Dellorto DHLA 40 carb set-up
Jan Hennig
I'm desperately looking for the right emulsion tube for Dellorto DHLA
40 carbs for 105 series (GTV / berlina) car with 1750ccm engine. This
is what I found out so far:
Choke - 32mm
Main Jets - 135
Air Corrector - 200
Idle Jet - 50
Is there anybody out there who knows the right emulsion tube? The
number should be 7772.??
For the 1.8 liter Alfetta the emulsion tube is 7772.10. But the whole
Alfetta set-up does not work on my 105 series car.
Thanks!
Jan
GJS
Jan Hennig wrote:
Assumption : Carburettors are pre Emission DHLA 40 ie no letter such as H
or G etc after the DHLA
Then the Emulsion tube is 7772.5
However if not Pre emision carbs then let me know.
Jan Hennig
>
> Assumption : Carburettors are pre Emission DHLA 40 ie no letter such as H
> or G etc after the DHLA
>
> Then the Emulsion tube is 7772.5
> However if not Pre emision carbs then let me know.
Hi GLS,
things are a little bit complicated. The carbs are DHLA 40 H (from a
Alfetta/series 116 car) but I would like to change the set up to get
the pre emission jetting to use them on a series 105/GTV. So if the
7772.5 emulsion tube matches the other jets I have listed then it's
exactly what I'm looking for.
Thank you!
Jan
GJS
Jan Hennig wrote:
Actually the H series would have used 7772.11 for both 1.8 and 2.0 engines.
Main jets 145 or 148 and 210 air corrector (Probably should be reduced to 200 as Alfa run a bit
lean above 4500 RPM with 210 air corrector.)
Idle jet 55 or 57 or 58
However you should be able to get the 7772.5 to work but you will have to use the larger idle
jets(start with 55 and work up because the Emission Carbs have a larger 220 air corrector for
the Idle system. If you do not use the larger idle jets the engine will run lean as it gets
closer to the 3000 rpm change over from idles to mains. This change over point is higher than
the pre emission carbs which had the idle air correction hole in the idle jet holder and not in
the top of the carburetor near the main jet air correctors. NB this means that Idle jet air
correction is fixed and cannot be changed by using older style Idle jet holders.
Also you will be able to get the DHLA H to work with the 7772.11 as the extra holes in the
Emulsion tube are only there for better mixing of air and fuel.And the dirrent tube diameters
can be balance with the Air correcoter and main jet sizes. The only danger is if an Air
corrector hole is at fuel level in the carburetor so that it becomes open too soon the engine
will run very rough at about 2500-3000 RPM.
This can be corrected by changing the fuel level in the float bowl. Not a fun job to get
correct but I have done it before :-)
Jan Hennig
earlier. It took me a few weeks to find out about the difference
between DHLA type H and "normal" DHLA's.
My plan is to remove the "fixed" idle air correctors (size 220) and
replace them by a set of interchangeble "home made" air jets (size
about 140). I will use the standard pre emission jetting (135, 200,
7772.5, 50) and my "special" idle air corrector. I'm rather optimistic
this will work, because I made some tests with a reduced idle air
corrector (reduced by a piece of wire put inside) and my engine
stopped hesitating between idle and 3000 rpm which was a problem
before. However this will take some time, but you can be sure I'll
come up with some questions if I run into mayor problems :-)
GJS
Jan Hennig wrote:
If you have the carburetors on the car I would try 55-58(start with 58 and
work down) idle jets in the existing system. It should work quite well as
an interim measure. The 50's with the large 220 idle air corrector are too
small and the engine will run lean.
The modification suggested will work but I would try the above suggestion
first.(assuming Carbs are still in thge car :-).
Simon James Grundy
ordinary solder, and then drill the smaller hole through the solder you've
put in the jet. That way you can do it as many times as you like; if it's
wrong, heat it up again, blow it all out and go again.
works a treat, do it all the time at work
cheers, sjg
--
Simon James Grundy (take out the tomatoes before replying)
Alfasud SC 1.7 8v
and Mum said: "What's wrong with Uranus?!"
TRASHCnewsaccountTHE TRASH@btopenworld.thetrashcom nick
It sez 'ere (in Italian):
for 1750 105 cars, the 40 DHLA:
Diffusore: 32
Centratore: 7848.1
Jets:
Massimo: 128
Potenza: nothing
Minimo: 50
Pompa: 33 (with 2 lines underneath - like "=". no idea what it means as I
don't have the whole book)
Avviamento: 70
Emulsionatore Max: 7772.1
Emulsionatore Avviam.:7482.1
Calibratore Max: 200
Calibratore Min: 7850.1
Valvola A Spillo: 150
Galleggiante: 7298.1
Posizione Galleggiante (= mm): 14,5 "divided by sign" 15
Portata Pompa: # 7,5
The above is assuming your carbs have tabs showing "5211P" and "5212 A" on
them. The numbers for the carbs on 116 and some of the 1750 105 cars are
different.
I hope this helps and hope somebody know what all the above means.
zaheer...@gmail.com
zulu
> Pls guys i need help finding the correct jetting sizes for my 2.0 turbo carbs
>
Stef
forums are much more alive these days.
Don't know the answer to this question, but if you post a question I know
the answer too, I might answer. ;-)
This dutch forum is very active (if you can read it):
http://forum.alfaclub.nl/index.php
Here's an english forum:
http://www.alfabb.com/
And there are probably al lot more. But it would be nice to get some traffic
back in this group. :-)
--
Stef (remove caps, dashes and .invalid from e-mail address to reply by mail)
First Law of Socio-Genetics:
Celibacy is not hereditary.
werner...@gmail.com
Regards