Generators used in high altitudes

[rving4us]

Does anyone know if the Champion Inverter generators will run in the Canadian Rockies and Alaska? Will be there this summer and will need ti use a generator at times.
Thanks

[pianotuna]

Hi Boon Docker,

I drive 48 mph and on the flat I get an honest 11 mpg US. If I drive 50, it costs me 1 mpg.

I do have air tabs, but they appear to just make the inside of the RV a lot quieter regarding wind noise. If I'm able to follow a big truck or have a tail wind then the air tabs appear to make a difference in mileage.

I do have taller than OEM tires because I wanted to improve weight capacity. The OEM driver's rear was right on the edge of the capacity so when they aged out I moved up. To do so required buying seven new rims.

[MEXICOWANDERER]

Living at 9,000 ft, I tuned an around-town service truck to run as best it could.

Like my LPG pickup it took 12.5 - 1 pistons, a Crower Camshaft with high lift rather short duration and little overlap. one and one half degrees ********. A modified HEI distributor, with 30 degrees mechanical advance and fourteen initial. I hate Holley carburetors, but I used a 390 CFM, re-jetted and with 4.5 power valve. Simply rejetting the original engine didn't do snot except gain a tiny fraction of gas mileage. The truck hauled a 6-7 Detroit prime mover and 60 Kw Lima generator and a filled 260 gallon diesel tank to 11,200 feet without complaint. The cooling system was filled and the engine had 6 gallons of oil in it. I did not dare take the truck to <4K ft altitude. I sold it, as a matter of fact, in Mammoth, to a local "rancher" as a farm utility truck.


*********censored. Oops I meant to write the camshaft as being installed timed at mentally developed challenged one and a half degrees. Ever play in Reno or Vegas at a "Mentally Developed Challenged" table? Whatever you do don't bet on "The Field"

As an FAA PMA my experiences occurred on the ground. I heard so many different pilot "opinions" about "tweaking" fuel mixtures I grew deaf to comments. I specialized in Continental and Lycoming electrical, engine starter motors, alternators, and OVL systems.

Re-jetting a low compression engine for high altitude is about as worthwhile as polishing the finish for better mileage. It just wasn't worth it not even close. I did shave the cylinder heads on a Witte diesel about .200" to raise compression at 9,800 ft and that worked -way- better than throwing a new pill in the injector system to lean it out. Sticking a turbo on works best.

If it won't work, buy a bigger gen or a brand known to work at the altitude you camp at, is my recommendation.

[Boon_Docker]

pianotuna wrote:
Well, I do often refer to my class C as a "flying brick", when it comes to fuel economy.

Boon Docker wrote:
Now pay attention OP, never use an under powered generator when flying over the Rockies. :B

I'm curious, what average mpg do you get with your motorhome.

[pianotuna]

Well, I do often refer to my class C as a "flying brick", when it comes to fuel economy.

Boon Docker wrote:
Now pay attention OP, never use an under powered generator when flying over the Rockies. :B

[Boon_Docker]

Now pay attention OP, never use an under powered generator when flying over the Rockies. :B

[NinerBikes]

Chum lee wrote:
Road runner wrote: "I didn't mean to say that one could get MSL power at altitude by leaning the mixture. I do feel like the amount of power gained with leaning the mixture is more than small. Taking off from Denver in a loaded 172 with the mixture full rich will leave you sweating bullets as the runway end approaches and you're still on the ground."

If I recall correctly, the Pilots Operating Handbooks I have read say not to take off full rich above +- 5000' MSL. Instead lean for best power on run up.

I hear ya about Denver. Try doing the same thing at Mamouth Lakes, CA on a hot day! Density altitudes are often over 11,000 feet in summer. I believe the field elevation is over 7000' MSL

Chum lee

Mammoth Lakes. 85 F on a July day is pretty thin air up there.Airport

Back to generators... the Honda EU7000i is fuel injected, not carbureted... self compensating for elevation, but a bit big for camping.

[Chum_lee]

Road runner wrote: "I didn't mean to say that one could get MSL power at altitude by leaning the mixture. I do feel like the amount of power gained with leaning the mixture is more than small. Taking off from Denver in a loaded 172 with the mixture full rich will leave you sweating bullets as the runway end approaches and you're still on the ground."

If I recall correctly, the Pilots Operating Handbooks I have read say not to take off full rich above +- 5000' MSL. Instead lean for best power on run up.

I hear ya about Denver. Try doing the same thing at Mamouth Lakes, CA on a hot day! Density altitudes are often over 11,000 feet in summer. I believe the field elevation is over 7000' MSL

Chum lee

[SkiSmuggs]

rving4us wrote:
Thanks everyone, I have a 3500/4000 champion,but it is a little loud. What every I decide it will not be used much Just will be staying in a couple rv parks with no power and I use a CPAP machine. Don't think the batteries will last running it.
Thanks again.

Most CPAPs run at 12V with the power brick converting from 110v. I ordered 12v cables for both my CPAPs and they use very little battery during the night running direct from a 12v outlet instead of having the overhead of an inverter. Installed a 12 receptacle on my head board using the reading light wires.
Also, there are high altitude jets for the Yamaha M80 engine.

[joshuajim]

Licensed pilot here too. Leaning the powerplant at altitude DOES NOT increase power, it reduces power loss due to incorrest stoichiometric ratio.

[road-runner]

CJW8 wrote:

I am a licensed pilot and have worked on small engines all my life. When a pilot leans the mixture as he gains altitude, he only gains a small but noticeable amount of power because he is getting the mixture right for the altitude. That power will still be less than he would have at a lower altitude with the proper mixture.

I didn't mean to say that one could get MSL power at altitude by leaning the mixture. I do feel like the amount of power gained with leaning the mixture is more than small. Taking off from Denver in a loaded 172 with the mixture full rich will leave you sweating bullets as the runway end approaches and you're still on the ground.

[Kayteg1]

Well... I drove my 32' Bounder with old carburated engine over 12,000' without any modification.
Sure on curvy mountain roads I did not use full power.
They were no boat engine modifications available at Lake Tahoe neither.

[Chum_lee]

All good points above. I am a licensed pilot too and have worked on many different engines with carburetors and/or fuel injection for years. We are a little off topic, but the purpose for running an engine rich at high power settings (like on take off in an airplane or at maximum load in a generator) is to reduce cylinder head, exhaust valve, and exhaust gas temperatures. It also cools the intake charge when the excess fuel evaporates (but does not burn because of lack of oxygen) reducing the possibility for detonation. It can eventually foul spark plugs, build combustion chamber deposits, and, dilute the engine oil with fuel if done too often and for too long. It also slightly slows the flame speed in the combustion chamber.

To be clear to the originals posters question, yes, you could tune most generators to operate at altitude, but, don't expect them to perform at the specifications the manufacturers publish for operation at sea level and standard conditions. (29.92 inches Hg, 59 degrees F, and low humidity)

Chum lee

[JiminDenver]

I am a RC pilot and if I were to take one of my planes tuned at 5000 ft and try to fly it at 10,000 ft, it wouldn't run worth a dang. The adjustment isn't much, the advantage is huge. You would be surprised how much more power you have to hang on the front to get the same as you would at sea level.

Also running a generator rich will foul the plug and clog the spark arrestor faster. Champions high altitude jet is only good for 3000 ft unless they changed something.

I live high altitude, I camp twice that. Been there, done that. 😉

[loggenrock]

OK, the Rockies I can understand... A LOT of where we visited in AK is at sea level, so no issue there...! ST

[CJW8]

road-runner wrote:

Jetting just trims the fuel to match the lower volume of available air at higher altitude. It will not gain you any power unless it is running so rich it will not run well. In that case, jetting will only get you to the point that Chum Lee mentions above.

I think anybody who flies a gasoline powered airplane will disagree with this statement. The rich mixture engine runs smoothly at high altitudes, and has a very noticeable power increase when the mixture is leaned out. As would be expected, fuel consumption also goes down.

I am a licensed pilot and have worked on small engines all my life. When a pilot leans the mixture as he gains altitude, he only gains a small but noticeable amount of power because he is getting the mixture right for the altitude. That power will still be less than he would have at a lower altitude with the proper mixture.