Hey guys!

Since the folks on the forum were so helpful when I was doing the swap on my Cento, and there seems to be a lack of information regarding simple 8V swaps on MPIs, as well as gearbox swaps, read ahead for more info!

Firstly I would like to thank four people for their invaluable input before and while I was performing work on my car. Those would be (in no particular order): cc1, fingers99, woj and Cento186.

This guide will cover three separate aspects of swaps that can be done in MPI Seicentos, particularly the base models like mine, but some of this may also apply to Sporting models or older Sei/Cinqs:

  • Swapping a 1242 8V FIRE onto your Cento
  • Swapping the C526 gearbox with a C514
  • Using the P75 head and it's advantages/disadvantages

As mentioned before, you don't have to do all of these. You can do any of them in separate, although since I was doing all of them, I will go through the process all in one go.

NOTICE: I advice EVERYONE to read through the whole guide in order to familiarize themselves with the process prior to actually doing things.

First of all, here's what you will definitely need.

For the 1242 8V conversion:

  • A complete block off a Punto MK2 or Panda MK2 (FIRE P60 SMPI).
  • A P866 cam and respective shims would be a good idea, although optional.
  • 5 liters of diluted coolant (buy it bottled or dilute it yourself).
  • Some copper grease.
  • Head gasket (unless you have a complete P60 engine).
  • Head bolts (unless you have a complete P60 engine).

For the C526 to C514 gearbox conversion:

  • A C514 gearbox, preferably off a Cinq/Sei Sporting.
  • A C514 gearbox off a Punto 55 may also work, although unsure on this.
  • Selector cable brackets from a Sporting (these are cheap at FIAT).
  • All the selector gear and linkage from a Sporting (get from scrappy)
  • VSS Sensor off a Sei Sporting MPI (alt. a Punto MK2 sensor can be made to fit).
  • Rear lower gearbox mount bracket (you can reuse the rubber mount from the C526).
  • Transmission shafts (complete) from a cinq or sei Sporting.
  • Flywheel from a Punto MK1 or MK2, or a Panda.
  • Clutch kit (must match the flywheel you got. A 1.2 16V flywheel might be a good choice).
  • Some wiring will be needed, so be handy with electronics.
  • 2 liters of 75W90 API GL5 gearbox oil
  • A new clutch cable (it's the 700 something millimeter size one).

For the P75 head conversion*:

  • An engine head off a Punto 75 or Palio 75
  • Headgasket kit
  • Timing belt kit fit for a Punto MK2 60
  • Camshaft pulley off your original engine (or PMK2).
  • Punto 75 manifold gasket

* Note on the 75 head conversion: There seems to be not much to gain from it, since the better porting on the 75 head will be defeated by the plastic manifold on the Sei. Also, this WILL cause you problems later, as you will need to properly seal the manifold against the head surface. A Punto 75 gasket may solve these issues.

Honestly though, you're better off just swapping the camshaft onto a Sei or PMK2 head. Read more about this later.

A few other optional parts you will want to get:

  • New thermostat (change it while you're at it).
  • New spark plugs (definitely change them).
  • New water pump (unless you know the service history of donor engine).
  • You'll need an engine hoist, or at least another pair of strong arms and be handy with the hydraulic jack. The hoist will make lowering the engine simpler though.

Finally, a small note. This swap was made bearing in mind the idea that the car must look as if it is completely stock. Portuguese law require cars to be kept completely unmodified, so there's a lot of margin for improvements if you consider making some performance changes (like using P75 intake manifold, custom intake, exhaust headers, etc). Those won't be covered here.

Also, download the Seicento technical manual from the downloads section. It contains all the torque specs for the bolts, which you will need (also handy for disassembling things).

Onward then, to the work at hand!