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Messages - sajohnson

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16
General Discussion / Re: PC on the cover of FMCA magazine again
« on: March 31, 2012, 11:32:38 pm »
Ok, forget the 2350, I want the 2910T!  <j/k>  ;-)

Very nice write-up.  Well deserved!

17
The 3.0L and all other commonn rail diesels are not suppose to ilde but I do not know exaclty why that is.  Driving around the block or being able to "up idle" by using the cruise control setting as was the case on other diesels that I have owned is just not a feature on the 3.0L.  Perhaps Sprinter owners can share what the verbage says in their new Sprinter books.  In my 3.0L jeep book it is bold to not idle period.

Very interesting.

I'm not familiar with your particular model Jeep.  I see Chrysler is planning to make a diesel Grand Cherokee for 2013.  Is the 3.0L in your Jeep the same gasoline engine that M-B used in the 2008 USDM Sprinter?

The only info I have so far is the fact that M-B offers the "high idle preset" as an option.  It is specifically designed for long-term idling.  It would seem to me that if extended idling was harmful, M-B would not have that as an option.  After all, they have to warranty the Sprinter engine for 5 years/100,000 miles, and the emission controls even longer.

I do recall hearing that the I-5 in the previous model diesel _did_ have problems that were due to extended idling (EGR valve trouble maybe?).

After reading your post, it occurred to me that I could download the Sprinter owners manual from M-B and search it.  I looked for the word "idle" and found a grand total of two (2) in the entire 292(!) page manual.  One was the recommendation to let it idle for two minutes before shutting it down, to allow the coolant to get back to normal temp.  The other was something about the "Overrun cut-off".

The search continues...

18
I a post above I mentioned factory installed auxiliary A/C units.  It turns out M-B offers one for the passenger van version of the Sprinter:

http://www.mbsprinterusa.com/build-and-equip/passenger-van/12#byoPackages

Obviously, it only works while the engine is running.  I can see why RV mfrs use electric A/C units -- they can serve double duty -- running off of shore power when parked and off of the generator while driving.

It would be neat if the RV mfrs were to offer an optional aux A/C unit that has it's own engine-driven compressor like the one above, in addition to the standard unit (which would still be required).  The aux unit would have the advantage of not needing 120 Vac to operate -- so the generator would not have to be run while driving (or in situations where running the generator is not allowed or frowned on) -- saving LP and keeping things quieter.  The regular electric A/C unit could be used when shore power is available.

I know -- pie-in-the-sky, but an interesting idea (to me anyway).

Sherman

19
Go to Google and search for something like "does idling your car engine for long periods harm the engine"?  You'll find, as usual, a fair amount of discussion, but I think you'll find the majority view is that it can hurt the engine, the catalytic converter, and the environment.  My memory of the military is that the one exception are the big multifuel trucks which are better off if left idling rather than being shut down for short periods of time.  The most reliable of these answers probably come from people like Click and Clack on NPR or other practicing mechanics.  Check it out and see what you think.

Jerry

Good suggestion -- I'm going to try and get a definitive answer from both Ford and M-B.

When it comes to questions like this, my impression is that many people (including myself) have opinions, but that our opinions may be based on hearsay, not fact. 

I certainly don't know what the answer is.  I know that the big diesels (semis, locomotives) are left idling for hours or even days.  Some truckers don't ever shut their engines off during the winter months -- and they run for a million miles or more before needing to be overhauled.  Needless to say though, a big Cummins or Detroit Diesel is different from the M-B V-6 diesel in the Sprinter.

As for gasoline engines, taxis, police cruisers, and ambulances often idle for extended periods and they still get good life out of them -- police cruisers are often sold to taxi companies when they have about 100K miles on them, and then the taxi company will put another 100K or so on the engine.  There again, the engines in these vehicles are different from the V-10 in the E-350/450 at least in some ways. 

Due to variations in design, it may be that while some gas and diesel engines can be idled for hundreds or even thousands of hours, others cannot.  Many owners manuals consider extended idling "severe service" that requires more frequent oil changes.

The environment is always a concern.  Of course I would never leave any engine idling for no reason.  I am considering whether it might make sense to do so when the batteries need to be recharged -- as an alternative to running the generator.  My guess would be that although it is much larger, the V-6 diesel runs cleaner than the diesel genset, and probably the gasoline generator as well.  On the other hand the LP genset might be cleaner than the V-6 diesel.  So, depending on which generator would otherwise be used, idling the V-6 might actually be better for the environment.

I'm going to try and find some answers, but I strongly suspect that it is ok to idle the Sprinter for extended periods since M-B offers that optional "high idle preset".  The description says:

~~~~~

High Idle - Preset
Details & Technology
This electronic RPM governor maintains a constant RPM, e.g. for auxiliary drive operation.
Under load change, RPM may fluctuate by approx. +/- 50 RPM (depending on engine, loadand RPM).
The standard factory setting is 950 RPM. Higher or lower RPM can be programmed usingthe Star Diagnosis system.
Benefits

    Constant rpm

Necessary if a virtually constant rpm must be maintained in order to operate an auxiliary unitsuch as a pump.
BenefitRemarks
Not suitable for operating 220V generators!Recommended for:- Ambulances- Shuttle services- Applications with longer idle times

~~~~~

Sounds pretty slick.  I wonder if it can be installed by a Sprinter service facility?

Sherman

 

20
Sherman
The 3.0L can NOT be idled at all.  Doing so other than for a couple minutes to cool the turbo down  will do long term damage to the engine.  The V -10 CAN IDLE ALL DAY.  THANKS

All I have to go on is what I've read from the owners of each chassis -- almost all say the V-6 can be idled indefinitely but that excessive idling harms most gasoline engines, including the V-10 Ford.

In fact, M-B offers a stepped-up/fast idle as an option for Sprinters in "applications with longer idle times" -- see "High Idle Preset":
http://www.mbsprinterusa.com/build-and-equip/cab-chassis/14#byoPackages

That would seem to indicate that extended idling is ok, but I'll have to see if I can find a definitive answer(s) from Ford and/or M-B.

I like the idea of being able to idle the Sprinter for as long as necessary while using 1/4 of the fuel the V-10 does, so I hope what I've read previously is correct.

There is very little that's a deal killer at this point, but there are many things that put points in one column or another -- tip the scales back and forth as it were.  This is one of them -- especially given the generator problems and limitations.  

I'll do a little research and report back.

BTW -- if you could point me in the right direction (mfr info from Ford and/or M-B) that would save me some time.  Offhand I'm not sure that idling is something either of them will cover in the usual consumer sections of their website.  

21
Unless special ordered, the 2350 and 2400 models are built on E350 and Sprinter chassis. Consequently, the E450 chassis is irrelevant for this example.
The PC models built on the Ford E350 chassis are 9'10" high.
The PC models built on the Sprinter chassis are 10'1" high.
Simply judging from photos on the PC site, the rear extreme wheel width of the Sprinter is 10 to 12" narrower than the Ford.
A taller object on a narrower base results in a higher center of gravity and reduced resistance to sway and/or rollover (draw the triangles).
Granted, these are extremes and electronic stability control can help. But it cannot change the physics involved.

As I said, I agree.  We're on the same page here.

ESC, etc, can only make the best use of the available traction.  The laws of physics still apply.

Assuming the coaches are identical (placement of water tanks, appliances, cabinets, etc) then the Sprinter would be slightly more top-heavy since it's 3" taller.

The track of the Ford is clearly wider and that increases stability.

I am still curious about the center of gravity of each cab chassis and each complete RV -- but from their appearance, without having any additional info, I'd feel safer traversing a slope or driving through heavy cross winds in the Ford.

22
I don't have a PC yet, but ..... ran across a Alberta couple who did and they do NOT have a gen.   What they do have is 340 WATTS of SOLAR that meets their purpose when DRY camping, as we were doing.   The solar does a good job of keeping the house batteries up, even with watching DVD's in the evening they said.   He meantioned that IF the solar doesn't do it, they can just start the Sprinter engine and charge the batteries if necessary...

That sounds good.  I've been interested in alternative energy since I was a teenager, so I've been planning to use solar.  

I'm glad to know it's ok to just use the Sprinter's engine to charge the house batteries.  

I do like my A/C though, so we'd need some type of generator.  Maybe the LP genset with an extra tank would be enough.

[The following is just rambling for the sake of conversation]:

I recall in the early 1970s my family had a Ford van that had an A/C unit on the floor in the rear.  I'm not sure why we had it but that was a great vehicle to tour the Southwest in!  I remember it blew out such cold air we could see our breath in front of it!  I guess maybe it was supposed to be a refrigerated delivery van.  Anyway, I brought that up because I was thinking it would be neat if RVs came with roof-mounted units like that -- no need for a generator (at least not for the A/C).  On second thought, while that would work fine going down the road, it would require that the engine be left running to run the A/C.  That might be ok for diesels but I'm not sure about gas engines.  As I understand it, gas engines aren't supposed to be idled for long periods of time.  I've read that diesels burn about 1/4 as much fuel while idling, but I wonder how the fuel required to run the Sprinter at a stepped up idle would compare with the fuel used to  run a diesel generator?

As I said, the above is just 'what if?'  I know the RV mfrs won't be using A/C units like that anytime soon.  

Anyone have any idea how running the engine (gas or diesel) to charge the house batteries compares with running a generator -- gas, diesel, or LP as far as fuel usage?  I'm just curious.  I like the option of running the engine instead of the generator since it should be quieter.  Maybe doing that and some solar panels would be enough to keep the batteries charged and an LP generator with a second LP tank would give us enough run time for the A/C unit while still having enough LP for hot water, heat, cooking, and the fridge.  It would be great if that would work because as was pointed out above, LP gensets are lighter and cheaper.  They also run much cleaner and are what is installed in most rigs anyway.

[End of ramble]

Sherman
 

23
Sherman,

I thought I posted my response but don't see it here.

Yes it is "gasoline" in the PC.  As ragoodsp  posted that sucker in the HR was heavy, installed weight IIRC was ~ 1200lbs genset/radiator/water/etc.  Diesel fuel price in our ownership was consistently 30-40% higher $'s, upside is that there is more energy in a gallon of diesel vs gasoline, BUT NOT 30-40% MORE ENERGY.  Another upside to the HR the genset would run everything at once in the MH.  Another downside to a 2 fuel vehicle is the increased support weight of both tanks, I think because of the seperation layer in diesel that those tanks are still metal.  But with a diesel in a PC you would still have 2 systems and you are adding a third fuel system.  As far as exhaust goes the diesel runs cooler so attendant parts can be smaller, and were, compared to the gasoline genset in the PC.  LImited use, including storage will present a water/fuel separation layer in a diesel system and  is something that is mandatory to take care, including frequent filter changes on the genset and addition of chemicals that "supposedly" treat the condition.  That happened as part of the larger picture on the HR but would have to be addressed separately on a
PC.  Twas me, I would investigate a much larger or even two equal sized propane tanks.  In my mind at least the overall weight gain would be small[er (much??)] compared to adding a diesel genset and fuel tank.

L. G.

I like the larger and/or dual LP tank idea.  That might be the best solution.

WRT the diesel generator, I wouldn't be adding a diesel tank since I'm planning to buy a 2350 on a Sprinter.

24
I think that everyone comes up with different answers about generators.  If you're diesel powered, you have the choice of  a costly, noisy, diesel or an LP model that's sucking up your very limited supply of furnace, water heater, sometimes refrigerator, and cooktop fuel.  What you really have to look at is what are you going to use the generator for.  We tend to put very little hours on our generator, primarily using it to run the microwave and A/C when we stop to eat lunch at a roadside park or rest stop.  We hate RV parks that are what I call parking lots with hookups, but we do look for state parks and other wooded facilities with a minimum of water and electricity and preferably sewer hookups.  Consequently, if I had a diesel unit, I could probably use an LP generator with no problems at all.  How much are you going to use your generator??

Jerry

Sigh...another dilemma.  ;-)

Since we like the idea of dry camping/boondocking I imagine we'll use the generator frequently -- typically in the way Ron does, to keep the batteries charged -- and then run off of the batteries/inverter.  

We have a similar setup here at the house -- 12 golf cart batteries and a pair of inverters for a whole-house UPS.  If the batteries were to ever get fully discharged, we would run our generator at close to full load (the inverters have an adjustable charge rate) long enough to charge them back up and then turn it off.  Fortunately we've never had to run the generator -- the batteries will run our essential loads for about 24 hours.

The loads in a RV are less of course, but there is much less battery capacity as well.  Without having actual experience or doing load calculations I'm not sure how often we'd have to recharge the batteries, but I'm guessing that running the generator once or twice a day would be enough.  Maybe less without using the furnace fan, or any other significant loads.

If that were the extent of it we could probably get by with the LP genset but I really like the idea of having the potential extended run time of a gas or diesel (dep. on chassis) generator, primarily to run the A/C.

I am concerned about the negatives that you all mentioned though -- additional weight, extra expense, and exhaust fumes.

I suppose noise is an issue with any generator (LP, gas, or diesel) but my understanding is that diesel units may be a bit louder than the others.  Any opinions about that?  I suppose if they're all obnoxiously loud it's a mute point.

To avoid the noise, I've read that some RV owners carry a small, portable, Honda gas generator.  I've heard them run and they are _very_ quiet.  They also have the advantage of being able to be set away from the RV.  IIRC, they aren't particularly powerful though -- maybe 1-2KW depending on the model.  That would be fine for charging the batteries and/or running small loads but I'm wondering about the A/C unit and the microwave.  Actually, the microwave might use 700-800 watts and could be run off of the batteries/inverter for a short time if the outlet was wired that way (we do that here at home).  So I'm sure even a small Honda generator could handle the microwave, but I don't have a sense of what sort of load the A/C unit represents.  An A/C unit might not take too much when running but could be hard to start.  Anyone know the minimum size generator required to start the A/C unit?

<Thinking out loud at this point>  Of course, it wouldn't be practical to run the A/C unit from a portable generator, even if it could handle the load, because the fuel tank would need to be refilled every few hours.  Then there's the issue of carrying enough fuel.  One Jerry can might fit on the hitch mounted carrier, but that amount of fuel won't last very long if the generator is running the A/C.

And so we arrive back at square one...  ;-)

What do you all think?  Is it worth carrying a small Honda generator for routine battery charging and all loads except the A/C unit?  Or does the OE on board generator charge the batteries fast enough that the noise generally isn't an issue?

It looks like PC installs a high quality Xantrex pure sine wave inverter in their rigs.  I seem to recall seeing ratings of 1,800 to 2,000 watts, does that sound right?  If so, that's much better than just about any other class B+/C I've looked at.  As I said above, an inverter that size could easily run the microwave and two decent deep cycle batteries could supply enough juice for short periods of time -- but I gather the microwave outlet isn't wired that way?

One final thought -- I know most diesel engines can be idled for hours on end without harm and take about 1/4 of the fuel that a gas engine does while idling.  Would it make sense to charge the house batteries that way?  That wouldn't solve the A/C issue but would provide extended run time for everything else while conserving the LP and being relatively quiet and fume free.

Thanks!

Sherman  



25
As an unbiased engineer, I don't credit stability control as having a complete ability to compensate for the difference in the rear track/wheel width to height ratio between the Sprinter and the Ford. Electronics cannot completely compensate for the physics regarding the moment of lever difference (the center of gravity is considerably lower on the Ford than the Sprinter and that is what, pound for pound, counteracts inertia/swaying once initiated).
I've driven both and the Sprinter is not as stable as the Ford on secondary roads. Try a fast lane change on both and you can easily experience the difference.
This is not an opinion but a statement founded on facts.

As an unbiased technician I agree.  ;-)

All the electronics in the world cannot overcome the laws of physics -- only make the best of any given situation.  Everything else equal, it stands to reason that the the vehicle with the wider track would be more stable.  If the Ford also has a lower center of gravity then it should be even better yet.

I'm not doubting what you said about the center of gravity, just curious -- where did you get your information?  I could search but I'm being lazy.  ;-)  It isn't something that comes up frequently in RV forums.  In fact, IIRC, this is the first time I've ever discussed it with anyone.  With the E-350/450 being heavier duty vehicles with much higher GVWRs I would have thought they might have the higher center of gravity -- or are you referring to the complete 2350/2400 rigs?

Thanks,
Sherman

26

Some people say they'd never have a diesel genset, no matter what.  

Any comments or opinions?

Thanks!

Sherman

I had a 7.5 ONAN in the front of a 34' HR Ambassador, water cooled 3 cylinder.  No problems, not noisy at all, could not hear it in the rear of the coach.  It's another engine to maintain and fairly expensive.  Smell was no worse than the pusher diesel.  Never had a trouble code on it, can't say the same for the Cummins that was "outback".  Parts (filters) came from Cummins (do they own ONAN??) and they discount nothing for anyone near as I could tell.
Come to think about it the generator was "the" bright spot on that MH.  I'll stick with PC and the gas generator on mine.

Thanks lghjr, that's good to know.

Just to clarify, when you say gas you mean gasoline, correct?

I suppose I could have somehow included gas along with diesel (vs. LP).  Different fuel but same idea -- running the generator off of whichever fuel the coach uses so that you (potentially) have a greater supply of fuel, and do not use up your LP running the generator since it is needed for cooking, hot water, heating, and the fridge.

I'd like to have the ability to be 'self-contained' for as long as possible and it seems that running the generator on diesel (w/ the Sprinter) or gasoline (w/ the Ford) would be a good idea.  Credit to Ron for pointing that out to me over on RV.net a few months back.  There are so many things like that -- facts that are blazingly obvious to an experienced RVer that just don't occur to rookies.

I wonder if your good experience with your diesel genset might have been at least in part because it was larger and water cooled.  Perhaps it had better emissions controls and a bigger, quieter muffler?  Just guessing.  I know I've read multiple complaints from RV owners about the smaller diesel units that are typically installed in class C rigs.  Many talk about purchasing an aftermarket exhaust extension kit that routes the exhaust up along the ladder and above the roofline.  This was/is due to fumes getting into the coach.

Thanks,
Sherman

27
I see my thread has had its tail chopped off!  ;-)

In an earlier post (on March 13) I wrote:

"What are some options that are worth looking for?  I was thinking about the: passenger swivel seat; leather; fantastic vent; insulated glass; back-up monitor; leveling jacks (weight may be an issue though); mirror w/ compass and outside temp; diesel generator.  Any suggestions/thoughts?"

There were some very thoughtful replies.  I'm not asking people to repeat themselves, but if anyone has anything they'd like to add that would be very helpful.

Another way of asking the question might be -- are there any options that you wish you would have gotten?  In particular, options that must be added at the factory (as opposed  to those which can be added later)?

If we were to order new, I'm thinking we'd pass on the mirror w/ compass and outside temp -- it seems expensive, and there are alternatives.

In that previous post, I went to write:

"I know diesel gensets can be louder than LP fueled ones, and they can be smelly.  The reason I'm considering one is to conserve LP.  Even with a larger LP tank it is an issue, and the PC rigs have relatively small 42 lb LP tanks."

Diesel gensets have serious drawbacks, but I really like the idea of leaving the LP for refrigeration, heat, hot water, and cooking.

Some people say they'd never have a diesel genset, no matter what. 

Any comments or opinions?

Thanks!

Sherman

28
Regarding Sprinter service:

I emailed the guy I know who owns a 2006 WGO View that he bought new.  He has over 100,000 miles on it (and is on the road right now with his wife).  He had this to say:
 
"Dodge Sprinters must all be out of warranty by now. Mine is Dodge (of course) and I have no problem getting MB or Freightliner service, providing they sell Sprinters. The woman @ MB was confused. Moreover, I am treated as royalty."

I find it interesting how people have such wildly different experiences getting their Sprinters serviced.

Sherman
 

29
I agree Ron, the rear track on the Sprinter does seem narrow -- the Ford looks better.  Most mfrs' class C coaches look a bit too wide for the Sprinter.

I recall that this came up over on the RV.net forum a while back.  Some people were questioning the relative stability of the Sprinter.  Everything being equal, it would make sense that the Ford would have more inherent stability.  The Sprinter may have more sophisticated electronic stability control (ESC) -- or not, I don't really know, but that might be a factor.

Both chassis seem to be able to 'keep the shiny side up' as the truckers say.   

30
I think I see now where the contradictory information on the ability to use hydraulic levellers on the Sprinter based motorhomes came from.  The great majority of the earlier Sprinters were simply the standard long wheebase unibody vans equipped as motorhomes.  The newer Class B and C motorhomes are now on a cab chassis unit resembling the Ford cutaway that has a real frame on it.  The concern as I read it on some postings was that the old unibody did not take well to being torqued by lifting with a leveller and did not have good places to attach the leveller.  I think that all went away with the more conventional frame.

Jerry

Very helpful Jerry, thanks!

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