BMC 1.8 diesel - which oil?
Andrew Denny
asked them what brand of oil they recommended. The guy on the phone
said 'CC grade - the sort you can buy for about £3 at supermarkets -
and change it regularly every 100-150 hours'
In fact, he said it was better to use this very cheap oil in my BMC,
rather than a modern one stuffed full of detergents, additives, etc,
which was designed for a more modern design of engine.
Recently I asked a (road/van) diesel engineer, and he scoffed, and
said it didn't matter what the BMC was driving, nor the fact that the
engine was a 50 year old design -- he said I was risking a lot of
damage in getting the cheaper oil.
Who is right? I hope AMC is, because for the last three oil changes
I've been using the CCheap stuff as they suggested and its under £3 at
ASDA. No disasters so far, but I don't want to be a hostage to
fortune.
Tony Brooks
wrote:
I do not have time to go through the whole argument here, but, thanks
to a sheeth of accademic reports on the subject of diesel bore
glazing, via Lister Petter, and the experience of a friend on British
Gas vans, I am reasonably convinced that there is a good case for oils
with a high API (American Petrolium Institute) be a contributor of
bore glazing in inland marine diesels. - so in my view your AMC are
probably correct.
I am not quiet so convinced by the 100 - 150 hours argument because
this could have you changing it every two weeks in the summer and such
intensive use would TEND to boil off the conensation in the oil,
however with less intensive use those hours might be required.
Tony Brooks
Prepair Ltd
wrote:
>I have a BMC 1.8 engine, marinised by AMC. Last year I phoned and
This has been aired at some length before, and the views are still
valid.
Diesels need detergent oil to keep particulate matter in suspension,
mainly from blow-by past the rings at low temperatures, usually in the
warming-up period.
Because most boat engines don't get properly hot in use, the
additional problem of condensation accumulation rears its head, and
the other problems add up from there.
If you are prepared to change the oil at short intervals, then any
good quality basic engine oil will do the job for you, but you will
lose the 'benefit' of some of the more interesting and useful
additives.
Bore glazing is directly related to slow running and idling for long
periods in diesels, as the temperature in the cylinders does not reach
the point where the pistons are expanded fully into the bores and the
rings do not get the support required against the cylinder walls.
Although the figures are in thousands of an inch, the problem is a
real one and can be lessened by regular runs at highish power to get
the engine up to proper temperature and working for its living.
Modern oils such as fully synthetic types are intended for engines
working at high speeds and powers, but they are also usable for
slow-revving angines, it's just that the specialised additives don't
get activated.
Personally I never use cheap oils, but I know plenty of people that
do, and seem to get away with it. The choice is with the engine owner
or operator, and I would suggest that more frequent changes would
negate any financial savings made from using the cheaper oil anyway.
We are paying less than £10 a gallon +vat for Vauxhall fully
synthetic oil, while a good standard oil is Shell Four Seasons.
Kind regards,
Peter
Peter Forbes
Prepair Ltd
Luton, UK
email: pre...@easynet.co.uk
home: die...@easynet.co.uk
Thys de Wet
If your diesel engine is not 'working' really hard, chances are that your
motor may glaze the cylinder bores. I had it on a Caterpillar Diesel
engine. After a new ring job and honing cylinders, we used Shell X100 30SAE
(El cheapo) After a proper running-in period, during which she was worked
hard to get the operating temperature up to normal we used Shell Rimula 30
SAE. Of course the SAE rating of the oil is dependant on the average
seasonal temperature. So it may differ.
T de Wet in South Africa
"martinp" <mar...@wanadoo.nl> wrote in message
news:ea8muu8ne8brrliug...@4ax.com...
> On 1 Dec 2002 16:44:59 -0800, d...@grannybuttons.com (Andrew Denny)
> wrote:
>
> > I have a BMC 1.8 engine, marinised by AMC. Last year I phoned and
> > asked them what brand of oil they recommended. The guy on the phone
> > said 'CC grade - the sort you can buy for about £3 at supermarkets -
> > and change it regularly every 100-150 hours'
> >
> > In fact, he said it was better to use this very cheap oil in my BMC,
> > rather than a modern one stuffed full of detergents, additives, etc,
> > which was designed for a more modern design of engine.
> >
> > Recently I asked a (road/van) diesel engineer, and he scoffed, and
> > said it didn't matter what the BMC was driving, nor the fact that the
> > engine was a 50 year old design -- he said I was risking a lot of
> > damage in getting the cheaper oil.
>
> we were also advised by our local supplier of oils at avast discount,
> not to use modern oils to lubricate our engine. The oil we wanted to
> buy was almost twice the price of the oil he recommended. I still
> bought the expensive oil.
> --
> m.
Tony Brooks
wrote:
>As an aside:
>
>If your diesel engine is not 'working' really hard, chances are that your
>motor may glaze the cylinder bores. I had it on a Caterpillar Diesel
>engine. After a new ring job and honing cylinders, we used Shell X100 30SAE
>(El cheapo) After a proper running-in period, during which she was worked
>hard to get the operating temperature up to normal we used Shell Rimula 30
>SAE. Of course the SAE rating of the oil is dependant on the average
>seasonal temperature. So it may differ.
>
>T de Wet in South Africa
Just to make sure there is no confusion. There is cheap oil, and
lower specification oil.
Cheap oil may not have an API specification, however low spec oil that
is good quality (and usually cheaper that higher spec oil) will.
The API spec is the thing that describes the performance of the oil,
the SAE rating only shows its viscosity (runnyness) when it went into
the can.
Both the above oils will have an API spec. Always buy on both SAE
rating and API spec., do not worry overmuch about brand names.
Tony Brooks
Neil Arlidge
> ..............the problem is a
> real one and can be lessened by regular runs at highish power to get
> the engine up to proper temperature and working for its living.
I have some tips on doing this! ;-)
--
Neil Arlidge - NB Earnest (15.5 hours flat out)
Follow the travels of the TNC at http://www.tuesdaynightclub.co.uk
Ed. Harris
We've always been told to use CD grade at the highest (CC can be difficult
to get hold of). The original maintenance handbook specified 150 hours
between changes but ours sometimes needs it be 100 hours.
We found to our cost that our engine *insists* on 20/50. Anything thinner
and it just runs out through the seals (especially the purpose made Lister
Oil) but with 20/50 it doesn't use a drop between changes.
--
Ed. NB Guinevere on the Nene
==
David
> In article <8a647e1e.0212...@posting.google.com>,
> Andrew Denny <d...@grannybuttons.com> wrote:
> > I have a BMC 1.8 engine, marinised by AMC. Last year I phoned and asked
> > them what brand of oil they recommended. The guy on the phone said 'CC
> > grade - the sort you can buy for about £3 at supermarkets - and change
> > it regularly every 100-150 hours'
>
> > In fact, he said it was better to use this very cheap oil in my BMC,
> > rather than a modern one stuffed full of detergents, additives, etc,
> > which was designed for a more modern design of engine.
>
> > Recently I asked a (road/van) diesel engineer, and he scoffed, and said
> > it didn't matter what the BMC was driving, nor the fact that the engine
> > was a 50 year old design -- he said I was risking a lot of damage in
> > getting the cheaper oil.
>
> > Who is right? I hope AMC is, because for the last three oil changes
> > I've been using the CCheap stuff as they suggested and its under £3 at
> > ASDA. No disasters so far, but I don't want to be a hostage to fortune.
>
My BMC 1.8 manual says:
Oil Minimum Performance Level - MIL-L-2104B A.P.I.-SE/CC or MIL-L-46152
I'd still be guided by Tony or AMC though - they must know these engines inside out.
David
timleech
<pre...@easynet.co.uk> wrote:
>Personally I never use cheap oils, but I know plenty of people that
>do, and seem to get away with it. The choice is with the engine owner
>or operator, and I would suggest that more frequent changes would
>negate any financial savings made from using the cheaper oil anyway.
>
Is the main point not to save money on the cost of the oil, rather to
use a lower specification of oil, ie less complex additives rather
than a 'cheaper' basic lubricant, which can perfectly well come from a
major oil company if you can find one which still does it.
Oil additives have been developed specifically to cope with the
conditions in modern turbocharged diesels, plus I suppose long high
speed runs such as in motorway driving, the lower specs just
represent what was the norm 30 or more years ago.
I suspect you will find that the smaller oil blenders, such as Morris
and Rock oil, who do still offer CC or CD grade oils, get their main
ingredients from the likes of Shell anyway <G>
It's not a new problem - Gardners were issuing warnings about using
'turbo' oils in their engines 30 years ago, in the days before they
started fitting turbochargers themselves!
Cheers
Tim
Tim Leech
Dutton Dry-Dock
timl...@dutondok.u-net.com
Traditional & Modern canal craft repairs
Martin E Phillips
2002, timleech <timl...@dutondok.u-net.com> writes
>I suspect you will find that the smaller oil blenders, such as Morris
>and Rock oil, who do still offer CC or CD grade oils, get their main
>ingredients from the likes of Shell anyway <G>
ISTR buying a container of Castrol GTX in the summer "for the older
engine" rated at API CD - or am I mistaken? Think it was 20W50 or
thereabouts. Still cost over a tenner for 4.5 l.
Wassail!
--
Martin E Phillips nb Boden, Splatt Bridge
http://www.g4cio.demon.co.uk
Homebrewing, black pudding, boats, morris dancing, ham radio and more!
The Gloucester-Sharpness canal page http://www.glos-sharpness.org.uk
Andrew Denny
and a couple of direct emails (many thanks!) I've done a little more
homework.
I was impressed by The Engine Oil Bible, which taught me a fair bit
more (http://www.fernblatt.com/longhurst/engineoil_bible.html ) and a
couple more of very interesting links from that site.
Best regds
Andrew Denny