32/36 DFEV conversion

[Johnny2dogs]

32/36 DFEV purchased on line (saved about $100) A few questions. 71 spider 1600cc eng Stock intake (going soon to headers)Do I need to drill and tap for the bowl over flow ? and what to do with the emission routings ?

[So Cal Mark]

the carbs don't have an overflow, emission carbs had a vent for vapors only that was routed to the evap cannister. Unless you have emission testing, don't worry about it. Cap any other emission ports and do without it

[mbouse]

yeah, if you have to meet emission testing then that carb won't help you.

also, you may wanna check into idle jetting. that carb may have too big of jets for your engine.

[bradartigue]

You bought a good carburetor for your motor! The DFEV is similar in most respects to the DHSA stock 1608 carburetor you replaced. What I'm writing here applies to *most* DFEVs bought from Weber distributors:

- The linkage is not set up for your FIAT. If you have the black "finger" thing on the carb throttle linkage then you can do one of a few things: (1) remove it, cut the "fingers" off, leaving the hole for the choke rod and take the ball lever from your DHSA and mount it in front of the black piece. This allows you to just hook up the carb and go. (2) buy the lever with the ball from Pierce Manifolds, it has the hole for the choke and you simply replace the black thingy. Either way you need to have that choke rod hooked up.

- The main idle jet may be too big. It most likely needs to be a 45 and is likely a 50. When you initially tune the carburetor if you cannot get it to idle without being rich then go down to a 45 on the main idle jet only.

I have complete tuning instructions online: http://www.artigue.com/fiat it is the first book (90+ pages of fun).

Now, here are the other things you need to know:

- The fuel return needs to be blocked off. It is the tube that points up near the driver's side firewall just under the master cylinder. You do not use it with a DFEV. If you have a strong desire to use fuel return then you can buy fuel filters with three ports and hook the smallest one to the return port. Fuel return prevents vapor lock but is otherwise useless.

- 1608 ran the charcoal can into the intake manifold, not the carb, so there are no changes there.

- The vacuum for the fast idle solenoid and the solenoid itself can be removed. The +12V lead from the solenoid can be used to run the electric choke on the DFEV.

Have fun

Brad

[chrisg]

if you haven't also planned on doing so, you should, if possible, change the intake manifold to the '74 1800 style...or, at the very least make sure you aren't routing a 32mm throat into a 28mm hole.

also, I just did the same conversion on a '71 1608 car & concur w/ Brad & others that it's a great setup/improvement. I lightened the main idle jet & jetted the secondary circuit almost like the original DHSA carb was jetted (155 main/150 air, if I recall...but I'm not at home nor do I have notes).....it appears to be spot on for my particular setup.

[dirkdantuma]

I'm also going to do a conversion to the DFEV from my 32/36 ADFA on my 75 Spider. The bottom mounting plate is much thinner on the DFEV than on original so the threads on the bolts don't go far enough. Do I just use spacer on the bolts or do I need some sort of spacer on the bottom of the carb?
Thanks folks!
Dirk

[So Cal Mark]

performance-wise, you're better off to put a spacer under the carb

[HOLLYWOODSPIDER]

I've got this same carb on a '78 1800. I bought it used, and have some questions.

1. Should I be able to see large drops of gas coming out of the main venturi?

2. What are appropriate main and secondary jet sizes? I have stock engine and exhaust.

I have 45, 50 and 60 jets to fiddle with. When I run 45 main/50 secondary, the car idles alright, but there is no accelleration, before or after the secondary opens.

When I run 50 main/45 secondary, I get great accelleration, but it idles terribly, and I can see gas dripping out of the main venturi. Lots. And I'm getting violent backfiring.

When I run 60 main/45 secondary, it idles really smooth, but won't come down below 1800rpm, even with the mixture screw fully seated. Accelleration is great.


Any ideas or recommendations?

Also, I have to get california smogged soon. Is it going to be possible with this carb?

[So Cal Mark]

just as important is the low speed jet. You'll be running on the low speed jet up to about 3500rpm. You should only see fuel from the main discharge nozzle when the throttle is open. Jet size won't affect that, but float level and idle speed will.
To pass the smog check, you're going to have to make it look like the evap cannister is connected as well as all of the other emission equipment

[HOLLYWOODSPIDER]

What and where is the low speed jet?

[So Cal Mark]

just above and over from the accel pump cover, where the idle cutoff solenoid was on your old carb

[HOLLYWOODSPIDER]

That's the one I have been calling the Main jet.

Now I'm at 45 Main/60 Secondary. Does that seem appropriate?

I adjusted the float level a whole lot, and it seems to be idling smoothly with no backfiring. However, in the process I seem to have lost the size 50 jet.

[thechadzone]

I recently installed a 32/36 DFAV carb onto the 1.8 manifold & head that are installed on a two liter block. I've been told that the increase in compression that the 1.8 top end does on the 2.0 engine allows that engine to make better use of the larger secondary barrel. I'd like to see some numbers regarding how much the head and manifold swaps improve the two liter.

The A designation on the DFAV is the electric choke that replaced my car's manual choke. I'm told that this is the only difference between the DFEV and DFAV. I wired the choke to the coil, and it opens & closes the carbs very well. I was using some kind of 32mm factory carb before, and I was blown away by the differences that the carb made. I don't miss using the manual choke.

This combination of parts with an Empi air cleaner, and a new Monza exhaust (minus its resonator) has a nice growling sound that creates big smiles during deceleration from the tops of the gears. The new carb sounds deeper than the old one above 4 grand on the tach. I've been driving the s**t out of it lately around the lake to the local yacht club, and it tops 100MPH with impressive grace. Not bad for a carb that I stole from my older brother's '7o's Volkswagen bus...

I just won an eBay.it auction for an original dual carb intake (the Chromodora "waffle top" piece) complete with original Solex 40 P11 carbs that were said to be in "ottimo stato" in the auction. 140 Euros translated to something like 180 dollars before shipping. Thank you all for not bidding... I'll miss my DFAV carb, and I may give it back to my bro!