Simple question, not a debate please

[RickNC]

Originally Posted by Crasher

I second this method. When climbing up to the Eisenhauer tunnel west of Denver towing our Avalanche (total weight is 46,000#), I set the cruise at 36 mph in third gear. The rpms stay at 1900 and the temp runs up to 210 when the fan clutch kicks in. The temp drops to 185 and stays in that range. I could run faster, but have never had a reason to. Being retired, time is free.

I used to go through that tunnel a couple times a week when I was working out there in the 1980's. IIRC there is about 10-11 miles of grade on either side. In time the difference between 70mph and 35mph is only about 9 minutes. In the Ford f350 truck I drove then, the fuel difference was nearly a 1/4 tank .

[Finance]

Float the valves on a Triton? I'd like to see that.

[twinboat]

Originally Posted by Quincy

I suppose I could get my V 10 over a six percent grade faster than I do if I were to floor it also. I just read a post about a couple who have a blown motor in the shop and wondered how they climb hills. Only 36K and lost a valve.

I am surprised at what seems like allot of drivers who think it is ok to hammer it down and climb the grade as fast as possible. Nothing could be worse for the motor unless you drain the oil before you do it.

The transmission is just for that purpose, getting up a grade without floating the valves or stalling the motor. Both can be damaging to the engine.

The difference between a 5 and a 6 speed transmission is negligible when climbing a hill. The first 5 gears have the same or close to the same ratio in either transmission. Gears 5 is an overdrive gear in both transmissions at about .8 to 1. 6th gear is a second OD gear at roughly .6 or so to 1.

The trick is to keep the motor running at its sweet spot (about 3000rpm) through the entire climb. That way the sound level dosent blow you out of the drivers seat and the valve float does not blow the engine.

What ever speed it takes to maintain 3000 rpm or so is the speed and gear you should be in.

So much for the no debate request.

3000 RPMs is way below the V10s sweet spot.

[TriMoot]

Although we've had a couple of medium length trips, just two weeks ago we encountered a long fairly steep grade going up and down the Chief Joseph Pass in Montana in the Bitterroot mountains.

As I normally do I hit the OD button on our 97 RexAir on a F53 Ford chassis with the 460 engine and started up. As we were grinding our way up the hill (And I can't for the life of me recall what the RPM's were) all of a sudden the RPM's dropped down and the speed started to drop. I wasn't sure what had happened, and I think I started giving it more gas, but there wasn't a lot to 'give', so I believe I dropped it down to into 2nd and continued to grind up the hill but now at a slower speed. And even if I gave it all the gas it needed it wasn't climbing any faster.

So my question is...what am I doing wrong? Should I not drop the overdrive out 1st and just shift into 2nd? I'm not in any hurry, just wanting to know why it acted they way it did and is that normal?

I don't recall having any issues 2 years ago when we were traveling down to N California from Spokane, WA, so I guess I'm concerned something has changed or I'm just not paying close enough attention.

Thanks.

[ernest917]

Sorry but I find it difficult to believe that a gasser passes a diesel climbing a grade....

Had a gasser - now a diesel and there's no way a gasser will climb a grade faster/easier than my diesel...

[Crasher]

Originally Posted by ernest917

Sorry but I find it difficult to believe that a gasser passes a diesel climbing a grade....

Had a gasser - now a diesel and there's no way a gasser will climb a grade faster/easier than my diesel...

I've had gassers pass my on a grade. However, pulling our 12,000# trailer, we grossed out at 52,000#. The gassers were probably half that weight or less. Load them up like a DP and they might make it up an 8-10% grade. It's all about weight or the lack of it.

[hohenwald48]

Originally Posted by twinboat

3000 RPMs is way below the V10s sweet spot.

I usually run around 3500-4000 when pulling a grade. Even that is probably a little low.

[hohenwald48]

Originally Posted by Quincy

I suppose I could get my V 10 over a six percent grade faster than I do if I were to floor it also. I just read a post about a couple who have a blown motor in the shop and wondered how they climb hills. Only 36K and lost a valve.

I doubt their motor problem had anything to do with speed or excessive RPM's since the V-10 is rev limited by the ECM.

[ScopeGuard]

Here you go,
https://youtu.be/CyKmsWXdkkY
27' gas coach v-10 6% grade

[coachmanjay]

How long is a pice of string? It depends. Have a 2013 Class C E450 with a Banks with over 30,000 miles and have tracked fuel usage since leaving the factory with numerous trips over the same roads. The Banks improved milage slightly, but a great improvement in acceleration. What that has not been mentioned is I get different mileage over the same roads depending on air temperature, wind speed, travel speed and what is seldom mentioned is the composition of the fuel, ethanol, octane and additives that vary by location. Don’t ever remember dropping down to 20 mph usually 40/45 on most of the passes in Western USA

[IggyTech]

Originally Posted by Jlferg2

My v10 in a35 footer towing a pt cruiser did 40 to 45 up teton pass. That is mostly 10 % grade. Passed several diesels.

I also done this 10% grade going up to the Teton Pass.
It was pedal to the metal but I did maintain 45 mph and got to the top to clean my pants out.


Note: I have 60,300 miles on my rig and it runs like a top and never blown anything in the engine.
The Ford V-10 is a solid engine and has proven itself over 20 years I think now.

[Crasher]

That 10% grade on Teton Pass west of Jackson can be a real pucker experience. One time descending the east side in an 03 40' Phaeton, I found that I had to use the brakes more than I wanted to even with the exhaust brake on. I noticed the brakes were fading and was only 1/2 way down. I pulled over to the side and was able to come to a complete stop only after putting the trans into neutral. I waited 30 minutes for them to cool down before proceeding down. I later discovered that my trailer brakes were not working. Have been over the pass several times since with no problems, but I gained a lot of respect for a long 10% grade. I much prefer going up to down.

[Dav L]

The times my V10 power to weight ratio was a concern was when driving with families in other RVs and a pickup truck. Hard to keep the group together up / down the hills. And we were in last place pulling into McDonald's when most were already done ordering. That was one of the thoughts that lead to getting a DP. Now, with the DP, no problems climbing. Always more power than a semi but non necessarily the fastest up the hill compared to the cars. The V10 was almost always the slowest up the hill compared to all others. I admit I wasn't putting the pedal to the metal as I didn't want to stress all parts to their max. Putting sound isolation materials under the dog house was great to keep the racket of the engine spinning out of the passenger compartment. No issue with that in the DP (engine in rear).

Downhill, the Jake is great. Hardly need to touch the brakes. I do try to not use it in populated areas for noise reasons. But it's nice to know I have cool fresh brakes if the Jake isn't cutting it (hasn't been an issue on any downhill). I seem to go slower down the hill than up, but that's because I never know what's around the next turn (up or downhill, steep turn etc). Something next generation navigation systems might help with.

[Mr_D]

Engine brakes (jake brake) on MH's are exhausted through the muffler. They do not make much noise so no reason not to use then. They are not like the ones years ago.