upgrade progression options for a stock 75

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valkyrcustoms
Posts: 63
Joined: Wed Aug 28, 2013 10:56 pm
Your car is a: 1975 Fiat 124 spider
Location: Austin, TX

upgrade progression options for a stock 75

Post by valkyrcustoms »

Ok, so I've searched through the forum and seen upgrades for the 2l engines and some 1.8 going to dual idf's and what not but that's not really what I'm looking for. I currently have a Stock 1975 with the 1.8l that has experienced terminal carb problems. Rather than look for an original replacement, I would like to upgrade the carb to something that has an electric choke and better performance.Now, this is just the first step in upgrades i would like to do to the engine, so I would like a carb that I can "grow into," so to speak. I have removed all the smog equipment and plugged the extra holes and have converted to electronic ignition (for more reliable starts here in the humid hill country). I have seen the 32/36 (DFEV???) but am wondering if this is my only or best option. In the future I would like to upgrade the exhaust, maybe some cams and higher compression pistons and would like to not have to get another bigger carb when i do those upgrades. I'd like to drive this car as often as I can, not my only car but would love to have it as a daily if possible. So ease of maintenance and reliability are key issues. I don't want an all out performance monster or track day car but definitely would like to participate in spirited driving runs and be able to keep up with newer cars.

So what are my options here, and what would be a good progression of upgrades for the engine; exhaust then cams then pistons, or pistons then exhaust then cams, etc?... What else, short or larger valves and extensive head work could be done?
-Rudy O.
1975 Fiat 124 Spider (1756) [Jackie]
1975 Kawasaki KZ400 [Sofia]
1982 Honda CB750f [Amelia]
131
Posts: 672
Joined: Sun Nov 14, 2010 1:13 am
Your car is a: 1982 131 Superbrava warmed 2.0 litre.
Location: Tasmania, Australia

Re: upgrade progression options for a stock 75

Post by 131 »

The 34ADF or ADFA is a good carb, 24/26mm venturies, stock on 2 litre 131s in OZ, or an ADM, same as ADFA except 27/29mm venturies and electric choke, a great upgrade on a 2 litre. A bit hard to track down in the US though I imagine, you mob seem to have issues with finding decent manifolds too.

http://www.ebay.com.au/itm/Ford-XD-XE-X ... 2a4eb693a0

You may be able to convince the seller to remove the carb and send it over.
Mick.

'82 2litre 131, rally cams, IDFs & headers.
vandor
Posts: 3996
Joined: Sat May 23, 2009 1:23 pm
Your car is a: 1971 124 Spider
Location: Texas, USA

Re: upgrade progression options for a stock 75

Post by vandor »

Your two options are the 32/36 DFEV in either Weber or EMPI form, or the 34ADF.
They will be about the same as far as performance goes. The DFEV cost less and has an electric choke, but needs an aftermarket air cleaner.
The 34ADf has water choke and you can use your stock air cleaner. It just depends on what is important to you.
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
valkyrcustoms
Posts: 63
Joined: Wed Aug 28, 2013 10:56 pm
Your car is a: 1975 Fiat 124 spider
Location: Austin, TX

Re: upgrade progression options for a stock 75

Post by valkyrcustoms »

What else would I need besides the air cleaner for the dfev. I have the cable style throttle. Isn't the dfev a linkage type?
-Rudy O.
1975 Fiat 124 Spider (1756) [Jackie]
1975 Kawasaki KZ400 [Sofia]
1982 Honda CB750f [Amelia]
TimpanogosSlim
Posts: 237
Joined: Wed Feb 06, 2013 12:45 pm
Your car is a: 1977 124 Spider

Re: upgrade progression options for a stock 75

Post by TimpanogosSlim »

valkyrcustoms wrote:What else would I need besides the air cleaner for the dfev. I have the cable style throttle. Isn't the dfev a linkage type?
cable straight to the carburetor, or cable to some linkage attached to the valve cover?
valkyrcustoms
Posts: 63
Joined: Wed Aug 28, 2013 10:56 pm
Your car is a: 1975 Fiat 124 spider
Location: Austin, TX

Re: upgrade progression options for a stock 75

Post by valkyrcustoms »

I have the throttle cable straight to the carb.
-Rudy O.
1975 Fiat 124 Spider (1756) [Jackie]
1975 Kawasaki KZ400 [Sofia]
1982 Honda CB750f [Amelia]
vandor
Posts: 3996
Joined: Sat May 23, 2009 1:23 pm
Your car is a: 1971 124 Spider
Location: Texas, USA

Re: upgrade progression options for a stock 75

Post by vandor »

valkyrcustoms wrote:What else would I need besides the air cleaner for the dfev. I have the cable style throttle. Isn't the dfev a linkage type?
If you get a DFEV from a Fiat parts vendor then they will be able to provide the proper setup to make everything work.
There is an addition piece that goes on the end of the throttle cable that you need for the '75.

You will also need to use shorter studs on the manifold, as the stock carb has a super thick base. The length of the studs depends on the spacer you use under the carb. It's best to put a spacer under there to even out the fuel distribution. We sell a 14mm one that comes with gaskets, but there are all kinds available.

You can use the wire that went to the idle solenoid for the electric choke. You will have to block off the fuel return hose and remove any emission hoses in case they are still present.
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
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RoyBatty
Posts: 852
Joined: Sat Aug 28, 2010 11:44 pm
Your car is a: 1975 124 Spider - 1971 124 Sport Coupe
Location: Locust Grove, VA

Re: upgrade progression options for a stock 75

Post by RoyBatty »

The spool drum I your stock carb can be swapped onto your replacement carb with just a little tweaking. It's worth it to keep the factory cable setup. I was able to do this with the empi 32/36 and the twin IDFs and it had always worked great.
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bradartigue
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Your car is a: 1970 Sport Spider
Location: Atlanta, GA

Re: upgrade progression options for a stock 75

Post by bradartigue »

Or you could put this on it:

http://www.ebay.com/itm/LANCIA-GAMMA-20 ... 0440912927

36ADL. The beast.
TimpanogosSlim
Posts: 237
Joined: Wed Feb 06, 2013 12:45 pm
Your car is a: 1977 124 Spider

Re: upgrade progression options for a stock 75

Post by TimpanogosSlim »

If you're up for rebuilding it yourself, the 32/36 dfev and dfav are not hard to find used. The dfav is a dfev with a water choke instead of an electric choke.

One thing to look out for is that some of the beetle carburetors have the linkage on the wrong side. But i spent less than $100 on a used 32/36 DFAV, rebuild kit, and additional parts not in the rebuild kit such as the power valve and a new electric choke (you just bolt it on in place of the water choke)

In retrospect there's an argument for the water choke. But whatever.

It was not hard work, and the diagrams are available online.

With regard to the air cleaner, the really old single carb air cleaners have a diamond shaped mouth like the DFAV and DFEV. Those are smaller, less desirable air cleaners, but in theory you can use the rubber from the old air cleaner and modify the later air cleaner housing to accept it - minor cutting and drilling and some silicone involved. I've got the parts to do this, but have not done it yet.

The little lunchbox air cleaners are not expensive.

Oh, and you will want a spacer between carburetor and manifold.
valkyrcustoms
Posts: 63
Joined: Wed Aug 28, 2013 10:56 pm
Your car is a: 1975 Fiat 124 spider
Location: Austin, TX

Re: upgrade progression options for a stock 75

Post by valkyrcustoms »

bradartigue wrote:Or you could put this on it:

http://www.ebay.com/itm/LANCIA-GAMMA-20 ... 0440912927

36ADL. The beast.
Hey brad, what linkage would I need to make this work with my 75 (cable direct to carbs) or would I be able to swap the throttle cam from my 32adfa to keep my cable setup like others have suggested for the dfev.
I read the write up on using the adl on a fiat but I see it was a 2l with mods. I understand to get the most out of it I would have to modify my engine, but would I be able to use it with my engine in stock form without adverse effects, ie: running rich/fouling plugs, or bogging down the engine, etc...?
Last edited by valkyrcustoms on Sat Apr 11, 2015 12:27 am, edited 1 time in total.
-Rudy O.
1975 Fiat 124 Spider (1756) [Jackie]
1975 Kawasaki KZ400 [Sofia]
1982 Honda CB750f [Amelia]
valkyrcustoms
Posts: 63
Joined: Wed Aug 28, 2013 10:56 pm
Your car is a: 1975 Fiat 124 spider
Location: Austin, TX

Re: upgrade progression options for a stock 75

Post by valkyrcustoms »

As a general question about some of these carbs. Can the water choke be swapped out for an electric version? What about on the adl that brad suggested? What are the advantages/ disadvantages of each, ie: water vs electric?
Last edited by valkyrcustoms on Sat Apr 11, 2015 1:56 am, edited 1 time in total.
-Rudy O.
1975 Fiat 124 Spider (1756) [Jackie]
1975 Kawasaki KZ400 [Sofia]
1982 Honda CB750f [Amelia]
So Cal Mark

Re: upgrade progression options for a stock 75

Post by So Cal Mark »

the electric choke is an easy conversion
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RoyBatty
Posts: 852
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Your car is a: 1975 124 Spider - 1971 124 Sport Coupe
Location: Locust Grove, VA

Re: upgrade progression options for a stock 75

Post by RoyBatty »

Mark,
Do you mean converting a water choke carb to use an electric choke?
Or switching from a carb with a water choke to a different carb with an electric choke?
Or both?
131
Posts: 672
Joined: Sun Nov 14, 2010 1:13 am
Your car is a: 1982 131 Superbrava warmed 2.0 litre.
Location: Tasmania, Australia

Re: upgrade progression options for a stock 75

Post by 131 »

valkyrcustoms wrote:Can the water choke be swapped out for an electric version?
The electric choke on the ADM is interchangeable with the water choke on the ADFA, probably other versions too.
Mick.

'82 2litre 131, rally cams, IDFs & headers.
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