Oils

[Andy G]

Hmm, there surely has to be a reason why Screwfix say it's suitable for lawnmowers, stationary engines and generators but don't mention old motorbikes?!...
I know little about the science of oils but I'm going to guess that it has something to do with operating temperature, and how the viscosity falls away as stuff gets hotter than the average lawnmower. But....
Why not put it in your chaincase, it'll work there, and as said, it's cheaper than many.

[clive]

Well I am rather cheap. I have always recycled used SAE 50 through the primary chaincase on my singles. As they leak the oil is gradually spread around and about. Never thought I would need sae 30 in it and no problem experienced.
Admittedly on the twins which have aluminium chaincases I have used 20/50, 50 or if touring 10 40 because its all I could get. Maybe the multi grade has contributed to the hammering up of the tangs on the clutch plates or maybev its just the enormous power of an AMC 600 twin.

[Mollbhan]

Well the hottest I have ever seen the oil get on my G80 could never be described as hot so the cheapest screwfix oil is probably vastly superior to the recommended 1948 oils, however the difference in expense is so small it aint worth bothering about. I don't think these engines are terribly fussy,I say just use the oil you want.

[SPRIDDLER]

Screwfix has a (no nonsense oil) which I am told is grade 30 with no additives, perfect for the chaincase, I use it in the engine too and have never had any problems. Being fairly cheap oil changes are not expensive.

Morris quote their oil as meeting API/SD CC with this info........

Description
Golden Film Classic Motor Oils are a specialist range of high quality, low detergent/dispersant monograde
lubricants. These oils are suitable for use in naturally aspirated four stroke petrol and diesel engines and classic
gearbox designs.
Applications
Golden Film Classic Motor Oils are recommended for use in veteran, classic and vintage cars, motorcycles,
commercial vehicles and tractors, where engine design and tolerances prohibit the use of modern multigrade, high
additive level oils. Modern dispersant additives keep combustion chamber contamination suspended in the
lubricant, allowing full flow cartridge filters to remove it. Early oil filtration, usually in the form of a mesh gauze or
strainer, is not efficient enough to remove this suspended material. Golden Film Motor Oils are low dispersant oils
and allow the suspended matter to drop harmlessly into the sump.
Golden Film Classic Motor Oils also have enhanced anti-foam properties ensuring optimised performance in
motorcycle and automotive classic gearbox designs.
Golden Film SAE 30 and SAE 40 are ideal choices for lightly loaded diesel engines used in canal boats, watercraft,
older generators (e.g. Lister, Perkins), etc., where they can dramatically reduce the likelihood of bore glazing.
Furthermore, the low level of detergent / dispersant makes Golden Film SAE 30 an ideal choice for 1960s/70s VW
air-cooled engines without full flow filters.
Performance Level
API SD / CC


Screwfix quote that their oil meets API SF/CF specification/applications

From an independent technical report it would seem that both may be suitable:

API Classifications, Gasoline

SA – Obsolete, not suitable for engines built after 1930.

SB – Obsolete, not suitable for engines built after 1951.

SC - Obsolete, not suitable for engines built after 1967.

SD - Obsolete, not suitable for engines built after 1971.

(WARNING: Lubricants in these classifications may cause damage to modern engines)

SE - Obsolete, not suitable for engines built after 1979.

SF - Obsolete, not suitable for engines built after 1988.

SG -Obsolete, not suitable for engines built after 1993.

SH - Obsolete, not suitable for engines built after 1996.

(WARNING: Lubricants in these classifications may not provide adequate sludge protection)

[Andy G]

Morris quote their oil as meeting API/SD CC with this info........

.....These oils are suitable for use in naturally aspirated four stroke petrol and diesel engines and classic
gearbox...

Just for heaven's sake don't risk it in your lawnmower!



Seriously tho, that's a very interesting read Spriddler. Thanks.

[SPRIDDLER]

Yes Andy, it is interesting although I had a desperate lady phone me whilst I was writing and the call lasted for the past hour or so, so I didn't get around to checking whether the API number refers specifically to the oil quality or whether it just defines its general applications and it's a bit too late to delve deeper now.

[g5wqian]

engine,gearbox,primary case i just use sae 50 classic oil all year round , i dont really use my old bikes in winter due to salt on roads and to be honest i dont like the corrosion it causes .
plenty of classic type oils available on likes of ebay from places like smith allan , westway, comma classic , silkolene etc .
i use sae50 in gearbox and in chaincase but have used atf [red] in chaincase so i can see if any leaks are from there or other sources .
there wouldnt be a problem using sae 50 40 or 30 grade oil viscosity in your engine , it will all work , its when you dont have any oil in that youll have problems .
spark plugs , well take your pick really , champion n5C is my commonly used type but have also used ngk b5es , ac 43xl , lodge hbln, although theres plenty of other worthy makes to use that other fellas and ladies will tell you about ..
i did used to use N4C plugs but found they sooted up in my twin and single so i dropped to an N5C and much better for my style of riding around the lanes .
you can get thin fork oil in 1 litre bottles from westway , sae 5 to 15 in various values if ever needed

https://www.westwayoils.co.uk/collections/classic-oils

https://www.westwayoils.co.uk/collectio ... ils?page=2

cheers
ian

[shaunstaples]

I’ve been doing my own research, as more often these days for me “ it’s not what it says on the tin “.
My engine appears to me to be quite worn, but new to my bike I’m no expert.
The previous owner said he was running on sae40, so as normal for me new oil, new filters to start with. On my first run out in the spring, I stopped and the oil was barely warm, I noticed that dipping my finger in the new 40 grade was like water with hardly a trace left on my finger. (Not a scientific test but scared the hell out of me)
So out with that and in with sae50, in comparison this still feels like oil even when hot. But as I said my engine is ready for attention so ideal for nursing and seeing which oil can perform miracles?
The pressure hits 120psi relief no matter what oil is in but when warm ( 5 miles) with sae40 there’s barely a flicker of the needle, with sae50 I could hit 10psi with a good rev.
The sae40 was behind the 50, but the pressure drop wasn’t as extreme as the thinning of the 40 grade which surprised me, I expected the pressure to increase more.
Now I’m in the process of fitting an inline filter to the oil return so have had the courage to move over to multigrade.
I’ve only tried what I had on the shelf and that was 20/50 which boosted warm pressure to 20psi and lastly trying 10/60 (Subaru I’m told) which again has raised warm pressure to just under 30psi with a rev.
Most of the manufacturers provide viscosity at 100 deg so you can get a good comparison between the grades and even the brands.
For me a full flow filter and multigrade is a great improvement for twins.
I’ve seen 10/60 and 20/60 for around £30 per 5 litres so that with my £4 Dacia filter is about best value for money I can find.

[Expat]

Settled on using Valvoline straight 50 high zinc for pushrod engines out here in my G3 single when living where outdoor temps ranged between 10 -35C, with a 20-50 bike oil in the chain case and a 70-90 gear oil in the gear box. Thinking now after moving house to where current outdoor temps are around 10 C and dropping, that the 50 is too viscous and will change to a 20-50 as used in other bikes, at least until temps rise again. G3 has a cartridge filter in the return line.

[AngleseyAJS]

Thank you for all the replys, all very interesting and while these old engines will most definitely work better with any modern oil it's great to hear people's opinions.

On a side not they were gritting like crazy last night while collecting my son from scouts, no more riding for me!

Thanks again for the really useful information and opinions