High Elevation 4 wheeling 10'000-13'000 above sea level

I was interested in knowing the limitations of a CJ5. Would I run into trouble if i took my CJ5 to high? Wasn't sure if theres something special I need to do to it in order to not run into any problems and get stranded. It runs using a new Chevy 4 bolt 350 engine.

Thanks

 

I din't notice any real difference in performance up to 9000'. That's the highest trail I've been on. However, I live at 6000 and my engine is tuned to that elevation. If you live at a low elevation and run trails as high as you mentioned, I'm sure you'd see a difference.

 

I live at 6600 ft we tune em at this level, it's only 20 minutes from my front door and I can be at 8000 ft. As we start going up we have to stop and adjust the carb here and there, also doing it on the way back down. Still fight the off camber/incline issues no resolve to that.

 

The air gets less dense as altitude increases, so ideally you'll want to adjust the mixture to compensate. Fuel injection does that automatically, but a carburetor needs different main jets to change the mixture. Not something you can do so easily.

You'll get less power at altitude, regardless of whether the mixture is ideally set or not.

If you have a carburetor and an automatic choke, you may need to hold it open to get the engine to start when cold.

 

I just change the jets when going to Colorado, never had to retinker with the carb after that, no problems.
if it's a little sluggish, you can always advance the timing 5* or so.
I did not change them when I wheeled with Patrick 2 years ago and had no issues at his elevation

 

If change in altitude is a significant problem for you, many (all?) Motorcraft 2150s 2V carbs are equipped with an altitude compensator. The 2150 is the evolution of the well-known 2100, and will work on any application a 2100 will.

 

My daily driver is a 81 Cherokee with 360 and 2 barrel motorcraft carb as mentioned by timgr above.it has the " Altitude Compensating Aneroid Barometer " and a Two Stage power valve that is calibrated for use above 4500 feet, I have altitude variations from 2000 to 8000+ here and it works great, Some research into what options were available for high altitude use on your carb model may pay off. Best of luck to you.

 

I had loading up problems at higher alttitudes. (I'm running a V-6 with a Quadra Jet 4bbl carb.) I had to change jets to a smaller size. Now I don't have any problems.

 

I think Im going to go with one of those fi kits. I don't want to have to fiddle with jets and stuff if I run into any issues up there.

 

From the Solex experience w/ the BMW's I have had, decrease the jet size about 0.01" dia for every 1000ft in elevation change. Solex did have an altitude compensation device in some carbs, but they were prone to failure, and basically limited the fuel delivery to the main jet circuit. I am running a Solex on the F134, (yes it IS non-stock) and after tweaking the jets, does seem to run quite well. I'll live with the increased richness on the trail (when Melvin actually leaves the garage...)
JonVO