So my 16v Build. From the date this thread was created you can tell it's been a long time since I started this build. I don't have many pictures i'm afraid of the build.
There is my SPI Seicento Sporting. Its far from a clean example few marks and dents as you'd expect from an almost 20 year old car. Supposed to be only 60,000 odd thousand miles on it. Chose this car simply because the SPI is easier for the 16v conversion. I then manage to pick up a Mk1 Punto ELX with the 1.2 16v engine. this also just had about 60,000 miles and was a completely original car and the price i got it for felt like a steal. haven't came across anymore for sale since.
Like all the other 16v conversions mine wasn't really any different to others out there. Wasted no time in stripping the engine out of the Punto and gave the engine a full service, timing belt, all oil seals, plugs leads etc. This wasn't a complicated job, no different to removing an engine from any other car. Next i pulled the original 1.1 from the Seicento. Again nothing out of the ordinary. Once the engine was out it was time to start swapping parts. One of the well known parts that needed to be swapped was the auxiliary driver belt pulley. Swapped the 1.1 pulley to the 1.2. the next issue is the crankshaft position sensor. To overcome this the some of the original sensor mount was cut away to fit in the sensor. ( I did think of changing the whole pump assembly but felt it was just easier to cut away the metal work).
Engine mounts then had to swapped from the 1.1 to the 1.2. The 1.1 alternator also had to be used. One problem I had here was when mounted the two pulleys didn't seem to match up and after a short time the belt shredded to bits. I solved this by just placing a few washers behind the alternator to space it out a little bit further haven't had issues since.
Engine was more or less ready to drop into the Seicento by now (I ahve probably forgotten something). Engine went in smooth enough just a lot of back and forward and double checking. The inlet manifold is tight up against the heater blower covering but it does fit in. Next issue was the timing belt cover rubbing up against the slam panel. Again this is a common well documented problem. I just filed down the cover and bent the metal work ever so slightly forward by the headlight and it all fits nice and snug. Plumbing for coolant then had to be sorted. I used most of the Seicentos piping and just had to extend the piping that goes to the heater matrix. Most of the pipe connectors on the engine match up in around the area the 1.1's would have been anyway. Fuel lines were next. I cut back some of the metal fuel pipes back a small bit and then used some standard fuel pipe to connect up the inlet manifold on the 1.2. I did make use of the pipes that came off the Punto due to the 1.1 and 1.2 having different fuel connectors.
The biggest issue I then had was wiring and getting the car to run. I used the 1.2 engine wiring loom and extended all the wires in this which took a while (around 40 solder joints!). This was done so I could mount the new 1.2 ecu in the original mounting spot in the Seicento. The most difficult part was the D4 connector. While there is lots of wiring diagrams on here they were almost all for Cinquecentos. As a result all the color coding was different and I was running into issues trying to figure out what wire went where. I did trace out basic ones like fuel pump and the fuel pump relay. Eventually after lots of searching on here I found one post with a correct diagram that worked for me. Next problem I had was immobilizer issues. I was using the Punto code box, ecu and I had the key placed in the key reader but the car was still showing the immobilizer light. Talking to a local mechanic friend he told me he could remove the immobilizer from the ecu. Week later and I had the ecu back. Plugged it all in. No light anymore! Checked to make sure I had spark, which I did. Turned the key and it went straight away. Huge relief getting the engine going, But revving it slightly caused it to misfire and splutter almost like it was being over fulled. At this stage I had not wired the carbon canister in. Most people seemed to be leaving it off so I didn't think much of it till I had ran out of options and decided to connect it up. This sorted all the running issues and it is now running very well.
Anything after this was more or less just putting everything back together. I Have the original Seicento gearbox and clutch in the car right now. Car still needs an exhaust which is next on the list. I have a set of coilovers to go into the car now and I do have the Punto brakes to go on the car which is something I'm debating hence the hence questions about gearboxes because I have the Punto wheels to use. Other small things I have added is a temperature gauge, a kill switch and I extented the engine diagnostic port inside the car so I can plug a laptop inside the car.
Future plans for the car are to strip the whole interior out and get a cage for it. Due to insurance in Ireland and my age I cant afford to put it on the road. I am planning on mostly doing track days in the car. This the engine bay right now on the car, and yes the car was crashed at some stage before which you can see from the painted slam panel. I'm sure I have forgotten loads as the whole process was slow taking several months due to work and college getting in the way. I'd be glad to help anyone wanting to do the conversion and I would highly recommend it.
Shane