After the restauration of a Fiat 127 MK2 I decided to restore a Fiat 127 MK1, with the famous Abarth Preparation, kind of an Ultimate OHV engine. Probably not everyone would do the same changes as I am planning but I have discovered that each one as its own ideas when talking about engine tuning.
​
Once again, I defined the budget beforehand. I searched in the internet a car that would fit my budget and still gave me enough room to do all the changes I wanted. I looked for a rust-free car, which is very difficult as Fiat's body panels are not famous for its resistance to corrosion.
​
I started looking for a nice car and found it, a yellow car that looked rust free. I started to build the kind of car I would want in terms of specifications:
​
- Engine: 1050cc from A112 Abarth. Very expensive (2000€ or more) but for a Ultimate OHV, no other engine would be appropriate.
- Valves 32-28. I know that the final limit would be 33-29 but the intake and exhaust valves in each cylinder would be too close and a small vibration can lead to catastrophic consequences. Even with 32-28 is already dangerously close.
- Port and Polish the cylinder head - enlarge and polish exhaust ports, and enlarge the intake matching it with the manifold
- Weber DCNF 36 - very rare and expensive, but very good for small engines and therefore used extensively in Italy in the the OHV engines. It has synchronized opening and is vertical and not horizontal, very important in the engine. With this carb, the orientation would need to be changed too. A lot of work.
- Drilled discs- A112 Abarth Trophy cars used drilled discs and if it was enough for them, for me should also work.
- Direct exhaust system with minimal restrictions (4-2-1 manifold and direct pipe)
- New shock absorbers and lowering springs
- Larger tyres 165/55 R13 should be enough.
When I started to take out all the interiors, as in all restoration projects some unfortunate surprises appeared. I decided to send it to a professional to sand the car and repair all rust. I do not have the expertise nor the patience for this kind of work.
While the car is prepared for sandblasting and I wait for sunny weather, I started to buy the material. For now I already have:
Interior:
- Sporty steering wheel but not the modern rally ones, it is not appropriate for such a car.
- Abarth Tachometer
- 2 extra-lights 16cm but can also add another 2 extra of 11mm like in the Fiat 127 MK2
Exterior:
- GR2 Wheel arches will give an aggressive look and with the larger wheel size is important to avoid stones against the rest of the car.
Mechanical parts
- Found one Weber 36 DCNF. I am going to change the orientation of the carb and will try to create separate runners for each side of the cylinder head, it will improve acceleration linearity.
- New shock absorbers already there, still missing the springs.
- New parts for the braking system, Brembo pads, New rear drums and pads from Bosh, new flexible tubes, everything.
- Drilled Brembo Sport discs: Made of a compound more resistant to heat that should provide better braking.
- Direct exhaust system with muffler already bought, still need to adapt to the car.
- Abarth Carter protection something important in rally, in the last one I saw a car with it carter broken to pieces in the first stage. I do not want that.
​
Update 19-12-2016
​
A quick long due update.
​
Bodywork:
​
After sand blasting the engine bay and floor to remove all rust, and with a power tool removed all old paint to make sure no surprise would be below the paint, the car is finally ready for the paint job.
​
Some pictiures below. First before the sand blasting, the others after the sand blasting and preparing for paint.
​
All the bodywork is above my knowledge, so I left it to a professional to sand blast and paint the rest of the car.
Mechanically things are also going at a good pace.
​
Engine
I bought the 1050cc engine from Italy, it was impossible to source one in Portugal. I opened the engine and took it to a professional engine house.
​
He noticed it was was repaired recently, Cylinders had no marks of usage and pistons had little carbon on it. So with new rings it will be perfect. On the head, he advised me not to go for 32-28mm valves, they would be too close together and would start to burn between them (he said Mini owners normaly do that mistake, increasing the valves too much together and soon they are opening the engine again). Also, the 29-26 is made for stock manifold, bad head castings and long usage (lot of miles) so he said it was not a bad combination de 32-26mm valves, it would not impact performance heavily since all the rest was improved. Main impact would be at high RPM, at low RPM should not have a large impact,
​
Due to compression ratio, I am using an original Fiat 127 head and not the A112, to have the chamber without the bowl. The cylinder head combustion chamber is also going to be re-bored to deshroud the intake valve to flow better, all done by a professional as I do not have the tools nor the experience to do it.
​
As he is the professional and a lot of experience, I listened to him, Order the 32mm valves, port&polish exhaust properly. The engine is now at the workshop.
​
I already have with me a 5 speed gearbox from a Fiat Panda with low milage. The 5 speed gearbox will improve highway travel speed and with a 1050cc engine it more than deserve the 5th speed.
​
Brakes
I was able to source after a lot of patience some Brembo Sport Drilled Discs. According the the workshop that sold me the discs, the sport line is made of a compound that overheats less. And in fact, the discs look differently
​
Update 04-04-2017
​
​
Another update on the car. Things have been going slowly as normal in this projects. But I decided to do an update anyways.
​
Brakes
​
Some suface rust so I stripped it clean and repair with new shoes and Drums. Painted the drums were from Brembo so I painted them red, it looks cool.
​
​
​
​
​
​
​
Engine
​
Engine is back from workshop, now is time to assemble everything. Larger intake valves look very good. Head was skimmed to make it plain although it was good before. Painted the exhaust manifold and the valve cover. Everything is ready to put together. I will send it to a special workshop to make sure the right torques are used.
​
​
​
New va​lve seats to take the new valves with 31mm. Looks very good.
New valves in place. I have also changed the exhaust valve to a new one, as this one is already old. Do not have the picture of the new exhaust valves.
​
As said by the Workshop specialist, the valves already are very close, increasing the exhaust valve would make them very close together. It was a good call to keep it stock. So now it is 31-26mm valves. 83% Exhaust/Intake ratio is very good.
Close indeed, but not problematic. +2mm in Exhaust side would be problematic.
Abarth 4-2-1 exhaust manifold painted red. Ready to fit. High temperature paint so it will hold together one used.
Valve cover also paited. Hopefully it will look good in the ende
New rings and pistons. Since it was open, time to put everything new.
Intake manifold and DCNF Carburator. The head was all ported and the intake port was increased to match the intake manifold. READY TO RACE the engine!
Update 23-01-2018
​
So, last couple of months were a race to have the car finalized for the Rally Portugal Histórico. I had to ask a mechanic to put the car all together professionally and send it to a electrician to rebuild the electric part. As it was professionally built I do not have a lot of photos on the process, so I will just leave here the final work.
