Older "mechanical" Cummins vs. newer electronic ones

Topic: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred? (Read 2276 times) previous topic - next topic

Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

November 09, 2015, 07:54:46 pm

I'm a Foretravellin' full-timer wannabe back again with a new question - and please forgive me if it has been beaten to death already - I couldn't find a thread, but if one exists I'll be happy for a reference!

As mentioned in an earlier post, I have been researching with great gusto [obsessive] in preparation to full time in an older Foretravel (looking right now like a '96-'02 U270/U295s, probably 36'). [By the way, if anyone is looking I have found a bunch currently for sale from many different sources, all $60k and under. I wish I were ready to make the move now!]

I have taken to heart the warning that simpler is good, as it confirms my own experience with technology. Working in technical fields much of my life has taught me that simpler is usually more robust. While I enjoy luxury as much as anyone else, I don't have the pocketbook or the faith in complex technology knowing that comfort and convenience in electromechanical systems usually comes in a more complex, less robust package - those points of failure really add up!

I have read with great interest the thread started by AndiT1 about buying a (much) older Foretravel. In that discussion it was generally agreed that older non-electronic Cummins diesels are preferred over newer electronic ones, and the dividing line is somewhere around the 2000 model year. I'm guessing that's analogous to the older car engines vs. the newer ones with the emissions controls? The thing that strikes me though about the car engines is that a well made one doesn't have to be touched for the first 100,000 miles, and after that you pretty much change the plugs and timing belt (if it has one). That was my experience with a '91 Acura I bought with 186,000 miles on it. I traded it at just over 300,000 miles because 6 yrs on New England's salted roads made it not worth replacing worn suspension components due to seriously rusted underbody. The drive train was still raring to go, and the car didn't owe me a penny. I still miss it!
I don't see a down side to that, but I gather the differences between the older and newer Cummins diesels is not so benign? Any info would be much appreciated! You folks are incredibly generous with your experiences and have made this wannabe want to join you! NOTE: I am signed up for a NRVIA 5-day hands-on course in New Braunfels, TX to get some exposure to RV systems, and I'm hoping to prepare me not only to evaluate my own purchase, but also to do pre-purchase inspections as a sideline. Beyond just having an interest in general, I believe it's about time people can call on a professional to evaluate a rig before buying - the same way you can for a sticks and bricks house. Depending on what I learn about diesels (no experience with them so far) I might even consider one of the even older coaches (unibody/Grand Villa) when the time comes 2 years from now. Right now I just don't have any knowledge or experience with diesels that I would have the confidence to manage one.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #1 – November 09, 2015, 08:13:54 pm

Ran across a country coach allure I sold new to joe and Vicki Kieva in 1996. They were the Rv lifestyle folks at the FMCA rally's and wrote articles for all the mags over the years.

Coach was in my local cummins dealer for oil and filter stuff.

Looked at the 8.3 cummins spin on filter visible from the back of the engine door and it had black marker writing on it indicating it was replaced at a recent date.

Service manager looked and no major issues had occurred ever.

Told them the cc was good like the Foretravels and am happy it worked for them as well as I told them it would

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #2 – November 09, 2015, 08:15:23 pm

My opinion is this,the last 30 years has been working as a gas compressor mechanic.We recently purchased a 96U270 with a
mechanical 8.3 cummins engine,for me this is a very easy engine to work on and parts are readily available.Engine blocks
are priced anywhere from $5000.00 to $10,000.00. Heads and turbos are cheap.

I would say the more work you can do yourself the better off you are with a older unit,if you don't do any yourself then a
newer one may be better for you.

We were in your position and not ready to buy but the deal of the century came along.If one comes along now that in a year
from now will be gone and priced 10 or 15K more try and find a way to buy it.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #3 – November 09, 2015, 08:21:02 pm

Years ago I did things like replace engines, replace cylinder heads, perform all maintenance including tune-ups - all on (don't laugh) pre-1970 VW engines.

While I wouldn't hesitate to dig into a project like that, I won't have the infrastructure (garage, chain fall, torque wrenches... etc, etc) to do anything like rebuild a diesel engine, let along an old VW engine.

So maybe one of the newer engines would make more sense? I'll be at the mercy of a diesel shop either way...

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #4 – November 09, 2015, 08:25:56 pm

Older ones are almost impossible to kill.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #5 – November 09, 2015, 08:43:41 pm

Short answer: Find a Foretravel coach that fits your budget, will serve your needs, has been used regularly and gently, and has been properly maintained.

We have owned a 1997 U295 since 2010. It is one of the last Foretravel coaches to use the Cummin C8.3, a mechanical (no electronic control module) engine. We get about 7 mpg pulling a car and driving about 65 mph on good highways. My understanding is that the engines with electronic controls get about 8 mpg. Acceleration and performance are similar. Foretravel general sized engines based on the weight of the rig.

My "target" coach was a 2000 model 36' U320. However, price and availability led us to buy the 1997 model at less than half the price of the newer coach (five years ago). I think I would like to have an electronically controlled engine, but the mechanical engine has served us very well. I expect the 1997 U295 will serve us as long as we choose to have a class A motorhome.

The issues we have fixed on the C8.3 engine include a new lift pump, throttle return springs (simple fix), replacing a couple of bolts that vibrated out of the throttle bracket assembly, and replacement of the exhaust manifold. The coach is in the shop for the manifold replacement now. The engine has about 130,000 miles on it. Shrinkage of the exhaust manifold is a common problem on that vintage of C8.3. Cummins redesigned the manifold so that the replacement is not likely to fail.

We participated in the North to Alaska 2014 Motorcade. Our was the oldest, smallest coach. The coach performed on par with all of the other coaches. I expect any Foretravel coach of the models you are considering will serve you well, if it has been maintained properly. My observation is that the U270 is the least complex and provides the most storage.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #6 – November 09, 2015, 10:39:23 pm

There is nothing to worry about with a electronic engine. The problem engines are the EGR equipped engines. And the engines produced after them.The emissions engines EGR systems and smog systems are where all the trouble is. That's where the repair cost goes through the roof . Detroit Diesel pioneered electronic engine controls in the 80's. Cummins, Caterpillar, followed suite in the 90's.
Over the road trucks prior to 2003 were almost bulletproof racking over a million miles before needing a overhaul. Stay clear of the emissions engines and whether you get a mechanical or electronic you will have a very very dependable rig.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #7 – November 09, 2015, 10:59:01 pm

Sorry, but I don't know where the EGR diesels start to appear in the Foretravel model years. Is there a telltale sign for any year?

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #8 – November 09, 2015, 11:09:21 pm

Quote from: RT_Geezer – November 09, 2015, 10:59:01 pm

Sorry, but I don't know where the EGR diesels start to appear in the Foretravel model years. Is there a telltale sign for any year?

It would be around 2003 and newer. I own a semi truck and have quite s few people I know that have bought new trucks peterbilt,kenworth etc,as glider kits . these are brand new trucks with no engine then putting in a pre 2003 non egr engine because they are so reliable.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #9 – November 09, 2015, 11:13:43 pm

Quote from: stump – November 09, 2015, 11:09:21 pm

It would be around 2003 and newer. I own a semi truck and have quite s few people I know that have bought new trucks peterbilt,kenworth etc,as glider kits . these are brand new trucks with no engine then putting in a pre 2003 non egr engine because they are so reliable.

Exactly

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #10 – November 09, 2015, 11:51:48 pm

Non-EGR cummins have a red valve covers so call "Red Tops". Well at least that is what my mechanic said.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #11 – November 10, 2015, 12:03:18 am

Quote from: Willy White – November 09, 2015, 11:51:48 pm

Non-EGR cummins have a red valve covers so call "Red Tops". Well at least that is what my mechanic said.

My 2003 has red valve covers, so EGR must have come somewhat later.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #12 – November 10, 2015, 12:46:23 am

Heavy-Duty Engines. Heavy-duty applications of EGR date back to at least 1977 when the technology was used on some naturally aspirated engines—such as Caterpillar's 3208—to comply with California's 5 g/bhp-hr NOx+HC limit for heavy-duty diesel engines. However, through the 1980s and 1990s the use of EGR on heavy-duty engines remained limited—EGR was not required to meet regulatory emission standards and the application of the technology was driven primarily by incentives such as the US EPA voluntary "low emission vehicle" certification program.

The wide scale launch of cooled EGR on heavy-duty engines that attracted a lot of attention to the technology took place in late 2002 in the North American market. This momentous introduction was in part triggered by the Consent Decrees and the political upheaval that surrounded the issue of "dual-mapping" that led to the 1998 settlement between the US EPA, the Department of Justice and the heavy-duty diesel engine manufacturers[EPA 1998. The Consent Decrees advanced the implementation of the EPA 2004 emission standards by 15 months, to October 2002, putting heavy-duty engine manufacturers under extreme pressure to quickly select a technology capable of achieving the new NOx limits of approximately 2 g/bhp-hr. High pressure loop cooled EGR was the most expedient in-cylinder NOx reduction technology that could achieve this emission level[Dennis 1999. In October 2002, several heavy-duty engine manufacturers introduced their new EPA-certified engines equipped with EGR systems. There was a considerable apprehension in the field regarding the performance, fuel economy, and the durability of these new engines. While initial statements from fleet managers appeared to praise the new technology [DDC 2003, some users have complained of the increase in fuel consumption. For EPA 2007, EGR continued to be the primary NOx reduction technology and allowed a number of engine makers to reach about 1 g/bhp-hr NOx. For EPA 2010, the 0.2 g/bhp-hr NOx limit proved to be too low to be effectively reached with EGR alone and additional help from NOx aftertreatment was required. Navistar—the only manufacturer to temporarily use EGR without aftertreatment for EPA 2010—was able to do so only by certifying engines to 0.4-0.5 g/bhp-hr NOx and making up the difference with credits.

In Europe, a couple of heavy-duty on-road engine makers introduced EGR-only engines at the Euro IV stage, with the remainder relying solely on urea SCR. By Euro V, the engine makers using EGR also adopted urea SCR to supplement their EGR strategies, while most manufacturer's continued to rely on urea SCR only solutions. For Euro VI, the use of EGR became more widespread and many engine manufacturers introduced some combination of EGR and urea SCR. However, the use of EGR was often minimized to certain low load conditions and no EGR was used at higher operating conditions such as highway cruise. Some manufacturers (Iveco, Scania) also introduced SCR-only Euro VI engines, without EGR.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #13 – November 10, 2015, 01:31:37 am

The electronic engines are worth about 5-7% better mileage with the common rail injection adding another 5-7%

Bosch inline pumps get their lubrication from the engine oil system. Many rotary injection pumps (Perkins, Cummins, VW) use diesel as the lubricant. The inline pumps last forever. The rotary pumps may have a good lifespan but many do not. In many cases, the seal fails and they start leaking diesel everywhere. The inline pumps may installed (with new injector pipes) as a conversion.

Common rail engines use a different system entirely.

Late engines (2007 up) require ULSD (ultra low sulfur diesel) <15ppm while the earlier engines are OK with LSD with a maximum of 500ppm. Translation is fuel in the U.S. is OK, Mexico only close to the border can ULSD be found or in the Mexico City area. The rest of the country is LSD. Europe is all ULSD. ULSD requires higher quality oil to refine and has slightly less energy so mileage will go down very slightly. The proposed Trans-Canada pipeline would have only been able to supply poor quality oil and would not have been suitable for making diesel or fuel oil.

Pierce

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #14 – November 10, 2015, 07:26:21 am

I don't think there's any reason not to own one of the pre-EGR electronic engines. Our 1995 U320 has an electronic M11 engine with over 160,000 miles. It has given us zero problems over the past three years, and the records provided by the previous owners indicate that the only significant issue over its lifetime was to have the turbo rebuilt at one point. I am extremely pleased with our setup.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #15 – November 10, 2015, 08:08:57 am

I've read some places that the mechanical 8.3 get better MPG than the electronic ones. Who knows, though.

There are some advantaged to an electronic engine. Much more parameters are available and using scan tools, you really can see more into what is going on with the engine. The downside is, it isn't as simple to survive a zombie EMP Apocalypse. But you have an electronic allison transmission, so you'd be in trouble anyway.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #16 – November 10, 2015, 08:15:49 am

This pretty much sums it up, (The Consent Decrees advanced the implementation of the EPA 2004 emission standards by 15 months, to October 2002, putting heavy-duty engine manufacturers under extreme pressure to quickly select a technology capable of achieving the new NOx limits of approximately 2 g/bhp-hr.)
The Government wanted it now and the manufacturers had to come up with a bandaid quick! The public of course paid the price, pretty much business as usual in that aspect.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #17 – November 10, 2015, 08:40:25 am

I did a little poking around and found among Barry Brideau's posted information the following:

"In 2002, upgraded to the CM875 fuel system wich included an EGR valve for EPA emission compliance."

and above that on the same page...

"ISM (non-EGR) = 1999 to 2003 (280 to 450 hp)"

Cummins Engines - Years of Production and available Horse Power

So I would guess that it took some time for the newer engines to make their way into Foretravel production - at least that's how I interpret it. So I would expect some 2003 models to have the EGR engine - maybe not. In any case, it appears that between '96/'97 and '02/'03 are the years for electronic engines with no EGR. (On the same page above Barry tells us that Cummins added electronics in '96.) I guess the boundary years of '96/'97 and '02/'03 would require closer inspection to tell whether the engine has electronic or mechanical controls and an EGR or not. Does this sound correct to those who have *actual* experience with these things (as opposed to myself who can only read about it - so far)?

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #18 – November 10, 2015, 08:52:30 am

I find the mechanical 8.3 300 hp. U295 consistently gets 1.5 mpg better than the 450 hp U320. Load the 300 heavy and pull mountains at max and the fuel mileage can drop to below that of the 450. There are some differences in towed weight and coach weight, along with driving habits primarily associated with having 450 hp on tap. I believe the newer engines with common rail fuel systems will beat both of them for efficiency.

A good comparison would be a pre 2000 model Dodge pickup with a 12 valve Cummins, and a post 2000 model. Not too many owners will dispute the reliability and lower cost of operation, overall, of the 12 valve compared to the others, but they lack big hp and gee whiz features of the newer models.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #19 – November 10, 2015, 08:58:30 am

Quote from: RT_Geezer – November 10, 2015, 08:40:25 am

I guess the boundary years of '96/'97 and '02/'03 would require closer inspection to tell whether the engine has electronic or mechanical controls and an EGR or not. Does this sound correct to those who have *actual* experience with these things (as opposed to myself who can only read about it - so far)?

Our 1995 U320 has the electronic M11. Others will need to answer when the 8.3 went from mechanical to electronic.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #20 – November 10, 2015, 09:04:30 am

I have model year 1998 and it's mechanical 8.3. I'm pretty sure model year '99 was electronic, but there may be some transition year RVs.

The downside of the 8.3 is the electronic acuated king control. It's pretty reliable, and the company is still around to fix it, but it does fail sometimes. Luckily a string works pretty well!

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #21 – November 10, 2015, 09:42:26 am

Quote

Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reading the thread sounds like some are recommending that you should not purchase a coach newer than 2002, seriously?

The M11/ISM with EGR is a solid engine that has many millions of miles on them, you should not give a second thought on owning one, or owning a coach that has an electronically controlled engine.

The only concerns anyone should have are if the engine requires DEF (extra stuff to take care of, extra room taken up, extra cost to run) or if it has an ISX 650 and maybe 600 since those seem to have a problems.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #22 – November 10, 2015, 10:49:10 am

Yes..1999 was the first year for the ISC 8.3 Cummins engine fully electronic in Foretravels. And, I love Forrests's 325 HP C8.3 Cummins mecjanical engine. Bullet proof engine. Simplicity without hassle. I do not know how much of a polluter it is, but certainly more so than the newer electronic versions. Not proud of that, but it is what it is as Dave M would say.

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #23 – November 10, 2015, 02:34:02 pm

Quote from: Willy White – November 09, 2015, 11:51:48 pm

Non-EGR cummins have a red valve covers so call "Red Tops". Well at least that is what my mechanic said.

I have a 500 ISM in our 2007 with "red top" valve covers. I had heard this indicated these engines were "derated", so who knows. Brett would probably be a definitive source on this.

Don

Re: Older "mechanical" Cummins vs. newer electronic ones - why are they preferred?

Reply #24 – November 10, 2015, 02:36:23 pm

Actually, for the most accurate information on your engine, call Cummins with your engine serial number:

Cummins 800 343-7357

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