Slobber

[Gregory OConnor]

Leroy, most of my experience has been without critical/helpful feed
back. With lack of understanding of every engines need I am
Constantly doing the same things wrong. Often the same assumed
treatment and care for different engines is the reason for early
failure. IE , Run a Cat3208 at 2800rpm and it purrs ;run a DD8V92 at
2800rpm and it blows up. I pose a statement with question marks
which denote that my conclusion is unfounded. I should change my
signature line to include ??? because for most of it, I dont know
what the hell I am doing.

I think we can all agree that with this forum, members opinions and
shared experience with conclusions to problems make ownership of a
WLodge easier and peaceful. Owners manuals and Spec books help but
they are written by people for people with way more prerequisite
knowledge then most of us. Then their is the 'tried and true'
developments which change and improve the operation and care since
the engine and manual creation.

The forums are a great place to share opinions. I have many. I assume
opinions is what IT implies when folks say "You are full of it"????

Please dont assume I am correct, please correct me or add confidence
to my assumptions

GregoryO'Connor
94ptRomoland
???????????


--- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
wrote:
>
> You may be correct. Certainly you have more experience with diesel
engines than most of us because of your business. I have concluded
in my case that oil consumption is in fact being burned and shoved
out the exhaust primarily because it is not deposited on the ground.
> I believe you are correct that the crankcase is not vented through
the slobber tubes. l have yet to determine after studying my DD
manuals where the crankcase ventilation happens. I think it comes
off of two vents on top of the valve covers exiting two tubes
extending below the oil pan.(in my case)
> That being said, I get confused because the DD manual states the
ventilation system is positive and the vent and scavenger system
(slobber tubes)is somehow interconnected through the heads, if I am
reading it correctly.
> I dont' plan to lose any sleep over this but any input would be
appreciated.
>
> Leroy Eckert
> 1990WB-40"Smoke N Mirrors"
> Niceville, FL
>
>
>
> ----- Original Message -----
> From: Gregory OConnor
> To: WanderlodgeForum@yahoogroups.com
> Sent: Friday, April 20, 2007 11:46 PM
> Subject: [WanderlodgeForum] Re: Slobber tube - need to service
>
>
> I wonder if most of the oil loss is burnt? I think the bird
droppings
> out the slobbertubes is combustion byproduct;blower seal leak;
and
> dirty condensation????? I would not be surprised if the collected
> slobber found in a custom crap can below the tubes has little to
do
> with the amount of oil loss in the crankcase??? I also dont think
the
> crankcase is vented through the slobbertube?
>
> GregoryO'Connor
> 94ptRomolandCa
>
> --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> wrote:
> >
> > Thank you for posting that Greg. I hope there is nothing wrong
> with my engine. I have cleaned the slobber tubes that hang to the
> road on my coach several times. Very little residue drops out of
> them on my engine. The engine is dry also.
> > On my last trip from Niceville to San Antonio then SPI and back
I
> added two quarts of oil. Based upon what I read, it is small oil
> usage. I don't know the exact milage because I generally do not
> track that but 1800-2000 total miles I guess.
> > Leroy Eckert
> > 1990 WB-40"Smoke N Mirrors"
> > Niceville, FL
> >
> >
> > ----- Original Message -----
> > From: Gregory OConnor
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Friday, April 20, 2007 7:59 PM
> > Subject: [WanderlodgeForum] Re: Slobber tube - need to service
> >
> >
> > Below is a cut and paste of a post by JimS from the very
informal
> > WanderlodgeAll group.
> > xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > I found this article once upon a time-I forget where. One of the
> > members asked me to post it here.
> >
> > Quote
> >
> > "The 92-series Detroits are two-cycle engines.
> >
> > All current production diesels are 4-cycle.
> >
> > Detroit stopped production on the 2-strokers due to EPA
> > requirements - and for no other reason. They simply would not
meed
> > EPA emissions requirements on or off-road, no matter what they
> > tried - and try mightily they did, with their DDEC and then
DDEC-
> II
> > (electronic control) systems.
> >
> > Ultimately, they were forced into 4-stroke production.
> >
> > It is true that modern electronic engines get better fuel
> > efficiency. However, there is a LOT to be said for a basic
engine
> > design that goes back to WWII!
> >
> > I have 6V92s on my boat (two of 'em.) Detroit's basic design was
> > simplicity itself, and ingenious. The supercharger on these
> engines
> > is necessary; they will not run without them. There is no intake
> > valve system at all. The valves are all for exhaust; as the
piston
> > moves down on a power stroke, the exhaust valves open and at the
> > same time the piston uncovers a port, much like a 2-stroke
> outboard
> > motor, that leads to an airbox that is pressurized by the
blower.
> > The clean air forces out the exhaust. When the piston moves back
> > upward the valves close and the ports are covered; compression
> > occurs, and fuel is injected at the appropriate time. Injection
is
> > performed by a cam-driven unit injector. The design is extremely
> > simple - ingenious, really. The emissions problem comes from
being
> > unable to perfectly scavenge the exhaust. However, these engines
> > tend to run very low EGTs compared to 4-stroke turbodiesels due
to
> > the overabundance of air that flows through them on a given
power
> > cycle.
> >
> > The nice thing about Detroits is that there is no high-pressure
> > injection pump or electronics. They will run, once started, so
> long
> > as they have fuel and compression. You can also replace the
entire
> > fuel system (the injectors) for about $100 a hole and the low
> > pressure fuel lift pump for a couple hundred bucks - these are
> unit
> > injector engines. With under $200 worth of special tools you can
> > keep a Detroit running in tip-top shape for a loooong time, and
> > properly maintained they are great motors. They have a
reputation
> > (somewhat earned) as oil leakers, which is due to the fact that
> > Detroit made the blocks so they could be "doubled" - thus, you
> have
> > 6V92s, 8V92s, 12V92s (two 6V92s end-to-end) and 16V92s (two
8V92s
> > end to end!) This, however, means there are oil ports and such
on
> > the ends of the blocks that have plugs in them and thus they
tend
> to
> > leak oil....
> >
> > The other thing to be aware of is that Detroits are quite
> > inexpensive to get parts for. A cylinder kit, for example, is
> about
> > $600 - that's the liner, piston, con-rod, rings, etc - the whole
> > shot. One new hole, coming up. So for about $5k in parts you
can
> do
> > a complete kit replacement, and it can be done "in-frame" -
> without
> > pulling the motor.
> >
> > Detroits have no glow plugs and "off the shelf" no starting
> assist.
> > They are ENTIRELY dependant on engine compression to start. They
> > also require (not recommend, REQUIRE) straight weight 40 grade
Cx-
> II
> > oil. Multigrade oils are strictly forbidden due to the high
shear
> > strength required by the injector followers - you WILL destroy
> cams
> > if you run a 15W40 in them, for example, and you'll also get
> > incessant low oil pressure warnings and probably a spun main to
go
> > with it. Unlike "modern" diesels its not uncommon (nor a
problem)
> to
> > have oil pressure readings as low as 10psi at idle when fully
> warmed
> > up! Normal oil pressure at power (1800 rpmish) is in the 45-
50psi
> > range though, just like modern engines. What this means is that
in
> > cold weather you need STOUT batteries or you will not be able to
> > roll them over at a high enough RPM to get 'em to light. Block
> > heaters are strongly recommended for the winter months. Ether is
> > very dangerous to use on these engines; I know people who have
and
> > do, but my recommendation is "never" on a Detroit.
> >
> > The nemesis on the 92 Series Detroits is overheating. This is a
> wet
> > liner design with elastomer (O-ring) seals at the top and
bottom
> of
> > the cylinder liner. If you overheat these engines, even just a
> bit,
> > the liner seals will be compromised. The result will be oil to
> > cooling system leaks, and if not caught very quickly, damage to
> the
> > mains or even worse, a spun main and damaged crank. Cooling
system
> > maintenance is THE big deal on these motors. Keep them running
> cool
> > and all is well. Let them get hot and you will be rebuilding
them.
> >
> > Also, later versions of these engines in "turbo" trim used
> > aftercoolers, which are under the blower. That needs to be kept
> > clean; getting to it requires removing the blower, which
requires
> > disturbing the governor and fuel rack. Its not a tough job, but
it
> > is a pain in the butt. Thus, its important to avoid exhaust
leaks
> > and use a good air cleaner so that becomes an infrequent problem
> > rather than a frequent one.
> >
> > Finally, there is the matter of airbox drains. The airbox on a
> > Detroit is where the blower "accumulates" the charge for
> scavenging
> > and the new combustion cycle. The blower seals, as the blower
> ages,
> > and turbo seals will eventually leak small amounts of oil, and
the
> > compression and then cooling of the air charge causes water to
> > condense. The airbox drains allow this accumulated crud out of
the
> > airbox instead of having it sucked into the cylinders where it
> will
> > cause abnormal wear. On turbo motors there are check valves
> located
> > at each drain; these must work properly. If they stick open or
> > closed its bad news; many people neglect these service items.
They
> > should be pulled and cleaned at every oil change, and if you
have
> > motors where Detroit routed them back to the oil pan (they did
on
> > some motors, as the EPA had a kitten about the original design
> which
> > just allowed the slop to go onto the road) you will do your
> engine a
> > huge favor by removing that and routing them to a "crap can"
that
> > you then empty once in a while (at oil change intervals is a
good
> > choice.)
> >
> > I'm very much "up" on the 92-series engines, since I own two and
> > maintain them myself. Set up for reasonable power levels (500HP
> from
> > an 8V92TA is reasonable) and proper maintenance they provide
> > extraordinarily good service. The 8V89TA CAN be "hot-rodded" to
as
> > far as 750HP quite cheaply just by changing injectors and a few
> > other things - don't be tempted, as the service life in that
> > configuration can be as short as 1500 hours or less between
> > overhauls!
> >
> > The DDEC and DDEC-II versions of these engines replace the
> > mechanical fuel rack with electronic control of the injectors
and
> a
> > bunch of sensors in an attempt to get cleaner and more fuel-
> > efficient operation from them. Its mostly successful, but now
> you're
> > into the computer-controlled realm and simple mechanical
> maintenance
> > procedures go out the window.
> >
> > If I was going to own a Detroit-powered coach, I'd want one with
> > mechanical injection - if I'm gonna buy an electronic engine, I
> want
> > one of the new design ones, as if I'm gonna get the warts I
want
> the
> > benefits too. With a handful of parts and a few tools on board
I
> can
> > fix these things by the side of the road if necessary so long
as I
> > haven't spun a main or something equally catastrophic -
something
> > you simply won't be doing with "today's technology".
> >
> > End quote
> >
> > Regards,
> > Jim S
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>