I think you shouldn't have to go below 54 for sure
Carburetor Jets 4000 ft. elevation
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Carburetor Jets 4000 ft. elevation
I have a motorcraft 2150 carb... moved it up to El Paso (4000 ft. elevation) from San Antonio (~500 ft. elevation)...
What size of jets do I need to accommodate the difference in elevation? I don't know what it has currently, though I rebuilt the carb I put the original jets back in. Truck is running well, actually, but does seem like it could be leaned up a bit.
What size of jets do I need to accommodate the difference in elevation? I don't know what it has currently, though I rebuilt the carb I put the original jets back in. Truck is running well, actually, but does seem like it could be leaned up a bit.
Rabbit-Hole Researcher
Joined: Feb 2004
Posts: 466
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From: Middle of Ohio
Li'tl leaner
Leaner with altitude: Oh, you might try going two numbers smaller, like 56F down to 54F. Also, you may reset your idle mixture.
But not as much as you'd think: With the added altitude, you will get colder temperatures, thus a denser oxygen charge. You might seasonally richen the mixture just a tad for winter. This might not be the time to lean it out much, heading into the Holidays. It will be 47 in El Paso tomorrow.
A little more ignition advance is common at higher altitudes. Maybe 2 or 3 degrees more. Not if you will pull a trailer or heavy load, though. Now you are in the hilly country!
Make sure your heat stove and pipe are in place and working correctly.
You can go a tick richer on the choke housing. This will give you a few moments more fast idle, and prevent a few chilly-morning stalls.
My $0.02,
Kevin
But not as much as you'd think: With the added altitude, you will get colder temperatures, thus a denser oxygen charge. You might seasonally richen the mixture just a tad for winter. This might not be the time to lean it out much, heading into the Holidays. It will be 47 in El Paso tomorrow.
A little more ignition advance is common at higher altitudes. Maybe 2 or 3 degrees more. Not if you will pull a trailer or heavy load, though. Now you are in the hilly country!
Make sure your heat stove and pipe are in place and working correctly.
You can go a tick richer on the choke housing. This will give you a few moments more fast idle, and prevent a few chilly-morning stalls.
My $0.02,
Kevin
Last edited by 1972-34ton; Dec 9, 2011 at 09:26 PM. Reason: Snarky comments from those who didn't read it carefully.
Hotshot
Joined: Apr 2009
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From: Stanley, VA
You lose aprox. 2 1/2% power for every 1000 ft of elevation because of the lower density and less oxygen.
This is also the reason why you can run higher compression and more advance, the cylinder pressure is lower.
Even at ~4000 ft altitude, El Paso ain't that cool. Just went through a couple of weeks ago...not very cool.
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I would def. classify El Paso as generally, "not cool"... temperature wise. I was referring to the thinner oxygen concentration specifically. Truck seems to run fine, and haven't noticed any lack of power (though I haven't driven this truck before the engine swap etc.) and no black smoke. Timing is advanced slightly and the truck idles fine.
I've just been told the standard is to rejet the carb with that change in altitude... Thanks for the advice!
I've just been told the standard is to rejet the carb with that change in altitude... Thanks for the advice!
Cross-Country
Joined: Dec 2010
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From: El Paso
Hey there XLT I'm here in El Paso too, for a while now. Glad to see ya bout the place. Not really sure where you can go to get the jets round here, but I'll shoot you the info when I can find out. I hafta go looking for adj screw on my 2100 since someone filed down the tips on both needles.
Cross-Country
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From: El Paso
Wow just got a look at the date on this line. How did this get here so far down the line with no new thread?
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Cross-Country
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Depending on which 1975/79 2150 series carb it is (there are 10 possibiles!), the jets could be 0-10,000 ft. (#54F) / 0-5,000 ft / 5,000-10,000 ft. / 10,000 to 15,000 ft.
I looked thru the myriad 2150 carb parts lists yesterday for jets for a member moving from N'awlins to Colorado Springs.
These jets are not specific to the 2150, were also used in the 2100 series, and in 1-6 Auto-Lite/Motorcraft 1V carbs.
I looked thru the myriad 2150 carb parts lists yesterday for jets for a member moving from N'awlins to Colorado Springs.
These jets are not specific to the 2150, were also used in the 2100 series, and in 1-6 Auto-Lite/Motorcraft 1V carbs.
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Thanks, NumberDummy.... that gives me an idea... It doesn't seem to be running terribly rich, but as I said, I would surely like to have the correct ones in there.
Dulock... what side of town are you on?
Dulock... what side of town are you on?
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