Whuts up guys, do u guys know what is the highest power rating achieved with the 1500 in NA form and what mods needs to be done. what would be the biggest cam etc. Thanx
Technical NA 1500 x19
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Technical NA 1500 x19
unoracer
New member
I am just having my race engine rebuilt, which is the 1498cc unit. It is fully lightened/balanced bottom end, pbs oil baffle plate, 87.00 pistons, jupiter power race head (3 angle cut seats, 40mm inlets, 35mm exhaust valves, race valve springs, 11:1 comp ratio, Piper 320 race cam, and Twin 45 dcoe webers. The last rolling road tune I had gave 173bhp at the flywheel. I am hoping it may even have a couple more this time around. I think I am pretty near the limit on bhp. I will have it rolling roaded around mid April time and so will post results as I get them for you.
OP
OP
thanx, pretty impressive power u getting there
Hi there I am much the same as uno racer my 1600 uno has been on the dyno at 156bhp at the wheels and that is with all the same gear as unoracers but with a quite mild cam that produces high torque not max hp. The cam is an aliquati item direct from italy. We would always like more horse power from the big high horse power cam from aliquati, but were advised that the power was very peaky and you would realy need a close ratio gearbox maximise it. As it is the extra torque we have is great on the race track with good pull out of the corners.
I dont know about the 1500 but I do know that dallara in the late 70s were getting over 190bhp out of the 1300cc running 48mm DCOE carbs, now that was big!!!!
I dont know about the 1500 but I do know that dallara in the late 70s were getting over 190bhp out of the 1300cc running 48mm DCOE carbs, now that was big!!!!
jimbro1000
Established member
The dallara engines are a bit misleading. Early cars used the 1300 but later cars were using a bigger engine with a custom built 16v head.
They had big reliability problems too - if you look at the history of the cars you will find that they didn't actually finish many races but then again this was GT racing and the races were much longer and it wasn't always the engine that failed.
If you ever get to look at how the cars were screwed together you will find that in some cases it is something of a miracle that the cars even got through qualifying and practice!
Now - my post from earlier that the site wouldn't accept because something broke:
The most you can reasonably get from the 1300 is around the 170bhp mark, for the 1500 the figure is around the 190bhp. I'm not saying these are absolute final figures as they are based on fairly old fuelling systems but they were proven reliable.
With modern management and fuel injection I'm pretty sure you could improve upon the "classic" setup which relied on mechanical fuel injection. Peak figures may be similar but overall performance is likely to be increased.
In terms of modifications the list is fairly lengthy. The head is a full on race job - chambers matched, 3 angle valve seats, enlarged inlet valve (maybe even reducing the size of the exhaust), relieved valve guides, ports enlarged and reprofiled, light valves, etc. The camshaft is likely to be a very aggressive profile with high duration, lift and overlap. The block will be overbored, destressed, lightweight balanced pistons and conrods, compression ratio raised to around 14:1 (racefuel only), crank lightened balanced and likely reshaped while the oil supply would be a dry sump arrangement with two or three scavenger pumps.
If you were to go down a more complex (and expensive route) there have been custom 16v heads built in the past that pushed the "maximum" figure upwards.
There have been stroker kits that took the 1500 engine up beyond 1600cc and while this only produces a moderate increase in peak power the gain in torque is more than worth the effort.
Ultimately though there are limits on what the block can handle, by modern standards it isn't that stiff and once the limits are exceeded all sorts of nasty things can happen. The block design itself was revised for the later punto gt's to increase the strength and this actually provides an extra benefit with oil sprays to the back of the pistons.
They had big reliability problems too - if you look at the history of the cars you will find that they didn't actually finish many races but then again this was GT racing and the races were much longer and it wasn't always the engine that failed.
If you ever get to look at how the cars were screwed together you will find that in some cases it is something of a miracle that the cars even got through qualifying and practice!
Now - my post from earlier that the site wouldn't accept because something broke:
The most you can reasonably get from the 1300 is around the 170bhp mark, for the 1500 the figure is around the 190bhp. I'm not saying these are absolute final figures as they are based on fairly old fuelling systems but they were proven reliable.
With modern management and fuel injection I'm pretty sure you could improve upon the "classic" setup which relied on mechanical fuel injection. Peak figures may be similar but overall performance is likely to be increased.
In terms of modifications the list is fairly lengthy. The head is a full on race job - chambers matched, 3 angle valve seats, enlarged inlet valve (maybe even reducing the size of the exhaust), relieved valve guides, ports enlarged and reprofiled, light valves, etc. The camshaft is likely to be a very aggressive profile with high duration, lift and overlap. The block will be overbored, destressed, lightweight balanced pistons and conrods, compression ratio raised to around 14:1 (racefuel only), crank lightened balanced and likely reshaped while the oil supply would be a dry sump arrangement with two or three scavenger pumps.
If you were to go down a more complex (and expensive route) there have been custom 16v heads built in the past that pushed the "maximum" figure upwards.
There have been stroker kits that took the 1500 engine up beyond 1600cc and while this only produces a moderate increase in peak power the gain in torque is more than worth the effort.
Ultimately though there are limits on what the block can handle, by modern standards it isn't that stiff and once the limits are exceeded all sorts of nasty things can happen. The block design itself was revised for the later punto gt's to increase the strength and this actually provides an extra benefit with oil sprays to the back of the pistons.
jimbro1000
Established member
Just a small note, if you want to know more about the Dallara cars (and engines) I suggest you look here: http://www.sfconline.org.uk/models/icsunonove/icsunonove.asp
OP
OP
we'll if i get the head flowed and ported,intake matched to head,40mm side draughts,276 deg cam,11:1 cr, balanced bottom end.what kind of power can i expect from that?.
jimbro1000
Established member
Finger in the air - I would say between 130bhp and 145bhp at the flywheel
A 276 cam profile is not hugely more aggressive than the standard european spec camshaft (272 degrees duration). I would suggest something between 280 and 288 degrees duration and stay away from manufacturers like piper and kent for the cam (only really likely if you are in the uk) as they don't seem to really understand the kind of profile needed for the Fiat SOHC engine.
Assuming you have ready access to quality fuel (98-100RON) then I would also recommend a higher compression ratio but that may require some custom pistons. Don't try taking too much material off the head face or decking the block, it can be done that way but it doesn't give the best results. A set of forged pistons is also the best choice for reliability, the standard pistons are good but they aren't *that* good.
You aren't going to see any major increases in power without sorting out the head. The standard inlet valves are too small and the head will need the combustion chambers matching and the ports evened up (if not opened up). Unoracer has a good lead there as Jupiter Racing can provide a superbly finished head with all the work already completed.
The carburettors are also likely to be too big for the specification you've outlined. A set of 38's would be more appropriate for road use, 40's for competition use where you want fuelling efficiency further up the rev-range. Preferable choice would be a set of throttle bodies and engine management to get the best out of it and it also allows you to run a much more aggressive cam profile without major sacrifices to low speed maneuvering.
A 276 cam profile is not hugely more aggressive than the standard european spec camshaft (272 degrees duration). I would suggest something between 280 and 288 degrees duration and stay away from manufacturers like piper and kent for the cam (only really likely if you are in the uk) as they don't seem to really understand the kind of profile needed for the Fiat SOHC engine.
Assuming you have ready access to quality fuel (98-100RON) then I would also recommend a higher compression ratio but that may require some custom pistons. Don't try taking too much material off the head face or decking the block, it can be done that way but it doesn't give the best results. A set of forged pistons is also the best choice for reliability, the standard pistons are good but they aren't *that* good.
You aren't going to see any major increases in power without sorting out the head. The standard inlet valves are too small and the head will need the combustion chambers matching and the ports evened up (if not opened up). Unoracer has a good lead there as Jupiter Racing can provide a superbly finished head with all the work already completed.
The carburettors are also likely to be too big for the specification you've outlined. A set of 38's would be more appropriate for road use, 40's for competition use where you want fuelling efficiency further up the rev-range. Preferable choice would be a set of throttle bodies and engine management to get the best out of it and it also allows you to run a much more aggressive cam profile without major sacrifices to low speed maneuvering.
sumplug
Established member
Compression ratio is too high for road use. try 10;5-1, with a 285 degree rally cam. Run 98-100 ron petrol. 40's will be ok, but you will need to use smaller chokes.
Be careful who you use to gasflow the head. This head is not the easiest to get right, and you need someone like Guy Croft who has vast experiance with this engine to do it right for you.
The bottom end is pretty robust as standard, so it depends on your budget if you want to beef it up for more revs. I would talk with someone like Guy Croft or Richard Beaty [WDR Direct], who will advise you the spec.
Andy.
Be careful who you use to gasflow the head. This head is not the easiest to get right, and you need someone like Guy Croft who has vast experiance with this engine to do it right for you.
The bottom end is pretty robust as standard, so it depends on your budget if you want to beef it up for more revs. I would talk with someone like Guy Croft or Richard Beaty [WDR Direct], who will advise you the spec.
Andy.
nateelgrate
New member
I have a 1980 which I bought for $100. Bondo'd the car up, primered it, it looks pretty nice even primered, I have 2006 Sunfire Seats, and some new interior parts. This car is gonna be about $400 total, and have a sweet interior (including clarion cd player). So i would love to get more than 85 crank horsepower out of it. the CHEAP way, anyway i could clear up a dozen ponies or so easily? Thanks
