ESE's works engine tuner

[Muhr]

When flowsimulating, are you simulating constant flow or flow with high pressure that gets lower as the piston moves further down the bore, and that actually gets below 1bar absolute at btdc?

I´d say constant flow is way off from what´s happing for real in the transfers.

I agree with its complexity to recreate this in the computer. There of my interest in the results TDC211 has. What I do is like a flow bench, but at significantly higher flow speeds, which is required for air to begin to vary in density.

[tdc211]

I agree with its complexity to recreate this in the computer. There of my interest in the results TDC211 has. What I do is like a flow bench, but at significantly higher flow speeds, which is required for air to begin to vary in density.

And what changes combustion efficeny?
The density?

[wobbly]

DEA use a pulsed flow bench, that effectively recreates the actual flow regime in the transfers .
This gives a much more accurate representation of reality and can be used reliably to predict power.
I met Yamaha's GP technical director in 2000 and he said that that they had just reached the stage where using the CNC Czech flow visualizer
they could accurately predict the power by being able to see and analyse the trapping and scavenging efficiency of the ports in a cylinder.
They had used it to develop the 250 ( title winning twin ) after years of not being even close in Hp , though that was also in part due to finally ditching the stupid oversquare bore size.

[oktrg500]

Hey, where's Adegnes our favourite Norwegian shed drinking scooter fiend these days?

https://www.youtube.com/results?sp=C...troke+stuffing

[dutchpower]

DEA use a pulsed flow bench, that effectively recreates the actual flow regime in the transfers .
This gives a much more accurate representation of reality and can be used reliably to predict power.
I met Yamaha's GP technical director in 2000 and he said that that they had just reached the stage where using the CNC Czech flow visualizer
they could accurately predict the power by being able to see and analyse the trapping and scavenging efficiency of the ports in a cylinder.
They had used it to develop the 250 ( title winning twin ) after years of not being even close in Hp , though that was also in part due to finally ditching the stupid oversquare bore size.

Anemometric bench

[jamathi]

DEA use a pulsed flow bench, that effectively recreates the actual flow regime in the transfers .
This gives a much more accurate representation of reality and can be used reliably to predict power.
I met Yamaha's GP technical director in 2000 and he said that that they had just reached the stage where using the CNC Czech flow visualizer
they could accurately predict the power by being able to see and analyse the trapping and scavenging efficiency of the ports in a cylinder.
They had used it to develop the 250 ( title winning twin ) after years of not being even close in Hp , though that was also in part due to finally ditching the stupid oversquare bore size.

Yamaha won the title because Guy Coulon, tech 3's chief mechanic, made copies of the Honda cylinders for their Yamaha's, without Czech flow visualizer. They also used a copy of the Aprilia fairing, offered to them by an ex-Aprilia aerodynamicist. We had such a Czech flow visualizer at Aprilia, it proved to be completely useless. DEA made his own, I don't know of any results.. The best pulsed flowbench is the engine itself....

[SwePatrick]

After years of flow testing I concluded that flow testing the transfers makes no sense.
More flow often means less power.
So we decided that power-testing was the best thing to do!

That´s exactly what my own logic says to me.
One cannot copy real world scenarios.

Pressure oscillation in crankhouse.
Backpressure from exhaust varies.
Piston moves and disturbes flow.
The ports are fully open on a fraction of a second.

And so on and so on.

I would say that an electrical engine that pulls the engine to test at different rpm´s, whole cranksystem with piston etc etc is about as close as you can get if you measure the air pumped through the cylinder.
But when adding spark,fuel and a pipe, all is changing as there comes a lot of new variables in the game.

So, dyno is by far the best.

[ken seeber]

The racetrack is the ultimate tool, the dyno being the second most representative. However there are lots of other tools eg EngMod, Frit’s FOS exhaust formula, Jante rigs, Gordon Blair’s CO2 single cycle rig, empirical guides for port areas, etc, etc. If DEA have success with their rig then for them they have a good tool to shorten dev’t costs and time…

Importantly, 2 hours and Jack Miller is off from P2…can’t wait.

[jamathi]

The racetrack is the ultimate tool, the dyno being the second most representative. However there are lots of other tools eg EngMod, Frit’s FOS exhaust formula, Jante rigs, Gordon Blair’s CO2 single cycle rig, empirical guides for port areas, etc, etc. If DEA have success with their rig then for them they have a good tool to shorten dev’t costs and time…

Importantly, 2 hours and Jack Miller is off from P2…can’t wait.

DEA is not going very well. they will probably transfer to Slovenia....

[Frits Overmars]

DEA is not going very well. they will probably transfer to Slovenia....

It's already been done. Last week Andrea told me that he has now finished moving all his equipment, including his magnesium foundry, to Romania.
Italian tax legislation made it impossible for him to make a profit, so he felt forced to move out.

[SwePatrick]

The racetrack is the ultimate tool, the dyno being the second most representative.

Yeah,, only problem i ain´t got a track in my garage =)

[Peter1962]

It's already been done. Last week Andrea told me that he has now finished moving all his equipment, including his magnesium foundry, to Romania.
Italian tax legislation made it impossible for him to make a profit, so he felt forced to move out.

Will he still be active in contruction of 2 stroke competition engines ? The 125cc kart market seems to become a TM-only market...

[Frits Overmars]

Will he still be active in contruction of 2 stroke competition engines ? The 125cc kart market seems to become a TM-only market...

Yes he will. And it's true that TM has a firm grip on the 125 cc shifter kart market, although DEA has a beautiful KZ125 engine; the only one in its class with a balance shaft and a coolant pump, while all other engines rely on a rear axle-driven pump that does nothing for engine cooling when you are gassing it on the start line.

[schutten]

Will he still be active in contruction of 2 stroke competition engines ? The 125cc kart market seems to become a TM-only market...

But yesterday Patrik Hajek became FIA ​​Karting World Champion with a VORTEX engine.
Maybe more vortex from now on :P

[Muhr]

And what changes combustion efficeny?
The density?

What I can see in sim is that if you are flowing at higher speeds you can see that the smaller transfer is picking up speed further down in the transfer because of it seems to have a less tendency to choke as we approach the transfer port . You can begin to see it after about 0.0008 sec. On the left incompressible, right compressible, up speed and down pressure / density. If this would have any effect in reality then it should start to be clear after 10000 rpm