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Wow, you certainly put some thought into that post! Appreciated..
Yep, it is fairly common knowledge that putting detergent oil into a used engine
that has been running non-detergent oil is a big no-no for exactly the reasons you
stated. I've torn apart a few engines run on non-det oil and it is exactly as you
said, the corners of the oil pan typically are filled with sludge which resembles
heavy tar along with a ton of deposits. I've seen the same thing in the bottom end
of air compressor pumps. Hence putting something like detergent oil into such an
engine could be disastrous if all of that stuff started coming loose.
Regarding oils and old LOs. I think that everyone needs to remember that the 30W
oil of long ago is pretty much non-existent now. Even the 30W non detergent stuff
you can buy is of a much different quality than the oil of WWII.
Regarding multigrade oils, while I agree that putting a 5W-50 oil in a vehicle
designed for 30W non-detergent oil might not be a good idea, using straight 30W oil
in a vehicle that will be possibly run in 95+ degree temps under heavy load is also
not a good idea. Of course if you are blessed to live in a climate that varys very
slightly then beside my jealousy, 30W oil is probably a no brainer. Why make life
anymore complicated! Just buy a bunch of 30W oil and forget about it. However for
those of us not so blessed who live in the midwest (lows of 24 degrees two days ago,
highs of 70+ this weekend - I have to check to see whether I need to wear long johns
or shorts on a daily basis) multigrade oils are a great thing. I car start my
trucks in above zero weather with no problem (no spun rod bearings) and not have to
worry about losing a bearing due to thinning oil in 97 degree temps in July. I
think if it's good enough for the army, then I can probably get by with it also,
hence all of my trucks, tractors and older engines run on Rotella 15W-40 bought in 6
gallon cases at Sam's club. Even, my WWII design Onan CCK powered welder even has
new specs that saw 15W-40 is the correct oil after a rebuild.
Another point, the 10W-30 of long ago is not the 10W-30 of today either. Remember
the SA grade? What are we up to now, SJ grade? The specs have changed
significantly. Try finding long fiber wheel bearing grease that I have been told is
supposed to be used in my M51 wheel bearings. I ask the local parts guy do you have
any long fiber wheel bearing grease? Long fiber what? is my reply. (:-<) Oh
well.
FWIW,
Dave
Richard Notton wrote:
> *This message was transferred with a trial version of CommuniGate(tm) Pro*
>
> -----Original Message-----
> From: mblair1@home.net <mblair1@home.net>
> To: Military Vehicles List <mil-veh@uller.skylee.com>
> Date: 15 April 2000 04:08
> Subject: Re: [MV] Oil changes
>
> I have to agree with Mark, now this may run on a bit so all you people
> disinterested in lube oil should hit delete here.
>
> >
> >"Sean Bathrick" <Bathrick@imcchemicals.com> wrote:
> >> Kind of along the same topic. I did an oil change in my M38A1 last
> >> year and decided to use 5W-50 oil instead of the NAPA 30
> >> non-detergent.
> >[...]
> >> Never will I run multi-viscosity oil in my jeep or truck again. Just
> >> my 2 cents.
> >
> I think Sean said he had non-detergent SAE30 in the engine previously and here's
> a potential problem.
>
> The Allied armies changed to detergent oils in 1942, it is well recorded in the
> Ford CMP manuals and shows it was called then H.D.30. The feature of
> non-detergent oils is the deposition of heavy sludge around the quieter corners
> of the engine and it is recognised that simply changing to detergent oil on a
> well used and sludged engine would be problematical.
>
> The detergent oil will shift all the accumulated deposits and carry it off round
> the system likely choking the filter and fine oil drillings in short order. The
> example of the Ford CMP manual recognises this and defines a flushing procedure
> followed by several very low mileage oil changes, in clean new engines or
> re-builds this is not a problem at all, Ford actually state the chassis and
> engine number at which H.D.30 was used in manufacture.
>
> So we can put a stake in the ground for the introduction and retrospective use
> in Allied MV's at 1942, H.D.30 later becomes SAE 30 to MIL-O-2104B (C and D now)
> and the UK OMD 110.
>
> >I don't understand why folks run anything other than what the
> >manufacturer and/or lube order recommends.
> >
> I agree with Mark, there may very well be some motors that will accept or
> benefit from the use of a multi-grade but without the resources of the
> manufacturer who can tell, certainly the multigrades didn't appear until around
> the 70's so we can only surmise when engine designers used these properties in
> new designs.
>
> Multi-grade seems to be aimed more at the domestic market to alleviate potential
> domestic car hassles and is in any case only a straight oil with much added
> chemical wizardry, largely long-chain polymers, to counteract thinning with
> temperature, difficult cold starts and excessive cold oil pressures, cynically
> you could consider multi-grade lube to be a production easement for all these to
> allow cheap manufacturer design where they are forced into high efficiency, lean
> burning hot engines with just adequate batteries and starters, apart from
> liaison duty OD sprayed domestic types the mil likely has no time for this in
> actual mil specific fighting vehicles.
>
> The current multigrades we use domestically are typically running as a hot SAE
> 30 anyway and I really wonder if the "magical" 5W-40 brown glug we tip in our
> cars is still actually 5W-40 after the first 1000 miles. . . . . . . . . . . .
>
> >If the LO calls for a single-grade oil, it doesn't seem to me to be a
> >good idea to substitute a multi-grade oil. I realize that it can be a
> >pain to change oil seasonally in areas with wide temperature swings,
> >but in areas where it's not necessary (like where I live),
> >
> The typical specified ambient operating range of SAE 30 isn't really that bad,
> 23ºF to 89ºF is specified by RR for the B Range mil engine and that covers most
> of the world, surprisingly many big diesels and other continuously thrashed
> engines like those found in contractors small plant (Honda, Briggs & Stratton)
> specify SAE 30 only.
>
> There is a worrying feature of multigrades that has a direct bearing on heavily
> worked engines where these are specifically designed to be heavy consumers of
> oil to achieve continuous operation in that multigrades will leave a metallic
> ash when burnt which is aggressively destructive to piston rings, not a problem
> in the virtually zero oil consumption car engine but of concern in designs
> intended to use oil heavily.
>
> Consulting with both RR specialist engine division here and the tech departments
> of several multi-national oil companies, they all agreed without prompting that
> multigrades were potentially unsuitable in designed high consumption engines and
> further that the straight 30 is mechanically stronger, as most 50s - 70s UK MVs
> specify OMD 110 (SAE 30) for gearbox (not transfer note) use also they strongly
> advised against a multigrade here.
>
> The B81 in the FV623 has "2 galls" stamped in the dipstick between "Max" and
> "Min" so you tend to get blasé about 1/2 gallon top-ups. . . . . . . . !!
>
> I would be wary of putting too much store by what the oil pressure gauge says,
> if its in the makers stated range with the specified oil all's well, however,
> using thicker stuff by way of a multigrade or whatever to get a satisfyingly
> high reading is just covering things up.
>
> We need to be aware that the gauge, if its not lying that is, simply tells you
> the pressure at the tapping point which may or may not have anything to do with
> a sufficiency of lube reaching the critical far corners of the engine, high
> readings could actually be indicative that the far end main and big-end bearings
> are being starved.
>
> >I see *no*
> >reason to use anything other than the recommended oil. The recommended
> >oil for both my deuce and my HMMWV at the temperatures they encounter
> >is plain ol' SAE 30, year-round, period.
> >
> Quite so.
> The HMMWV engine is hardly an old W.W.II design either.
>
> >My trucks get Rotella SAE 30 all year round, and in the unlikely event
> >that I move somewhere that gets under 15 degrees F in the winter, I'll
> >use the oil(s) recommended by my LOs. I don't design engines for a
> >living, so I know better than to second-guess the engine manufacturer.
> >
> Rotella 30 is a good, high detergent SAE 30 and likely MIL-O-2104D qualified.
> I don't design engines either which is why I consulted with those who do.
>
> >Just my two cents worth. Use whatever oil you want... but don't sell
> >me your old truck if you don't follow the LO.
> >
> Perhaps we should bear in mind that the excellent attributes of un-glamorous SAE
> 30 are not screamed from every bill-hoarding, race car and the TV. . . . . . . .
> . . .
>
> The last quote from the divisional manager of RR Specialist Engines to me was:
> "We designed, tested and qualified the engine range with SAE 30/OMD 110, but its
> your engine now so you can put in it what you like."
>
> I like detergent SAE 30 to MIL-0-2104D, efficient and cheap without a
> multi-million ad campaign to support.
>
> Richard
> (Southampton - England)
>
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This archive was generated by hypermail 2b29 : Mon May 01 2000 - 05:30:05 PDT