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engine oil
Posted: Thu Aug 02, 2012 1:21 pm
by izzi
Hi,
Can anyone tell me what would be the side effects, or harm to the engine, if a part synthetic oil or even a different recommended oil grade was put into the engine as part of a routine service.
Roy.

Re: engine oil
Posted: Thu Aug 02, 2012 1:55 pm
by JOWETTJAVELIN
Why, are you thinking of doing it? A 10w40 is too thin and will be burnt more readily.
Stick to a quality 20w50, I use Halford's 'Classic' greenbase oil, but some people use other stuff - it's personal choice.
Don't mix oils either.
Re: engine oil
Posted: Thu Aug 02, 2012 5:22 pm
by dalebrignall
go for a decent 20/50 the engine is designed for that b and q do some decent speck stuff in a blue bottle .
Re: engine oil
Posted: Thu Aug 02, 2012 5:46 pm
by izzi
Hi,
My reason for asking is, If you suspect that the correct oil was not used during a recent service.
thanks,
Roy
Re: engine oil
Posted: Thu Aug 02, 2012 6:05 pm
by ampwhu
think of it like this.......... did they use 10W40 in 1963? did they know what synthetic was back then?
just stick to mineral oils, it was good enough back then, it's good enough for today. simples.
Re: engine oil
Posted: Thu Aug 02, 2012 6:07 pm
by JOWETTJAVELIN
If only the garage he took it to thought like that - and they're meant to be 'professionals'.

Re: engine oil
Posted: Thu Aug 02, 2012 7:29 pm
by izzi
Hi,
Thanks,
I think I was being a little to paranoid with the garage.
The garage just answered my call and told me they used Comma classic 20/50.
"I do like the name Jowett Javelin, Another classic car".
Roy.

Re: engine oil
Posted: Fri Aug 03, 2012 12:02 am
by mike.perry
ampwhu wrote:think of it like this.......... did they use 10W40 in 1963? did they know what synthetic was back then?
just stick to mineral oils, it was good enough back then, it's good enough for today. simples.
In1963 they used SAE30 monograde. That does not mean that we should continue to use monograde oil. Oils have improved. It was standard practice to drop the sump to clean the sludge out when carrying out an oil change
Re: engine oil
Posted: Fri Aug 03, 2012 9:31 pm
by MikeNash
My BMC workshop manual recommends SAE 30 for "Tropical and temperate down to 32F" and so often I wonder we seem to have stuck in a SAE 20/50 rut. I've used 10/40 diesel oil and seen no noticeable differences in leakage or consumption (the engine was already down to 200-250 miles to the pint) but now with a better motor I intend to do a few readings with the usual Wilkinsons' 20-50 (£9 a gallon) and then to move to a cheap SAE 5-30 synthetic and see what difference it makes. I hope for a few more miles to the gall.
If I remember it right we became enamoured with 20-50 when Duckham's 20-50 became widely available in the 1960s. 20/30 was around in the late 1950s (Castrolite and Esso Extra I think) but they were more expensive and in the dodgey old wagons I drove in the early 60s Duckham's definitely helped winter starting (anyone remember 1963 -and the short battery life we had then?) and cut the leaks when hot. Duckham's was - and is - good, but there's no denying that modern synthetics are better.
Anyway in a few months I'll go for the BMC's recommended SAE30 for the top temp viscosity and try SAE 5 for the low temp (SAE 0 is just too expensive) and see how I get on. Regards, MikeN.
Re: engine oil
Posted: Fri Aug 03, 2012 10:56 pm
by lambrettalad
Newtons 30 was good but in the 60's I changed to duck hams 20 /50 ,a lovely green oil with zero problems
Re: engine oil
Posted: Fri Aug 03, 2012 11:06 pm
by JOWETTJAVELIN
lambrettalad wrote:Newtons 30 was good but in the 60's I changed to duck hams 20 /50 ,a lovely green oil with zero problems
I used Duckham's too but they stopped making it some years ago.

Since then switched to Halford's Classic 20/50 - green, mineral and smells the same as Duckhams, who knows it might well be Duckham's?
Re: engine oil
Posted: Sat Aug 04, 2012 9:07 am
by izzi
Hi,
I seemed to have opened a can of interesting worms regarding engine oil,
Apparently Duckhams/Castrol, stopped using green dye.( for health reasons ! ).
Mobil 1 once claimed to be the best oil in the world.( I think they still hold this claim ).
When all these higher grade oil companies changed there package labels Etc;, the unsold cans were sent to other well known companies to blend into there own named brand.( supermarkets Etc;)
I have now learned that that only harm a good fully synthetic oil can do to my engine is possibly find a way to leak through through cork and hard seals.
Can this all be correct or possibly not ?
Roy.

Re: engine oil
Posted: Sat Aug 04, 2012 9:32 am
by mike.perry
One way to find out is to fill a worn engine with synthetic oil, take the car for a run down the motorway and watch the oil pressure gauge
Re: engine oil
Posted: Sat Aug 04, 2012 7:21 pm
by bmcecosse
Anyone know what a 'synthetic' oil is ? What was it before it was made into oil???
The very best oil used to be Castrol R = Racing. Not inexpensive !! That wonderful smell !!! Based on Castor oil - I do believe the origin of the 'Castrol' name. Snag was the whole engine had to be spotlessly clean internally.
Re: engine oil
Posted: Sat Aug 04, 2012 7:34 pm
by chrisryder
bmcecosse wrote:Anyone know what a 'synthetic' oil is ? What was it before it was made into oil???

From a quick internet search 'Mineral Oil is almost entirely made up of natural substances, whereas Synthetic Oil has other chemical products added to enhance its performance'.
Re: engine oil
Posted: Sat Aug 04, 2012 7:38 pm
by bmcecosse
'Yes - I too can search the 'net. But ALL oils have 'chemicals' added to them - surely something described as 'synthetic' means it has been assembled entirely from 'chemicals' - and not from 'natural' materials.
Re: engine oil
Posted: Sat Aug 04, 2012 9:10 pm
by ben-me-123
"synthetic" as I understand from my knowledge of Chemistry is basically "made in labs" whereas other methods don't "make" the product but filter it out... modern cars should prefer synthetic because it can be tailored to specific engines etc (and vice versa)... it's come about because they can synthesise lots of 'stuff' (top A level Chem word there) easier now...
Re: engine oil
Posted: Sun Aug 05, 2012 7:17 am
by izzi
Hi,
Bmcecosse is correct in what 'synthetic' should mean.
However the oil giants somehow managed to get agreement to make it completely legal to label these oils as 'synthetic'.
Makes you think what other things these oil giants have arranged to pull the wool over us.
Roy.

Re: engine oil
Posted: Sun Aug 05, 2012 8:50 am
by IslipMinor
That wonderful smell !!! Based on Castor oil
When the restoration was completed in 1998, we used a new synthetic oil from Castrol called 'RS', grade was 10W/60, was fully synthetic AND had a whiff of the glorious castor oil smell from the old Castrol R days - wonderful! My wife did not appreciate it very much though, and it is her car!
After a few years the oil became Castrol Edge and lost the castor smell, but we still use the same 10W/60 grade version of it. Mobil have recently produced a same grade version of their Mobil 1 full synthetic, followed by most of the major oil suppliers.
If moving to either a part synthetic or full synthetic, never use either when running in new rings - they never will! Always use a good quality mineral oil for 500-1000 miles and then change to a synthetic type oil.
40-60 year old engines are not made to the same manufacturing tolerances as today and need a bit more help from the lubrication medium. The old 30 grade was around long before motorways and long stretches of dual carriageways and I would suggest that typical modern driving will create higher oil temperatures than in days of yore. BMC/BL changed their standard oil spec to 20W/50 to recognise the changed driving conditions and any additional oil viscosity at higher temperatures will give added protection to the engine.
Mike,
I will be very interested to hear the results of the fuel consumption comparions and whether there is any noticeable difference in leaks?
Re: engine oil
Posted: Sun Aug 05, 2012 9:06 am
by mike.perry
I filled my old Suffolk Punch lawnmower with Castrol R. The smell of Brooklands cutting my back lawn
