Oil

On Wednesday, in article
<[email protected]>
[email protected] "Badger" wrote:

> "Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
> news:[email protected]...
> >
> >
> > As long as the oil pressure does not drop off the scale when idling and it
> > is not consumed at an accelerated rate then the difference in viscosity is
> > of no consequence.
> >
>
> WRONG! Pressure will be maintained at the pump relief valve (and gauge, if
> one is fitted) but this is not a true representation of what is happening
> within the rest of the engine. Every bearing surface is an orifice, the
> thinner the fluid is then the greater the flow rate across the orifice for a
> given pressure. As we are talking dynamic pressures not static, the pressure
> beyond that orifice will be lower than before it, this repeating through the
> engine until there is virtually no pressure (or flow) at the rear main
> bearing! The firther away you go from the pump outlet, the lower the oil
> pressure becomes at each successive bearing, amplified by the use of a
> thinner fluid.

It's a long time since I was taught anything about viscosity, but
there's something which feels odd about this...

[thinks]

I think that the critical aspect is the pipework between the orifices,
and the total possible flow. Pressure is a secondary effect here. The
pump doesn't shift any more volume with a thinner oil, while each
orifice can pass more oil. So there's not enough oil being pumped
through the system to meet all the demands, and the differences in the
pipework, distance and size and such, decide which bearing gets what
oil there is.

Is that right?

If you could pump more oil, it'd be different.

I expect the design of the oil passages in an engine is very important,
so that the more distant bearings still get oil.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"I am Number Two," said Penfold. "You are Number Six."

In message <[email protected]>
"Badger" <[email protected]> wrote:

>
> "Austin Shackles" <[email protected]> wrote in message
> news:[email protected]...
> > On or around Wed, 20 Apr 2005 08:31:24 +0000 (UTC), beamendsltd
> > <[email protected]> enlightened us thusly:
> >
> >>
> >>ETC6099 3.5 Efi
> >>ETC8686 3.9 Efi
> >>
> >
> > 's more about the cam timings, though - the early 3.5 and the 3.9 have
> > identical profiles, 2 degrees different in timing, IIRC.
>
> Yes, the early 3.5 carb and the 3.9efi are same profiles but 3.9efi is 2
> degrees advanced. 3.5EFI rangie is a totally different profile.
> Richard, do you have different cam part no's listed for rr3.5efi and disco
> 3.5efi?
> Badger.
>
>

Not in effect - the 3.9 (ERR8686) superceeds to
RRR5924 in both cases, though this mentioned in the
Discovery parts book and not in the RR one.

Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Helping keep Land Rovers on and off the road to annoy the Lib Dems

"Badger" wrote ...
>>>
>>> Well I just went and bought some Castrol Longlife 11 oil for the wife's
>>> BMW 330i...£39.99 for 4 litres.
>>> Thought I was seeing things when she rang it up.
>
> Nope, it's dear stuff. Ought to be Castrol SLX Longlife I though, not II,
> that's a VW spec.

Looking at the "can" again it says Castrol SLX Longlife 11 and the Halfords
book said that was the one for the BMW 330i petrol.
I hope they are right.

--
Regards
Bob
In Runnymede, 17 miles West of London

On or around Wed, 20 Apr 2005 12:12:32 +0000 (UTC), "Badger"
<[email protected]> enlightened us thusly:

>
>"Austin Shackles" <[email protected]> wrote in message
>news:[email protected]...
>
>> True nuff. Mind, the handbook for my (H-plate) one lists the thinner oils
>> as well, but the really thin ones have temperature restrictions. It's
>> rare
>> that it's hot enough in this country to really need the "50" bit, I
>> reckon -
>> plus, decent quality "40" has a chance of staying in grade when up to
>> temperature, and I suspect that the crappier "50s" may not.
>
>Your last sentence carries a lot of truth in it Austin, especially the bit
>about crappier oils, however if I were running a thinner oil than 20W50 I'd
>fit an MGBV8 pressure relief valve spring to up the pressure by 15psi or so
>(tested with a gauge, not believing the std pressures as quoted anyway!)
>simply to ensure an adequate flow to the rerar mains.

that might make sense. I might bung a gauge on it, to see what it's doing.
--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
Blue: The sky is blue for a reason. Blue light is a source of strength
and harmony in the cosmos. Create a blue light in your life by
telephoning the police
from the Little Book of Complete B***ocks by Alistair Beaton.

On or around Wed, 20 Apr 2005 12:17:17 +0000 (UTC), beamendsltd
<[email protected]> enlightened us thusly:

>In message <[email protected]>
> Austin Shackles <[email protected]> wrote:
>
>> On or around Wed, 20 Apr 2005 08:31:24 +0000 (UTC), beamendsltd
>> <[email protected]> enlightened us thusly:
>>
>> >
>> >ETC6099 3.5 Efi
>> >ETC8686 3.9 Efi
>> >
>>
>> 's more about the cam timings, though - the early 3.5 and the 3.9 have
>> identical profiles, 2 degrees different in timing, IIRC.
>
>Early ones are:
>ETC6849 - 3.5 Carb 26D, 27D engines
>ETC6850 - 3.5 Carb 28D, 29D, 30D engines.
>
>Todays quiz - what's the difference between these two?
>Answers on a post card!

I could probably look it up, but I suspect the answer is either "nothing" or
possibly "has facility to fit fuel pump cam" and "doesn't".

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
Blue: The sky is blue for a reason. Blue light is a source of strength
and harmony in the cosmos. Create a blue light in your life by
telephoning the police
from the Little Book of Complete B***ocks by Alistair Beaton.

""David G. Bell"" <[email protected]> wrote in message
news:[email protected]...
> On Wednesday, in article
> <[email protected]>
> [email protected] "Badger" wrote:
>
>> "Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
>> news:[email protected]...
>> >
>> >
>> > As long as the oil pressure does not drop off the scale when idling and
>> > it
>> > is not consumed at an accelerated rate then the difference in viscosity
>> > is
>> > of no consequence.
>> >
>>
>> WRONG! Pressure will be maintained at the pump relief valve (and gauge,
>> if
>> one is fitted) but this is not a true representation of what is happening
>> within the rest of the engine. Every bearing surface is an orifice, the
>> thinner the fluid is then the greater the flow rate across the orifice
>> for a
>> given pressure. As we are talking dynamic pressures not static, the
>> pressure
>> beyond that orifice will be lower than before it, this repeating through
>> the
>> engine until there is virtually no pressure (or flow) at the rear main
>> bearing! The firther away you go from the pump outlet, the lower the oil
>> pressure becomes at each successive bearing, amplified by the use of a
>> thinner fluid.
>
> It's a long time since I was taught anything about viscosity, but
> there's something which feels odd about this...
>
> [thinks]
>
> I think that the critical aspect is the pipework between the orifices,
> and the total possible flow. Pressure is a secondary effect here. The
> pump doesn't shift any more volume with a thinner oil, while each
> orifice can pass more oil. So there's not enough oil being pumped
> through the system to meet all the demands, and the differences in the
> pipework, distance and size and such, decide which bearing gets what
> oil there is.
>
> Is that right?
>
> If you could pump more oil, it'd be different.
>
> I expect the design of the oil passages in an engine is very important,
> so that the more distant bearings still get oil.
>

The main thing wrong with his argument is his understanding of the
difference in viscosity between a 10w/40 and a 15w/40 oil.
At operating temperature both are the same viscosity. At ambient temperature
the 10w/40 is marginally thinner or lighter but is still substantially
heavier or thicker than either at operating temperature.
Either of these oils is good for the V8 and no difference should be
noticeable and no harm will be caused by either even in the long term.

Huw

"Badger" <[email protected]> wrote in message
news:[email protected]...
>
> "Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
> news:[email protected]...
>>
>> "Bob Hobden" <[email protected]> wrote in message
>> news:[email protected]...
>>>
>>>
>>> Well I just went and bought some Castrol Longlife 11 oil for the wife's
>>> BMW 330i...£39.99 for 4 litres.
>>> Thought I was seeing things when she rang it up.
>
> Nope, it's dear stuff. Ought to be Castrol SLX Longlife I though, not II,
> that's a VW spec.

True, and mostly a 0w/30 viscosity

>
>> Well now, the BMW engines fitted to Range Rover calls for the same oil
>> when fitted to a BMW but no mention is made of it in the Range Rover
>> handbook which specifies [only the need for] ACEA A3 for petrol versions
>> and B3 for diesel engines. These are the same engines fitted with the
>> same computerised service interval monitor which results in approximately
>> the same mileage drain intervals as in a BMW car. My diesel RR version
>> needs changing at about every 14500 miles.
>> The viscosity specified as suitable for the UK BMW engines include
>> anything between 5w/30 to 10w/40 including 10w/30 and 5w/40 of course. In
>> fact there would be no problem with A3/B3 0w/40 viscosity [such as Mobil1
>> 0w/40 for petrol engines but no other viscosity of Mobil1] although this
>> one grade is not specifically mentioned in the handbook as a suitable
>> grade.
>>
>> There is a wide range of oils commonly available which meet these
>> criteria without costing an arm and a leg.
>>
>
> Does the Rangie book call for just the basic spec Huw, or does it say that
> the oil must meet the Longlife criteria as well?

No mention of any other specification than ACEA A3/B3 as approriate.


I wouldn't dream of putting
> an oil in my 330d that didn't meet the Longlife I spec, based on the
> potential wallet-destroying properties of the potential repair bills if it
> all went pear-shaped.

I wouldn't dream of using a non synthetic oil in it, yet those
specifications can be met by high quality mineral oils. Strange.


> Please tell me of the other oils you know of that meet the Longlife I spec
> other than SLX and Mobil1, would be handy to know.
>

Only the 0w/40 viscosity Mobil 1 is suitable because, last time I looked, it
was the only half suitable viscosity that met the basic ACEA A3.

Actually anything that meets mb229.3 will exceed Longlife1.
The implication from the current Range Rover handbook is that anything that
meets both ACEA A3 and B3 and is within a suitable range of viscosities will
meet LL1. Or at least is good for long drain intervals in BMW engines.
A further implication is that a long drain mulifleet oil such as the Q8
mentioned at the top of this post will be good for a BMW engine for longest
drain intervals. Personally I use large volumes of the same specification
oil in my fleet but not in my Range Rover thank you.
I don't even use an oil that pretends to meet LL1 or ACEA A3/B3 in my diesel
BMW engine. Instead I use an oil that meets heavy duty specification ACEA E4
[which is much higher rated than E5 which the Q8 meets] and mb228.5 ultra
long drain type.
But that's just me using overkill.

Huw

>The main thing wrong with his argument is his understanding of the
>difference in viscosity between a 10w/40 and a 15w/40 oil.
>At operating temperature both are the same viscosity. At ambient temperature
>the 10w/40 is marginally thinner or lighter but is still substantially
>heavier or thicker than either at operating temperature.
>Either of these oils is good for the V8 and no difference should be
>noticeable and no harm will be caused by either even in the long term.
>
>Huw
>

The comparison here, however, is between 20W50 and 15W40, isn't it?




--

Tim Hobbs

'58 Series 2 88" aka "Stig"
'77 101FC Ambulance aka "Burrt"
'03 Volvo V70

"Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
news:[email protected]...
>
""David G. Bell"" <[email protected]> wrote in message
news:[email protected]...

>>
>> It's a long time since I was taught anything about viscosity, but
>> there's something which feels odd about this...
>>
>> [thinks]
>>
>> I think that the critical aspect is the pipework between the orifices,
>> and the total possible flow. Pressure is a secondary effect here. The
>> pump doesn't shift any more volume with a thinner oil, while each
>> orifice can pass more oil. So there's not enough oil being pumped
>> through the system to meet all the demands, and the differences in the
>> pipework, distance and size and such, decide which bearing gets what
>> oil there is.
>>
>> Is that right?

That's exactly what I was trying to say!

>>
>> If you could pump more oil, it'd be different.

Hence the fitting of the MGB relief spring, upping the pressure will give a
bit of a flow increase.

>>
>> I expect the design of the oil passages in an engine is very important,
>> so that the more distant bearings still get oil.

Indeed, but the V8 feeds all its oil from the pump to the offside cam
follower gallery first, with a cross-drilling arrangement to the nearside,
there are separate drillings from there to feed the mains (and onwards to
the big-ends via the crank drillings, with a small jet feed to the opposing
bores from the con-rod caps), cam bearings and a feed to each head. The cam
lobes are fed by oil seeping past the lower circumference of the cam
follower and also return oil down the valley from the heads giving a
"drip-feed" onto the cam.

>>
>
> The main thing wrong with his argument is his understanding of the
> difference in viscosity between a 10w/40 and a 15w/40 oil.

I understand that perfectly Hew, BUT we are talking about the difference
between either 10W40 (or 15W40) and 20W50. It's the 50 bit that's different,
please see that.

> At operating temperature both are the same viscosity.

Only if you are referring to 10W40 and 15W40!

> At ambient temperature the 10w/40 is marginally thinner or lighter but is
> still substantially heavier or thicker than either at operating
> temperature.
> Either of these oils is good for the V8 and no difference should be
> noticeable and no harm will be caused by either even in the long term.

Bull, from what I've seen over the years dismantling and rebuilding them.
The use of a lighter weight oil than **W50 WILL cause accelerated wear of
the rear main and no's 7&8 big-end shells. Landrover changed the
recommendation based, as I have already stated, on market forces - I.E. the
availability of certain grades. They don't care, because by the time the
accelerated wear is an issue, the thing is out of warranty and not their
problem anymore. The same reason for them never changing the rocker arm or
shaft lubrication design, a known wear point. The engine's original
designers deemed it not to be an issue for the exact same reasons of
warranty!!

--
Badger.
B.H.Engineering,
Rover V8 engine specialists.
www.bhengineering.co.uk
www.roverv8engines.com

"Bob Hobden" <[email protected]> wrote in message
news:[email protected]...
>
> "Badger" wrote ...
>>>>
>>>> Well I just went and bought some Castrol Longlife 11 oil for the wife's
>>>> BMW 330i...£39.99 for 4 litres.
>>>> Thought I was seeing things when she rang it up.
>>
>> Nope, it's dear stuff. Ought to be Castrol SLX Longlife I though, not II,
>> that's a VW spec.
>
> Looking at the "can" again it says Castrol SLX Longlife 11 and the
> Halfords book said that was the one for the BMW 330i petrol.
> I hope they are right.

Probably won't do any harm, but Longlife I is the BMW spec, Longlife II is
the VAG spec.
Badger.

"Austin Shackles" <[email protected]> wrote in message
news:[email protected]...
> On or around Wed, 20 Apr 2005 12:17:17 +0000 (UTC), beamendsltd
> <[email protected]> enlightened us thusly:
>
>>In message <[email protected]>
>> Austin Shackles <[email protected]> wrote:
>>
>>> On or around Wed, 20 Apr 2005 08:31:24 +0000 (UTC), beamendsltd
>>> <[email protected]> enlightened us thusly:
>>>
>>> >
>>> >ETC6099 3.5 Efi
>>> >ETC8686 3.9 Efi
>>> >
>>>
>>> 's more about the cam timings, though - the early 3.5 and the 3.9 have
>>> identical profiles, 2 degrees different in timing, IIRC.
>>
>>Early ones are:
>>ETC6849 - 3.5 Carb 26D, 27D engines
>>ETC6850 - 3.5 Carb 28D, 29D, 30D engines.
>>
>>Todays quiz - what's the difference between these two?
>>Answers on a post card!
>
> I could probably look it up, but I suspect the answer is either "nothing"
> or
> possibly "has facility to fit fuel pump cam" and "doesn't".

Can't remember which one is which off the top of my head, but one is 285
degrees duration, timing as follows
IO 30 btdc, IC 75 abdc, EO 68 bbdc, EC 37 atdc.
Other is 280 duration,
IO 36 IC 64 EO 74 EC 26.
The 285 cam gives slightly more top-end and was used on all SD1, and
landrover low compression engines, the 280 was a later profile only used on
higher compression (9.35) engines, designed to flatten out the torque curve
slightly, trading off a couple of bhp.
The valve lift for each is the same at 0.390" and they are physically
interchangeable, the fuel pump cam being a separate item fitted between the
sprocket and dizzy drive gear.

--
Badger.
B.H.Engineering,
Rover V8 engine specialists.
www.bhengineering.co.uk
www.roverv8engines.com

"Tim Hobbs" <[email protected]> wrote in message
news:[email protected]...
> >The main thing wrong with his argument is his understanding of the
>>difference in viscosity between a 10w/40 and a 15w/40 oil.
>>At operating temperature both are the same viscosity. At ambient
>>temperature
>>the 10w/40 is marginally thinner or lighter but is still substantially
>>heavier or thicker than either at operating temperature.
>>Either of these oils is good for the V8 and no difference should be
>>noticeable and no harm will be caused by either even in the long term.
>>
>>Huw
>>
>
> The comparison here, however, is between 20W50 and 15W40, isn't it?
>
>

Woops yes. Too many posts of mine on the same subject and just back from
more than 200 miles of country road miles.
I used 15w/40 in my '86 V8 for more than 80,000 miles and never had any
issue. In fact I have never used a 20w/50 in any car since a 1958 Morris
1000 with pillar arm indicators.
All engines are just not that fussy about viscosity apart from certain
semi-race engines like BMW'M' that just consume thin oil at an unacceptable
rate. I have yet to find a normal engine that is not happy with quite a
selection of viscosities.

Specifically referring to the Land Rover V8 engine, my 1987 workshop manual
supplement LSM180 WS1 section 9, page 3 for all climates and conditions,
lists and recommends every viscosity from 5w/30 [from -30 to +30C] through
all permutations to 25w50 [+10 to 50+C]. In the chart section specifically
for temperate climates, the majority of named and branded oils are 10w/40
and 15w/40 with a sprinkling of 10w/40's and one 15w/50. There is not one
20w/50 mentioned, not that this makes it unsuitable of course. This is from
section 9 page 1.

So where anyone got the idea that only 20w/50 is suitable beats me. AFAIK
this range of suitable oils remained for a very long time, from early
carburettor engines to later 3.9's etc.

Huw

"Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
news:[email protected]...
>
>
> Specifically referring to the Land Rover V8 engine, my 1987 workshop
> manual supplement LSM180 WS1 section 9, page 3 for all climates and
> conditions, lists and recommends every viscosity from 5w/30 [from -30 to
> +30C] through all permutations to 25w50 [+10 to 50+C]. In the chart
> section specifically for temperate climates, the majority of named and
> branded oils are 10w/40 and 15w/40 with a sprinkling of 10w/40's and one
> 15w/50. There is not one 20w/50 mentioned, not that this makes it
> unsuitable of course. This is from section 9 page 1.

OK, Landrover quote the oil pressure as being 35 + or - 5psi at 2400rpm,
hot. Try doing an oil pressure check with a calibrated gauge, first with
20W50, then with 5W30. You'll be lucky to see 30 with the heavier oil
anyway, and you'll struggle to maintain 20 to 25 with the thinner stuff.
That is a fact that you can prove for yourself, and it's obvious that the
lower pressure (due to the internal clearances within the pump and relief
valve) will give lower flow. You are referring to a book published in 1987,
when 20W50 was pretty hard to find anyway. Remember what I said about market
forces etc....?

> So where anyone got the idea that only 20w/50 is suitable beats me. AFAIK
> this range of suitable oils remained for a very long time, from early
> carburettor engines to later 3.9's etc.

All original books for the engine, regardless of whether it was in a Buick
skylark, an Oldsmobile Cutlass or an early landrover product, an early SD1
or a P6, all quoted 20W50 as the correct grade. The engine design never
changed up until the introduction of the serpentine variant, so what is your
reasoning for the change in recommendation other than market forces? There
was certainly no engineering explanation. The engine's lubrication was
designed to pump a heavy weight oil in volume, not a lighter weight at
pressure. the lubrication was marginal, even on the early engines, which was
why the pump was enlarged to increase flow on the SD1 "redesign", along with
better crank oil seals, but the recommendation was still 20W50.
Badger.

"Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
news:[email protected]...
>
> "Badger" <[email protected]> wrote in message
> news:[email protected]...
>>
>> "Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
>> news:[email protected]...
>>>
>>> "Bob Hobden" <[email protected]> wrote in message
>>> news:[email protected]...
>>>>
>>>>
>>>> Well I just went and bought some Castrol Longlife 11 oil for the wife's
>>>> BMW 330i...£39.99 for 4 litres.
>>>> Thought I was seeing things when she rang it up.
>>
>> Nope, it's dear stuff. Ought to be Castrol SLX Longlife I though, not II,
>> that's a VW spec.
>
> True, and mostly a 0w/30 viscosity
>
>>
>>> Well now, the BMW engines fitted to Range Rover calls for the same oil
>>> when fitted to a BMW but no mention is made of it in the Range Rover
>>> handbook which specifies [only the need for] ACEA A3 for petrol versions
>>> and B3 for diesel engines. These are the same engines fitted with the
>>> same computerised service interval monitor which results in
>>> approximately the same mileage drain intervals as in a BMW car. My
>>> diesel RR version needs changing at about every 14500 miles.
>>> The viscosity specified as suitable for the UK BMW engines include
>>> anything between 5w/30 to 10w/40 including 10w/30 and 5w/40 of course.
>>> In fact there would be no problem with A3/B3 0w/40 viscosity [such as
>>> Mobil1 0w/40 for petrol engines but no other viscosity of Mobil1]
>>> although this one grade is not specifically mentioned in the handbook as
>>> a suitable grade.
>>>
>>> There is a wide range of oils commonly available which meet these
>>> criteria without costing an arm and a leg.
>>>
>>
>> Does the Rangie book call for just the basic spec Huw, or does it say
>> that the oil must meet the Longlife criteria as well?
>
> No mention of any other specification than ACEA A3/B3 as approriate.
>
>
> I wouldn't dream of putting
>> an oil in my 330d that didn't meet the Longlife I spec, based on the
>> potential wallet-destroying properties of the potential repair bills if
>> it all went pear-shaped.
>
> I wouldn't dream of using a non synthetic oil in it, yet those
> specifications can be met by high quality mineral oils. Strange.
>
>
>> Please tell me of the other oils you know of that meet the Longlife I
>> spec other than SLX and Mobil1, would be handy to know.
>>
>
> Only the 0w/40 viscosity Mobil 1 is suitable because, last time I looked,
> it was the only half suitable viscosity that met the basic ACEA A3.
>
> Actually anything that meets mb229.3 will exceed Longlife1.
> The implication from the current Range Rover handbook is that anything
> that meets both ACEA A3 and B3 and is within a suitable range of
> viscosities will meet LL1. Or at least is good for long drain intervals in
> BMW engines.
> A further implication is that a long drain mulifleet oil such as the Q8
> mentioned at the top of this post will be good for a BMW engine for
> longest drain intervals. Personally I use large volumes of the same
> specification oil in my fleet but not in my Range Rover thank you.
> I don't even use an oil that pretends to meet LL1 or ACEA A3/B3 in my
> diesel BMW engine. Instead I use an oil that meets heavy duty
> specification ACEA E4 [which is much higher rated than E5 which the Q8
> meets] and mb228.5 ultra long drain type.
> But that's just me using overkill.

Interesting stuff, thanks Hew.
Badger.

"Badger" <[email protected]> wrote in message
news:[email protected]...
>
> "Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
> news:[email protected]...
>>
>>
>> Specifically referring to the Land Rover V8 engine, my 1987 workshop
>> manual supplement LSM180 WS1 section 9, page 3 for all climates and
>> conditions, lists and recommends every viscosity from 5w/30 [from -30 to
>> +30C] through all permutations to 25w50 [+10 to 50+C]. In the chart
>> section specifically for temperate climates, the majority of named and
>> branded oils are 10w/40 and 15w/40 with a sprinkling of 10w/40's and one
>> 15w/50. There is not one 20w/50 mentioned, not that this makes it
>> unsuitable of course. This is from section 9 page 1.
>
> OK, Landrover quote the oil pressure as being 35 + or - 5psi at 2400rpm,
> hot. Try doing an oil pressure check with a calibrated gauge, first with
> 20W50, then with 5W30. You'll be lucky to see 30 with the heavier oil
> anyway, and you'll struggle to maintain 20 to 25 with the thinner stuff.
> That is a fact that you can prove for yourself, and it's obvious that the
> lower pressure (due to the internal clearances within the pump and relief
> valve) will give lower flow. You are referring to a book published in
> 1987, when 20W50 was pretty hard to find anyway. Remember what I said
> about market forces etc....?
>
>> So where anyone got the idea that only 20w/50 is suitable beats me. AFAIK
>> this range of suitable oils remained for a very long time, from early
>> carburettor engines to later 3.9's etc.
>
> All original books for the engine, regardless of whether it was in a Buick
> skylark, an Oldsmobile Cutlass or an early landrover product, an early SD1
> or a P6, all quoted 20W50 as the correct grade. The engine design never
> changed up until the introduction of the serpentine variant, so what is
> your reasoning for the change in recommendation other than market forces?
> There was certainly no engineering explanation. The engine's lubrication
> was designed to pump a heavy weight oil in volume, not a lighter weight at
> pressure. the lubrication was marginal, even on the early engines, which
> was why the pump was enlarged to increase flow on the SD1 "redesign",
> along with better crank oil seals, but the recommendation was still 20W50.
> Badger.
>

All I can say is that the recommendation I quote is from the official
workshop manual where even the lightest viscosities available at the time
were acceptable within the limits I quoted. 20w/50 was certainly more common
in '87 than it is today. 20w/50 was probably the fashionable oil of the day
in the very early days when Rover built these things but that is not to say
that a lighter oil was ever detrimental and certainly the manufacturers
would not allow an oil to be used that was detrimental. Marketing has
nothing to do with it, because all of the viscosities are and were and
continue to be commonly available. No one particular viscosity was or is
specified for the temperature range encountered in the UK.

Huw

"Badger" <[email protected]> wrote in message
news:[email protected]...
>
> "Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
> news:[email protected]...
>>
> ""David G. Bell"" <[email protected]> wrote in message
> news:[email protected]...
>
>>>
>>> It's a long time since I was taught anything about viscosity, but
>>> there's something which feels odd about this...
>>>
>>> [thinks]
>>>
>>> I think that the critical aspect is the pipework between the orifices,
>>> and the total possible flow. Pressure is a secondary effect here. The
>>> pump doesn't shift any more volume with a thinner oil, while each
>>> orifice can pass more oil. So there's not enough oil being pumped
>>> through the system to meet all the demands, and the differences in the
>>> pipework, distance and size and such, decide which bearing gets what
>>> oil there is.
>>>
>>> Is that right?
>
> That's exactly what I was trying to say!
>
>>>
>>> If you could pump more oil, it'd be different.
>
> Hence the fitting of the MGB relief spring, upping the pressure will give
> a bit of a flow increase.
>
>>>
>>> I expect the design of the oil passages in an engine is very important,
>>> so that the more distant bearings still get oil.
>
> Indeed, but the V8 feeds all its oil from the pump to the offside cam
> follower gallery first, with a cross-drilling arrangement to the nearside,
> there are separate drillings from there to feed the mains (and onwards to
> the big-ends via the crank drillings, with a small jet feed to the
> opposing bores from the con-rod caps), cam bearings and a feed to each
> head. The cam lobes are fed by oil seeping past the lower circumference of
> the cam follower and also return oil down the valley from the heads giving
> a "drip-feed" onto the cam.
>
>>>
>>
>> The main thing wrong with his argument is his understanding of the
>> difference in viscosity between a 10w/40 and a 15w/40 oil.
>
> I understand that perfectly Hew, BUT we are talking about the difference
> between either 10W40 (or 15W40) and 20W50. It's the 50 bit that's
> different, please see that.
>
>> At operating temperature both are the same viscosity.
>
> Only if you are referring to 10W40 and 15W40!
>
>> At ambient temperature the 10w/40 is marginally thinner or lighter but is
>> still substantially heavier or thicker than either at operating
>> temperature.
>> Either of these oils is good for the V8 and no difference should be
>> noticeable and no harm will be caused by either even in the long term.
>
> Bull, from what I've seen over the years dismantling and rebuilding them.
> The use of a lighter weight oil than **W50 WILL cause accelerated wear of
> the rear main and no's 7&8 big-end shells. Landrover changed the
> recommendation based, as I have already stated, on market forces - I.E.
> the availability of certain grades. They don't care, because by the time
> the accelerated wear is an issue, the thing is out of warranty and not
> their problem anymore. The same reason for them never changing the rocker
> arm or shaft lubrication design, a known wear point. The engine's original
> designers deemed it not to be an issue for the exact same reasons of
> warranty!!
>

In other words they are crap engines.

Huw

Huw wrote:

> Actually anything that meets mb229.3 will exceed Longlife1.
> The implication from the current Range Rover handbook is that anything that
> meets both ACEA A3 and B3 and is within a suitable range of viscosities will
> meet LL1. Or at least is good for long drain intervals in BMW engines.
> A further implication is that a long drain mulifleet oil such as the Q8
> mentioned at the top of this post will be good for a BMW engine for longest
> drain intervals. Personally I use large volumes of the same specification
> oil in my fleet but not in my Range Rover thank you.
> I don't even use an oil that pretends to meet LL1 or ACEA A3/B3 in my diesel
> BMW engine. Instead I use an oil that meets heavy duty specification ACEA E4
> [which is much higher rated than E5 which the Q8 meets] and mb228.5 ultra
> long drain type.

For general info the ACEA oil sequences can be found here:

http://www.infineum.com/information/tables.html

together with the API specs and the SAE J300 limits. Note that in J300
the HTHS viscosity of the thicker xxW40 and all xxW50 oils are both set
to be 3.7mPas (cP) or greater. This test is run at 150degC under
conditions similar to those in the big end bearing giving a very good
indication of working viscosity, so whoever commented on them both being
"thicker" oils was quite right. The big differences are evident at low
temperatures.

Lizzy

"Badger" wrote after
>
> "Bob Hobden" said ...
>>
>>>>>
>>>>> Well I just went and bought some Castrol Longlife 11 oil for the
>>>>> wife's BMW 330i...£39.99 for 4 litres.
>>>>> Thought I was seeing things when she rang it up.
>>>
>>> Nope, it's dear stuff. Ought to be Castrol SLX Longlife I though, not
>>> II, that's a VW spec.
>>
>> Looking at the "can" again it says Castrol SLX Longlife 11 and the
>> Halfords book said that was the one for the BMW 330i petrol.
>> I hope they are right.
>
> Probably won't do any harm, but Longlife I is the BMW spec, Longlife II is
> the VAG spec.

Oh damn! Must have misread it, why don't they say Longlife BMW and Longlife
Vag, using 1 and 11 sounds just like an update.
I wonder what the difference is, I'll ring Castrol Tech Help tomorrow and
ask that and what to do. Mind you I only used a litre at the most so I can't
think it can do any harm. Only a couple of thousand miles to a full oil
change too.

--
Regards
Bob
In Runnymede, 17 miles West of London

"Lizzy Taylor" <[email protected]> wrote in message
news:[email protected]...
> Huw wrote:
>
>> Actually anything that meets mb229.3 will exceed Longlife1.
>> The implication from the current Range Rover handbook is that anything
>> that meets both ACEA A3 and B3 and is within a suitable range of
>> viscosities will meet LL1. Or at least is good for long drain intervals
>> in BMW engines.
>> A further implication is that a long drain mulifleet oil such as the Q8
>> mentioned at the top of this post will be good for a BMW engine for
>> longest drain intervals. Personally I use large volumes of the same
>> specification oil in my fleet but not in my Range Rover thank you.
>> I don't even use an oil that pretends to meet LL1 or ACEA A3/B3 in my
>> diesel BMW engine. Instead I use an oil that meets heavy duty
>> specification ACEA E4 [which is much higher rated than E5 which the Q8
>> meets] and mb228.5 ultra long drain type.
>
> For general info the ACEA oil sequences can be found here:
>
> http://www.infineum.com/information/tables.html
>
> together with the API specs and the SAE J300 limits. Note that in J300
> the HTHS viscosity of the thicker xxW40 and all xxW50 oils are both set
> to be 3.7mPas (cP) or greater. This test is run at 150degC under
> conditions similar to those in the big end bearing giving a very good
> indication of working viscosity, so whoever commented on them both being
> "thicker" oils was quite right. The big differences are evident at low
> temperatures.
>
> Lizzy

You're my kind of woman Lizzy ;-) We should meet up and get slippery LOL

Huw

Huw wrote:

> You're my kind of woman Lizzy ;-)

Actually,She's exactly MY kind of woman.

Slippery or not.

Steve