Fiat 500L becomes a 500 Abarth Lusso - Part 4
A Bigger Engine and 126 Transmission
Old 500 Engine and Transmission Removed
New 126 Transmission The original transmission was uprated with a 126 version imported with the engine from Italy. This is required, as the 650cc engine from the 126, has different mounting face from the 500. I have also installed new Abarth racing spec drive shafts (on advice and supplied from Middle Barton), and shown in parts area (Part 1).
The later 126 transmission designs are based on the original 500 layout, but with several improvements on the weaknesses inherent in the 500 designs.The 126 gearbox provides a good next step and will take double the torque of the 500 with these mods.
The original Fiat 500 had a non-synchromesh (crash) gearbox, so installing the 126 4-speed, synchromesh, manual transmission was going to be a big improvement. The 126 gearbox, has synchromesh on second, third and fourth gears, is an easier gearbox to use, and has a higher nal drive ratio (ideal for running 13 diameter wheels and tyres), so it's more relaxed. Both the 126 and later 850s still suffer from a fragile differential. though stronger than the 500. Its something you need to check for fatigue cracks and wear regularly. Luckily, the differential is showing no fretting and less than 10 degrees of backlash (measured at tyre). The diff is noisy in operation, even when in good shape. And its well worth experimenting with oils for a longer quieter differential life. I have gone with Hypoid Gear Oil - SAE 90 or 85 W 90. The Ratios are 3.25/2.07/1.30/0.57 with a nal drive ratio of 4.88. (N.B. To calculate the gear ratio of an 18/34 gear set, divide the 34 by 18 i.e 34/18 = 1.88:1).
Clutch An uprated clutch that bolts straight in was installed. It is more reliable at higher power outputs, its pressure plate will take up to about 60bhp and equivalent torque, while the diaphram will help provide a smoother change with a better thrust bearing.
Engine Initially I have installed a lightly modied single port Fiat 126 engine, delivered used from Italy, but was overhauled and rebuilt from bottom end up, with new gaskets, rings, etc. A new single-port cylinder head was imported from U.K. and installed after free-owing and porting. At the time of engine installation, new engine and transmission mountings and bushings were installed, along with a tuned, free-ow mufer being constructed. This was done to rst satisfy me that the car was sorted out, with the correct braking and handling setup. Afterwards, I will then choose which way to improve the motive power. A big advantage of this engine was the electric, push-button starter (previously a cable pull), and the upgrade to an alternator instead of an antiquated dynamo, for electrical charging.
Rebuilt 126 Engine below :
Ready for engine/transmission installation (note the new coil springs and dampers already installed).
Later options could be modify the 650cc engine into a big-valve, dual-port, Dellorto carburettor, screamer modify it into a lower-rpm, single-port turbocharged brute or, convert to an EV (electric vehicle); a good idea in these ecology-minded days.
It's running really well, and the 650cc engine makes a surprising difference over the original 500cc (but certainly no speed demon).

End of Part 4

Fiat 500L becomes a 500 Abarth Lusso - Part 1

Vehicle History

The original car was a personal import into Canada from Italy. It arrived here as a 1970 Fiat 500L. Fiat in Canada never sold them, so this was very rst Fiat 500 brought to Canada! The L stands for Lusso or luxury version. I bought this car on the 24th July 2004. From then on it was tucked away during our Ontario winters, and used only on good days. Considering it age, it had a very limited road mileage, and after much research, I determined what modications I wanted to make during the build. During the 60s, Abarth managed to homologate his small, agile, winning racing cars, with a propped-open rear engine cover, using the pretence that he required this for extra cooling, when in fact he had realised that he would gain 10 mph on the straights, due to the improved aerodynamics. And this was over a decade before Porsche arrived with the 911 and its rear spoilers. These Abarths competed with much larger and more powerful cars including american V8s, yet still were successful in winning races.
My love for the 500s in open-engine-cover style, with european group 5 arch ares, made this an easy option, as basis for styling. I henceforth set about acquiring the parts to get started. The parts came in from Italy, U.K., and Poland. After ordering the rst set of parts, work began in 2005, when the car had completed 63,000km. Please note : I will go through all done in sequence, but will delve into each item in more detail, later, in other forum areas. For example, I say here about installing suspension, but the technicalities, such as spring rates, etc., will be expanded upon elsewhere.

The First Set of Parts

Parts choices need to be made and acquired before beginning modications. For instance which wheels and tyres (and arch extensions) to have. If you intend to go to water cooling (for a bigger engine), means getting the right engine cover stays/struts. Its vital to have those parts present during the build.

Parts - Mechanical

It is important to match the modied reverse-eye front spring height with lowered rear coil springs (note on the transverse leaf spring, that the lateral spring eyes are substantial and located above the spring line to increase lowering of front). Below, Koni dampers and coil springs.
Nice big front disc brake conversion kit (from european Ford Fiesta MkIII). Its important to keep the front and rear brakes in balance, as the tendency is to assume that bigger front brakes are sufcient, but the 500 being rear-engined and rear wheel drive, larger rear hubs and brakes should be installed. With that in mind, I have purchased larger rear drum brakes from a Polish 126P, and refurbished with new bearings, shoes and cylinders (in bottom-left of image above). Keeping shoes and drums on the rear still work well, and provides a better handbrake, but there are rear disc brake kits available.
Nice big abarth drive shafts. As I was installing the larger 650cc engine and transmission, I required the different and beeer driveshafts from the 500R.
Parts - Body The famous Abarth engine cover struts.
A big choice for the look of the car is the wheel tyre and arch ares. These are european groupe 5 arch ares, but the amount of work to prepare the wing and arch area is considerable, as it intrudes into the car a lot on such small car. Its also important to size the wheels and tyres precisely to the car.
Parts - Wheels & Tyres A new set of 7 x 13 Minilite wheels, from UK, were selected, after much searching and determination of t and correct ET/offset for the 500. These were required to clear larger front and rear brakes, along with the change of wheel stud PCD of 4 x 98mm. (the standard PCD for modern Fiat Group cars). New low-prole Radials (175/50HR13) were also installed.

Interior Parts

At this stage, I had decided to retain a standard interior, except for alloy pedals, gear knob and gated shifter. The carpet is new and rear seats are removed (weight reduction), and the rear area to be soundproofed and upholstered (possibly an area for battery stowage if later carrying out an EV (electric vehicle) conversion.

End of Part 1