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Engines and Carburettors for Fiat 500 Classic Cars – an Overview

List of engine numbers of Fiat 500 & 126 classic cars

Identify the currently installed engine in your classic Fiat 500 or Fiat 126 by its engine number.
Here, you can find information about the engines of the classic Fiat 500 and Fiat 126 models.

Where do I find the engine identification number (EIN)?

The engine number is stamped on the engine block where it is clearly visible.
Possible locations of the EIN:
  • to the right of the fuel pump
  • to the left of the engine suspension at the rear crossbar
  • above and behind the upper (clearly visible) part of the V-belt
engine identification number (EIN) Fiat 500 Oldtimer

Overview: List of engines – Fiat 500 & Fiat 126

Choose the model whose prefix matches the one of the motor number you are looking for.
Click on the corresponding entry to expand it and get additional details about that engine.
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 66 mm
Stroke 70 mm
Compression 6,55 : 1
Torque 27 Nm (2500/min)
HP 13,5
Carburettor Weber 24 IMB (until 10/57)
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 66 mm
Stroke 70 mm
Compression 6,55 : 1
Torque 27 Nm (2500/min)
HP 15
Carburettor Weber 26 IMB (from 10/57)
Weber 26 IMB 1 (from 03/58)
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 67,4 mm
Stroke 70 mm
Compression 8,6 : 1
Torque 41 Nm (3500/min)
HP 21,5
Carburettor Weber 26 IMB 2
Weber 26 IMB 3 (from 10/59)
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 67,4 mm
Stroke 70 mm
Compression 7,1 : 1
Torque 35 Nm (3500/min)
HP 17,5
Carburettor Weber 26 IMB 1
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 67,4 mm
Stroke 70 mm
Compression 7,1 : 1
Torque 36 Nm (3200/min)
HP 18
Carburettor Weber 26 OC
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 67,4 mm
Stroke 70 mm
Compression 7,1 : 1
Torque 31 Nm (2200/min)
HP 18
Carburettor Weber 26 IMB 4
Weber 26 IMB 10 (from 03/70)
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 73,5 mm
Stroke 70 mm
Compression 7,5 : 1
Torque 36 Nm (2800/min)
HP 18
Carburettor Weber 24 IMB
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 73,5 mm
Stroke 70 mm
Compression 7,5 : 1
Torque 40 Nm (3400/min)
HP 23
Carburettor Weber 28 IMB
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 77 mm
Stroke 70 mm
Compression 7,5 : 1
Torque 42 Nm (3000/min)
HP 24
Carburettor Weber 28 IMB
Bore
Stroke
Compression
Torque
HP
Carburettor
Bore 80 mm
Stroke 70 mm
Compression 8,6 : 1
Torque 50 Nm (2000/min)
PS 26
Carburettor Weber 30 DGF

List of Weber carburettors for the Fiat 500 from 1957 to 1977

This page summarises the data of the various Weber carburettors that were installed in Fiat 500 models during their years of manufacture.
The list shows all Weber carburettors used, together with the respective Fiat 500 models.
It lists the diameters of the nozzles and years of manufacture as of which the carburettors were installed.
All carburettor data can be found below the information about the engines of the classic Fiat 500 and Fiat 126 models.

Overview: List of Weber carburettors – Fiat 500

  • On which Fiat 500 model was a particular Weber carburettor (originally) used?
  • When were the carburettors built in?
  • Calibration data for the respective Weber carburettor models such as
    • Diameter of venturi
    • Diameter of main jet
    • Diameter of idle jet
    • Diameter of easy start jet

Data Weber carburetors Fiat 500 classic

Idle jet: Diameter 0,45 mm all Versions
Starting jet: Diameter 0,90 mm all Versions (Giardiniera 0,80 mm)
Version
from / to
Type
Diffuser
Main jet
Version Nuova 500
from / to until 10/57
Type Weber 24 IMB
Diffuser 18 mm
Main jet 0,90 mm
Version 500 N
from / to from 10/57
Type Weber 26 IMB
Diffuser 20 mm
Main jet 1,10 mm
Version 500 N
from / to from 03/58
Type Weber 26 IMB 1
Diffuser 21 mm
Main jet 1,12 mm
Version 500 Sport
from / to until 10/59
Type Weber 26 IMB 2
Diffuser 22 mm
Main jet 1,25 mm
Version 500 Sport
from / to from 10/59
Type Weber 26 IMB 3
Diffuser 22 mm
Main jet 1,25 mm
Version 500 D
from / to until 11/61
Type Weber 26 IMB 1
Diffuser 21 mm
Main jet 1,12 mm
Version 500 D
from / to from 11/61
Type Weber 26 IMB 4
Diffuser 21 mm
Main jet 1,12 mm
Version 500 F/L
from / to until 02/70
Type Weber 26 IMB 4
Diffuser 21 mm
Main jet 1,12 mm
Version 500 F/L
from / to from 02/70
Type Weber 26 IMB 10
Diffuser 21 mm
Main jet 1,12 mm
Version 500 R
from / to all
Type Weber 24 IMB
Diffuser 18 mm
Main jet 0,90 mm
Version Giardiniera
from / to all
Type Weber 26 OC
Diffuser 20 mm
Main jet 1,05 mm