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Author Topic: CAt vs Cummins for my next rig - diesel pusher  (Read 24323 times)

joester

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CAt vs Cummins for my next rig - diesel pusher
« on: October 16, 2006, 02:11:43 PM »
I thought I'd post a new question I have after talking to my mechanic.
without posting what he told me, I thought I'd ask owners of each and what they have experienced.
I'm looking for a short (32-34) diesel pusher, and so far really like the Holiday Rambler Neptune pbd,which is basically the same as the Monaco Cayman.
I believe these come with the Cummins ISB 300 hp engine.
what are your experiences with these rigs and more particularly this engine.
thanks so much.
any info on rigs with a similar CAT engine would be great help to me - and what makes use the CAT engines?
tener corazón de oro

1991 Tioga class C

Chet18013

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #1 on: October 16, 2006, 06:07:49 PM »
Both are good engines. I have a CAT in the motorhome and have a Cummins in my truck.  I would not hesitate to have either one , or even a Detroit, in our next MH--that is if we ever wear out the one we have.

Chet18013
Chet18013
Full time in a 45' '04 Monaco Signature
towing a 2014 Jeep Grand Cherokee diesel

Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #2 on: October 16, 2006, 06:33:12 PM »
Like Chet, I wouldn't hesitate to have either one. We have a Cummins in our coach and a pair of big CATs in our boat. We have forum members with both makes in their respective motorhome and I don't recall hearing or reading any dissatisfaction with either one.

We had an issue when both CATs broke turbo studs while we were at sea, but we were able to get home safely and CAT went out of their way to take care of the repair and cover collateral damage.

A friend and forum member recently had to be towed when his new coach with an ISX Cummins engine broke down one day out of the factory and the nearest Cummins dealer/tech couldn't fix it. But the problem was resolved promptly by Cummins once they were towed to a knowledgeable facility.
« Last Edit: October 16, 2006, 08:36:03 PM by Tom »
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BernieD

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #3 on: October 16, 2006, 06:45:36 PM »
Joe

I have had both a CAT and a Cummins engines in my 2 coaches. Both were/are fine engines. I do question the ISB engine in a full sized Class A coach. Everyone that I know that has that engine in a coach has been disappointed. Major problem is low torque, about 600#/ft IIRC.
Bernie & Marlene Dobrin
Home is Goodyear, AZ
Missing our Travel Supreme

Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #4 on: October 16, 2006, 06:50:14 PM »
I do question the ISB engine in a full sized Class A coach.

Bernie, I was about to do the same, but realized he's talking about a "short" (32-34 foot) coach. It would be good to know the weight of that coach.
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Smoky

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #5 on: October 16, 2006, 08:30:59 PM »
I have a Cummins 330 in my coach and I have been very pleased with it.

Originally, when I first started shopping for a coach i only looked at those with Caterpillar.  All my life I had admired Caterpillar equipment and thought it was the premier diesel.

But then I became attracted to Newmar motorcoaches.  I was disappointed that the current Newmar offering in the 2005 year was all Cummins.  I did some research and the more i researched the more I liked what I saw.  We had our first visit to a Cummins shop in Bakersfiled California and were VERY impressed with them.
Smoky S  Ham radio - W3PY

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Jackliz

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #6 on: October 16, 2006, 09:09:32 PM »
I thought I'd post a new question I have after talking to my mechanic.
without posting what he told me, I thought I'd ask owners of each and what they have experienced.
I'm looking for a short (32-34) diesel pusher, and so far really like the Holiday Rambler Neptune pbd,which is basically the same as the Monaco Cayman.
I believe these come with the Cummins ISB 300 hp engine.
what are your experiences with these rigs and more particularly this engine.
thanks so much.


Detroit first, then a Cummins.

Jack and Liz
Blue Bird Wanderlodge with 500 HP Detroit Diesel, 8V92

Regards,
Jack and Liz Pearce and Oreo the Escape Cat
Fulltiming in a 1993 Wanderlodge WB 40 ft
Dhanis, TX - Winter
Buena Vista, CO - Summer

blueblood

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #7 on: October 17, 2006, 09:05:49 AM »
Joe

I have had both a CAT and a Cummins engines in my 2 coaches. Both were/are fine engines. I do question the ISB engine in a full sized Class A coach. Everyone that I know that has that engine in a coach has been disappointed. Major problem is low torque, about 600#/ft IIRC.

Bernie _ I and a lot of my friends had the ISB275/300 in FW Discovery at ~24,000 GVW and liked them very much. We got close to 10-11 MPG and could clear mountains at 35-45 MPH. In fact a close friend of mine has a trailer with his Corvette in it and has had good performance across US and up to Alaska. Torque is a contant 660 ft lbs across the entire operating RPM so it gives better performance than some engines with advertised higher peak torques at RPM that are not in operating range.
« Last Edit: October 17, 2006, 09:08:08 AM by blueblood »
Leo

BernieD

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #8 on: October 17, 2006, 11:35:34 AM »
Bernie _ I and a lot of my friends had the ISB275/300 in FW Discovery at ~24,000 GVW and liked them very much. We got close to 10-11 MPG and could clear mountains at 35-45 MPH. In fact a close friend of mine has a trailer with his Corvette in it and has had good performance across US and up to Alaska. Torque is a contant 660 ft lbs across the entire operating RPM so it gives better performance than some engines with advertised higher peak torques at RPM that are not in operating range.

Leo

I am glad that you are having good results with your ISB. My comments were based on friends that have/had coaches with the ISB engine.
Bernie & Marlene Dobrin
Home is Goodyear, AZ
Missing our Travel Supreme

joester

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #9 on: October 17, 2006, 11:40:46 AM »
thanks for all the replies.
my mechanic mentioned that he had not worked on the most recent Cummins engines, but the earlier (pre-2003) engines he had worked on were not made as well as the CAT's he had worked on. I'll pass on the info on the Cummins you have shared, and ask him to ask around with other mechanics as to the newer engines.
I did notice the torque on the Cummins is about 660, whereas the CAT 350 hp says that it has 860 - 200 ft/lbs of torque seems to be a big difference.
the Holiday and Monaco I like are about 25k lbs empty - probably 32k lbs loaded - is the 300 hp with 660 ft'lbs torque enough for me to climb thru the rockies with no trouble?
what about with a car or trailer in tow?
I appreciate the help - when I do finally make the step up, we will be keeping it for quite a while, so I want to be sure to ask all the questions now.
thanks for all your input.
tener corazón de oro

1991 Tioga class C

CurtRR

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #10 on: October 17, 2006, 02:53:32 PM »
Different size engines, but I noticed that Country Coach, in their new Tribute 260, charge extra for a 400 hp. Cummins over a 400 hp. Cat.
Don't think of it as "retiring to the Fulltimer Lifestyle.""  Think of it as "Unemployed with no fixed address."

BernieD

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #11 on: October 17, 2006, 05:24:33 PM »
Different size engines, but I noticed that Country Coach, in their new Tribute 260, charge extra for a 400 hp. Cummins over a 400 hp. Cat.

The Cummins ISL 400 has 1200 #/ft of torque, I believe the CAT only has 1050. Also, the ISL 400 probably includes an engine compression brake (similar to but with a different name and design as the Jake Brake), while the CAT probably includes an exhaust brake. The exhaust brake works well but not as well as the engine brake.
Bernie & Marlene Dobrin
Home is Goodyear, AZ
Missing our Travel Supreme

Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #12 on: October 17, 2006, 06:12:04 PM »
Bernie,

CAT has an option for the Jake brake, but I don't know which engines do/don't have the option and it may not be offered as an option on some coaches with CAT engines.

The CAT engines in our boat have provision for Jake brakes, but they wouldn't do much for slowing the boat down  ;D
« Last Edit: October 17, 2006, 06:19:16 PM by Tom »
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BernieD

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #13 on: October 17, 2006, 07:34:33 PM »

CAT has an option for the Jake brake, but I don't know which engines do/don't have the option and it may not be offered as an option on some coaches with CAT engines.


Tom

True there is an option but unless the coach builder decides to order his chassis from the chassis builder with that option when he places his oriiginal order and specs, it will be either very expensive or very long delivery time or both.
Bernie & Marlene Dobrin
Home is Goodyear, AZ
Missing our Travel Supreme

Terry A. Brewer

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #14 on: October 17, 2006, 08:58:21 PM »
Tom

Cat C-10's and above have 3 stage jake brakes....at least at Country Coach.


joester

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #15 on: January 21, 2008, 03:20:24 PM »
resurrecting this thread I started a while back - still considering the plusses/minuses for each of these -
say compare a 300-325 ISB Cummins with a 325 CAT - years 2005-2007.
any further input for me? I still like the 32pbd Cayman/Neptunes, but am more open now to a 34'.
I've added the Fleetwood Expedition to my list of potential rigs - saw a 2005 34h I like - I believe it has the 325 CAT. I like the 3 slides so much more than the 2 - the living area gets so much bigger when open.
tener corazón de oro

1991 Tioga class C

Mblaster

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #16 on: January 21, 2008, 09:44:09 PM »
Do the fleetwoods that you are looking at have rear or side radiators?
01 Southwind 32V w/slide
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BernieD

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #17 on: January 21, 2008, 10:28:47 PM »
resurrecting this thread I started a while back - still considering the plusses/minuses for each of these -
say compare a 300-325 ISB Cummins with a 325 CAT - years 2005-2007.

Both are excellent, fairly bullet proof engines. Not sure about the specs for those years, but generally, the CAT torque figure was significantly higher than that of the ISB. With a choice of the two, I'd take the CAT.
Bernie & Marlene Dobrin
Home is Goodyear, AZ
Missing our Travel Supreme

Ron

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #18 on: January 22, 2008, 08:10:21 AM »
Based on the way Cummins reacted t the problem on some of their ISL engines of installing an idiot light warning that the engine is about to come apart I vote for the Cat.  We do have a Cummins but I sure wouldn't buy another from a company that  installs an idiot light instead of ficing a manufacturing defect. JMHO.
Ron & Sam-home is where we park it. Currently located   HERE

joester

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #19 on: January 22, 2008, 08:29:06 AM »
have not looked THAT close on the Fleetwood Expedition to see where radiator location is - but really like the floorplan with the 3 slides - the living area opens up nicely.
as to the Cummins, not sure if the ISL is that similar to the ISB that are in the  32pbd Cayman/Neptune I like so much.
I can see where torque difference would make a difference, but in a 32pbd - wouldn't 660# be sufficient?
I'm still not so sure I want to go 34', but like I said, the floorplan and the CAT make the newer fleetwood 34h a nice rig to consider.
thanks for the input.
tener corazón de oro

1991 Tioga class C

Gary RV Roamer

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #20 on: January 22, 2008, 08:38:51 AM »
The smaller engines and lower end rigs generally have rear radiators rather than side.  Side rads cost more and use up some bay space, so they tend to appear only on larger and higher end rigs.

As for Cummins vs Cat, I would ignore that factor in choosing a rig.  They are both excellent and service is widely available for both.
Gary
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Ron

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #21 on: January 22, 2008, 08:48:14 AM »
I have lost confidence in Cummins.  I know the big problem I mentioned occured on ISL engines but based on the Cummins recall and fix of installing a warning light to let the driver know that failure will occur shortly rather than fixing the manufacturing defect I would wonder what they would do if a new engine had a manufacturing defect.  Things can and do happen during manufacture.  But the ONLY proper way to fix a manufacturing defect is to fix it not install a warning light.  For me we have had our last MH powered by Cummins.  JMHO
Ron & Sam-home is where we park it. Currently located   HERE

Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #22 on: January 22, 2008, 10:29:58 AM »
I wouldn't be so quick to criticize Cummins; At least they made customers aware of a potential issue. We have the other brand in our boat and had to limp home when both engines broke studs holding the turbos. The resulting mess wasn't pretty - air filters clogged, engines sucked the filters down, soot bypassed the squished filters, and every square inch of the engines, transmissions and engine room was covered in black, oily soot. Had to dismantle the salon to raise the decks so the techs could remove the blocked aftercoolers and replace the broken turbo studs.

There had been a "service bulletin" issued to dealers with a specific instruction "do not replace until failure occurs". I read it when a tech inadvertently left it on the boat. The engine manufacturer paid for almost all the cleanup, salon teardown, and repair work, for which I was grateful. Fortunately, we were relatively close to shore, nearing the end of a journey up the CA coast. But, had we been 20 miles offshore in bad weather, that could have been a lot more serious than it was. Had I been notified of a potential problem, I would have had the simple replacement of studs done before we left home.
« Last Edit: January 22, 2008, 10:31:43 AM by Tom »
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Ron

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #23 on: January 22, 2008, 10:43:31 AM »
IMHO Cummins should have been required to fix the manufacturing defect that could lead to the engine dumping its guts out all over the highway which could very well be a safety issue.  It sure would not give sombody any comfort to know they have a light that will illuminate letting them know their engine is about to sprew its insides all over the road.  What if this happend on a bridge or anywhere that there was not room to pull over.  Very good potentional for an accident IMHO.   Like I said when I heard of the Cummins fix I lost ALL confidence in them.  IMHO Cummins should have fixed the internal manufacturing defect insted of expecting their affected customers to worry if and when their warning light would illuminate.
« Last Edit: January 22, 2008, 10:47:10 AM by Ron »
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Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #24 on: January 22, 2008, 10:54:15 AM »
Understood Ron, but at least they were warned the engine might fail and had the option to stay home. I'd much prefer to break down on a highway bridge than 20 miles offshore in bad weather.

On the first leg of the same trip, we had to head for the nearest port of refuge when the weather forecast was dead wrong. I found myself having to make a wide U-turn in 20'+ seas, heading to a strange harbor while dodging reefs and praying we wouldn't capsize. Had we lost power at that point, we would have been in a world of trouble.
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Ron

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #25 on: January 22, 2008, 11:05:41 AM »
Understood Ron, but at least they were warned the engine might fail and had the option to stay home. I'd much prefer to break down on a highway bridge than 20 miles offshore in bad weather.

About that option do you know anybody that bought a motorhome to stay home.  I don't really consider that a good option.  IMHO The ONLY proper way to address that issue would have been for Cummins to fix their manufacturing defect.  I know that the defective part was supplied by to Cummins by one of their vendors but surely Cummins should be inspecting the components they are installing on a new engine.
Quote
On the first leg of the same trip, we had to head for the nearest port of refuge when the weather forecast was dead wrong. I found myself having to make a wide U-turn in 20'+ seas, heading to a strange harbor while dodging reefs and praying we wouldn't capsize. Had we lost power at that point, we would have been in a world of trouble.
 

Glad you didn't have engine failure at that critical time. 

How comfortable would you feel taking the boat out if it had a pair of the affected Cummins ISL engines and Cummins had fixed the problem by installing an idiot light?
« Last Edit: January 22, 2008, 11:08:06 AM by Ron »
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Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #26 on: January 22, 2008, 11:22:49 AM »
Based on the two stories, which engine would you have in your next coach? I'd much prefer to be told and be able to make the decision to leave or stay home than unwittingly put lives in jeopardy because I didn't know there was a potential issue. One of my worst fears is drowning.
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Ron

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #27 on: January 22, 2008, 11:33:43 AM »
Let me put it this way would you buy a brand new coach knowing that the engine has a manufacturing defect as some of the ISL?  Probably not.  Now would you buy a used coach if it had an idiot light installed to warn you that the engine is about to fail because the engine has a manufacturing defect?  Also probably not.
Ron & Sam-home is where we park it. Currently located   HERE

Tom

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #28 on: January 22, 2008, 12:15:54 PM »
Maybe I wouldn't buy either next time around Ron, but that does limit the options. Personally, despite the two stories, I believe both brands of engine are OK and, given some of the alternatives, are good value. I might think twice about buying a coach having the 'known bad' engine, but wouldn't rule out other engines from the same manufacturer.

OTOH I'm not planning on buying another coach or another boat. We're quite happy with the ones we have  ;D
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Ron

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Re: CAt vs Cummins for my next rig - diesel pusher
« Reply #29 on: January 22, 2008, 12:22:53 PM »
We are not planning on buying another coach for the same reason.  However, I have told American coach that I will not even consider a new coach with a Cummins engine.  Interesting I am not the only one that feels this way.
Ron & Sam-home is where we park it. Currently located   HERE