Tuning 1.2 c newbie tune up?

[loveshandbags]

The big breather linking the cam cover & the airbox.

Would be interested to see how this looks when you have it done.

 

[gazz_bee]

Also you're lucky to get 69bhp from the 500 since the Panda owners only get 60bhp.

Depends on the age of the Panda. Euro IV Panda 1.2's are 60bhp, Euro V 1.2's are 69bhp.

 

[loveshandbags]

Depends on the age of the Panda. Euro IV Panda 1.2's are 60bhp, Euro V 1.2's are 69bhp.

The majority of Pandas (prior to the New Panda 2012) are only 60bhp since the 69bhp model only come out after July 2011. The 500 always had 69bhp from the 1.2 and they could have been Euro V compliant at the very start.

 

[alexGS]

I often wondered why a 16V head wasn't put on the 1.2 like on the other Fiats but then they had the 1.4 for that.

Yes, very good point... for example the Punto Sporting had a 1.2 16v engine with 80bhp for the 2001 models (85 for earlier cars?). As well as making the engine more complicated/expensive, the benefit of the better breathing through 16 valves is only apparent at higher revs, so it is tuned for that, and therefore becomes less efficient at lower revs, assuming there is no variable valve timing (which there isn't on these engines). The torque peak - handy for pulling up hills - moves up to over 4000RPM.

For fuel economy you want the engine operating at low revs AND at peak efficiency - this cannot be achieved with the 16v, but is easy to achieve with the 8v - so I think that is why FIAT chose the 8v for the 500. That way, they had their 1.2 8v 'economy' engine, and their 1.4 16v 'performance' engine, with a noticeable difference between them. Then along came the Abarth and the TwinAir... and the diesels, of course...

-Alex

 

[loveshandbags]

Yes, very good point... for example the Punto Sporting had a 1.2 16v engine with 80bhp for the 2001 models (85 for earlier cars?). As well as making the engine more complicated/expensive, the benefit of the better breathing through 16 valves is only apparent at higher revs, so it is tuned for that, and therefore becomes less efficient at lower revs, assuming there is no variable valve timing (which there isn't on these engines). The torque peak - handy for pulling up hills - moves up to over 4000RPM.

For fuel economy you want the engine operating at low revs AND at peak efficiency - this cannot be achieved with the 16v, but is easy to achieve with the 8v - so I think that is why FIAT chose the 8v for the 500. That way, they had their 1.2 8v 'economy' engine, and their 1.4 16v 'performance' engine, with a noticeable difference between them. Then along came the Abarth and the TwinAir... and the diesels, of course...

-Alex

Changing a 8V head to a 16V raises the torque peak from 3000rpm (looking at the GP 1.4 8V) to 4250rpm for the 1.4 16V with 131Nm. In the 1.2 16V it was 4000rpm @ 115Nm (which is at a lower RPM than the 1.4 16V) but it is the same as the 1.4 16V multi-air which is currently available in the Fiat / Alfa range & the US 500.
The 1.4 16V starjet had specs of 125Nm @ 4500 so at least that was improved to 131Nm @ 4250 rpm in the now discounted 1.4.
Did not know that Punto owners with 1.2 16V were getting head gasket issues but the 1.4 16V has a reputation for being a 'hardy' engine.
Did find that the 1.4 was happiest when it was coming on cam near 4000 rpm and the fuel consumption was OK when compared with the other models in the range.

 

[DaveMcT]

1275 BL Minis could be persuaded to 100bhp with twin SU carburettors, Race cams and split Webers went to 120bhp. So I'm sure a much more modern engine can get similar power with less work. At the minimum it would need a gas flowed head, sporty cam and full exhaust including manifold, but consumption will increase and it will be seriously not cheap to do. It would need brakes and suspension upgrades as well. Then dont forget a new mortgage to cover the insurance

Changing the car for a faster model would be cheaper than modding the 1.2 and you get more toys to play with.

Best option is posh petrol as it optimises the ignition timing. Cheap petrol causes the spark to fire late so more heat is lost down the exhaust pipe.

 

[alexGS]

1275 BL Minis could be persuaded to 100bhp with twin SU carburettors, Race cams and split Webers went to 120bhp. So I'm sure a much more modern engine can get similar power with less work.

I think you make a good point, but things are so different now to then. A more typical power output for a twin-SU 1275cc A-series was 65bhp, but the engine would not meet today's emissions regulations even in that tune, nor would it feel as tractable, smooth, and quiet as a standard 1.2L today. So the standard engine already delivers large improvements over the standard engine 30 years ago, even though the power figure might appear similar. Actually the standard engine then was more likely to be a 1000cc with about 40bhp. Yet the standard engine now bears little resemblance to a racing unit. The development has moved in different directions.

Most modern small engines have been designed for their purpose and designed around production costs and efficiency; they are no longer race engines de-tuned for the road. I'm not sure there is that reserve for high-performance tuning that you might think. For example, with the long stroke for torque at low speeds, how high can the rev limit be raised? With the weight-saving thin open-deck block, how likely is it to crack under stress? And is there any such thing as a long-duration, high-lift cam for the FIRE engine? Will it fit in the cam-in-head design? Can double valve springs fit? What about high-flow injectors? Is there a short, fat manifold kit available?

Back in the 70s the FIAT 128 had an extremely short stroke: 80mm bore and 55mm stroke (1116cc), overhead cam and double valve springs as standard. A number of desirable race-engine features had been grafted in to the all-new engine design. Strangled with a single carb and tiny exhaust, 55bhp meant the engine had a lot more to give. Race versions existed with fuel injection and 150bhp at 10,000RPM, and that wasn't even a crossflow design. I doubt anyone has achieved this with an 8v FIRE engine, and there is a dearth of performance parts available compared against those older engines.

Why? I guess the answer lies somewhere between the easy availability of turbocharged petrol and diesel engines, and the difficulty in achieving emissions certification for any aftermarket modifications.

It would therefore be a real challenge to tune a modern small non-turbo engine - many parts like plastic manifolds would have to be thrown out or re-engineered - and not cost effective in the slightest. But it would be fun to see someone achieve it.

Instead we should probably recognise the steady improvements that have been made to the 1.2 in its standard form. Such wide gear ratios and quiet cruising at speeds up to 100mph would have been unthinkable with a 1.2 four-cylinder engine 30 years ago. And you do get a substantial power boost over the original 999cc FIRE engine from 1986 (45bhp).

-Alex

 

[306maxi]

Instead we should probably recognise the steady improvements that have been made to the 1.2 in its standard form. Such wide gear ratios and quiet cruising at speeds up to 100mph would have been unthinkable with a 1.2 four-cylinder engine 30 years ago.

Yup. I cruised through Europe last week and at times was doing 80-90 for hours on end. You wouldn't think of that with an older engine...... My 504 used to shoot oil out the dipstick when you were doing those sorts of speeds!

 

[Venters]

Group n cinqs were running about 120bhp out of the 1.1 8v fire.

 

[loveshandbags]

I think you make a good point, but things are so different now to then. A more typical power output for a twin-SU 1275cc A-series was 65bhp, but the engine would not meet today's emissions regulations even in that tune, nor would it feel as tractable, smooth, and quiet as a standard 1.2L today. So the standard engine already delivers large improvements over the standard engine 30 years ago, even though the power figure might appear similar. Actually the standard engine then was more likely to be a 1000cc with about 40bhp. Yet the standard engine now bears little resemblance to a racing unit. The development has moved in different directions.

Most modern small engines have been designed for their purpose and designed around production costs and efficiency; they are no longer race engines de-tuned for the road. I'm not sure there is that reserve for high-performance tuning that you might think. For example, with the long stroke for torque at low speeds, how high can the rev limit be raised? With the weight-saving thin open-deck block, how likely is it to crack under stress? And is there any such thing as a long-duration, high-lift cam for the FIRE engine? Will it fit in the cam-in-head design? Can double valve springs fit? What about high-flow injectors? Is there a short, fat manifold kit available?

Back in the 70s the FIAT 128 had an extremely short stroke: 80mm bore and 55mm stroke (1116cc), overhead cam and double valve springs as standard. A number of desirable race-engine features had been grafted in to the all-new engine design. Strangled with a single carb and tiny exhaust, 55bhp meant the engine had a lot more to give. Race versions existed with fuel injection and 150bhp at 10,000RPM, and that wasn't even a crossflow design. I doubt anyone has achieved this with an 8v FIRE engine, and there is a dearth of performance parts available compared against those older engines.

Why? I guess the answer lies somewhere between the easy availability of turbocharged petrol and diesel engines, and the difficulty in achieving emissions certification for any aftermarket modifications.

It would therefore be a real challenge to tune a modern small non-turbo engine - many parts like plastic manifolds would have to be thrown out or re-engineered - and not cost effective in the slightest. But it would be fun to see someone achieve it.

Instead we should probably recognise the steady improvements that have been made to the 1.2 in its standard form. Such wide gear ratios and quiet cruising at speeds up to 100mph would have been unthinkable with a 1.2 four-cylinder engine 30 years ago. And you do get a substantial power boost over the original 999cc FIRE engine from 1986 (45bhp).

-Alex

Here is a link on what you can do if you want to explore options to get more power out of a 1.2 - this is going outside the 'brief' of a tune-up.

A limiting factor on revs on a 1.4 is the hyradulic setup - you can't get beyond 7,000 rpm. There's a thread on changing the cam on the 1.4 to a hotter one but it ain't cheap (£500 ?) but some opt for it in preference to a port & polish. Emissions go 'out the window' with this mod. Don't know what can be done with the 1.2.

On a 127 sport I had a twin choke weber but the most it gave on the open road was 35mpg with it's south american 1049cc engine. In 127CL form with a 'standard' carb it gave 40mpg. Nowadays you can get power & economy with the 'modern' engines whilst in the 'old days' you had one or the other.

There was also the concept of a blueprint engine e.g. Ford's engines were mad money and some ended up putting Vauxhall engines in to get the 150bhp which didn't sit too well with some.

Not too sure about a 1.2 cruising at 100mph all day but in a 1.4 you can do 95mph in 'comfort', road premitting of course.