Altitude Problems?

[z boy mn]

Hey everyone! I purchased my first Z (a 1972 240) last week and am having some issues with shipping. I have a few days vacation coming up and if they still can't find a driver I'm thinking of going out to pick it up and drive it home. BUT, it's in Denver...at 5200 feet above sea level, and has been jetted and tuned for that altitude. I'd be driving it to MN (which is at 1400 feet above sea level). The seller mentioned early on that it would probably need to be re-tuned and re-jetted once it gets here as it's a very rich set-up...but...if I drive it here, will I hurt anything? I'm worried about burning up parts on the newly overhauled engine!

Any thoughts or suggestions would be appreciated!

[Healey Z]

Z boy. These SU carbs are pretty simple. You will likely need to richen your mixture. You can do that by turning the knob at the bottom of the carb clockwise (looking down on it). I would first see how it runs, and adjust both a quarter turn at a time. My car let me know when it was running too lean; it would stumble at constant speed.

Edited March 5, 2012 by Healey Z

[Bruce Palmer]

As you reach lower altitude it'll start popping thru the carbs. That lean. Like has been stated just drop the nozzles like a half turn per and you decend. the carbs will let you know when they are happy. You start blowing black smoke your fat. take the nozzle back up a tick.

When you get 'em home pull them off and see if they are our carbs. There will be an inscrition on the butterfly saying they are our carbs. If so we can maybe help determing if they have undersize noozles installed for the hogher altitude.

[z boy mn]

Thank you everyone for your suggestions...but...I am clearly a Z virgin as I forgot to mention that the carbs are dual webers DVG 32/36's. I don't know which jets are in them now, but I'm guessing I'll have to replace them when I get it to MN. They operate with the same principle, though, yes?

P.S. Anyone know how to make my profile picture show up next to my name? I thought it was a size thing so I used a smaller image, but I still am the anonymous "grey" person.

Edited March 5, 2012 by z boy mn

[Bruce Palmer]

Well then that shows, in large part, the workaday differences between Hitachis and what you have. With Hitachis you could have made things right without even removing the air cleaner.

Not lambasting webers, they are what they are, but it would be interesting to hear what you end up having to spend to get them right once you get them home....

[LeonV]

Thank you everyone for your suggestions...but...I am clearly a Z virgin as I forgot to mention that the carbs are dual webers DVG 32/36's. I don't know which jets are in them now, but I'm guessing I'll have to replace them when I get it to MN. They operate with the same principle, though, yes?

P.S. Anyone know how to make my profile picture show up next to my name? I thought it was a size thing so I used a smaller image, but I still am the anonymous "grey" person.

DGVs and SUs are both carbs, but that's just about where the similarities end. They operate with different principles. The SU is a variable venturi carb with just one jet, or circuit, to work with and uses a tapered needle within a moving piston to meter fuel correctly. The DGV is a fixed venturi, air-bleed carburetor and uses multiple jets/circuits to meter fuel.

With that said, if they are currently jetted rich as the current owner postulates, then they may work fine at your altitude. In order to really tune the carbs, a wideband O2 sensor and gauge are highly recommended. Otherwise, you're just guessing and getting within the ballpark of where you want to be.

Edited March 5, 2012 by LeonV

[Arne]

P.S. Anyone know how to make my profile picture show up next to my name? I thought it was a size thing so I used a smaller image, but I still am the anonymous "grey" person.

The image next to your user name is your avatar, not the profile picture. Look for the avatar in your profile settings.

[Willoughby Z]

...P.S. Anyone know how to make my profile picture show up next to my name? I thought it was a size thing so I used a smaller image, but I still am the anonymous "grey" person.

Top of the page> Settings> My Settings> Avatar>Custom avatar> Browse

150x150 pixels or 488kb (whichever is smaller)

Assuming you found all that?

[z boy mn]

I (think) I have my avatar up, and I can't wait to learn how to play with the Webers. I've seen the jet kits, and I have a friend who's willing to help me tune them.

I spoke to a technician at Redline (http://www.redlineweber.com/) and when I get the car I'm going to find out if the jets are stock or not. If not, I'll order the stock ones and go from there. Or...should I just order a complete kit? The seller thought he used the original jets that came with them, so with any luck I won't need new ones...it will just be about adjusting the ones I have.

Anyway...VERY excited for Wednesday--VROOOOOOM!

[LeonV]

There isn't really a "stock" with the DGVs since they never came on the car, but were an aftermarket bolt-on. IMO, I wouldn't spend any money or even much time on them, I would either get round-tops or triples. Downdrafts don't make much sense on an inline engine.

Good luck and enjoy the drive!

[5thhorsemann]

There isn't really a "stock" with the DGVs since they never came on the car, but were an aftermarket bolt-on. IMO, I wouldn't spend any money or even much time on them, I would either get round-tops or triples. Downdrafts don't make much sense on an inline engine.

Good luck and enjoy the drive!

Yea, go with the round tops unless the engine has been really modified.

[sblake01]

Well then that shows, in large part, the workaday differences between Hitachis and what you have. With Hitachis you could have made things right without even removing the air cleaner.

Not lambasting webers, they are what they are, but it would be interesting to hear what you end up having to spend to get them right once you get them home....

If you have someone who knows Webers, the cost of setting them up properly would be less than a 'new' set of SUs.