Scania L94UB CNG

[PoweredByCNG]

G'day all,

Do the newer ACTION Scania L94UBs fitted with the OC9 G02 260 engine perform noticeably better than the earlier ones fitted with the OSC9 G01 engine?  Are the gearshift points set differently?  I remember watching a video of an earlier unit where the gearchanges were horribly slow and delayed.

[CNG]

I don't think so, it was probably the bus itself :)

[Buzz Killington]

I don't get Scanias all that often, but to my recollection the later ones (362 on) are somewhat smoother.

Someone who catches them (or drives them) more often would be able to tell you for sure.

[Snorzac]

I find that the best ones are anything from 368 to 373 excluding 372 which is completely different to all of them. They seem to get off the mark a little quicker and the gearboxes are slightly smoother.

[Irisbus Rider]

The changes are definately evident in 362, 367-373 compared to the remainder of the fleet. From my experiences, the gear changes in the first few gears in these buses are quite sudden, which does not rev the engine out, opposed to the remainder of the Scanias (320-361, 363-366).

The performance is much better in the buses equipped with the "OC9 G02" engine, hands down. It almost feels like there is more torque in the "OC9 G02" engines, I'm not sure.

I for one, would be interested if you could post the specs of the two engines, "Powered By CNG", if you have the data, that is.

[PoweredByCNG]

OSC9 G01 (Euro 3): 191kW @ 2000rpm, 970Nm @ 1400rpm
OSC9 G01a (Euro 5/EEV): 191kW @ 2000rpm, 990Nm @ 1250-1400rpm
OC9 G02 260: 191kW @ 2000rpm, 1100Nm @ 1000-1400rpm
OC9 G03 300: 221kW @ 2000rpm, 1250Nm @ 1000-1400rpm

All the above engines are based on the Euro 3 6-cylinder 9-litre engine and have IMPCO fuel delivery systems, comprising of an air-valve mixer and multi-stage regulator.  All are full-time lean-burn (Lambda > 1.5) and have two way (oxydising) catalytic converters.

The OC9 G04/G05 engines reportedly have sequential gas injection, EGR, variable geometrey turbocharging, stoichiometric (Lambda = 1) combustion with three way catalytic converter and other emissions-reducing features.  These new engines are based on the Euro 4 diesel 8.9-litre 5-cylinder engines with 4-valves per cylinder.

[Irisbus Rider]

Fantastic, thanks very much for those stats. And those stats explain the way the buses behave, as the buses fitted with the OC9 G02 engines do have that 'push', which is explained by the torque and the range at which the maximum torque is delivered.

But wow, 970Nm of torque for the OSC9 G01 buses is pathetic, that somewhat explains the poor performance displayed by them.

[PoweredByCNG]

You think 970Nm @ 1400rpm is bad?  Mercedes-Benz gas buses of that era had 880Nm @ 1000rpm and MANs were worse - 860Nm @ 1000rpm.  I still reckon that a good Mercedes-Benz O 405 NH CNG would outperform an early Scania L94UB CNG though mainly due to lack of turbo-lag and because some 90% of peak torque is available from idle on the 12-litre Merc engine.

[Irisbus Rider]

You think 970Nm @ 1400rpm is bad?  Mercedes-Benz gas buses of that era had 880Nm @ 1000rpm and MANs were worse - 860Nm @ 1000rpm.

I didn't think a bus could get slower than an L94 on gas, ha ha, seems as though I was wrong!