What happens when a carbed car makes an upward elevation change of about 3000 feet? Does it go rich or lean? Can it damage the engine?

um, I'm guessing it might get leaner, but the air is less dense too, so it prolly just reduces performance. I don't think it would damage anything.

As you change altitude, the air becomes less dense. This results in more fuel with less air which equals a rich mixture.

This assumes you tuned the carbs at a lower altitude.

Go high enough, you could foul your plugs.

Now if you tune for high altitude and you go to sea level you will run way lean and possibly burn a few things up.

It goes rich. less air + same amount of fuel=more unburned fuel after combustion



Ferg

Edit: Gumby beat me to it...

Gets fatter...... less oxygen at elevation. Same amount of fuel.

NOTE: In reality. There is a bit less exhaust back pressure as you increase in altitude. Which helps to slight;y even out the fat condition.

C

Yes... it's tuned for my lower elevation.

I just don't want to harm the engine.

So is 3000-3500 feet enough to do any harm?

And I'm not cruising around up there. Just going to GF's house and back.

3K feet is fine for short lengths of time... worst case you foul a plug or 2, no biggy.

BJH

You will be fine.

I bought my car last year in Portland, It's now living at 5500 feet, and I have not touched the carbs yet, I know I'm running rich, but not enough to foul plugs or make it run horrible.



Ferg

less dense air should pull less fuel through the venturi though. Thats why I phrased my answer the way I did.....

it's exactly what ron said: air density. a/d is effected by pressure, altitude, temperature, and to some extent, humidity. jet to your local conditions.

but don't worry about 3000 feet.

Oh Mah Gawd Ferg ..... how can you possibly stand the soot in your exhaust pipe. It's gonna come out, soil the chrome on your back bumper and deposit on the paint.

Dude,

914s have been traversing elevations since the beginning of their manufacturing. In Europe... Even more than here.

Think about it.... ALL cars were carbed for the first 80 years of manufaturing.

And all L-Jet, D-Jet, and any FI system has been at every elevation possible.... With no harm to an engine.

And I have never heard that you shouldn't take a car into the mountains because you will hurt your engine....


The flip side of this is... If you have a carbed engine that has been setup for ragged edge performance. And it was setup in a high elevation. THEN you drop down to a much lower elevation. And you hammer it.... You could hurt the engine from running lean.

I say go beat the hell out of it and have fun.

And send us pics of your girlfriend.

Your Favorite Voyeur

Twystd1

thanks....
Looks like I'm good

we'll decide if you're good or not... Based on the afformentioned pics

BJH