Conflicting Model/Engine Info

[bradbig]

Hi gang.
I just took possession of a 1974 Spider. There was an owner's manual in the glove box titled "Fiat Spider Sport 1800" , so I thought I had the 1.8 litre engine. But, in the engine compartment, in front of the radiator there's a sticker that says "Model 124 Sport Spider 1600". The sticker on the door jamb of the driver's door says " Fiat 124 CS (NOT CS1, just CS) Spider, Ident. # 0070383" which does make it a 1974 model, but the sticker also says manufactured in 07/73. The tag on the firewall says "124CS 0070383" with a 132AC.040.3 engine, which I think designates the 1.8 litre engine. So, I have some conflicting info. I have what looks like an original factory sticker in front of the radiator that says "1600", but based on the year and serial # it should have the 1.8, I think. Any thoughts? I know many cars have engines and chassis and parts scavenged from multiple vehicles. I consider the metal tag on the firewall to be the most reliable indicator. Any help or clarification would be appreciated. Thanks.

[bradartigue]

There are no good indicators except the markings on the individual parts. In your case:

124CS is a 1973 FIAT 124 Spider Spider. The CS was made for 1973 only.
The engine block 132AC.040.3 is the 1592cc motor.

Early 1973's had the 125 engine - a 1608cc motor - and late 73's had the 132AC motor - the 1592cc. In 1974 FIAT introduced the CS1, which was a 132A1 motor and displaced 1756cc. The first CS1 VIN is 71650, you are 70383, a solid 73 CS.

Sometimes the cars sat on lots into the later model year and were titled as such, but your car is a 73.

It's actually a pretty rare car, the 1592 was only made for a year.

[bradbig]

Thanks so much for the info. That is helpful, but a little bit of a surprise. I've done a fair amount of reading on the various earlier engines. They all seem very similar in terms of design, except for the displacement. Is the overall reliability of the 1592 cc engine on par with the 1.8 litre version? Does anyone know of any consistent problems or issues with the 1592 cc engine? I wonder why they only used that engine for such a short time, or switched to it from the previous version. Does anyone know?

[DanD]

IIRC, the 1800 has a heavier crank and rods than an early 1608, but the same stroke. larger diameter pistons are what give it greater displacement. Your engine has the heavier crank and rods of the new engines, with smaller diameter pistons, to give it the smaller displacement. It is a good engine, but it has more inertial mass than an earlier engine.

If it were bored out, it would become an 1800. BTW, the 1800 motor has the same pistons as the 2000, but I believe the 2000 has a taller block and a crank that increases the stroke to bring the engine up to 2 liters. Bored out 1800 engines make a nice unit, as they have the shorter stroke, and this makes them a rev happy engine. Ultimately, the longer stroke on the 2 liter makes them torque-ier.

[bradartigue]

Thanks so much for the info. That is helpful, but a little bit of a surprise. I've done a fair amount of reading on the various earlier engines. They all seem very similar in terms of design, except for the displacement. Is the overall reliability of the 1592 cc engine on par with the 1.8 litre version? Does anyone know of any consistent problems or issues with the 1592 cc engine? I wonder why they only used that engine for such a short time, or switched to it from the previous version. Does anyone know?

There is nothing major about the motor any different than the 1800 or 2000 except that the displacement is a little less. It has the pistons from a 125 series (80mm) and the stroke of the 132 series. Oddly you can find vendors referencing pistons for the 1592 matching the 1800 and 2000 and other vendors matching the 1592 to 1438 and 1608. If you're interested in pistons go by bore size anyway.

As far as why it was likely the best balance between Italy taxing cars over 1600cc's in displacement and the USA adding emissions controls in 73, 74, that the 125 series could not meet. The 1592 wasn't particular popular as it underperformed relative to the 1608, but most of us who've owned them would say ALL of the motors underperformed compared to the 1608 except for the 2000FI. As for the 1592 it's most likely due to the wimpy carburetor they slapped on it in the USA vs. any particular issue with the motor itself...by all rights it should outperform the 1608 with the right carburetor installed on it. At the same time FIAT was competing with Alfa and Triumph and Datsun with 2L+ under the hood for the same price. By 1974 they had to introduce something competitive and ended up putting out probably the most balanced combination of all, the 1974 1.8L. Small bumpers, big carburetor, few emissions.