Jetting Recommendations 5200' 250 GTE

[Zanny1]

This is my 1st post on this website. I recently acquired a 1962 Series 2 GTE, sn 3177. The car was test driven in Houston, Texas on a hot humid day and performed perfectly. I was really surprised how user friendly these cars are (this will be my 9th Ferrari over a 25 year time frame). My last Ferrari was a 365 GTC/4, which I owned for 12 years.

Thanks to Monterey, the car will not be delivered to my residence in Prescott, Arizona until mid-late August. Elevation here is 5200', and obviously in Houston it is sea level. Does anyone on this site have experience in jetting the Weber 40 DCL for higher elevation? I will drive the car when it arrives and check the plugs..... hopefully fouling doesn't occur.

Finally, a search revealed that Bill and Joan Preston had ownership for the GTE registry 12 years ago. They apparently lived in Prescott. If anyone has a contact number here in Prescott, please PM me. A fellow 250 owner in this area would be an invaluable source of information.

Looking forward to participating and contributing to this fine website.
Mike

[DWR46]

Zanny: Start by going two sizes leaner than stock on the Main jets. That usually worked for the Colorado Grand event. Monitor the plugs and you will be fine.

[Zanny1]

Thanks for the reply, DWR.
What's the elevation at the Colorado grand event?
More important, do I risk an overly lean condition if I drive the car to Phoenix (which is at sea level)?

[Tom Wilson]

Welcome and glad to meet a new owner! I will send you Bill Prestons contact information and give you an update on the register. Looking forward to hearing about your adventures with the GTE.

[DWR46]

Zanny: If you intend to use the car throughout Arizona, try just one step leaner. Generally, on the dyno, we find the original factory settings too rich, especially on the top end. In the day, Ferrari was correctly concerned about burning pistons during sustained high speed running, so they added extra fuel. It was not actually needed, but kept warranty repairs down. Manufacturers still do this today and one of the most common "chip" changes is to lean out the high rpm running on today's engines. Denver is about 5,000 feet and the Grand goes up to about 10,000 feet.

[Jumprun]

I can't say about Ferrari but many vintage cars need the accelerator pump volume reduced under high hot conditions. The symptom are a stumble and cough when moving off from a stop.