Technical 2 carbs help!!
- Thread starter KHALooD
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Technical 2 carbs help!!
If i were you, i wouldnt think about having twin carbs on any engine unless you intend to use it for racing - due to the fact having 2 carbs reduces the intake pressure by half, so you need to be going quite fast and high revs to get any kind of airflow through the engine to take any advantage. Hope that makes sense 
In your other thread you say you have a '93 Mark 2 uno? If so, your car doesnt have a carb as such anyway. You have a throttle body (30mm i think) which is linked up to the fuel injection system and ECU.
There is a member on here called tricker, who will bore out throttle bodies to 40mm, which provides alot more power. You could also put on a Punto 60 or Cinq sporting throttle body (both are 32mm i think) which would give more of a kick.
There is a member on here called tricker, who will bore out throttle bodies to 40mm, which provides alot more power. You could also put on a Punto 60 or Cinq sporting throttle body (both are 32mm i think) which would give more of a kick.
KHALooD said:
There is a chance, just i thought they stopped making carb 45's after the first batch of Mk2's in 1991, and replaced with fuel injection/throttle bodies with an ECU. Was called the 1.0lIE from then on.
I think Luke's right in that the carb'd Uno 45's went out soon after the Mk2 Uno was introduced. I think these cars are pretty rare compared to the 999cc FIRE-engined 45. It's more likely that a 1993 car has fuel injection.
I once had a '91 Uno 45 that, like the Mk1 45, had the old 903cc pushrod engine (with carb and mechanical ignition). According to every motor factor I used, this car/engine combination didn't exist... e.g. I ordered a water pump for it, and the shop gave me one for the 45 FIRE engine, I took it back and they had to put it into their computer as a Mk1 Uno to get the right part.
I once had a '91 Uno 45 that, like the Mk1 45, had the old 903cc pushrod engine (with carb and mechanical ignition). According to every motor factor I used, this car/engine combination didn't exist... e.g. I ordered a water pump for it, and the shop gave me one for the 45 FIRE engine, I took it back and they had to put it into their computer as a Mk1 Uno to get the right part.
Hi All,
Welcome to the forum KHALooD
Egypt “in the house”
I would not say Unos were made the same all round the world
I reckon the Egypt Uno is crabbed as it’s described as a 45. do you know if it’s the 903cc or 999cc engine?
it might even be a MK 1 – do you have any pictures?
The UK Unos were all Injection in 1993 and bagged “1.0 IE” – not 45Formula (903) or 45 FIRE (999). Can’t remember why I uploaded it but see https://www.fiatforum.com/gallery/showphoto.php?photo=3806&size=big&sort=1&cat=602&page=1
Sorry that doesn’t answer your original question – the Uno 55 gained twin choke carburettor and became the Uno 60 – see above link in July 1985 –That was the Non-fire 1116 OHC engine but 5 HP is a lot.
I can’t confirm or recommend how the conversion should be done – Alex – Chas - Morten?
Kind Regards,
Welcome to the forum KHALooD
KHALooD said:
Egypt “in the house” I would not say Unos were made the same all round the world
I reckon the Egypt Uno is crabbed as it’s described as a 45. do you know if it’s the 903cc or 999cc engine?
it might even be a MK 1 – do you have any pictures?The UK Unos were all Injection in 1993 and bagged “1.0 IE” – not 45Formula (903) or 45 FIRE (999). Can’t remember why I uploaded it but see https://www.fiatforum.com/gallery/showphoto.php?photo=3806&size=big&sort=1&cat=602&page=1
Sorry that doesn’t answer your original question – the Uno 55 gained twin choke carburettor and became the Uno 60 – see above link in July 1985 –That was the Non-fire 1116 OHC engine but 5 HP is a lot.
I can’t confirm or recommend how the conversion should be done – Alex – Chas - Morten?
Kind Regards,
Regarding when the carburetors were phased out, I think that many mk2 Unos up to 1993 were carb equipped. I'm not 100% sure, but carbs became extinct when it became compulsory for all new cars in the UK to be fitted with a catalytic converter from January 1st 1993. This is because a 3 way catalytic converter will NOT work properly with a carburetor, so all new cars had to be fitted with fuel injection.
I also remember that the date for all new cars to be fitted with a 3 way Cat was moved forwards because many manufacturers still had loads of unsold carburetor equipped cars. It may even have been January 1st 1994. This allowed all the carb equipped cars to be sold before fuel injection became mandatory.
So Khalood may well have a 1993 Uno fitted with a carb!
As to a twin carburetor or even twin choke arrangement, as far as I know Fiat never supplied the FIRE engine with one.
To go down this route, you'd have to have a custom made manifold built to take two carbs or a twin choke carb. Unfortunately I don't think any twin carb will fit the standard FIRE intake manifold.
If you really want to go down this route you'd be better off going for a twin choke carburetor as they are much more reliable and easier to set up than twin carburetors. With twin carbs, you'd have to have a linkage that would operate both throttles, plus you'd have the hassle of balancing the carbs so the engine would run properly.
With a twin choke carb you have no such problems. They normally work by having one barrel (venturi) opening under normal driving conditions, and a second barrel that opens when the throttle pedal is pushed down by more than 50%. That way under normal driving you only use the 1st barrel, but when you want greater acceleration/ power you push the throttle pedal down further and open the 2nd barrel as well. In effect you the best of both worlds, a single carb for normal driving and a twin carb for when more power is needed.
I looked at doing this with my old FIRE engine Uno 45. I had (still have in fact!) the twin choke carburetor from an old mk1 1.3 Uno SX. However, the intake manifold would have to be modified to take it as the carb FIRE manifold only has a two bolt fixing whereas the twin choke carb has four. Also, the carb to intake holes were totally different for the twin choke carburetor. On top of that you would have to make up a new throttle cable bracket as the ohc non FIRE engine uses a different cable to the FIRE carburetor.
All in it seemed like too much hassle so I never did get round to it.
However, different carburetor setups HAVE been done on the FIRE engine! Thing is, it doesn't look like a bolt on conversion and would I assume need custom made parts and a bit of work.
Check out the talented Smokeme's website. Smokeme specialises in turbo charging engines, but in some of his galleries there are pictures of Fiat Pandas running the FIRE engine equipped with what looks like Twin Webers, another with FOUR bike carburetors (!) and also a totally different engine installed in the third.
For the Twin Carbs/ Bike Carbs check out this link: http://smokeme.coconia.net/things done to panda engines.htm
For the rest of Smokeme's website go here:
http://smokeme.coconia.net/index.htm
Anything is possible if you have the money/ time/ facilities. Perhaps Smokeme is the guy to ask because he has been involved in making things like one off manifolds. But sadly there isn't a bolt in swap for the standard single choke Weber carb, so you're going to have to do a bit of work if you want to fit something different.
Best of luck!
Chas
I also remember that the date for all new cars to be fitted with a 3 way Cat was moved forwards because many manufacturers still had loads of unsold carburetor equipped cars. It may even have been January 1st 1994. This allowed all the carb equipped cars to be sold before fuel injection became mandatory.
So Khalood may well have a 1993 Uno fitted with a carb!
As to a twin carburetor or even twin choke arrangement, as far as I know Fiat never supplied the FIRE engine with one.
To go down this route, you'd have to have a custom made manifold built to take two carbs or a twin choke carb. Unfortunately I don't think any twin carb will fit the standard FIRE intake manifold.
If you really want to go down this route you'd be better off going for a twin choke carburetor as they are much more reliable and easier to set up than twin carburetors. With twin carbs, you'd have to have a linkage that would operate both throttles, plus you'd have the hassle of balancing the carbs so the engine would run properly.
With a twin choke carb you have no such problems. They normally work by having one barrel (venturi) opening under normal driving conditions, and a second barrel that opens when the throttle pedal is pushed down by more than 50%. That way under normal driving you only use the 1st barrel, but when you want greater acceleration/ power you push the throttle pedal down further and open the 2nd barrel as well. In effect you the best of both worlds, a single carb for normal driving and a twin carb for when more power is needed.
I looked at doing this with my old FIRE engine Uno 45. I had (still have in fact!) the twin choke carburetor from an old mk1 1.3 Uno SX. However, the intake manifold would have to be modified to take it as the carb FIRE manifold only has a two bolt fixing whereas the twin choke carb has four. Also, the carb to intake holes were totally different for the twin choke carburetor. On top of that you would have to make up a new throttle cable bracket as the ohc non FIRE engine uses a different cable to the FIRE carburetor.
All in it seemed like too much hassle so I never did get round to it.
However, different carburetor setups HAVE been done on the FIRE engine! Thing is, it doesn't look like a bolt on conversion and would I assume need custom made parts and a bit of work.
Check out the talented Smokeme's website. Smokeme specialises in turbo charging engines, but in some of his galleries there are pictures of Fiat Pandas running the FIRE engine equipped with what looks like Twin Webers, another with FOUR bike carburetors (!) and also a totally different engine installed in the third.
For the Twin Carbs/ Bike Carbs check out this link: http://smokeme.coconia.net/things done to panda engines.htm
For the rest of Smokeme's website go here:
http://smokeme.coconia.net/index.htm
Anything is possible if you have the money/ time/ facilities. Perhaps Smokeme is the guy to ask because he has been involved in making things like one off manifolds. But sadly there isn't a bolt in swap for the standard single choke Weber carb, so you're going to have to do a bit of work if you want to fit something different.
Best of luck!
Chas
Last edited:
Forgot to mention. The Fiat Panda 4x4 had a 1.0 litre FIRE engine fitted, but produced an extra 5 bhp (wow!) compared with the standard 1.0. Doesn't sound like a lot, but when you only have 45bhp to begin with 5 bhp is a welcome increase!
I don't know how they got the extra power, but think I read somewhere that it was done by using a different camshaft. They may have even used a slightly different distributor and/ or carburetor, but I've never been able to find out what exactly they did to get the extra power.
So that's an avenue to look down if you want to get an extra 5bhp!
Chas
I don't know how they got the extra power, but think I read somewhere that it was done by using a different camshaft. They may have even used a slightly different distributor and/ or carburetor, but I've never been able to find out what exactly they did to get the extra power.
So that's an avenue to look down if you want to get an extra 5bhp!
Chas
phil_harry
Member
JonnyBoy said:
I had the same problem with my mk 1 uno, which had a FIRE engine. Took it for an oil change and the computer assumed as it was a mk 1 it was a 903cc. A few miles down the road and i had no oil left due to the incorrect filter, i was lucky the engine didn't seize but it knackered the head gasket
SuperUno
Member
1986Uno45S said:
I looked into this early this year, the Panda 4x4 FIRE engine has a different cam, slightly better overlap. Also the carb setting are very vey slightly different to cope with the increase in air flow. But you could try fitting the carb from a 1108cc Uno FIRE engine as these has very slightly setting to cope with the extra air flow. But you have to remember you have to getting this extra air flow to benefit from it.
Cheers
Matt
edTV1
New member
Hi, most of the surplus carbs are probably exported to other countries like mine (Philippines) I drive a 94 fiat uno .45 with carbs too. If memory serves me right it's a weber carb. Can't check the garage the car is at the shop being painted.
For those who can remember the 1360cc Talbot Samba S, Rallye and Peugeot 205 GT, they all ran two single downdraft solex carbs (32mm I think) and put out 79 bhp. These were very tractable engines and despite being almost 20 hp down on XR2's were actually quicker due to the way they made power through the full rev range.
Although you have slightly less vacuum at the carb venturi (someone previously mentioned less pressure at the intake manifold which isn't correct unless you're referring to forced induction engines) they still allowed good atomisation through the full rev range.
If you can do it, go for it. Stick with a couple of small carbs and you'll get a very tractable engine.
Although you have slightly less vacuum at the carb venturi (someone previously mentioned less pressure at the intake manifold which isn't correct unless you're referring to forced induction engines) they still allowed good atomisation through the full rev range.
If you can do it, go for it. Stick with a couple of small carbs and you'll get a very tractable engine.
The same Peugeot/ Citroen 1360cc engine was also later fitted to the AX GT and Peugeot 205 XS. In those applications it was fitted with a twin choke (not twin carb) setup, a Solex I think, and pushed out 85bhp!
I used to have an AX GT. Great handling, performance was pretty good up to 80mph, but it had the build quality of an Airfix Kit. I sold it on, saw sense, and bought a Fiat Uno again
For total performance, twin carbs are better than a twin choke. But for every day driving a twin choke carb is far more practical and easier to live with.
Chas
I used to have an AX GT. Great handling, performance was pretty good up to 80mph, but it had the build quality of an Airfix Kit. I sold it on, saw sense, and bought a Fiat Uno again
For total performance, twin carbs are better than a twin choke. But for every day driving a twin choke carb is far more practical and easier to live with.
Chas
