Pneumatic MotoGP

[imdying]

This should make for an interesting turn of events... http://uk.eurosport.yahoo.com/060720...ew-engine.html

[xwhatsit]

They've been doing that in F1 for some time, haven't they?

Super mega high revving MotoGP, woot.

[onearmedbandit]

Yeah they have. This should be interesting.

[slowpoke]

Hmmm, desmodromics vs pneumatics, things are about to get verrrry interesting.......

[steved]

Haven't Suzuki and Kawasaki been using Pneumatic valves on their MotoGP bikes for a little while already?

http://blogger.xs4all.nl/daisy/archi...03/254593.aspx

[steved]

They've been doing that in F1 for some time, haven't they?

Super mega high revving MotoGP, woot.

The problem will be not enough fuel. With the smaller 21L tank this year, you just can't keep increasing the revs to get more power. They are already pushing the envelope fuel-wise.

[TonyB]

Yeah, a few of them ran out just before the end of the race or on the cool down/ parade lap after. Buuuuuuut, the idea of high revving engine is to produce more HP by making the same torque higher up the rev range and make more torque at the back wheel by using lower gearing. Would reving higher necessarily use more fuel, particularly when the drag of operating valves no longer exists? I'm thinking they will be able to rev a whole lot higher and still use the same amount of fuel

[Mental Trousers]

That's a tad misleading. Pneumatic valves implies they get rid of the cams, cam chain etc, but they don't. All they do is remove the metal springs and replace them with pneumatic springs.
When you start getting silly revs out of engines the main limiting component is valve springs not being able to close the valves fast enough. If the valves don't close, the piston hits them and the engine becomes a handgrenade.
With gas, you just up the pressure when you up the revs. Then the limiting factors are things like conrods which have to hold onto even faster moving pistons.

[Skunk]

That's a tad misleading. Pneumatic valves implies they get rid of the cams, cam chain etc, but they don't. All they do is remove the metal springs and replace them with pneumatic springs.

That's true. But here's an interesting piece of info:

While pneumatic valve springs have become standard in Formula 1 engines, Renault has been researching computer controlled electromagnetic valves using no camshaft, to reduce moving parts while improving valve control.

Renault being the pneumatic valve 'inventors'.

[slowpoke]

I understood that they can already make bike engines capable of phenomenal revs thanks to improved metallurgy, titanium valves etc but the problem is one of useability and tractability rather than ultra high revs.
The pneumatics will be used to allow cam profiles where the valve is opened and closed incredibly quickly without losing control of the valve as happens with springs. This is also the advantage of Ducati's desmodromic system. Compared to conventional springs this means that for the same duration cam more time is spent with the valve in the desired position (open/closed) rather than in transition, hence the engine is more efficient.

[sAsLEX]

That's a tad misleading. Pneumatic valves implies they get rid of the cams, cam chain etc, but they don't. All they do is remove the metal springs and replace them with pneumatic springs.

I have seen truck engines or maybe a prototype, lower revs, using ECU controlled rather than cam controlled air valves ( that pneu word is too hard to spell!) .

As each cam profile is a compromise, Honda get round it by effectively using two cams in vtech, cant be too long before we have the EFI equivalent of valve control.

[Crowdog]

Solinoid valves or ECU controlled would be the way to go as your cam would become electronic so you could have it as mild or as wild as you want anywhere in the rev range

[cowpoos]

Buuuuuuut, the idea of high revving engine is to produce more HP by making the same torque higher up the rev range and make more torque at the back wheel by using lower gearing. Would reving higher necessarily use more fuel, particularly when the drag of operating valves no longer exists? I'm thinking they will be able to rev a whole lot higher and still use the same amount of fuel

theres a heap of mechanical losses in a high reving engine based on friction on the reciprcating parts...and the inertia created by the parts reciprocating and super high speeds is not at all desired from a handling point of veiw..the higher a engine revs the stronger metals have to be..and they also generally get a lil heavier...I could carry on...theres heaps of reasons why high reving engines are anti-productive...in 1974 the tz500 two stroke race bike made 95-ish hp...and rev ceiling of 10,000rpm...in 2002... 195hp and a rev ceiling of 12500rpm...so that tells us theres heaps you can do a engine with development that doesn't involve raising the rev ceiling...
also they have to make an engine that is easy to ride...that also has an cosistant as possible loading on the rear suspension as possible...beable to give a tyre a breather between power pulse's...which are all easier to achieve with a lower reving V-twin like power delivery...

That's a tad misleading. Pneumatic valves implies they get rid of the cams, cam chain etc, but they don't. All they do is remove the metal springs and replace them with pneumatic springs.
When you start getting silly revs out of engines the main limiting component is valve springs not being able to close the valves fast enough. If the valves don't close, the piston hits them and the engine becomes a handgrenade.
With gas, you just up the pressure when you up the revs. Then the limiting factors are things like conrods which have to hold onto even faster moving pistons.

yep yep yep!!!!!!

I understood that they can already make bike engines capable of phenomenal revs thanks to improved metallurgy, titanium valves etc but the problem is one of useability and tractability rather than ultra high revs.

yep yep yep!!

The pneumatics will be used to allow cam profiles where the valve is opened and closed incredibly quickly without losing control of the valve as happens with springs. This is also the advantage of Ducati's desmodromic system. Compared to conventional springs this means that for the same duration cam more time is spent with the valve in the desired position (open/closed) rather than in transition, hence the engine is more efficient.

thats exactly what I believe to be the reason for the change to puematic valve springs...more control at higher lifts and duration...with better over all control.

[cowpoos]

on a side note...I wonder if any of the big teams have experimented with rotary valves...they have the advantage of being incredibly efficent once refined!!!

[imdying]

Very interesting... but the reason I posted it in 'Racing' was more that it's Yamaha doing it. Should be good value given that currently the only thing that every race we wonder what the effect of 'extra speed' the Ducati has will be. What does this mean for the championship? A bold move propelling Yamaha to victory? Or something that'll all alfict reliability and hand the championship to Ducati? Yamaha will probably well have their shit together before they use it, but...