Supongo que el Beta1 es el que montan los First y Turbulences BETA y el Beta2 es el que montan los Tuscanis BETA.

Sacado de RDTiburon:

CitarInfo taken from: http://autoweb.drive.com.au/cms/A_55048/newsarticle.html

Engine upgrades replicate Elantra-from-Lantra improvements, ie:

Redesigned block with external contouring of cylinder bores (ilo flat sides), extra ribbing & one extra transaxle fixing point (now 5)(less NVH)
Crankshaft now has 8 counterweights ilo 4.(NVH)
Cast & ribbed aluminium sump pan (ilo pressed steel sheet) with stronger joint to transaxle (NVH)
Reshaped combustion chambers, ports & pistons (performance, [fuel] economy, emissions)
20mm longer intake rams, 8% smaller surge tank, resonator added, spark timing & valve lift optimized, lighter valve springs, denser conrod bearings, returnless fuel system (ilo return type) with higher fuel pressure & smaller injectors (torque spread & econ)
Cylinder head machined to more precise tolerances
Head gasket now 2-layer (ilo 3)
Idle speed reduced to 700 rpm from 800 rpm (NVH)
Hydraulic engine mounts (4) ilo rubber (NVH)
Heat shield installed between engine & air filter, reducing heating of induction air (+2% output).
New camcover with I-piece high-specific gravity polypropylene baffle (ilo 2-piece pp)
Oil flow reduced (econ)
Mechanical valve lash adjusters (solid lifters) replace hydraulic, improving valve clearance precision (durability).
Lower valve spring load reduces valve train friction (perf).
Engine cover installed (NVH & dress up engine bay)
Catalytic converter now upstream adjoining exhaust manifold (ilo under car) (emissions)
Other detail changes to: alternator, intake manifold brace, power steering & a/c pulleys, idle speed actuator, oil filler cap & drive plate between engine & torque converter

Tienen más diferencias de las que creía... me parece raro el ralentí a 700rpms en el Tusca, no es muy bajo? y nosotros lo tenemos a 800rpms? pues el mio por lo menos no es así, yo lo tengo por unas 900rpms, estando el motor en temperatura optima... en frio está a más de 1000rpms.

yo si en frio piso el embrague.. ay veces k sepone a 2000 jajajaj tengo un type r jajaj