Fiat DINO Weber 40DCNF12 stock jetting

Tech chat w/ Marc Matzer
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Joined: Tue Mar 21, 2006 1:15 pm

Fiat DINO Weber 40DCNF12 stock jetting

Post by Marc » Sun Jan 06, 2008 8:07 am

Main Venturi 32mm
Aux Venturis 4.5
Main jets 125
Emulsion tubes F24
Air Corectors 220
Idle Jet 50
Pump jet 45
Float valve 1.75
Choke Manual

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Location: Casper, WY


Post by fasterfiat » Fri Apr 17, 2009 11:14 am

I have an alquatti intake with two 40 dcnf carbs. Can you tell me a little more about the carbs? What were they originally intended for?
Robert Hall
68 Fiat Spider
76 Fiat Spider LT-1 Still blue
78 Fiat Spider redone in candy apple red
01 Chevy Crew Cab
Lot's of fiat parts:-)

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Post by Marc » Mon Apr 20, 2009 9:38 am

DCNF series carbs were inteneded for use on engines in a v configuration,where the float bowl faces the front of the car.I have an alquati intake and dcnf set as well.Took them off the car long ago.They will not work correctly on a spider,since the floats sit sideways,you will get surge and leaness depending on which way you turn,as well as richness on a straightaway because the float lifts on acceleration.They work well on transverse mounted engines,x1/9's etc.They were sold by some vendors I believe who didn't realize the problems associated with them.Idf's are the only kind that will work on your spider.Other problems with the dcnf's are the no# 4 mixture screw will hit the mastr vac unit when the engine is revved hard,you will have to build your self a linkage that will pull them open all the way,the bell crank stock system won't work on these as well.So if you figure a way to solve that,the carbs won't run correctly anyway.The F in DCNF stands for Ferrari,DCNL, L stands for Lamborgini.

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