42 DCNF on a Beta Coupe volumex

[monte]

I am finding it particularly difficult to get the standard 36DCA carb set up properly on the VX , the jettings seems ok but even with the factory instructions its proving imposable to adjust as per the instructions , as if parts of the auto choke have been replaced in the past with incorrect items ?
I am considering the 42 DCMF primarily because I have one , wonder is this a good choice ?
Whether I go with the 42 or perhaps a 40 I would welcome any advice on jetting and set up etc.
Thanks
Tom

[WestonE]

You will hate this, but just take the working car and both carbs to a rolling road experienced with Carbs like Northampton Motorsport and let them set it up. This will save hours of buying the wrong jets only to change them later.
Choose which ever DCNF is in the best condition. If you can and have the skill refurbish both with re-build kits it will increase there value and your options.

Unless you have changed both cams for IE items and fitted the smaller VX pulley favour the 40DNCF.

Change the fuel system for a Facet Silvertop competition or Red Top with a filterking and blanked return. Fit a filter before the Facet Pump and remove the manifold heating and electro valves. Add a heat resistant base gasket under the carb to reduce hot evaporation.

Clad the metal can air filter case underside with heat resistant material if you really insist on keeping it. Better run a heat resistant pipe (Grain silo hose is good) to a K&N Cone filter somewhere receiving cold air.

Finally make sure you have a great linkage that will connect well to the DCNF and move it precisely to fully open 

In OE Form the VX is a carb engine running an FI Pump with no pre filter from tanks now famous for pump killing crud. Worse the air going to the carb is pre-heated in the metal air filter box and heated air steals power and risks detonation. Keeping the carb isolated from the heat of the no longer water heated manifold stops fuel evaporation.

If you make these changes with a pair of Beta 2000 IE cam fitted you will have a much quicker car.

Or just randomly try jets for weeks before finally booking into the Rolling Road who already have them and the tools to test the car through the full range.

Eric     

[monte]

Thanks Eric, for your quick response, indeed you have given a lot to ponder, it clearly not just replace the DCA with a DCNF and all is well , indeed I can see the logic of what you propose as I have not been convinced the carburetor and the set adopted was ideal and seemed to be a series of compromises to fix one problem after the other,
Thanks Eric
Tom