Went over Wolf Creek pass today. Wow! Glad I wasn't in the coach. Thats some climb. About 10,500 feet at summit. The downhill would benefit from jakebrakes for sure.
Yeah, we I drove my bus home from Denver. Even 70 was scary so I played safe, went north and caught the 80 west to CA. Those hills do get a bit tall, lol
8v71's N/A without turbos you can here those saying "I think I can,I think I can" with the black smoke rolling,we have friends their MCI 7 with a 8v71 N/A he just runs out of power on Wolf Creek and turns around you see that often.Mount Evans really separates the men from boys in Co
Clifford - any guidelines on altitude and grade? Would be wonderful to have a table for an MCI with an 8V71 na showing limits. Maybe there is a simple rule like at sea level an 8v71na can take a x % grade then at 1000, 2000, etc, the grade it can get over goes down.
It would be pretty to find a percent power loss for every 1000 up but then translate that into speed or grade reductions.
Mt. Evans is limited to 25 or 30 foot length above the lake, but I've done it with a 35 footer with the frame dragging on the switchbacks, not a big parking area at the top if it's crowded
We've had our 4104 with NA 671 MT on top of everything including CN & AK since 1979 no Jakes - it's invigorating!
Quote from: niles500 on June 29, 2021, 02:12:52 AM
Mt. Evans is limited to 25 or 30 foot length above the lake, but I've done it with a 35 footer with the frame dragging on the switchbacks, not a big parking area at the top if it's crowded
I did it in our MCI 5 not a good experience at all
Quoteit's invigorating!
Dan, Is that your way of saying. "Thank god we survived!"
lol
Quote from: dtcerrato on June 29, 2021, 03:28:18 AM
We've had our 4104 with NA 671 MT on top of everything including CN & AK since 1979 no Jakes - it's invigorating!
It is out there Dan you just haven't found it yet.N/A diesels the power drops like rock with altitude ,you can really see it on diesel N/A generators .The military sold off all their N/A Humvees they found out they were useless in the middle east
Clifford,
The military didn't sell off all the N/A Hummers primarily because of the N/A engine (and they didn't sell off all the N/A versions yet -- I know where there are lots and lots of them)
They were "useless" in the middle east because: 1) the makeshift armor added to them added so much weight that they were top heavy. 2) The makeshift armor didn't do squat to protect the occupants from an IED UNDER the vehicle. 3) The UP-ARMORED versions built(or retrofitted) by the Army Depots needed more OOMPH to push the 16 K lb + weight than the anemic 6.2 GM N/A could provide. 4) You train like you fight. Now the new standard is Armored Vehicles for "outside the wire" We are on our 3rd generation of MRAPS that I know of.
Quote from: pabusnut on June 29, 2021, 09:04:27 AM
Clifford,
The military didn't sell off all the N/A Hummers primarily because of the N/A engine (and they didn't sell off all the N/A versions yet -- I know where there are lots and lots of them)
They were "useless" in the middle east because: 1) the makeshift armor added to them added so much weight that they were top heavy. 2) The makeshift armor didn't do squat to protect the occupants from an IED UNDER the vehicle. 3) The UP-ARMORED versions built(or retrofitted) by the Army Depots needed more OOMPH to push the 16 K lb + weight than the anemic 6.2 GM N/A could provide. 4) You train like you fight. Now the new standard is Armored Vehicles for "outside the wire" We are on our 3rd generation of MRAPS that I know of.
I know were there are 1500 Humvees with the 6.2 for sale acres of Humvees at the marine base I bought a new 6.2 there for 1 of my Humvees there ,cannot understand the waste paying 88 grand for Humvees and selling it for 10 grand when you could upgrade the engine for 5 grand,such a waste.Some Humvees made in the 90's have less than 3000 total miles. Now they are into emissions doing away with trucks that cost the tax payer a 1/2 million bucks.Sicking to see the 2008 models Humvees selling for pennies
Clifford,
I know more about DOD and wasteful spending than I care to admit. Even our "off road engines" must be CARB compliant now thanks to the EnviroNazis. When I was in Afghanistan the last time(2014) wearing the uniform, I saw literally hundreds of perfectly good MRAPS cut up because "they are too expensive to ship back home"!!!
Defense spending is about "good jobs in my district" and nothing more. It doesn't matter whether it meets the operational requirement of the Military Services or not. And it doesn't matter which "side of the aisle" they sit on.
Quote from: pabusnut on June 29, 2021, 10:13:11 AM
Clifford,
I know more about DOD and wasteful spending than I care to admit. Even our "off road engines" must be CARB compliant now thanks to the EnviroNazis. When I was in Afghanistan the last time(2014) wearing the uniform, I saw literally hundreds of perfectly good MRAPS cut up because "they are too expensive to ship back home"!!!
Defense spending is about "good jobs in my district" and nothing more. It doesn't matter whether it meets the operational requirement of the Military Services or not. And it doesn't matter which "side of the aisle" they sit on.
My neighbor is a retired captain from the military and he tells me when you budget if the money is not spent then they take it out of the next budget and you never got the money anyways or something like that is that true.LOL you pays the shipping on 150 Humvees goes to South America ?
Quote from: windtrader on June 28, 2021, 08:45:04 PM
Clifford - any guidelines on altitude and grade? Would be wonderful to have a table for an MCI with an 8V71 na showing limits. Maybe there is a simple rule like at sea level an 8v71na can take a x % grade then at 1000, 2000, etc, the grade it can get over goes down.
It would be pretty to find a percent power loss for every 1000 up but then translate that into speed or grade reductions.
Isn't there a simple number of how much atmospheric pressure decreases with altitude? 3%, 4% ? I don't know exactly how much. Wouldn't the oxygen content also decrease similarly, therefore making the engine's power output decrease the same? Or am I missing something here?!
When the first non-turbo EMD 567 locomotives engines were used in the mountains, there were big problems at altitude keeping the trains moving.
John
For every 1000 ft. of elevation you lose about 3% of air which also means you lose about 3% of your power.
We derate furnaces at 4% per 1000 ft or down into 80% at 5000 ft and 32% down leaving 68% at 8000 ft. You can do the math for 12000 ft. Now that is just how much we cut back on the fuel supplied to keep it burning properly. I don't know how that translates into power loss for a vehicle.
Something to ponder before you head that direction.
Melbo
I'm so excited - an ON topic answer. We must be all experts at taking a topic into the dirt faster than anyplace. lol
Quote from: windtrader on June 30, 2021, 07:53:56 PM
I'm so excited - an ON topic answer. We must be all experts at taking a topic into the dirt faster than anyplace. lol
Same principal it is the fuel to air ratio,I remember changing jets in the carbureted engines for altitude changes or you had a dog now electronics do that for you
Gotta adjust the carbs as you climb BUT they always love the flat land. I'm looking forward to driving my gas powered carbureted GMC to see how it does from Pie Town NM to Davenport Iowa. I'm not sure I would want to take it into too much altitude. 10,000 feet could test my confidence.
YMMV
Melbo
Ford used to have Denver heads for some of their cars. They provided higher compression ratio to deal with power loss at high altitude.
Sonja's van with a Onan has a adjustment dial on the carb you need to set when we go from the valley to Flagstaff or it won't make coffee
No instant for her, eh.😊
Quote from: chessie4905 on July 01, 2021, 07:31:59 AM
No instant for her, eh.😊
Nope she doesn't drink coffee of any type
Oh, no instant for you.😉
No power? No Kurig lol! ;D
Hope you don't like your coffee hot if you're headed to Denver.
Jim
As I remember it, there is roughly a 1% hp loss per 300 feet of altitude, so that would be about a 20% drop at 6000 ft. Definitely would be a good idea to disconnect the toad and drive it separately if you can if you are doing a 10,000 ft pass.
Quote from: Lin on July 01, 2021, 10:02:28 AM
As I remember it, there is roughly a 1% hp loss per 300 feet of altitude, so that would be about a 20% drop at 6000 ft. Definitely would be a good idea to disconnect the toad and drive it separately if you can if you are doing a 10,000 ft pass.
Lol, in lots of places we've had the bus we'd have never made it there without the toad - tow barred to the bus that is - yes, over the years more than (young & foolish ones) than now the wife and I have that drill down pat - goose the bus with the toad & that included break downs - toad has been a bail out while hooked to the bus. Not so much on our brake burn a couple years ago on the Icefield Parkway - wish we would have disconnected the toad prior, but sice then decreased our toad weight from 7000 to 4000#s and added supplemental toad brakes. :o
Remember the show ice road truckers? They had a few episodes about pusher trucks to help loads up the hills.
Let's see now; I would like like a Tesla cyber truck as my toad, with remote control to help push LOL!!!
Quote from: Lin on July 01, 2021, 10:02:28 AM
As I remember it, there is roughly a 1% hp loss per 300 feet of altitude, so that would be about a 20% drop at 6000 ft. Definitely would be a good idea to disconnect the toad and drive it separately if you can if you are doing a 10,000 ft pass.
I've done Wolf Creek pass at least 14 times in 21 years in my Eagle 10 because we like Durango, Pagosa and Southfork so much, spending lots of time there. It doesn't seem to matter whether I pull the Ford Escape or not. It's 22mph in 1st gear for me no matter what. I use the mister if the temp rises to 200. The tranny goes to about 210 on the climb and 225 on the descent using the retarder.
I don't like the westbound descent. It is really tough to keep the speed down. The east bound descent is not too bad.
David
Turbo engines only lose less than 1/2 the power as the the N/A engines with altitude changes fwiw.I noticed on some old Cat dozers with N/A engine the tag would tell you at what altitude the machine could be operated at above 2000 ft most were turbo engines
My Cat engine was rated to 10,000 ft.
Can't say what would happen at 10,000 feet, but in Santa Fe at 7,000+ feet I can tell you that our 8V71 NA struggled a bit. Lots of smoke when starting from a stop, and a bit when shifting. Loss of power made on-ramps painful - could probably have made a sandwich while we got up to speed. Good thing we were on vacation and not in a hurry.
I went through Wolf Creek Pass several times between South Fork and Durango back in the nineties, and I don't recall having any particular problems with my NA 8V71. You just had to be patient and enjoy the scenery.
I sent a 600kw generator powered by a 12V71 N/A from here to a another mine the company owned the elevation was 9000 ft and I had to install 2 turbos, the 12v71 N/A would only produce 400kw at 9000ft according to manual, smoked like crazy and ran hot
House was at about 1100 ft., did a job where i was at 10,000 ft. Equipment ran fine, had the tag about adjustment above 10,000 ft., top of the mountain was 10,021 ft so not a problem. On the other hand it took me a while to adjust when i was walking around doing things up there. :) Ran into the same thing when we moved from sea level to 6000 ft. Took awhile before the dog and i got used to it when hiking.....the second time we did that move i was a little smarter and took a couple of months to adjust before getting into any strenuous projects or hiking. ;)
In the mid 80s we backpacked 1/2 of the john muir trail. Went in at Bishop and 13 days later made the assent to Mt Whitney. The dissent from Whitney landed us at a pizza & beer joint in Lone Pine. When we were walking from the parking to the front door we felt super human floating across the ground - no we weren't high or drunk...
Yet. Lol
I don't remember all the details but the story goes a construction company from out of state bid a dam job at timberline and lost his A when the equipment would only get about 70% of the work done compared to work on the flat land
Wayne
All the later equipment had altitude compensating turbos over 10,000 ft you get your checkbook out BTDT