Carcano, perhaps the following will be of help. The tests were of a engine designed especially for alcohol with a 19.5 to 1 compression ratio and a three-way catalytic converter:
Engine Type 4 cyl., 4-stroke
Combustion Type PFI, SI
Displacement 1.9L
Valves per cylinder 2
Bore 79.5 mm
Stroke 95.6 mm
Compression Ratio 19.5:1
IVO -344o ATDC*
IVC -155 o ATDC*
EVO 152 o ATDC*
EVC 341 o ATDC*
Bowl Volume 18 cc
Clearance volume 26.4cc
Swirl Ratio 2.0
Injectors Holley, 36 lb/hr, 12-hole
nozzle
Rail Pressure 4 bar
Spark Plugs Champion recessed
gap, dual electrode
Turbocharger type Variable geometry
Exhaust
Aftertreatment
Ford FFV 2-stage,
three-way catalyst
Methanol-fueled
engines using high levels of EGR to modulate load [21-
23] have demonstrated efficiency gains of greater than
10% over throttled engines, while giving considerably
lower NOx emissions. Combining variable EGR rates
with variable intake manifold pressure allows for a wider
range of load control. This strategy has also been
shown as an effective means of achieving NOx levels
below 1.0 g/kW-hr and peak efficiency around 42% in DI,
lean stratified-charge methanol engines [23] and similar
improvements in PFI lean burn methanol engines [24].
In the present engine, EGR and boost levels are
maintained to achieve the best NOx and efficiency, and
still enabling MBT (or near MBT) spark timing at high
loads. Manifold absolute pressure (MAP) was varied
between 1.0-1.5 bar, while the maximum dilution level
was limited to about 50% EGR. Throttling, meanwhile,
was used only to achieve near-idle loads.
The engine is controlled to stoichiometric fueling,
enabling use of a three-way catalyst for attainment of
emissions at the levels required to achieve Federal Tier
II LDV standards. Earlier experience operating lean with
an oxidation catalyst [16] showed the ability to achieve
Tier II-level emissions on a methanol vehicle for all but
NOx, pointing to the need for a three-way catalyst.
http://www.epa.gov/otaq/presentations/sae-2002-01-2743.pdf
Edit: By the way, both methanol and ethanol were tested in the engine. Overall, methanol gave the best results. Methanol results were slightly better than diesel in a STOCK VW TDI engine, while ethanol was about equal. The VW diesel engine was burning petrodiesel. Now, remember the gains achieved with biodiesel over petrodiesel?