http://picasaweb.google.co.uk/lindborg.stuart/Z22VsSAAB
CBA to link them all direct, and my work block most photohost sites so
The nice clean spangly head is Matts (techieboy) and the grubby rusty cammed head is my SAAB 1.8 turbo head.
we measured the inlet cam profile on Matts head, although not 100% accurately as the timing protractor I had was too big to fit in the f**king slot lol. Ive got an idea to remedy that by testing on the bench and using the rocker ratio to get real lift.
As a "poor" guess/feel the inlet and exhaust cams are the same profile for both heads, but the overlap timing will be different for the SAAB due to FI requirements being different.
I know this is documented in the appendix of the GM tuning book.
There are casting differences between the two heads in that the oil run aways appear slightly different, maybe to hold oil round the FI head exhaust valves for cooling...
Also the obvious lug on the non chain end of the head over the exhaust valve... will work out how to get round that, but im thinking of just cutting the end of the cam off to keep the oilway pressureised
The Z22 valves have more of a depression in them leading to the head making a lower CR, so the small drop in CR between the FI and N/A engines is in the pistons (as one would hope for to be honest)
As a side note, Matts head has been ported and to be fair, a bloody good job imho. All the right bits have been worked, the correct finish has been left and the splitter is nice and sharp for both sides of the head. Should work rather well once he works out how to get it on the car nana.gif
CBA to link them all direct, and my work block most photohost sites so
The nice clean spangly head is Matts (techieboy) and the grubby rusty cammed head is my SAAB 1.8 turbo head.
we measured the inlet cam profile on Matts head, although not 100% accurately as the timing protractor I had was too big to fit in the f**king slot lol. Ive got an idea to remedy that by testing on the bench and using the rocker ratio to get real lift.
As a "poor" guess/feel the inlet and exhaust cams are the same profile for both heads, but the overlap timing will be different for the SAAB due to FI requirements being different.
I know this is documented in the appendix of the GM tuning book.
There are casting differences between the two heads in that the oil run aways appear slightly different, maybe to hold oil round the FI head exhaust valves for cooling...
Also the obvious lug on the non chain end of the head over the exhaust valve... will work out how to get round that, but im thinking of just cutting the end of the cam off to keep the oilway pressureised
The Z22 valves have more of a depression in them leading to the head making a lower CR, so the small drop in CR between the FI and N/A engines is in the pistons (as one would hope for to be honest)
As a side note, Matts head has been ported and to be fair, a bloody good job imho. All the right bits have been worked, the correct finish has been left and the splitter is nice and sharp for both sides of the head. Should work rather well once he works out how to get it on the car nana.gif
