So why on earth would I do something like that? I've owned and maintained my 98' Seicento sporting the past six years exclusively on information from this forum and it has been invaluable! This is my third Fiat, previous ones were a 90' Tipo and an 80-something Yugo Zastava (with an original fire engine), so I'm well groomed for adventurous engine parts swaps. My dad was a certified Fiat mechanic until 1983 so I grew up with Fiats to some extent. Yeah, I'm old and should be able to afford a proper car, but Fiats are a life long love affair.
Here's the deal: As a daily driver, the Seicento is plenty peppy, but driving it economically around 2000-2500 rpm in the is difficult as others have found out. The low weight of the car makes up for that to a great extent, but still. it is 25% to 30% higher in consumption than newer cars. The reason for this is it's aggressive camshaft 7 degrees overlap and high lift. So I looked around and found out that the newer punto 60 mk2 1242 don't have this high city consumption in NEDC test as earlier Fiats and what they have done differently is a lower lift, lower overlap cam. Looking at BSFC charts for both engines the Seicento reaches peak efficiency at 4000 rpm, whereas the newer Punto gets there around 2700-3100 rpm, which means that it is better matched for a life outside the track.
So I started to crunch numbers: If I correct for the Punto's larger frontal area but slightly lower, Cd the Seicento is still a less demanding car to push down the road ( around 20% less power needed at 100 kM/h. The Punto uses 4.8L/100kM and my Seicento 4.9L/100kM highway (which is spot on to what I achieve in real life too) All in all, I should be able to get around 4.4L/100kM and less than 4L/100kM at 60kM/h which I get now which suggests poor engine efficiency at low rpm. An added benefit would be less HC and other emissions!! (I'm going to get kicked out of this forum for being a wuss and not going for more power, I know).
The big question: does a 2000 Punto 60 mpi euro3 1242 camshaft still fit the 1108 head?? Worded differently; have anyone with a new punto swapped the cam for a more racy older mk1 one to gain top end power? are the "until 1999 1108cc" and the "post 1999 1242cc" heads still the same in respect to cams??
Valve clearance on the new Punto is 0.3 and 0.4 as opposed to the Seicentos 0.4 and 0.5, but that is not necessary a sign of incompatibility but could be due to less thermal expansion on a car not intended to be driven hard and stricter rev limiter? Valve shims are the same 31mm and pictures of the Punto cam looks to have the lobes and bearings the right places. On the older heads the cams were interchangeable between 1108 and 1242.
I do know I loose top end by that, possibly already at 4000 rpm, but this is something I really want to pursue because things like that are immensely fun.
Cheers
Here's the deal: As a daily driver, the Seicento is plenty peppy, but driving it economically around 2000-2500 rpm in the is difficult as others have found out. The low weight of the car makes up for that to a great extent, but still. it is 25% to 30% higher in consumption than newer cars. The reason for this is it's aggressive camshaft 7 degrees overlap and high lift. So I looked around and found out that the newer punto 60 mk2 1242 don't have this high city consumption in NEDC test as earlier Fiats and what they have done differently is a lower lift, lower overlap cam. Looking at BSFC charts for both engines the Seicento reaches peak efficiency at 4000 rpm, whereas the newer Punto gets there around 2700-3100 rpm, which means that it is better matched for a life outside the track.
So I started to crunch numbers: If I correct for the Punto's larger frontal area but slightly lower, Cd the Seicento is still a less demanding car to push down the road ( around 20% less power needed at 100 kM/h. The Punto uses 4.8L/100kM and my Seicento 4.9L/100kM highway (which is spot on to what I achieve in real life too) All in all, I should be able to get around 4.4L/100kM and less than 4L/100kM at 60kM/h which I get now which suggests poor engine efficiency at low rpm. An added benefit would be less HC and other emissions!! (I'm going to get kicked out of this forum for being a wuss and not going for more power, I know).
The big question: does a 2000 Punto 60 mpi euro3 1242 camshaft still fit the 1108 head?? Worded differently; have anyone with a new punto swapped the cam for a more racy older mk1 one to gain top end power? are the "until 1999 1108cc" and the "post 1999 1242cc" heads still the same in respect to cams??
Valve clearance on the new Punto is 0.3 and 0.4 as opposed to the Seicentos 0.4 and 0.5, but that is not necessary a sign of incompatibility but could be due to less thermal expansion on a car not intended to be driven hard and stricter rev limiter? Valve shims are the same 31mm and pictures of the Punto cam looks to have the lobes and bearings the right places. On the older heads the cams were interchangeable between 1108 and 1242.
I do know I loose top end by that, possibly already at 4000 rpm, but this is something I really want to pursue because things like that are immensely fun.
Cheers
