Modern Vespa

So, the Honda Sh300i has a 278cc engine producing 27 HP and the Vespa GTS300 has a 278cc producing 21 HP. I understand that each engine is tuned for the what the forces the body/frame, wheel sizes etc. can support, my question is, how is that actually achieved mechanically on the engines?

While in "A" school in San Diego many years ago, the "FM theory" was used as an explanation. FM Theory = F%cking Magic. They also said that fluorescent lights worked by sucking up the darkness, hence all that black stuff when they are no longer working.

Did this help? Didn't think so..

Don't know the ins and outs of Honda engine but my guess is compression ratio is different. Intake and exhaust could be more efficiently engineered too
Car tuners do this stuff all the time to achieve more power out of same cc

and everything else, its a honda
george

The BV 350 engine is 330cc, produces 33 hp, and it's a Piaggio!

I recognize a snarky sailor anytime, shipmate!

USN 67-87

ohh nice what about a 250cc honda only 70bhp as its the detuned version

http://www.gizmag.com/honda-road-legal-rc213v-motogp-replica/37986/

absolutely love my vespa, but compared to honda engineering ...............................

george

Don't look at horsepower, look at torque. A 300cc Ninja produces 35 horse at the rear wheel on a Dynojet dynamometer but only 18 lb. ft. of torque. That is scintillating power with a six speed transmission but would fall flat with CVT. Each engine is tuned for the job. A Honda is heavier than a Vespa so the wizards at Honda have to account for that to produce like acceleration with reliability. The same for the guys at Piaggio.

Hi mate not knocking Piaggio i love my little vespa,and the rc213 was just intended as a tongue in cheek joke really ,having owned dozens of bikes over the years and several hondas the build quality attention to detail and engineering is unequaled in my humble opinion
george

But...how it done? larger valves, compression ratio, different stroke...

On top of everything else already mentioned, remember that hp ratings are also a function of the revs. Two engines can produce similar torque, but if one of the engines has a shorter stroke and lower rotating mass, and thus is rated at higher rpm before cut-off, it will have higher hp (as long as the power hasn't fallen off).

MUCH engine in CAD, CFD, and single-cylinder test engine work usually pays off. No one item is key. Combustion quality is determined by chamber shape and chamber shape is primarily determined by valve size and angle.
Intake porting and air box shape and size help incoming air.
Exhaust port shape, direction and size along with port ID changes encourage scavenging of outgoing gasses.
Compression ratio, ie combustion pressure that is high without creating knocking is carefully tested.
Clean burning without carbon build ups (they create pre-ignition) is created through chamber design and finish.
Fuel preparation plays a big part in combustion quality. Injector orifice number, direction, size and location in intake tract are all important.
Honda probably spins their engines a bit higher for more gas flow.
Honda probably has higher quality casting/machining/finishing machines to provide lower friction and better combustion due to repeatable, high tolerances.
Too many variables to point at one in particular, but engines are pumps. The best "pumps" have high throughputs with low losses. High RPM's and tight tolerances create high throughputs with low losses.
The higher power engine will also require a design that can survive the extra power. Honda probably uses a great deal of FEA to determine the right thicknesses for case materials and has the higher quality materials to work with. Given their high volume position in the world of material business, they probably get the best metals, etc. They can push harder on their materials than a smaller company that uses a slightly less quality product.

It's all in your head...
Most of the difference is due to the head of the Piaggio Quasar engine. This is the same head used on the 125 liquid cooled engine, with the same size valves. The valves are very small for a 300, and it suffers as a result. If you look at the Aprilia 200 Scarabeo when it had the Rotax engine, compared to when Piaggio started putting their engine in it, the horsepower dropped about a third.
Piaggio is extremely optimistic in their horsepower and fuel economy figures too, So I would guess that the 300 Piaggio is at least 10-15 percent overstated.
By doing nothing more than putting the Malossi head on the Piaggio engine, you increase the horsepower dramatically, primarily because the valves are bigger.

Here's one for ya. The Honda sh150i is rated at 16HP. The Honda 250 Rebel is rated at 16HP. The SH runs on 87 octane, so it's not compression.

IIRC
Many years ago I read that theoretically the most efficient engine cylinder volume was only 9 cc.
Maybe OK for model A/C but don't think I'll wait for Vespa
to produce a 16.6 cylinder ET4 150.

A Honda Husqvara TE310 makes 30hp at the rear wheel. A GTS300 makes 16hp at the rear wheel.

My 1987 Honda XR200 (2-Valve) keeps up with a Piaggio BV350, at least until 75mph.

You can tune a motor for torque/horsepower, or longevity and reliability.

Vespas are mostly tuned for longevity and reliability, but they sacrifice performance in trade with lower compression ratios, smaller valves, CVT transmissions, and general lower performance. My Husqvarna needed oil changes every 1000 miles and to be re-ringd frequently, but it made a lot of horsepower for the size of motor it was. It had high compression, big valves, small oil capacity, and was considered a high performance motor. I would not consider the Vespa a high performance motor with 16 hp at the rear wheel (21 at the crank).

CVT transmissions are easy, but not very power efficient. Chain drives are more efficient.

A Honda Reflex 250 isn't as fast as a Vespa GTS250, but a SH300 is faster than a Vespa GTS300.

The Aprilia Rotax150 Sarabeo was wicked fast for a 150, but it's engine was based on a dirt bike motor. I used to see those pass me on the freeway at 75mph.

The Honda S2000 roadster mare more hp out of a 4-cylinder than the Mustang 5.0 liter did out of a V8 with more than twice the engine size.

I spouted a lot of info there. I hope any of it was of use. I would say the main point is performance versus longevity and reliability. The Vespas are more on the side of longevity and reliability. Honda makes a fantastic motor. I'd still rather have a Vespa to ride.

Hey, if you consider the Dyson guy, apparently spending a lot of time dissecting and testing one thing, you can still find improvements. (never owned a Dyson vacuum, but can understand the idea of constant tweaking on anything will probably lead to some gains.)

ROFLMAO. Priceless.

Piaggio, like most other manufacturers, designs their engines to accomplish what Piaggio wants to accomplish, which is to put a given vehicle of given performance on the road. The measure of the validity of that given vehicle with that given performance will be reflected in consumer acceptance.

Since neither statement was funny, I'm assuming you disagree?

I've personally owned both a Reflex and a GTS 250 and the GTS was definitely faster. I was always disappointed with the power to weight ratio of the Reflex. Even the factory specs show the Reflex at 2 fewer horsepower, 50 more pounds in weight, and 6mph lower top speed than the GTS. My personal experience was the same.

Most small displacement single cylinder Rotax motors are in dirt bikes and they make a lot of power. The Rotax motor in the Aprilia made a lot of power and in the context of the rest of my message it draws engineering from technology that mostly went into dirt bike motors. I wasn't intending to imply that the Scarabeo was manual transmission and chain drive.

Small rotax dirt bike motors are/were 2 stroke. The Scarabeo 150 motor is not a 2 Stroke engine. It would be fun if it was.

Rotax built a lot of 4 Stroke engines for Buell, Aprilia and BMW, including the first GS 650 single. They also build a lot of motors for Can-Am, the company that now owns Rotax, including a lot for ATVs. An ATV motor is closer in design to the Scarabeo 150 motor than a 2 Stroke dirt bike motor. The reason Rotax motors make more power has more to do with sound engineering than with 2 Stroke dirt bike motors.

But even before that, Rotax was building scooter motors in the 1950s, before they built dirt bike engines.

As far as using factory specs as an indication of performance, Piaggio imagines the 3V 150 has 12.7 horsepower, and the 2015 Honda PCX 150 has a claimed 13.4. Ride them both and then say there's .7 horsepower difference between the two engines. Ask anyone who rode a 3V Piaggio Fly in the 2014 Cannonball what it was like to be overtaken and passed on a long uphill stretch by a stock Honda Elite 110 with a claimed 8.9 horsepower. Piaggio's factory specs are about as optimistic as their claim of 120+ mpg.

The reason Honda, Suzuki and Yamaha scooter motors outperform Piaggio engines is better engineering, pure and simple. And there are many people who believe the engines from all three manufacturers will last longer and are more reliable than their Piaggio counterparts. Until Piaggio figured out a way to use as many parts from the Leader in their new Quasar engine as possible, they bought 250cc engines from Honda. That was probably the most reliable engine Piaggio has ever put in a scooter.

I'm pretty technical minded and well equipped, If I say so myself. So, after a thorough and extensive technical examination of my GTS 300 engine, I observed the following: the cylinder did not contain a horse. Therefore, the horsepower discussion seems quite rediculous. Next, I used accurate instruments to measure the engine's funpower. Surprisingly, I observed a readout of 147% on the funpower meter. To be sure, I recalibrated the instruments and performed two more tests (146% and 151%). This confirmes that the GTS 300 engine produces about half more funpower than a standard generic engine. Possibly, these excellent results might be due to the meticulous adjusting of the engine to the surrounding beautiful body parts.

I can only come to the following educated conclusion: it ain't the horsepower that makes the ride, but the funpower, and my GTS had plenty of it

PS: given my tremendous expertise in this field (six years kindergarten and a bachelor in Lego Technics) I will decline any biased test with wacky instruments or falsified reports that tries to prove the contrary. The tests and the accompanying results are supplied "as is" and without warranties of any kind, either expressed or implied, with respect to the beauty of the Vespa, its quality, performance, and absolute fitness for any particular purpose. In any event will the author of this test be liable for any direct, indirect or consequential fun, resulting out of the use of a Vespa! You have been warned!!!

You obviously know a lot about scooters, I would tend to respectfully disagree. The Yamaha Vino 50 and Zuma 50 were slower than the ET2. The Vino 125 and Zuma 125 were slower than most scooters in their class. The Metro and Ruckus are notorious for being frustratingly slow. The Big Ruckus and Reflex were slower than the GTS. The Burgman 400 isn't as quick as the Piaggio BV350. I have/had a lot of Hondas and think they build a fantastic motor. There are certainly examples of higher performance on both sides but I don't think it's plain and simple that Asian scooters perform better than Piaggio motored scooters.

I have owned several Honda and Yamaha scooters, as well as a half dozen Piaggio products. Based on my experience, you are exactly right!

Wife bought a brand new 2014 Giorno (Metropolitan) as her 1st scooter .

Dealer (unspecified dickwad in Toronto) assured her it had enough power for her to keep up with traffic in our small city. We were concerned as she is a normal sized 58 year old grandmother not some noriexic 16 year old schoolgirl .

We get it delivered to us and it wont even make 30mph. Honda won't do anything because they say it is the dealerships problem.

70 km on it and it sits in the garage unused.

Never buying a Honda again

To address the original question Piaggio clearly detune these engines for the Vespa range. No doubt this is partly for safety but also to show clear marketing differences with the Piaggio X and Beverly scooter ranges.

Given that it would be economically undesirable to change the engines mechanically any more than necessary it is most likely that all the differences are in the electronics and the intake/injection system.

I don't think this exact engine is currently used in X or Beverly models but it is used in the MP3 with practically the same power output. So no easy way of comparing components except by looking at the previous generation such as the X9 250 etc. The engine is essentially an overbored version of the 250 which produced the same power but at higher rpm. Piaggio obviously decided to use the extra capacity to increase torque and lower rpm making the engine a bit more flexible.

As mentioned above the RPM limit is set fairly low for this size of engine so that is the biggest single factor. But of course there should be corresponding benefits in low fuel consumption and engine and transmission longevity.

Without doubt, the 300 GTS engine could produce a lot more power. It doesn't because Piaggio/Vespa decided it's best like it is because of the type of bike it is. Engine size has less to do with the amount of power an engine designer can get out of a particular unit these days so comparisons between different brands and engine sizes is not helpful. Each engine is producing what the designer has determined it should produce in terms of power, and the way it should produce it. As Scooter West rightly says, Vespa came down on the side of reliability and longevity. Incidentally, I've spent years as a tech and in engine design and development. From what I know, Piaggio/Vespa has access to the most advanced engine design technology and materials going and is in no way inferior to Honda or any other manufacturer in the way it develops and builds engines. I base that on the strip downs I've made of Honda, Suzuki, Yamaha, Piaggio, Vespa engines and other bikes. Piaggio engines are noted for good reliability overall, just as the other major brands are. Occasionally you may get a glitch in production that causes an issue. This happens with all brands of bike engine, but thankfully is rare. Usually it's not the direct fault of the manufacturer, but often that of an ancillary supplier of gaskets or seals or some other component. And it has to be said, some owners cause their own problems too by using incorrect servicing methods and unsuitable or insufficient chemicals/coolants or oils in the engines. They then blame the manufacturers.

The discussion on more HP with the same CC is acutally the same as the discussion on the same power with less CC, often refered to as downsizing. Here in Europe, the general trend on car engines is to downsize, that is, getting more HP with smaller engines. My own car has a downsized engine, which indeed produces lots of HP for little CC's and gives excellent fuel consumption... when driving under normal conditions. If you pull out the magic tech HP (the little thing has a turbo, compressor and intercooler) it runs great, but fuel thirst goes way up. But in the end, most of us hardly actually need all those HP for normal driving. There's been a lot of discussion on the doswnsizing issue (read more HP per CC) with pros (consumption, effeciency) and cons (wear, problems with the hi-tech tricks).

For both car and scooter engines, the ideal engine would make as much HP as possible with a minimum on CCs and as little as possible technical tricks that fail as little as possible. This always leads to a trade-off. Some choose the path of max HP with all kinds of tricks that require more technical tricks and some go the path of less HP and simpeler technics. Both have their pros and cons.

In the end, HP or Nm on itself is not the criteria, but how the engine matches the vehicle's weight, desired speed and fuel consumption. I suppose Piaggio went for a simple low tech reliable engine. For it's purpose, the Vespa's 278cc delivers more than enough power. This is in line with their original way of designing their earliest Vespa's as simple mass produced low-tech reliable and easily maintained vehicles. Does this means that Honda engines are unreliable or mainanence heavy? Absolutely not, but each has it's own approach of things. I guess that if they needed more power, Piaggio would probably go for more CC's rather then for technical solutions.

interesting...so then I assume the Malossi head with bigger valves increases the HP and performance. If so, then that increase is acceleration, mid range or top speed?

the Malossi head has its effect almost entirely in the higher rev range.
Which to my surprise was not a negative trait at all, as it sometimes is on very high rev motorcycle engines

Automatic scooters are a little different than geared vehicles in the way performance parts affect them. On an automatic scooter, it revs up to high rpm any time you twist the throttle open, so you are really just tuning them or creating power for a specific rpm. The Malossi head does a great job at creating higher rpm power. Fortunately, any time you need power on a scooter, it jumps to high rpm, so where in the rev range the power is created has little effect on performance as long as you make sure power is created at an RPM that jives with your performance parts. You can adjust the rpm that the scooter revs out to by going to lighter or heavier roller weights. With geared scooters or motorcycles you have to pay more attention to how performance parts affect different rpms. To answer your question directly, the Malossi head benfits acceleration, mid-range, and top speed.

We just did dyno runs on a Sprint with and without various Malossi parts. I'll be posting results shortly.

I don't know if there are differences in models sold in Canada, but most 50cc scooters sold in the US are intentionally restricted by the manufacturer to 30 mph because they are intended to meet the registration and licensing requirements for mopeds rather than motorcycles. This sounds to me like either poor communication with the dealer or the dealer intentionally misled her. (bluntly, my own experience is that the Honda Metropolitan is slower than the second coming)

Thanks Scooter West, appropriate the detailed replay. Saw a video on Youtube where you installed the Malossi head on a black GTS, any feedback on performance or did you dyno it?