Help with Weber Carb

[Kevin Marsh]

I could use some suggestions for tuning a Weber 32/36 DGV carb to run at 4500 feet.
Some preliminary information on the engine; .060 overbore, Burlington counterbalanced crank with insert main bearings and insert connecting rods.Snyder 6:1 head, milled .025 because it had a twist so now perhaps 6.5:1?I am running an Otwell Health Heater (it was on the car when I drove it in High School in 1972), with an Aries exhaust system.I chose the Weber after reading all the positive posts with others using a similar engine configuration.
It came with the following settings: Idle Jets Primary, 55, Secondary 50. Main Jets Primary, 135, Secondary 140.Air Jets Primary 160, Secondary 165/
After completing the car last fall, I trailered it to my daughter’s home if Florida to visit them before they moved to Bahrain for two years. At sea level it ran beautifully. Now with the snow gone and warmer weather I am struggling at my altitude.I have been able to adjust the idle as configured, but the car runs rich and it hesitates under acceleration from 1500 to 1900 RPM and has terrible fuel mileage.
I have replaced the Primary Main Jet from 135 to 130, and the Primary Air jet from 160 to 170 with slight improvement. At the same time I purchased the Jets, I purchased a DVD from Pierce Manifolds to learn the tuning tricks and after watching it several times I have concluded that there is much more involved than swapping out the jets on a trial an error basis.With accelerator pump jets and emulsion tubes the combinations seem overwhelming.
To hopefully save some money on jets and the time needed to experiment with the numerous combinations, I am hoping someone here may have suggestions from their experiences tuning Webers for higher altitudes.
Any help is appreciated before I swap it all out for the Zenith….

[denis4x4]

Just finished the installation of a Weber on an engine very similar to yours. My house is at 6703' and just took it out of the box and adjusted the idle! I would talk to the people at Redline and also Steve Becker at Bert's Model A in Denver. Hardest part of my installation was getting the linkage working correctly so the secondary opened. Too, I'm running an electric fuel pump with 1.5 PSI. Also using a K&N filter off a 97 with the Redline adapter. Send me a PM with your email and I'll send some photos.

[Durango]

Are the spark plugs and the tail pipe black and sooty? If so make sure the fuel pressure is no higher than 3 1/2 pounds.
Larry

[V4F]

just call weber . very friendly & helpful .

[Benson]

My first thought, having used carburetored, 1960's electronic Fuel injected and CIS Fuel injected engines of various types for over 600,000 miles at altitudes from sea level and 9000 feet and as high as 14,000 feet, would be to start with the original jets.

One or two jet sizes makes big difference.

Additional info: Model A Zenith jets are all same for low or high altitude. Except for the main jet which is one thousands smaller.

The GAV allows for most of the adjustment for altitude changes

I think your problem is most likely the heat range of the spark plugs and as a result, the length of your trips.

When I lived 25 miles from town the Champion C16C (in 1979 Champion replaced these with W16Y) worked just fine. This trip was from 8000 feet down to 5000 feet.

Now I live in town and most trips are under 10 miles. Now the W16y plugs are too cold and foul out easily.

Autolite 3076 worked great before move ... I switched to 3077. (Note can not find 3077 now)

W18s work much better and stay clean.


I used to have a listing of Weber jet sizes as shipped but have misplaced it

[Juggler]

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You could try Sammy at Arizona Model A. He makes he Weber kit

480 782 0266