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Old 03-14-2015, 07:48 AM   #1
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450 small block vs 500 big block

The biggest difference, to me, is the torque. 1200+ in the 450 & 1600+ in the 500. But in the 2 coaches I am looking at (a new Dutch Star vs a new Mountain Aire) there is also a big difference in the empty weight of these 2 coaches. The Dutch Star is 7,200 lbs. lighter.

Assuming one is only towing a car that is in the 4,400 lbs. range as opposed to a heavy trailer or sorts, is the 450 going to be a problem on hills out west?
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Old 03-14-2015, 08:02 AM   #2
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My ISB 275 HP made a trip out west with no problem.
towing a 2,500 lb trailer.

Divide weight by torque on each one to find lbs to 1 ft lb.
Best to weigh both when ready to travel with all your stuff.
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Old 03-14-2015, 10:39 AM   #3
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We tow a Grand Cherokee Diesel (5000 lbs) behind our Dutch Star (ISL 450 hp) and on 6-8% grades we drop down to 50-55 mph. If a truck causes me to slow to 40-45 mph I can accelerate back up to 50 mph, but that's it.

I can't imagine the mpg is all that different.


Everything slows down on steep grades.



All that said; more power never hurts (unless you care about how much fuel you use).
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Old 03-14-2015, 07:02 PM   #4
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Quote:
Originally Posted by PDR John View Post
We tow a Grand Cherokee Diesel (5000 lbs) behind our Dutch Star (ISL 450 hp) and on 6-8% grades we drop down to 50-55 mph. If a truck causes me to slow to 40-45 mph I can accelerate back up to 50 mph, but that's it.
I wonder if extra 400 lbs. torque with the 500 does much better in a coach that is 7,300 lbs. heavier?
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Old 03-14-2015, 07:07 PM   #5
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400 extra ft/lbs of torque will more than offset the extra 7000# of weight.
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Old 03-15-2015, 09:28 AM   #6
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I would be curious about the radiator surface area of the two engines. In some of the 400 HP cummins engine freightliner did not have a large enough surface area and there were some heating issues. I would make sure the bigger engine had enough radiator to cool it. I have one of the freightliner engines with cooling issues and I have more than enough power to pull the hills out west towing my car. I just have to go down to such lower gears to keep the RPMs up for cooling I drop way down in speed.
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