Mountain RVing advice.

[Trails_And_Tail]

We're planning an extended RV trip for next spring that will put us in the mountains for part of it. Our Class C is a 1991 with a Ford 460 engine and automatic 3 speed (plus manual OD) transmission. The best specs I can find for this combination is 245 hp @ 2200 rpm and 400 lbs torque @ 4000 rpm. Which of these specs should I pay attention to? I'm looking for the optimum pull for the uphills and I'm not sure what would be a good starting place (rpm) to start looking for the "sweet spot". Any advice about this or anything else related to mountain travel would be greatly appreciated. BTW: I'm a bit of a sissy so I'll be planning to stay on Interstates as much as possible.

[More_To_See]

csamayfield55 wrote:

More To See wrote:

On a long climb it's best to occasionally back off the throttle occasionally for a moment..

I don't usually correct people on these forums but this is a stupid statement and will only help in losing momentum.To ever "cool your manifolds" you would have to stop, get out walk around and drink a coffee! maintain your speed, whatever that speed may be and watch those gauges!

The braking advise here was spot on! Keep em cool and use your engine to help

Chris

Guess that's why I run a Gear Vendor on my rig.

[Dave_H_M]

Man the last thing i would do when pulling a long grade is let up on the go pedal when I don't have to. Momentum is just too hard for me to bet back.

[Lynnmor]

Trails And Tails wrote:
The best specs I can find for this combination is 245 hp @ 2200 rpm and 400 lbs torque @ 4000 rpm. Which of these specs should I pay attention to? I'm looking for the optimum pull for the uphills and I'm not sure what would be a good starting place (rpm) to start looking for the "sweet spot".

I think that you have this reversed, the peak HP should be at the higher RPM. You will get the most power at the peak HP RPM. There is so much talk about torque and it is pretty much meaningless. Usually you will get the most efficiency at peak torque but that doesn't get you up the mountain... HP does.

Some will tell you to do stab braking, but that too is without merit. If you have problems with brakes overheating, you are simply using them too much. Brakes are a heat device and going thru high heat and no heat cycles repeatedly only causes periods of even higher heat followed by no added heat. The only way to reduce brake heat is to go slower, use a lower gear or pull over to let them cool.

[Geocritter]

Do not blow off people’s advice on brakes. My non-mechanic brother called me in a panic from up in the Sierra Nevada’s because he was having a severe and continuous problem with brake fade in his Ford powered 1991 Chinook. His problem was old brake fluid that had absorbed atmospheric moisture to the point where it lowered the temperature that his brake fluid would boil at. Since he’s my brother and I love him I flew out to California and rebuilt his entire brake system. But probably the one best thing I did was change out his DOT 3 brake fluid for severe duty DOT 5.1 brake fluid (not to be confused with DOT 5). DOT 5.1 brake fluid has a boiling point about 100 degrees Fahrenheit higher than the DOT 3 you probably have https://en.wikipedia.org/wiki/DOT_5.1 . BTW he never had brake problems again.

As others have done I highly recommend the Mountain Directory. I purchased it online in the Cascades after I smoked the brakes on my class A on a long long long downgrade. BTW my 460 V8 powered rig, which is pictured in my profile, had no trouble going up mountains (albeit slowly), but going down mountains was a true learning experience even with DOT 5.1 brake fluid. Another thing I recommend is tire pressure/temperature monitors. It was how I learned that my brakes were overheating.

Steve

[Roy_Lynne]

I'm also an engine listener as each one is different.

[mlts22]

On an extreme, I'd consider having the brake shoes replaced. It is $100 or so plus labor, but the most important thing isn't going to be how you climb the hill, it is how you are going to be stopping.

Another item that might come to mind is the transmission cooler. Using this post as a reference, I'd consider replacing the transmission cooler with an aftermarket cooler which has a lot more area. Transmissions function up to a certain temperature... then when they start hitting an inflection point (180-200 degrees), they cook quickly. This is especially important if towing.

Of course, with a newer model of class "C" with an OBD II port, having a Scangauge is good for temperature monitoring.

[navegator]

If your RV has a viscous fan clutch, going up hill it will engage and sound real loud, this is normal it means that the temperature in the radiator has gone up and needs a little more cooling, do not back off the gas, as stated before you will lose momentum and speed, this means that the engine now has to work harder since the gas pedal will be pushed in order to regain the speed lost, the harder it works the more heat generated.

To check if you have viscous fan clutch, with the engine turned OFF try to move the fan, if it moves with your hand, it might be a little hard then you have a fan that will engage at a certain temperature, do no confuse the engine fan with the air condition fan that sits in front of the radiator, the engine fan sits between the radiator and the engine, sometimes it is hard to see with all the tubes for the engine air intake and filter.

A month before your trip have the engine serviced, oil, oil filter, air filter, fuel filter, spark plugs, tires inspected and or replaced, generator serviced and the general condition of the unit checked, have the spare checked, potable water tank and supply lines, black tank, grey tank and drain valves checked, and make sure that brakes are in working order, that the brake pads still have life left.

Otherwise have a good trip

navegator

[2gypsies1]

You won't be able to visit places if you stay on the interstates. You're going to have to get off them at some time.

I, too, would advise you to purchase the "Mountain Directory for Truckers & RVers". It comes in western and eastern editions. It is cheaper if you buy from the publisher rather than through Amazon for some reason.

Plan to drive shorter days so the stress factor doesn't kick in.

[ol_Bombero-JC]

Trails And Tails wrote:
All good stuff so far, but I'm really curious about finding the best rpm for maximum pulling power with my rig. She's a bit elderly and I don't want to over-rev or lug the old gal.

Take your time.

Gear down as needed both to go *up* as well as saving your brakes while going *down*.

[csamayfield55x]

More To See wrote:

On a long climb it's best to occasionally back off the throttle occasionally for a moment..

I don't usually correct people on these forums but this is a stupid statement and will only help in losing momentum.To ever "cool your manifolds" you would have to stop, get out walk around and drink a coffee! maintain your speed, whatever that speed may be and watch those gauges!

The braking advise here was spot on! Keep em cool and use your engine to help

Chris

[NMDriver]

If you do need to brake going down hill, push down hard and release, repeat as needed. Do not ride the brake or try to slow down gradually. Of course, you brake before a curve, not in it.

[Terryallan]

Going up is easy, the art is in coming down. As mentioned. Use the gears to hold back the RV. On the interstates 2nd gear coming down may be all you need. However, on the really steep, and twisty mountain roads where the speed limit is usually 25, or 35 MPH. You will need to use 1st gear. And you will need to put it in first before you start down. DO not let it get away from you, keep it slow from the start. It is much easier to keep control, than it is to lose it, and try to get it back.

So go slow, and enjoy. Your gas engine will IF you use the gears, will save you from ever heating up the brakes

[Cummins12V98]

The fact is out in the Mountains you will have your foot mashed to the floor going up the Passes. Transmission will pick the gear. Just sit back and watch the fuel gage drop like a rock.

Have fun!

[Trails_And_Tail]

Yes, yes and yes again. This is the stuff I was looking for. Thank you everyone.