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NoFear · 09-03-2012, 08:13 PM

Any experience or word on this engine compared to 450 or 500 hp?

Mr_D · 09-03-2012, 08:18 PM

No real problems that I've heard of anywhere I've been.

NoFear · 09-03-2012, 08:39 PM

Decrease mileage?

szy · 09-04-2012, 01:23 PM

Only iffy engine Cummins ever made was a 5.9 ISB some internal bolt would work loos and either fall harmlessly to the oil pan or fall into the moving parts a self destruct the engine

SuperGewl · 09-04-2012, 09:59 PM

Quote:

Originally Posted by szy

Only iffy engine Cummins ever made was a 5.9 ISB some internal bolt would work loos and either fall harmlessly to the oil pan or fall into the moving parts a self destruct the engine

Not 100% true, only certain serial numbers were affected.

Now to answer the question a 600hp Cummins, and you ask if its better than a 450.

I know pwople that would kill for the 450 but a 600 would cause them to have heart attack of joy. You want to talk about power to get over the mountain while towing, OMG. I hopw it has the 4000 or beter Alison.

I'm sorry no brainer here, let's see Brigs & Statton 6hp, Fiat 4 bangger, toyota 6 cylinder and then the Big Boy 600 hp of get the heck out of my way house pulling power. No take the Briggs & Stratton

Cruzer · 09-05-2012, 08:07 AM

The 600 HP Cummins is the 15 liter ISX series. This is the big boy that is used in over the road trucks, although they are derated to lower horsepower ratings fior severe service. It's an excellent engine, meets current emisions, has excellent reliability, and performs well.

The older 450-500 HP Cummins were the 10.8 liter ISM series. They were good engines, although not the best Cummins ever made. The only ISMs that I've ever heard of serving up problems were the ones used in severe truck service, not RVs. With the move to EPA 2010 spec engines that used DEF, the ISM was dropped due to difficulty in meeting the new emissions requirements. Other than that, they were good engines.

The newer 500 HP DEF engines are now the 11.9 liter ISX12 series, which is basically the ISX engine with a smaller bore andstroke to keep the power levels down. The ISX12 does meet the EPA2010 emissions and offers the reliability of it's big brother.

Either engine is an excellent choice. Naturally, the 600 HP ISX will have more torque and horsepower so you'll be able to climb grades with ease, accelerate up ramps, etc with unmatched power and speed. The only downside is that larger displacement engines move more air through them and fuel and air is pretty much a fixed ratio so you'll be using more fuel. Although most 600 HP chassis are fitted with taller gear ratios so your engine RPM will be lower. I don't think that the fuel economy of the 600 HP ISX would be seriously degraded over the 500 HP ISX12. At least not enough to make one shy away from it.

cb5300 · 09-05-2012, 02:53 PM

Quote:

Originally Posted by NoFear

Any experience or word on this engine compared to 450 or 500 hp?

You will love the ISX engine

My Monaco Signature has the 600 in it ( I missed the 650 ISX by 2 stinking weeks..

) and at 1600 RPM (the "sweet spot") I run 70 mph (by GPS) and get around 7.0 mpg flat towing a Ford Explorer (doesn't even know it's there). It's really nice when you hit the mountains and you just motor right on up and over with no problems.

This set up is so much nicer than the 2007 Dynasty that I had. It had the ISL 400 and I always felt like the coach was to much for the motor.

vito.a · 09-05-2012, 03:12 PM

Cruzer explained it well. The Cummins ISX is the king of over the road truck diesel engines rated along side the Cat C15 (which is no longer in production). Torque is electronically limited to 1950 ft lbs to comply with the Allison 4000 transmission limits.