Hi Karl, Just to add to Uno racers comments I can tell you the following:
If the uno ever contained this engine? (1108cc FIRE)
Yes, it did. Only on post 1989 mk2 Unos though. You will find they are called '60' models. Mk1 60 models used the 1116cc Lampredi engine (totally different to the FIRE). 45 models had the 999cc FIRE, 70 models had the 1299/ 1301/ 1372cc Lampredi engine as did the Turbo. Mk2 Selecta models continued to use the older 1116cc Lampredi engine.
Therefore the Uno you want to look for is a mk2 '60' model with manual gearbox.
Was it always fuel injected or is there a carb version?
Fuel injection wasn't compulsory on 1108cc models until 1993 (when Cat convertors became mandatory). 1989 - 1992 mk2 '60' models could be had with the carburetored 1108cc FIRE engine. Post 1993 models all had SPI.
Did the uno Have a 4 speed box?
Yes, but only in the base models. There was basically three models. Base = denoted by just a number e.g. 45, 60. 'Super' models all came with 5 speeders = 45S, 60S. Then there was the top of the range available as an SX = 70SX (also a five speeder but a different bellhousing). The high performance turbo was known as the Turbo i.e. and used a Strada derived gearbox and then later on a Tipo type (I think?)
If you want a FIRE engine and four speed box you need a base model Uno (e.g. just a number) in 45 or 60 spec. All mk2 45/ 60 models will have FIREs, but mk1 60 models are no good (as mentioned above) and some of the mk1 45 models came with the very old over head valve engine. Mk1's are getting very hard to find now, and if a three door shell comes up in good nick they sell for good money! That's because all the Turbo boys are looking for clean shells to reshell their rusty Turbos into
What was the gearbox number?
I think Unoracer covered this in his post!
Could you separate the Diff from it?
I don't see why not. The mk1 FIRE and Lampredi engined Unos used the same type of gearboxes but with different bellhousings. If the 1500 Uno could have its diff removed then no doubt the 999cc gearbox could have it removed as well. I've never done this though so don't quote me!
Any other info will be greatly appreciative e.g rod or cable gear change
All Unos used rod change mechanisms as far as I know. Two rods are used, one for side to side selection and one for back and forwards. However, early mk1's had the rods going under the car to the bottom of the gearbox ('bottom change') whereas later mk1's and mk2's had rods going through the bulkhead to the top of the gearbox (top change). Later mk2 gearboxes were also Tipo derived (I think, or maybe Punto), and all later models came with hydraulic clutches (all mk1's and possibly some early mk2's used cable clutches.)
Glad to be of help! Post some pics of your race car!
By the way, there is plenty of tuning info on the FIRE engines. You're more likely to find info in the Cinquecento section as all the 'Sporting' models were fitted with the SPI 1108cc FIRE engines.
Chas