Community Forums

429CV23 · 09-14-2020, 07:18 PM

Our 'new' 2004 Country Coach 40' DP has the Cummins 8.3L ISC; 350hp/1050tq. It weighed 29,000lbs with 3/4 tank of fuel and a full fresh water tank (100gal). Towing a '99 Blazer 4-door (~4000lbs) she pulled just under 50mph up the NM side of Raton; fairly steep.

We sold our '97 Newmar Mountain Aire 37' gasser before purchasing the CC. The biggest plus to the diesel is setting the cruise at 67-68mph and just steering. The Newmar was so heavy for the 460ci/4spd auto (~19,000lbs) plus towing the Blazer, any small grade she'd downshift, and the RPMs would really jump. So then shut off the cruise, slow down until we crest the hill, reset cruise for a few minutes until it happened again.
Insurance and maintenance are more expensive, but worth it.

If you look at something with a CAT, make sure it has a wet PTO. In 2005, maybe later years as well, they had a dry PTO. There is a retrofit kit for the wet PTO, but it's a few thousand dollars.

With any coach you're serious about, research the issues with the engine. Some have serious gremlins down the road that can set you back $20k.

Ray,IN · 09-14-2020, 08:51 PM

The Cummins 650 HP engine has been problematic. Look in the Cummins engine forum for several threads concerning expensive rebuilds as a result of the problems. Cummins no longer makes that HP engine as a result.

jimmy braden · 09-14-2020, 09:08 PM

Quote:

Originally Posted by Ray,IN

The Cummins 650 HP engine has been problematic. Look in the Cummins engine forum for several threads concerning expensive rebuilds as a result of the problems. Cummins no longer makes that HP engine as a result.

Quote:

I keep reading about varied torgue ratings and that some people dont like the Cummings with 660 @ 1600 RPM.

Thats not the HP rating he referenced..
Its the torque rating ..

So, its not likely to be the 15L motor that is used for the 650HORSEPOWER ISX

In general, you dont see a lot of ISX in 2002-2008

Quote:

.
looking 2002-2008
$50-$75 Budget

But, you got much more experience than I.. by an order of magnitude...

https://www.irv2.com/forums/members/ray%2Cin-21218.html

Much respect..

Rob_M · 09-14-2020, 11:04 PM

8.3 or larger Cummins. It’s all about the torque. How much you need and how much you want are separate things lol.
Stay pre-emissions if you can. 2006-2007 ? or older with a side radiator for ease of maintenance. There are nice ones out there in your price range... or there were when I was looking last year.

Ray,IN · 09-14-2020, 11:12 PM

Quote:

Originally Posted by jimmy braden

Thats not the HP rating he referenced..
Its the torque rating ..

So, its not likely to be the 15L motor that is used for the 650HORSEPOWER ISX

In general, you dont see a lot of ISX in 2002-2008

But, you got much more experience than I.. by an order of magnitude...

https://www.irv2.com/forums/members/ray%2Cin-21218.html

Much respect..

Thanks for the catch! I misinterpreted what was written. I don't know of any diesel engine in a MH with only 660 lb/ft of torque at 1600 rpm; that would be quite puny.

jcussen · 09-14-2020, 11:22 PM

Quote:

Originally Posted by Ray,IN

Thanks for the catch! I misinterpreted what was written. I don't know of any diesel engine in a MH with only 660 lb/ft of torque at 1600 rpm; that would be quite puny.

A lot of newer coaches have the 6.7 with 660 ft/lb engine. Cost cutting measure, okay for a 24000 lb unit but not so good for a 30000 lb coach with a 5000 lb toad.

NoSparkPlug · 09-15-2020, 12:18 AM

The previous mentioning of Horsepower is nice. But if you want to be comfortable driving, Torque is where it’s at. Higher torque will help pull up that steep grade hill at a more steady speed than a higher horsepower number could.
My rig has 860 lb ft of torque with a 33000 GCWR. I frequent mountain grades and would probably be more comfortable driving with an added 200 lb ft of torque. Get it to 1200 lb ft of torque, I’d probably wouldn’t break a sweat and just kick back into my seat.
As posted earlier, it all personal preference. But for my taste, I would love to make my drive easier. But of course, there is always a cost…

Ivylog · 09-15-2020, 05:05 AM

While the ISX #6 valve is an expensive problem, the OP is looking for a 35-38’ rig...why bring up the ISX used in 42+ rigs???

texasrs · 09-15-2020, 05:48 AM

Quote:

Originally Posted by jcussen

Would look at either the Cummins ISC or ISL, you might also find some coaches with the ISM 450 hp and 1450 ft/lbs torque. That would be my choice.

JCUSSEN

Certainly agree with your recommendation of an ISM Cummins. They are practically bullet-proof.

MO Fred · 09-15-2020, 06:09 AM

I had an 8.3 Cummins in my previous coach with 800 ft lb. it was a real dog climbing hills pulling a small Mazda toad. I now have a Cat 12 with 1550 ft lb torque pulling an equinox.... difference is like night and day and such a joy to drive.

Rob_M · 09-15-2020, 06:39 AM

Quote:

Originally Posted by MO Fred

I had an 8.3 Cummins in my previous coach with 800 ft lb. it was a real dog climbing hills pulling a small Mazda toad. I now have a Cat 12 with 1550 ft lb torque pulling an equinox.... difference is like night and day and such a joy to drive.

He’s not going to find a 12L Cat in the size rig he’s looking for. Even at 40’ only a very few have the 12L Cat which is a great engine btw.

OP if you step up your search criteria to include 40’ you will have a greater selection of engine choices. And at 40’ with a tow bar(no tongue weight) you’re good to go without a tag axle. My rig is actually more stable in cross winds and truck traffic pulling my 7,000 pound Excursion than with no toad.

schad · 09-15-2020, 08:34 AM

Quote:

Originally Posted by jcussen

A lot of newer coaches have the 6.7 with 660 ft/lb engine. Cost cutting measure, okay for a 24000 lb unit but not so good for a 30000 lb coach with a 5000 lb toad.

The 6.7 is available in a lot of different torque/power configurations. Mine is 360hp/860ft-lbs. There are also 340hp and 320hp variants, with torque in the 700s and 600s respectively (if I remember correctly). Identical engine regardless of the ratings; the difference is the transmission. You need an Allison 3000 to get the maximum output of the engine. Anything below that and the engine is derated. This is doubly important for the OP, because I believe sub-3000 transmissions are also only rated for up to 5000lb towing. If his toad does actually weigh 6000lbs, he must get an Allison 3000 or better -- regardless of what engine he chooses.

But with that said, I'm really only familiar with post-emissions equipment, and based on his price range, the OP is probably looking at pre-emissions MHs. Transmission options may have been different back then.

Anecdotally, my coach-plus-toad probably weighs about 35,000 pounds. My engine is completely acceptable. I would not want anything smaller. I think an L9 (f/k/a ISL) with 450hp and 1250ft-lbs torque would be better, but that engine is typically only available in a coach that weighs 10,000+ pounds more. That extra weight will take away much, though not all, of the extra power/torque you gain.

Onthehunt49 · 09-15-2020, 10:04 AM

Thanks to everyone for all the replies.
From what I am seeing. About all the rigs 2003 to 2008 in my budget, have 660 to 860 lbs of torque. From 300 to 350 hp.

40 ft would be too long for my rv parking pad at my house. Gate to gate is 41 ft.
I would not be able to gat around rig.

deandec · 09-15-2020, 10:24 AM

FWIW, the higher torque focus depends on the weight of the coach and load it is trailering.

It will help significantly pushing the weight uphill.

But how often and for how many miles does the average trip include time going up steep grades? And why be in a hurry going uphill?

My WAG here in the West mountain ranges that it might be 3% of a daily trip.

It also is possibly 1% of the total mileage covered in the life of a MH

With a low torque engine, that can seem to be an eternity, but it isn't.

If you do not have a relaxed schedule, that grade pulling time can seem like eternity, but it is not.