That would be an interesting design...godlameroso wrote: ↑07 Apr 2017, 19:02Even more if the piston itself forms part of the pre-chamber. Then the flame jets can be incorporated into the piston crown.
That would be an interesting design...godlameroso wrote: ↑07 Apr 2017, 19:02Even more if the piston itself forms part of the pre-chamber. Then the flame jets can be incorporated into the piston crown.
Wazari hinted at this some 80 pages backdren wrote: ↑07 Apr 2017, 19:16That would be an interesting design...godlameroso wrote: ↑07 Apr 2017, 19:02Even more if the piston itself forms part of the pre-chamber. Then the flame jets can be incorporated into the piston crown.
As in torsional rubber dampers ? They are allowed but not very useful - they can only dampen (effectively splitting the resonating mode into 2 modes with smaller amplitudes) the frequency they are tuned for.
Where did this text come from? It seems to be incomplete and I'm curious to read more of it.FW17 wrote: ↑05 Apr 2017, 08:52How are these prechamber spark plugs different to TJI? Is it just the flame length and duration are longer? Or do they offer better control?Two types of pre-chamber spark plugs were sampled, i.e. a 3kΩ resistor pre-chamber spark plug and a non-resistor spark plug. The resistor pre-chamber spark plug has four injection orifices on the front end surface, while the non-resistor spark plug has three slightly smaller holes on the front end surface and three tiny holes on the side cylindrical surface for a better scavenging effect. A NGK resistor spark plug (5 kΩ) with a v-groove center electrode and a J-type ground electrode was also tested to benchmark the pre-chamber spark plugs.
Figure 1 gives the ignition flame images at 5ms after spark initiation for premixed methane-air mixtures with an excess air ratio of 1.6. It is clear that the ignition flame propagation for the two pre-chamber spark plugs was faster than the NGK spark plug. The non-resistor pre-chamber spark plug produced much faster flame jet due to the increased spark energy. The wrinkled flame front accelerated the combustion speed.
In the other experiment, we compared the ignition processes for the MXTL resistor pre-chamber spark plug, the Tongxin’s iridium fine electrode spark plug (EIX-BKR6 11) and thick electrode spark plug (E-BKR6). The excess air ratio of methane-air mixture was set at stoichiometric. Figure 2 shows the flame
images at 2ms and 4ms after spark initiation. It can be seen that the iridium fine electrode spark plug spark plug can produce a faster flame kernel growth than the thick electrode spark plug. The flame front
of the MXTL pre-chamber spark plug appears later than the other spark plugs, but the post-ignition flame propagation was accelerated due to the turbulent flame jet effect.
The ignition performance of non-resistor pre-chamber spark plug can be further enhanced via capacitor discharge. Figure 3 gives the flame images with enhanced capacitor discharge at excess air
ratio of 1.0, 1.2 and 1.4 respectively. It can be seen that the capacitor discharge significantly accelerated the flame jet velocity; hence it increased the ignition flame propagation especially prominent at lean mixtures.
New gearbox for Alonso...
I do not think so, but McLaren usually works well and fast, they have rolled little and slowly ... I really do not know what to think...Maybe it is not a complete redesign of the gearbox, they may have changed something in particular.godlameroso wrote: ↑07 Apr 2017, 23:59New gearbox for Alonso...
Surely McLaren couldn't have designed a new box in such a short time.
Except that in the 2-stroke, the DFI event has to take place in the short period after the exhaust port is closed by the piston prior to TDC, to avoid loss of charge/excess emission.Tommy Cookers wrote: ↑07 Apr 2017, 11:57no it's not equivalentJ.A.W. wrote:Bear in mind, the affordable/available BRP ETEC DI 'voice coil' system - is rated for use up to 10,000 rpm...
...& that - on a 2-stroke, which is equivalent to a 4-stroke turning 20,000 rpm...
because injection 'speed' ie time window available falls at higher rpm independent of number of injection events per cycle or per rev
unless we are happy to inject fuel rather early relative to combustion ?
And thats why Ferrari develop advanced 3D printing along with their vendor. Well, I miss wazari so muchgodlameroso wrote: ↑07 Apr 2017, 19:19Wazari hinted at this some 80 pages backdren wrote: ↑07 Apr 2017, 19:16That would be an interesting design...godlameroso wrote: ↑07 Apr 2017, 19:02Even more if the piston itself forms part of the pre-chamber. Then the flame jets can be incorporated into the piston crown.![]()
Mudflap wrote: ↑07 Apr 2017, 21:50As in torsional rubber dampers ? They are allowed but not very useful - they can only dampen (effectively splitting the resonating mode into 2 modes with smaller amplitudes) the frequency they are tuned for.
In comparison a viscous damper will dampen any mode (provided the shear rate stays within reasonable limits) while a pendulum damper will dampen a whole order.
No, not a torque converter - its a type of torsional damper, using viscous fluid..
http://www.apyeco.com/index.php/3-eco-f ... park-plugs3jawchuck wrote: ↑07 Apr 2017, 22:12Where did this text come from? It seems to be incomplete and I'm curious to read more of it.FW17 wrote: ↑05 Apr 2017, 08:52How are these prechamber spark plugs different to TJI? Is it just the flame length and duration are longer? Or do they offer better control?Two types of pre-chamber spark plugs were sampled, i.e. a 3kΩ resistor pre-chamber spark plug and a non-resistor spark plug. The resistor pre-chamber spark plug has four injection orifices on the front end surface, while the non-resistor spark plug has three slightly smaller holes on the front end surface and three tiny holes on the side cylindrical surface for a better scavenging effect. A NGK resistor spark plug (5 kΩ) with a v-groove center electrode and a J-type ground electrode was also tested to benchmark the pre-chamber spark plugs.
Figure 1 gives the ignition flame images at 5ms after spark initiation for premixed methane-air mixtures with an excess air ratio of 1.6. It is clear that the ignition flame propagation for the two pre-chamber spark plugs was faster than the NGK spark plug. The non-resistor pre-chamber spark plug produced much faster flame jet due to the increased spark energy. The wrinkled flame front accelerated the combustion speed.
In the other experiment, we compared the ignition processes for the MXTL resistor pre-chamber spark plug, the Tongxin’s iridium fine electrode spark plug (EIX-BKR6 11) and thick electrode spark plug (E-BKR6). The excess air ratio of methane-air mixture was set at stoichiometric. Figure 2 shows the flame
images at 2ms and 4ms after spark initiation. It can be seen that the iridium fine electrode spark plug spark plug can produce a faster flame kernel growth than the thick electrode spark plug. The flame front
of the MXTL pre-chamber spark plug appears later than the other spark plugs, but the post-ignition flame propagation was accelerated due to the turbulent flame jet effect.
The ignition performance of non-resistor pre-chamber spark plug can be further enhanced via capacitor discharge. Figure 3 gives the flame images with enhanced capacitor discharge at excess air
ratio of 1.0, 1.2 and 1.4 respectively. It can be seen that the capacitor discharge significantly accelerated the flame jet velocity; hence it increased the ignition flame propagation especially prominent at lean mixtures.
Only 11kph slower at the traps. I agree it seems like progress.godlameroso wrote:Probably talking about how good the Ferrari engine is.
In other news McLaren was 3 seconds off the pace in Melbourne, they're 2.5 seconds off the pace in a longer track, with a much longer straight, so I guess we can consider this progress. I didn't see any McLaren onboards, do they still have the grinding upshifts?