REPOWER

[David Burris]

Has anyone re-powered their Coach?  Considering, if possible, going from a 400 Cat to a 500 Cummins, in a 2008 Contessa.  Can this be done, and if so, what would be the approximate cost?

[Tom and Pam Brown]

I think the cost would be outragous.

New bell housing so the transmission would mount to the new engine.

New motor mounts to the engine.

New or changed plumbing for the fuel, water and air system.  Will the enginge fit into the old space without modification?

Also, the electronics would have to be at the very least modified to recognize the new power plant.

If you need or want more power then consider upgrading the Cat it will be less expensive with the fewest unknowns.

Have fun with your quest!

[Larry Fisk]

I have the C-13 525 hp Cat and am very pleased with its performance. Maybe that would be a possibility.

[Gerald Farris]

An engine exchange from a C9 Cat to a M11 Cummins would be a lot more money that it is worth. There are several modifications that can be done to your current engine to get more horsepower if you really do need more power.

The C9 marine engine will produce 567 BHP, so there is a potential for more HP in the C9 than the 400 that you are now rated at. There are several companies that modify diesel engines in trucks to increase performance if you are not worried about emissions.

The downside to any modification is that you will probably be kissing your Cat engine warranty goodbye. So stop and think, how many times do you really need more power and what would be the benefits of more power. You will get to the top of the hill a couple of minutes faster and you will get some bragging rights. The few minutes that you save in climbing the hill will be of questionable value since we drive these coaches because of the relaxed life style and not to race. The question on the bragging rights, you will have to place a value on that.

The bottom line is that if you want a lot more power, it would be a lot more cost effective to trade your Contessa for a 2007 to 2009 Marquis with a 600HP C15. That will give you the luxury, performance, and resale ability that an engine swap in your coach alone will not and at a reasonably compatible cost.

Gerald          

[David Burris]

Thanks,
I may have other issues??  It seems when I climb step grades, CO &  NC,  the engine will run hot, unless I gear down and get the RPM's in the 2000 range.  Would this be considered normal??

A friend following in the same mountains, with a 500 hp Cummins on a spartan, never gets over 200 degrees.  Of course he pulls the hills without having to manual down shift.  ANY insite on this?

[Richard And Babs Ames]

The RPM's needs to stay in the 2,000 RPM range for the best cooling and is normal.

[Joel Ashley]

I think Gerald hit it on the head.  There are plenty of cheaper ways to get more power, but if you want a bigger engine, you might as well buy one with a coach already around it.  You'll never get your money's worth any other way.  Your 42' coach is a fair amount of load for 400HP;  our 36' 400HP rig, on the other hand, has plenty of power and I'm more than happy with the combination.

-Joel

[Gerald Farris]

 So your complaint is not low power, it is insufficient cooling. Changing the engine out for that reason is a total waste of time and money. If you are sure that your radiator is clean, your best option is to just gear down and keep your RPMs up on the few occasions where it is needed. You can increase the cooling capacity of your coach with modifications if necessary, but if hill climbing is the only time that you notice a problem, the correction is easy and free, gear down.

The cooling system on a coach is sized by the design engineers to meet the perceived heat loads that it will have to deal with. If the cooling system is oversized for the heat load that it that it has to deal with, it will be more expensive as well as less fuel efficient. The radiator cooling fan on a diesel pusher can require as much as 60 HP just to drive the fan, so to much fan can be a problem. To much radiator can be a negative in the size needed for installation as well as overcooling the engine so that it can not run continually with the thermostat open to allow maximum coolant flow and even cooling throughout the engine.

The bottom line is, be certain that your radiator is clean, and if that does not sufficiently solve your problem, and you are opposed to gearing down, have a radiator company design a larger and more efficient radiator that can be mounted in your coach. Such a radiator will probably cost in the $3,000 to $5,000 range.

Gerald    

[Edward Buker]

The wisdom to replace the coach rather than try and modify it by repowering is right on. If you find you cannot tolerate your coaches performance then a trade would be the much better answer.

Our last coach was an 89 Contessa had a Cat 3208 and a 4 speed Allison. For 10 years of ownership, on major climbs, we would run for miles at 2800RPM in second gear at 35 miles an hour. At that speed the engine temperatures would rise to 200F. That speed and temperature was normal for that coach. Your 400hp Cat C7 certainly does a better job than that.

So the question is are you expecting too much or are you being short changed....That is hard to know. What is the normal climbing and cooling ability for a 400hp C9 in your Contessa? If possible running a test under the same conditions with another Contessa with the same drivetrain would give you the answer. You would need to find a volunteer to run that test....

The alternative to that would be to have a major Cat service center for trucks run a dyno test to be sure that you are getting the 400HP output that you should be getting and that the cooling fan RPM is normal under those conditions. If that is as it should be, the radiator is clean as Gerald states, and the radiator perimeter is isolated (mine uses a rubber material) so that hot exhausted air cannot be pulled around and enter the front side of the radiator. Also the fan shroud is as it should be, then you have the knowledge that your systems are working as designed. From there it is a matter of gaining some speed before a climb and optimizing your gear selection to keep the RPMs where you want them. I would think coming out of economy mode before a climb would also be a help here.

I would just want to be sure that you are getting the performance that you paid for and that you are operating the coach in a manner that optimizes its performance before looking at taking some drastic measures. Hope this helps.

Later Ed

[Bill Sprague]

Nobody mentioned the possibility of a faulty thermostat.  

Nor has anybody suggested a definition of HOT.  My Cummins runs at about 180 on the Aladdin.  Once, on a very long hill and very hot day, it crept up to around 200.  Alarmed, I got the book out and I think I remember the limit is about 220.  I had a long ways to go!  

Another possibility, maybe even a probability, is that the gauge is faulty.  My Aladdin readout is about 20 degrees cooler than the dash dial.  If you are defining HOT based on a dash dial readout, your engine may actually be running where it is supposed to.

[Gerald Farris]

Bill,
There is almost no chance that a faulty thermostat can cause the conditions that the coach owner explained.

Gerald

[LEAH DRAPER]

If Cat raised the HP from 400 to 425 on later models (or some) of the C9 Cat as well as the torque, why can't this also be done for those who have the C9 with only 400 HP??

[Robert Mathis]

Another big problem with adding more horsepower is that the more power you make, the more heat you generate. It is actually pretty easy to increase the horsepower of a modern electronically controlled diesel engine. A computer chip or "flash" can add as much as 100 horsepower. A larger exhaust, or bigger turbo can do wonders, but then you will need to increase the cooling system's capacity to match. A second problem with doing this is that under heavy loads, your exhaust gas temps will rise to the point where you can actually melt the turbo vanes. When I have "tricked up" my diesels in my trucks, I have always added a pyrometer to the exhuast system just before the turbo to monitor the EGT's. You would be amazed to see how fast and far they can climb. I would get a coach with a bigger engine already in place. Everything is designed around that engine and it's cooling needs.

[Gerald Farris]

Leah,
There is one concern in having the coach ECM (engine control module) reprogrammed or "flashed" to a higher horsepower rating that has not been mentioned. That is the cost of having the Cat dealer perform the reprogram.

Most Cat dealers will charge you one hour labor for the reprogram.
That is a reasonable and fair charge, but then you have to pay Caterpillar for the proprietary software that was downloaded into your ECM as well as the increase in warranty charges to cover you engine under warranty at the higher ratings if it is still under warranty as virtually all of the C9 engines are. I would expect the cost to be between $700 and $1,000 for something that you will rarely notice, if ever.

Gerald

[Bill Sprague]

Bill,
There is almost no chance that a faulty thermostat can cause the conditions that the coach owner explained.

Gerald

Gerald,

That's good to know, but why is it not likely to stick?  Doesn't it open and close to allow more or less coolant to flow to keep a stable operating temperature?  Do they fail to full open?

Thanks.

Bill