Alfa Pages

chpinto · Alfa Arna Joined: 04 Jan 2005 Posts: 7

I have this alfa 33 1350 dual carburetor dellorto 1990 which i bought secondhand sometime ago. As far as i can remember i could never get the tuning right. A few days ago i decided to clean both carbs, mount them again and give it another try. To my suprise the left carb is a 40 and the right one is a 36. The size of the jets, venturis, etc are diferent from one carb to the other. The question is: is it possible still to tune the car like this or should i get another 40 or 36 ? I am a bit confused. Fell free to give advice.
regards
chpinto

Sprintervention · Alfasud Joined: 30 Jul 2004 Posts: 60 Location: York

I think that it may be best to get another 36 carb, I have a 1500 sprint and that runs 36 IDF carbs to good effect. I think that the 36s will best suit the car as the 40 will not allow the car to accelerate as quickly as the 36, due to air speed differences. I don't think that you will ever manage to tune the two different carbs to the same state of tune, after you have spent all the money getting the jets, venturis etc to match you may as well have bought another carb to match.

Just my opinion but good luck whatever you choose to do.

Chris
_________________
1987 Alfa Sprint Veloce

Bellamachinna · Posted: Tue Mar 22, 2005 5:13 pm Post subject:

Hi

cpinto · Guest

Now you people really got me baffled. Let`s see : I have 2 alfas 33, one is a green 1991 1350 sportwagon dual carb and the other is a red 1990 1350 sportwagon dual carb. The green one has 2 dellorto 40 carbs. The red one has on the left a dellorto 40 carb and on the right a 36 dellorto. Which is the correct one ? Obviously the green one must be a series 3. But the red one? How can i tell the diference between a series 2 and a series 3 ?

regards
chpinto

Sprintervention · Alfasud Joined: 30 Jul 2004 Posts: 60 Location: York

OK, going to hold my hands up now:

Didn't know that the 33 1350 was fitted with twin 40s as standard, my suggestion is to find out if the 40 fitted with the 36 matches the twin 40s fitted to the other. If it does then get another to match that.

I guess that way you will find out if it is a series 2 or series 3.

Many appologies if I've confused things, I have only had Sprints and all 1500 Sprints were fitted with twin 36s, 1700 Sprints were fitted with 40s.

Chris
_________________
1987 Alfa Sprint Veloce

Ben_nz · Posted: Wed Mar 23, 2005 12:10 pm Post subject:

I'm confused now too. I thought you could tell whether it was a series 3 by glancing at the outside of the car and checking whether it had the facelift. And I thought that all series 3 cars had fuel injection.

chpinto · Alfa Arna Joined: 04 Jan 2005 Posts: 7

I have decided to buy a second hand dellorto 40 and i have taken it apart. Question : why the settings of the float everytime i open these carburetors are never according to the dellorto book or even the alfa workshop manual ? By this i mean : With the top cover and the gasket on a horizontal position i drop the float and measure 15 mm (maximum drop). The dellorto book says 12 to 13 mm and the alfa manual does not measure it like this. I try to measure the minimum opening as i bought it with the top cover upsidedown and measure 2 mm. The dellorto book says 5 to 6 mm. The alfa book says i must measure with the cover in a vertical position (21 mm). What is the right way ?
I am getting nuts
chpinto

Bellamachinna · Posted: Thu Mar 24, 2005 4:05 pm Post subject:

Hi...
The series 2 looks like this:

The series 3:

The series 1 difers to the series 2 in minor exterior details (front grille, alloys, rear lights, front indicators, etc...), but the greatest difference is in the interior (diferent dashboard, doorcards)

Hope this helps

cpinto · Guest

From your pictures i can see that both my cars are series 3. So the decision to buy a second hand dellorto 40 instead of a 36 was the correct one. But in this business there is always a risk invoved. For 35 euros i got the carburetor but after taking it apart the venturi and the main jet are bigger than the left hand delorto 40 carburetor (size 30 instead of 28 and size 135 instead of a 118). The scrapyard must have sampled it possibly from a different engine. Well you cannot win them all so i will try anyway to tune up the car this weekend.
regards
chpinto

Bellamachinna · Posted: Fri Mar 25, 2005 5:58 pm Post subject:

Hi

By memory, i believe that the sizes on your left hand carburetor are the correct ones. I cant remember the sizes for the series 2 carburetors, but it seems that you bought one carb, for an 1.7 engine. (series 2).

cpinto · Guest

Well i have mounted the right hand carburetor drla 40 d that i bought in the scrapyard. But i put a 122 main jet (pinched from the 36 dellorto) in it. Its working more or less ok but the idling is around 1100 -1200 rpm. I cannot get it lower without it stalling. Well where can i buy a 118 main jet and a 28 mm venturi ? These are the only diferences now between the 2 carburetors.

regards
chpinto

Admin · Posted: Sat Mar 26, 2005 12:25 pm Post subject:

Hi

Here is the jetting for the 33 and sud carbs:-

http://www.alfa-pages.co.uk/carbjet.htm

Really should make that into an easily found link.

All the best

Keith