best upgrade for alfetta gtv

[carlo rossi]

forget cams and 45s
the simple  way to get a faster alfa is the carbs jetting
up choke to33mm idles up and mains up and there you have it
12 hp overnight cost $150

[Duk]

Is this for a 2 litre?

If it is, they really should of had 33mm or even 34mm chokes straight off the bat.

From both a Haynes workshop manual for the Alfetta's, my Hawnes WS manual for Weber carbies and I also reckon an American book I have on Webers, all said that with only 1 tiny difference, the carby specs of the 1.8 and 2 litre carbies were exactly the same.
What is also the same is their quoted power; 120HP.

A 12hp increase is a nice little bonus for you.

[carlo rossi]

yes it is for a 2 litre as they  use the 32mm chokes from 1.6 ,1.8 and 2 litres
I think part of the problem why it wasnt offered was in the 70s no cnc machines and 33 mm chokes just werent made they made 34 s but for a standard application its alittle large and you loses its flexibilty and really larger cams should be utilized,
This is on  dellortos not sure about webers
trumpets will need slighlty larger jets again

[Duk]

The 2 carbs are so similar in their operation, that I'd guess they were the same specs for Dellorto's, too.

Something to keep in mind about car manufactures, is that they really are just running a business. So buying HEAPS of 1 type of component and using it over multiple different ranges, makes plenty of (financial) sense.
After all, it's not like they didn't know how to have fun, it's just that the accountants were a bunch of kill joy muppets....................... 

[carlo rossi]

yes and their main market was italy and they sold lots of 1.6 in fact  4 times more than 2,0 ltrs
so they didnt have alot of interest in the bigger cars which were mainly export and in america with californian pollution laws they made 1 model pretty much for all export models with minor differences

[Alfapride]

Hi there sounds interesting here are the original specs of the dellorto 40mm fitted to 2 liter alfetta which components below do you recommend changing?

Venturi: 32mm
Main jet: 1.45
Main emulsion tube: 7772-08-28
Main air metering jet: 2.10
Idle jet: 0.52 to 0.55 according to date of production
Idle air metering jet: 2.20
Progression holes: 1.2-1.6-1.6-1.5-1.5
Choke jet: 0.70 to 0.80 according to date of production
Choke air metering jet: 1.50 to 3.00 according to date of production
Choke emulsion tube: 7482.3
Acceleration pump jet: 0.33
Accelerator pump delivery volume (20 strokes each barrel): 5.0 to 6.0cc or 7.5 to 9.5cc according to date of production
Fuel inlet needle valve: 1.50

[carlo rossi]

2 ways to go if you keep that emulsion tube
33 choke
148 -150 main
59-60 idle jet
or if you have the 11 tube not the 8
then you change main to 152-155
and the idle mixture at 3 turns out

[carlo rossi]

probably should elaborate
with the emulsion 11 tube you change the idle to 60
and main depending on the characteristic you prefer 152 or 155
I am  also working on a  59 idle 150 main with a 10 emulsion tube setup
waiting on tubes
these setups are for what is probably referred too as a stage 1 development
lots of fun thou takes it from doughy to grunty
not that doughy is bad ,its just a tad boring

[DHDamo]

Carlo, I have emulsion tube .7 (its what came with car - from what I've found one of the richer ones) Any ideas what other jet sizes I should go? I like grunty

[carlo rossi]

what is the the carby model and year of car
sounds like an early e  series dellorto

[DHDamo]

Dellorto dhla 40 - not sure of specifics tho. 84 gtv

It did come with early style steel cylinder air filter - maybe it's has a swap job done on carbs too.

[carlo rossi]

on 1 side of the carby will be the word dellorto on the other sude will be dhla ?
can you tell mnje the ,main njet you have anf the air corrector on top of the stack and the idle that you run
all easily found under the rectangle cover held down by 2 screws  and then pull the jet holders out
most australian alfas have dhla f or g and 84 alfas  should be L series so you should see 40dhla L
on top of the second throat

[DHDamo]

Yep they are dhla40 L as you suggest.

I think idle/ choke is 55, main is 145, corrector is 200

Do they sound right?

[carlo rossi]

strange numbers ?
should be 240 or 210 for the air
145 or 148 for the main jets
and the idle should be 55 or 57 its not the choke the choke is the main venturi
can you check these numbers precisley and the emulsion tube number exactly

given that you need to purchase 33 mm venturi or as the english call chokes
you need a 148 main(you may have it already)((should))(((this depends on the emulsion numbers)))
you will need 59 idles

[DHDamo]

Ok, sorry for confusion - I'm new to this:

Both emulsion tubes 7772.7 and mains 145 and corrector (on top of emulsion? ) 200

Th other 2 smaller tubes both have a 55 jet on the btm - this is idle?

Venturi - based on my manual drawing, this is horizontal (not vertical like the others?) And is on the part that sticks up out the top of the carb between the 2 throats? This should be 33?

And 240 or 210 air, which will be better?

Will your numbers work with these emulsion tubes? I haven't read about these .7's anywhere else.

Car is registered but primarily used for track sprints and spirited highway driving.