Factory carberator

[toplessexpat]

i had never heard of a 38 ADL.

Fairly uncommon - fitted to the Lancia's. There's a 36 ADL on eBay right now...

http://www.ebay.com/itm/LANCIA-GAMMA-20 ... 1f&vxp=mtr

As for bogging - I was concerned, Csaba was concerned... 50 miles of spirited fun subsequently - it's not bogging down at all.

[racydave]

I think the definitive info put together by Brad Artique on carbs and engine mods will help you find what you are looking for. I run a 36ADL and it is a good choice, but not necessarily for a stock engine. IDF's are a good choice for modified engines, but require a lot of work to set up and keep in tune. Maybe Brad will add to this discussion.

[spiderrey]

I ran the 38 DGAS for a while. It was a nice setup, but i wanted my twins back. I remember modifying the arm on it so that I could take off from a start with out launching so hard. It was a little monster, ran real well though. i have a highly modified 2 liter so it was a good fit. Also no tinkering or balancing needed.

[toplessexpat]

Off topic - spiderrey - does your throttle cable really run between the wheels in that photo???

[spiderrey]

Yes, It DID. Many people were baffled when they saw that , just like you. I didn't run a cover, so over the top was out of the question. As I have an early car with a flat hood and a two liter. Not much room left on top. if you notice in the pic , it is bolted down at the thermostat housing. It didn't have enough play to interfere withe the wheels or belt. Never had an issue with it there. Any other routing wight have kinked the housing. I played with it for a while before I put it there. That cable is now hanging on the wall, its retired as I have moved on.

[MrJD]

Why did you go back to twins?

[toplessexpat]

I ran the 38 DGAS for a while.

So, did the orientation of the DGAS have an (adverse) impact on performance? The ADLs (and ADFs for that matter) have the barrels aligned at right angle to where the DGAS is in your pic. I seem to remember a thread where someone posted an article (translated from French) describing how the orientation of the carb impacted performance. It was a master class for me (an enthusiastic amateur in such matters!)

A

Update: found it! http://fiatspider.com/f08/viewtopic.php?f=19&t=24675

[spiderrey]

I didnt have any issues.

[MrJD]

If the 34 was so great... Why isnt it prevalent like the 32/36 is now?

Good things = more demand = more common. Why are the carbs we are talking about so rare then?

[spiderrey]

The 34 came on the 74 model year only. After that most cars were dogged with smog equipment. Im sure that had alot to do with it being changed for the 75 model year.

[fiat218]

I bought a 38dgas,but I am not going to use it

[MrJD]

Bare with me here people, I am a clueless guy trying to get an education, lol.

The 34 came on the 74 model year only. After that most cars were dogged with smog equipment. Im sure that had alot to do with it being changed for the 75 model year.

From Mirofiori

"Solid and extremely reliable, the 34ADF was provided (by Fiat, actually) as a bolt-on performance improvement for 1975+ Fiats."

I assume that is in Europe. BUT, if it is so good, I still do not see why they are so rare?

Now, just for arguments sake, 34 = the venturi size right? Carbs aren't really doing anything special, so a 34/34 would have an overall internal diameter of 68mm. A 32/36... also is 68mm. If you dyno the exact same car with both carbs... I just don't see how they would have much if any difference... other than much better mpg and driving characteristics with the 32/36... which is why I assume it is the prevalent carb these days.

[toplessexpat]

I'm not going to try to address this - I'm not knowledgeable enough.

However, Brad Artigue's work is kind of my core reference in fuel delivery matters (and other areas too as it happens).

http://www.artigue.com/fiat/ is a great place to start!

A

[MrJD]

id love to have some info about the 34/34 vs 32/36

But,

Here is another question: How is a 38/38 "too much carb" when lots of people on here are running dual IDF 44's? Is the way the IDF 44 delivers fuel super different? And with that in mind, if you had an adapter plate, could you run a single IDF with success on a single plane manifold?

[spiderrey]

A 38 is not to much carb. I would think a stock car would NEED a progressive 38. I ran a non progressive set up because I'm nowhere near stock. Had to modify the arm on it though so I could ease into it when needed.