California does it again

[big J]

The very fact that someone wants to be a politician should bar them from any sphere of influence for life.

[Guest Nogbad]

Is nobody going to talk about how long it takes an air-cooled engine to warm-up?

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Rather less time than a liquid cooled engine, hence the discovery that the old air cooled lumps have less trouble than expected with Euro 3.

[Guest Nogbad]

The very fact that someone wants to be a politician should bar them from any sphere of influence for life.

62844[/snapback]

 

I wouldn't mind being a politician.......

[big J]

I wouldn't mind being a politician.......

62846[/snapback]

 

I always wanted to be ..............................a lumberjack.

 

In the Canadian Rockies

 

Striding through the wilderness, logging the trees, the Maple, the Douglas Fir, the mighty Scots Pine

 

With my girl by my side

 

And singing, singing,singing..............

 

I'm a.........

[Guest Nogbad]

I always wanted to be ..............................a lumberjack.

 

In the Canadian Rockies

 

Striding through the wilderness, logging the trees, the Maple, the Douglas Fir, the mighty Scots Pine

 

With my girl by my side

 

And singing, singing,singing..............

 

I'm a.........

62848[/snapback]

 

lumberjack and I'm ok

 

I sleep all night and I work all day

 

I cut down trees, I eat my Lunch

 

I go to the lava... treee

 

on Wednesdays I go shopping, and have buttered scones for tea

 

Oh I'm a lumberjack.........

[big J]

There are now loads of folk, humming happily away

[Guest AdamofKC]

So... Air-cooled engine produce less overall harmfull emmissions due to the fact that they cannot run at higher rpms than lc engines?

 

Do dual plugs help the ac engine? And are more valves more efficient for emmision control in ac engines? Or does it just add to the problem?

[callison]

So... Air-cooled engine produce less overall harmfull emmissions due to the fact that they cannot run at higher rpms than lc engines?

Honda's air-cooled 125cc 5 cylinder ran 22,500 rpm.

 

Do dual plugs help the ac engine?

Yes for the two valve engine, no for a combustion chamber where the plug is centrally located such as the 4 valve engine.

 

And are more valves more efficient for emmision control in ac engines?  Or does it just add to the problem?

62862[/snapback]

Anything that promotes combustion efficiency is good for emission control. The downside is often added complexity.

 

Honesty forces me to state that I could be completely wrong on these replies.

[dlaing]

The very fact that someone wants to be a politician should bar them from any sphere of influence for life.

62844[/snapback]

I always wanted to be Lenin, so Communism could have been done correctly.

But some right wing tyrant like Stalin or Bush would have shot me in the back and taken my job.

[Guest Nogbad]

The reason air cooled engines have an advantage is in warmup time, and cold running emissions are given weight in the Euro3 test regime. Water has a high heat capacity, which is why it is an effective coolant. This slows the warmup time of an LC engine, making it run on the starting map for longer than the AC engine.

 

There is no connection between valve train design and emissions. Pushrod engines can be just as good, and an old style long stroke pushrod OHV engine like an HD is generally more thermodynamically efficient over its operating rev range than a short stroke motor.

 

4 valve heads are popular on performance engines as you get greater valve area with lower valve mass, allowing you to run higher revs. However, most vehicle engines don't run full throttle a significant part of the time. With 4 valves at low output, like city riding, the intake velocity can be too low, and this compromises mixing and worsens emissions and efficiency. In the real world, an out and out sportbike engine is not what you want at all.

 

Honda have tried to address this with VTEC where two of the four valves are hardly ever used. (I ask myself why these VFR800 riders want to carry around all that unused valve baggage, but heigh ho, there's no accounting for taste!)

 

Whether two plugs are better than 4 depends on the design of the piston and head. Two plugs can solve problems of excessive flame path, helping prevent knock and allowing higher rpm in an otherwise bad combustion chamber.

 

I guess Erik Buell has it right. The Firebolt is the best real roads sportsbike after all.

[belfastguzzi]

So... Air-cooled engine produce less overall harmfull emmissions

62862[/snapback]

This particular issue is just about warm-up time and the fact (it seems) that a-c warm-up quicker (they're not dumping their heat into water first) than l-c and so are coping better with the changed, tighter regulations. They're putting out less emmissions at the early cold to warm period – and the noise issue isn't so bad because they're measured at lower rpm.

[Skeeve]

It makes me wonder though how H-D gets passed all the tests.  The Motor Company sells their bikes world-wide without to much of a problem complying even with the Euro2 to 3 regulations.  H-D uses push-rods on their engines, no?  And the same for some of the Jap-4 cruisers too?  Someone correct me if I'm wrong about the push-rod stuff.

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They work very hard at it. They've redesigned their combustion chambers to make them more efficient than Guzzi's hemi head [hemi's only work well for 4v engines; 2v hemis wind up needing 2 plugs to get a good burn.] They use an under-square design which gives them a longer period for combustion to occur before pushing the gases out the exhaust. All together, it buys them enough space to get by the regs.

 

Ride on,

 

[Skeeve]

Could you define "freedom"?

 

KB

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Individual liberty, which of course carries with it the burden of individual responsibility.

 

"Freedom of choice is the freedom to starve." I forget who wrote that; it was an ex-slave who was trying to educate his fellow emancipees that they only had themselves to depend on now.

 

Harry S Truman and his "buck stops here" would be far the right of any of today's Republicans, & completely alien to modern Democrats. I suspect he wouldn't be too fond of the political animals infesting the halls of govt. here in the States these days, either.

 

Hey, I just came up w/ a great slogan for the new t-shirts! "Moto Guzzi - the ride starts here!"

[Skeeve]

I always wanted to be Lenin, so Communism could have been done correctly.

But some right wing tyrant like Stalin or Bush would have shot me in the back and taken my job.

62871[/snapback]

 

Don't be ridiculous! A right wing politician wouldn't be afraid to shoot you to your face; it's the left wing politicians that'll shoot you in the back!

[Skeeve]

4 valve heads are popular on performance engines as you get greater valve area with lower valve mass, allowing you to run higher revs. However, most vehicle engines don't run full throttle a significant part of the time. With 4 valves at low output, like city riding, the intake velocity can be too low, and this compromises mixing and worsens emissions and efficiency. In the real world, an out and out sportbike engine is not what you want at all.

 

Honda have tried to address this with VTEC where two of the four valves are hardly ever used. (I ask myself why these VFR800 riders want to carry around all that unused valve baggage, but heigh ho, there's no accounting for taste!)

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The irony being that Mother Honda, in all her wisdom(?), saddled the VTEC VFR with a dain-bramaged version of the real vvt tech used in their car engines, so that the pre-VTEC v4 engine makes more power throughout the range than the new; the "new & improved" engine only feels like it hits stronger when the VTEC kicks in because the low-rev performance has been somewhat strangled! Couple this with significantly more ex$pen$ive valve-servicing intervals, and you see why the pre-VTEC VFRs are holding their value on the used market so well, while the VTEC models sales are plummeting as word gets around...

 

What does this mean for us? It means that if Guzzi can get to market with some integrated bags on a sportier Breva or Griso, they might be able to siphon off some of Honda's lost VFR sales [since Triumph as also just stubbed their toe on the redesign of the ST...]