When registering my "new" 45, I found out that the value included in the registration card was 986 ccm. It is a 45 with higher trim (remote backdoor, econometer, clock etc.)
The registration card for the first one states 999 ccm (basic model without cigarette lighter).
Is it possible that there are two versions of the engine?
The clerk babbled something about 45/45S being different. I thought, based on the literature available to me, that "S" designation only stood for higher trim. Also, calculation of the volume based on bore/stroke gives 999 ccm.
Is this only a bureaucratic Catch 22, or are the 45/45S engines really different

Hi (CZ)enda,

The Uno 45 came with two engines to my knowledge – The 903cc and the 999cc. I think originally only the 45S had the 999, but I could be wrong.

What is your engine code on the VIN plate

Louie is right. The UK 45'S' models always came with the FIRE engine. The base model 45 could come with either the 999cc FIRE or the 903cc pushrod engine depending on year. My previous Uno was a base model (1986) without any fancy trim but came with a FIRE 999cc and a four speed gearbox.

The FIRE engined Unos came out in 1985, and initially the ohv 903cc was discontinued. Round about 1987, Fiat brought the ohv engines back. Why I have no idea as the FIRE is a much better engine The ohv engine has its roots back in the 1950's!

As for capacity, the one litre 45 Unos have always been 999cc. Whether there is a difference in European Unos I don't know. I think the capacity is cast onto the cylinder block, so have a look to make sure.

I've never heard of a 986cc FIRE engine! I think they only came as 748cc (not sure on the exact size), 999cc, 1108cc, 1242cc and there's a new 1.4 version that I don't know the exact capacity of. Some capacities could also be had with a 16 valve head depending on country, plus carburetor, SPI or MPI
fueling depending on the model. The Uno only came with carburetor or SPI versions of the FIRE and ohv engine, though the non FIRE turbo engine came with MPI.

The main difference between a base 45 and a 45 S is trim. The base models were incredibly basic, and as mentioned above, some could be had with the ohv or the FIRE engine between 1985 - 87. I think from 1987 onwards all base models had the ohv engine only, and all S models had the FIRE. Also, I think all base models only came with a four speed gearbox, whereas the 'S' models only came with a five speed.

Fiat works in funny ways!

This is somewhat tricky.
On the registration card for my first 45 (engine 156.A2.048) it states 999 ccm.
On the registration card for the second the code was changed from original 156.A2.048 to 156.A2.100 after engine overhaul (I thought 100 code had been used for Fire engine equipped with carb plus the "mysterious" Ecobox - an electropneumatic gizmo improving cold running properties).
However, on this second registration card, it says that the 156.A2.048 was 986 ccm .
The thing gets even more puzzling as a member of local forum said something to the effect that Fire engines indeed had 986 ccm and were changed to 999 ccm only after implementation of SPI, which led to power decrease and was balanced by adjusting the engine capacity... I do not think this is probable as the "legally" 999ccm 45 is equipped with a carb, but....
The thing gets darker and darker with every piece of information I receive, but it may simply be that registration clerks just made a mistake - either while entering the values for the first or second 45

156.A2.100 Ah?

Looks like you have a Lancia Y10 – page 4 on http://www.sun-diagnostics.com/products/scanner/afl-pdf/Lancia1X-EMS.pdf

























Only joking LOL http://www.chasti.ru/carparts/autoparts.php?fmodel=480 says it’s a 999 Uno – though could be wrong?



The Plot thickens. This page acknowledges a 986 cm³ (?) FIRE with code 156 A2.048 http://translate.google.com/transla...e.html&prev=/search?q=986+FIRE+FIAT&hl=en&lr= 9.86L is a bit on the big side for an Uno LOL

Finally this you’re your circumstances http://translate.google.com/transla...o.html&prev=/search?q=986+FIRE+FIAT&hl=en&lr= is a FIRE (ECO) 986 cm³ with code 156 A2.100

Looks like there was a 986 FIRE on the market. I wonder if this is a pushrod block referred to in this article https://www.fiatforum.com/showthread.php?t=42040

WOW! You almost scared me with the Lancia thing .
Now it is (almost) clear!
Thank you all for your effort !