get 5 litres of their classic 20w 50 for 15 squid - don't know when the offer finishes
 
#5 ·
Hi Wol,

duckhams was the green stuff --- my choice back then was either Duckhams or Castrol GTX
"back then" Duckhams was part of BP and Castrol wasn't. BP took over Castrol years ago and used the name and packaging instead of Duckhams.

There is plenty better now. Anyone who believes cheap oil from Halfwits in 2017 bears any relevance or relationship to Duckhams "back then" just because it's green also believes in little green men from a galaxy far, far away? ;)

Regards,
 
#10 · (Edited)
Some of the oils on sale today are to very old specifications.
EG Mobil 1 racing 10w40 = SJ Castrol Power 1 racing 10w40 = SL
Shell advance ultra10w40 = SL

http://www.api.org/products-and-ser...ies-and-documents/oil-categories#tab_gasoline

Readily available oil that meets the latest SM & SN specs is this Motul:

http://www.opieoils.co.uk/p-912-mot...oil-for-bikes-fully-synthetic-with-ester.aspx
Or this:
http://www.opieoils.co.uk/p-812-sil...-ester-full-synthetic-4t-bike-engine-oil.aspx

Triumph say for my Tiger 800 & 1050 must be SH or higher.
API spec:
SH Obsolete CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1996. May not provide adequate protection against build-up of engine sludge, oxidation, or wear.
 
#11 ·
Hi Paul,

Triumph say for my Tiger 800 & 1050 must be SH or higher.
API spec:
SH Obsolete CAUTION: Not suitable for use in most gasoline-powered automotive engines built after 1996. May not provide adequate protection against build-up of engine sludge, oxidation, or wear.
You are posting on a forum specifically for "Triumphs" built long before "1996".

By definition, that quote is from Hinckley "Triumph". The company has said on numerous occasions since it was formed that it does not have any interest in providing any technical help to owners of "Triumphs" it didn't make. Hinckley's only interest in Meriden or its products has only ever been plundering the history to market the current range.

Technically, in many countries, API SH or later-spec. oil is not good for Meriden Triumphs as, in those specs., specifically the amount of the zinc-based additive called ZDDP has been cut dramatically. There is considerable evidence that the Meriden Triumph tappet design requires the high levels of ZDDP as a high-pressure lubricant.

There are other additives that can give similar high-pressure protection and pass SH-on API specs. but you have to go to the specific oil maker/blender and know that you're talking to a tribologist (rather than a "customer service representative" or whatever :bluduh) to ask if any of those additives are used in that specific oil maker's/blender's motorcycle oil(s).

Hth.

Regards,
 
#13 · (Edited)
Paul49,you have to bear in mind that these high spec,oils are often not suitable in the primary as they are likely to make the clutch slip.Best way to buy is to buy an oil made for the motorcycle market marked 4T,or the old classic car oil 20/50 marketed by many companies.I get my extra ZDDP from the addition of STP additive.I suspect that modern 4T oil might be OK on its own in old engines but it would take thousands of miles to try out the theory. Best option,i think,is to use a traditional oil,20/50 and marketed as suitable for air cooled twins.

I am also using a 20/60 racing oil which does have some extra ZDDP and any other chemical that will stand abuse in an engine running at constantly varying temperatures.What i have noticed in the last 20 years is a lot less wear in the engine parts and tappet adjustment does not have to be altered very often now.I get no sludge build up and none of the creamy gunge that used to appear in primary cases and no clutch sticking.
The particular make of oil seems to make no difference as long as it is suitable for the clutch,so a 4T standard.
 
#14 · (Edited)
Thankyou rambo, I am fortunate when looking at engine oil, as you can see my old bike is an Ariel Huntmaster which although similar engine mechanicals to the old Meridens, it has separate primary oil & also a dry clutch, so I am not restricted to motorcycle specific oils. Smart design eh? Must have been that Turner fella before he got shipped off to sort Triumph out.

I was thinking some of the modern oils might contain additives somewhat better than were used back in the 1930's - 1950's when our old bikes were designed. Maybe not then, a bit like taking the lead out of petrol eh.

BTW: The Mobil Technical guy we had at a big Triumph meet told us it's a common mistake to put additives in oil such as STP, Wynns, etc. as it reduces other more important components of the oil. If it works fine for you then it must be ok he was likely nitpicking.
 
#18 ·
#20 · (Edited)
#23 ·
Hi Paul,

Problem with monogrades is when it's cold - I'm not talking about riding in the winter but more if you fancy an early-morning or late evening ride.

Without going too deep:-

. The "40", lacking a "W" ("Winter"), means a measured quantity will pass through a measured orifice in a particular time (say 40 seconds?) when it's at 100 degrees Centigrade.

. However, the "20W" of "20W50" means the the same measured quantity will pass through the same measured orifice in (for the sake of argument) half the time, so 20 seconds, when it's at zero degrees C. :thumb

. You know that oil gets thinner as it get hotter? Multigrades contain (amongst a lot of other things) Viscosity Index Improvers; essentially these curl up when the oil's cold and stretch out - thickening the base oil - as it heats up.

. So, while a 20 would be like water at 100 degrees C, with added VII, a 20W50 is as thick as a 50 at 100 degrees C.

. But you don't want an actual 50 when it's at zero degrees C 'cos it'll run like treacle.

Note that the above is a gross over-simplification of the subject of multigrade oil - don't be led to the idea that multis are always better than monos. If you want to know more, enter "multigrade oil" into your preferred internet search engine, and discover a cure for insomnia at the same time ... :bluduh

Hth.

Regards,
 
#24 ·
Good idea by Paul49 - how about a list of what make/type etc of oil you use in your Meriden Triumph twin --- not asking for any recomendations - just a list of currently / easily available oils that individuals can make their own choice from -- i will post a new thread to see what hapens
 
#25 · (Edited)
Back in our yoof, the straight 40's oil reasoning used to be explained as:

These old air cooled engines had greater bearing clearances so required a straight 40's rather than a 20w50 to take up those clearances when cold. When the engines were up to temperature the clearances & the oil were correct.

Might be BS but that's what we were taught back in the day.

Nowadays with water cooled engines, bearing fits can be a lot closer maintained by the cooling system & multi-grade oils specified for modern engines.
 
#28 ·
Hi Paul,

Might be BS
'Fraid no "might" about it.

Multigrades would not exist today if, when they first came to market, they didn't work in existing engines.

Meriden never built a water-cooled engine. It's entire output was air-cooled engines, with attendant bearing clearances. However, '69-on manuals show multigrade engine oil being recommended, without any changes to the relevant bearing clearances from '68 engines.

Plain bearings require oil pressure to make 'em work without wearing. The pressure is applied by the pump and some science within the bearing. The pump cannot pressurise thick cold oil, so the "science within the bearing" doesn't work and you get metal-to-metal contact. :(

You're partially-right about water-cooled engines having closer bearing fits maintained by more-consistent cooling. But no modern engine "nowadays" runs 20W50. Even in the 1960's and early 1970's, the Japanese bike makers - still almost entirely using air-cooled engines - regularly ran ads. in the bike papers and magazines telling owners to use 10W40 and not 20W50 (which took relatively much longer to pressurise the ohc plain bearings after start-up).

That said, realistically, your Huntmaster is not covering high mileages in extremes of temperature? At worst, it gets caught out in the rain on a cool evening? So any benefits from changing from straight 40 to 20W50 are likely to be minimal short- or medium-term.

Hth.

Regards,
 
#29 · (Edited)
No worries pal ^^^^ I respect everyone's opinion. it is very difficult to find hard facts on this subject.


I'm amazed all those engines are still around after running on 40 & 50 weight straight oil for all those years.

There are many opinions out there & many that can be disputed, some worth a read also, "It is not meat gravy":

http://www.badasscars.com/index.cfm...ct_id=102/category_id=13/mode=prod/prd102.htm
 
#30 ·
I understood was that for our bikes, with or without filters was how much detergent your oil carries.

Reasoning being that a high detergent oil will dissolve the crap in your sludge trap and elsewhere in your motor and send it round the engine causing wear.

so even if you have fitted an oil filter, you should still use a low detergent oil. Something marked as being suitable for a 50/60s vehicle would be fine.

If you have a rebuilt engine with clean sludge trap then your choice of oil would be wider but modern oils have a reduced ZDDP package because it does damage to Catalytic converters and ZDDP is needed for tappet /cam wear.

Halfords 20/50 sounds fine to me and change it every 1000 miles, fitting an oil filter would be no bad thing either.


Charles
 
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