Three nice Alfa 75's in Athens, Greece

What's your daily occupation?

I was never interested to go larger than factory engines. I believe if 3.2liters is not enough maybe we should buy an M3!!!
I was an Electronics Engineer but I am retired now, after working in the Aerospace industry for 36 years ...60 years old!
Jim K.

I'll have them if nobody else does. PM sent

I'll have them if nobody else does. PM sent. What mods do they need to run a 3L? Reason I'm asking is my South African 3L GTV came out with them on. Had some carb trouble and bought up some Alfa 6 carbs for spares. Car is now running with a mix of parts. I can't find any decent tuning info in english so I'm stuffed. Spent loads of cash having several "experts" work on the carbs and car still not running properly

Need help for your carbs? Please explain what is the problem?

Alfadave, you have PM.
I would treat V6 carbs the same as any others for 4cyl Alfa engines... 2xDHLA or 2xDCOE. The requirements are the same. Most important to synchronize throttles and set idle mixtures, but AFTER setting proper float levels. Before you deal with the carbs though, make sure you have enough fuel pressure and enough fuel flow for the power level you have. Of course, we are assuming an engine in good condition here, all jets are clean and there are no vacuum leaks anywhere...
FRPA40's had 29mm venturis in the 2liter engines and 32mm in 2.5 liters. Besides this basic difference, only idle jets and idle air jets were different between various engine versions. However, I don't have any information on settings for the SA 3liter engines (venturi size, jets etc).
Jim K.

That's a fair price Jim, but sadly I'll have to make another plan. Too rich for my blood.
My main issue with these carbs is I don't understand which screw does what setting.
Idle is a bit lumpy and won't idle under 1300 rpm. That I can live with but driving the car is not fun.
Under acceleration its ok. Not as strong as it should be, but smooth. Trouble is cruising.
It won't run constant speed without going mad. Shaking and smacking my knee with the gearlever.
If I gently accelerate its fine, but I can't keep accelerating forever. Speeding fines are expensive

I met a guy today with an Alfa 6 who says its most probably the bases that are rubbish. He says the bearings on the throttle shafts leak when they get old and cause air leaks. That's why the revs hang before settling on idle and most likely why the car won't run properly unless under full throttle when the air speed through the carb is high enough to negate the leaky base. I've spent so much on this car already that I'm at a loss as to what I must still do. These little bearings are expensive and there are 6 of the buggers! Then there are the bushes on the other end of the shaft and the tricky job of removing the butterflies without ruining the screws.

Not a happy Alfisti at the moment

Alfadave, carbs from the 3L South African GTV6 are not as standard (I mean not like in the Alfa6). Please explain exactly what is your problem. I also have a 3L SA GTV6 and I know this car ... quite well... You can contact me directly by email if you want. Cheers !

petrol quality is different from 1979 fuel quality.
Today, you have to increase richness by removing
iddle air of 220 by screwed ones at 160. It is explained in
the first page of my site with pictures. It gaves plenty of
torque from iddle to middle speed, smooth acceleration.
With a 60 iddle instead of 58.
For main circuit, take for air 180, main 145 and emulsion
tube number 4. All this stuff fron eurocarb ltd in england.
Perhaps a liitle difference with a 3 liter but we should be
near the truth to be in the dark side of the force... ;-)
Around 100000 km with this calibration no wear and
consumpsion as it was inezione...

Very good info 3litresourien (I like the name!!). I also doubt the bearings would cause so many problems to Alfadave. I insist on proper throttle alignment . Then, a very good way to test for idle mixture setting, is the old Gunson's Colortune set. Its great help if you're not too experienced with such work.
Jim K.

3litresourien, I have tried to see the pictures etc. on your website, unfortunately I'm a bit of a one trick pony. I only speak english and can't find what I'm looking for I'm battling just to use this forum. Luckily I've used similar ones and sort of remember where the buttons are, although I did mess up a few times already. My post above I thought was a reply to a private message but I see I posted to the open thread

I see no differences between the carbs and jet sizes between the Alfa 6 and GTV 3L. What am I missing? Also please can someone explain the throttle adjustment procedure and what the adjustment screws are. I see three per carb. Sorry guys, I have no idea what I am doing so I depend on help.

Thanks

The number on the jet is the same ... but look carefully at the hole, you should find something interesting!

Alfadave, if you are in south Africa, you may know that you have some big specialists of the 3L GTV6 in your country! Probably much easier to contact them...

Are they drilled out to another size?

I've had the car at a few "experts" and paid big money for little result... I won't mention names as I don't believe in running a man down

alfadave a écrit:

Are they drilled out to another size?

yes they are !

Bugger! I'm going to have to check them all. I've got a mixture of three different sets of carbs together on the car at the moment. Can you give me an idea of what exactly I'm looking for to check that I have the 3L parts fitted? That could explain a lot as to why the car is running poorly

Although as 3litresourien says I should replace all the jets with different sizes anyway so should I even bother or just order jets as per his suggestions?

I'll put a pic tomorrow to show you the difference but surely if you have carbs coming directly from Alfa6(s) and some coming from a true 3l gtv6, it could be a problem !

I'm sure that is part of the problem! I was always told they were the same. Shows what our "experts" know

I will give you the direct links to
understand.
I know that some differences exists in south africa
regarding altitude and jettings.
No easy as I write with my mobile phone.
I have to go to a computer with copy paste function...

For rs200: take care about redrilled jets, it could be just a trial from
nowhere without any official alteration.

For Jim: yes gunson's spark plugs are the easiest way to tune
iddle richness, with the help of 6 vaccum meters.

For all: butterflies have to be closed as possible wih enough gap in
the links to avoid opening due to dilatation when engine is hot.
The gap between pump levers and pump piston has to exist too.
Up right of each carbs, by pass screws to be closed first. To be open
with vaccum check only....

On a computer, it's easier!

Here:

http://alfasei.canalblog.com/archives/2008/12/01/11584560.html

Just follow steps given by pictures.

Check your fuel tank too, and if enough flow is given by fuel pump.

If any questions, don't hesitate to ask. But here on the forum is
better for all.

I'm first going to have to take the bastard things off AGAIN. Leaking fuel on the fuel rails AGAIN!! Wish these things had a quick release switch you could just press and they'd jump off the car, go lie on the workbench and strip themselves

Ha hA no...
It's not coming easy, and take care not to bend the carbs plates,
they will break... That's why I do the things good at first sake...

Do you have the workshop manual? Or else 2013 will be a hard year...