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Annoying Engine Regulations
2

Annoying Engine Regulations

Annoying Engine Regulations

(OP)
When I say my prototype is 50cc, I mean the volume of air moving into the cylinder is 50cc (49.5cc actually). Because I'm employing Low Temperature Combustion to prevent formation of NOx, however, my engine runs at now more than 0.48 equivalence (with 1.0 being stoichiometric). That means my effective displacement for comparison with other 50cc engines is 21.2 cc (meaning I'm putting in as much fuel as a 22.2 cc engine running at full stoichiometric). Why does this matter? Everyone regulates scooters to some cc figure (50cc being the lowest common figure) based on the amount of air they consume. As a result, I'm being penalized by the fact that I use Low Temperature Combustion to reduce emissions sad. Nonetheless, My analysis indicates an 11% improvement in torque, 76% reduction in fuel consumption, and 66% reduction in volume relative to the very popular GY6 engine (http://fixmychinesescooter.com/139qmb-gy6-50cc/) and even greater improvements relative to Honda's 50cc four-stroke (http://engines.honda.com/models/model-detail/gxh50).

RE: Annoying Engine Regulations

This is the least of your worries. My own opinion is that you'll learn about heat transfer and cylinder leakdown the hard way, to the extent that the engine simply won't start, in which case its legal classification won't matter much.

RE: Annoying Engine Regulations

(OP)
Brian,

Are you having a bad day? You don’t usually troll.

Rod

RE: Annoying Engine Regulations

Yes, sorry. Too many people not doing what they said they would ...

RE: Annoying Engine Regulations

(OP)
MotoLuber,

The intent of the 50cc limitation is to constrain deliverable power for safety reasons. Power is related to fuel load, not air volume, and an engine controller can intentionally limit peak fuel load (to limit maximum combustion pressure and temperature, for example). Thus, the intent of the regulation is not accurately expressed by the language, and it unnecessarily limits innovation. In this case, the innovation they're limiting is one tied directly to the emission of NOx, the most damaging greenhouse gas emitted by internal combustion. That doesn't seem very wise.

Rod

P.S. Before someone says "but an owner could reprogram the controller to deliver full fuel load," note my mechanical fuel injectors *can't* deliver more fuel than that required to develop 0.48 equivalence, and the engine's components and cooling system would be overstressed even if they could.

RE: Annoying Engine Regulations

Can you please cite or link to a regulation so we know what you're talking about?

Engine emissions are regulated based upon power output, not displacement. Not sure what safety regulation you're referring to that's based upon displacement, the only one remotely relevant I can think of is a few odd states' motorcycle licensing exemptions for scooters however I'm not sure how that's negatively impacting your design.

RE: Annoying Engine Regulations

Mopeds have the engine displacement "cast in stone" in the vehicle classification rules. Each province/state has their own set of classification rules but "moped" or "motorized bicycle" is always 50cc limit. There are some additional requirements pertaining to maximum speed, etc.

In my province it's in here: https://www.ontario.ca/laws/statute/90h08

and it's in the definitions:

“motor assisted bicycle” means a bicycle,
(a) that is fitted with pedals that are operable at all times to propel the bicycle,
(b) that weighs not more than fifty-five kilograms,
(c) that has no hand or foot operated clutch or gearbox driven by the motor and transferring power to the driven wheel,
(d) that has an attached motor driven by electricity or having a piston displacement of not more than fifty cubic centimetres, and
(e) that does not have sufficient power to enable the bicycle to attain a speed greater than 50 kilometres per hour on level ground within a distance of 2 kilometres from a standing start; (“cyclomoteur”)

RE: Annoying Engine Regulations

Interesting. Here stateside mopeds fall under the same legalities as scooters so there really isnt anything I'm aware of that limits them to 50cc, and some scooters are 600cc or more for highway use.

RE: Annoying Engine Regulations

The Commonwealth of Kentucky, USA has a Class E "moped license". Here a moped is defined as having: "No more than two (2) brake horsepower, a cylinder capacity not exceeding fifty (50) cubic centimeters, an automatic transmission not requiring clutching or shifting by the operator after the drive system is engaged, and capable of a maximum speed of not more than thirty (30) miles per hour." (reference KRS 189.285)

RE: Annoying Engine Regulations

(OP)
Wayne,

The definition of a "moped" varies all over the US. The regulations you cite from Kentucky are also poorly written. Torque at 2,626 RPM (for example) is what defines speed and, assuming the wheel rotation speed is maintained by an appropriate reduction gear, an engine producing 2 HP at 5xRPM will produce 5xTorque at the wheel compared to the same 2 HP engine running at 1x RPM directly attached to the wheel. That's a 5:1 range of vehicle performance! My point is that pseudo-technical laws written by lawyers are meaningless except for the *real* objective of "not more than thirty (30) miles per hour" (though they should add "at sea level on a level road on a calm day" to avoid other technical dodges of their intent).

This is also a great example of why governments should not be banning diesel, by the way. Properly designed and operated diesels with appropriate emissions controls produce no more emissions than a gasoline engine. Rather than target a technology, they should focus their attention on the objective (emissions) and employ effective testing that can't be gamed to keep industry honest. Such tests affect literally $1.6 trillion in auto sales globally, and manufacturers will game them if possible to improve or maintain sales. Thinking they won't is like playing with scorpions then getting upset when one stings. All this legal action against manufacturers is political gamesmanship to cover the fact that their testing methods are flawed IMHO.

Rod




RE: Annoying Engine Regulations

Maybe I'm a little slow on the uptake, but I'm still not grasping how you're design is being penalized or what the penalty is.

As far as I can tell, your 50cc design is being compared to other 50cc engines but since your design produces power similar to a 22cc engine you feel the comparison is unfair. What you want is to be able to compare a larger displacement engine (about 100cc) of your design which would use a volume of fuel comparable to other 50cc engines. Is that right or am I just missing the mark completely?

Andrew H.
www.mototribology.com

RE: Annoying Engine Regulations

Basically, despite the incomprehensible modelling of vehicle performance, RodRico has run into the main reason why 2 strokes took over the moped market (or indeed any capacity limited market such as the old 250cc limit in the UK for learner's bikes), designing a 50cc 4 stroke to give acceptable performance was beyond most manufacturers.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Annoying Engine Regulations

(OP)
Greg,

"Incomprehensible modelling of vehicle performance"?

One of the most popular scooter engines for home-builds is the 50cc four-stroke GY6 engine (http://fixmychinesescooter.com/139qmb-gy6-50cc/) made by any number of Chinese companies. It's basically an open-source design based on an old Honda engine, and it produces 3.1 HP at 7500 RPM with 2.3 lb-ft torque at 6500 RPM.

I have investigated the global scooter market, and I assure you 50cc four-stroke scooters are actually quite common. I expect them to expand their dominance as China, India, and Southeast Asia continue ramping up emissions requirements. Current manufacturers include Honda (http://powersports.honda.com/2018/metropolitan.asp...), Yamaha (https://www.yamahamotorsports.com/scooter/models/z...), and Vespa (http://www.vespa.com/us_EN/vespa-models/sprint/spr...).

Rod

RE: Annoying Engine Regulations

Your maths is incomprehensible, and shows a misunderstanding of gearing.

"50cc four-stroke scooters are actually quite common" because 2 strokes have been outlawed in many jurisdictions.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Annoying Engine Regulations

I find it hard to believe that 4-stroke scooters are the most common world wide. The reason I don' believe it is because the areas of the world with heavy scooter use also tend to also be the areas of the world without exhaust regulations.

Sure, everyone makes 4-stroke versions to sell in certain markets that require it, but it doesn't mean the 4-stroke engines dominate the global market.

RE: Annoying Engine Regulations

There's banning and banning. India effectively banned them by saying they must meet the same emissions regs as 4 strokes. Dhaka in Bangladesh just banned them outright (not just for sale) in 2002, same in Beijing last year. Many countries are banning them from sale in the next couple of years as a result of the Paris malarkey. The Phillipines, Taiwan, Europe, Canadia, Australia, Indonesia, Thailand all popped up in google. So a good spread of first AND third world countries are banning them or have banned them or have introduced emissions regs that are too hard to meet with 2 stroke tech.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Annoying Engine Regulations

It's roughly an 80:20 split between 4-stroke and 2-stroke in regard to all motorcycles. Obviously that includes many non-scooters, but scooters make up a huge proportion of the motorcycle market globally so that statistic should roughly bear some semblance to scooters.

Link
Link (Slide 37 has 2T sales stats)

The thing about 4-stroke scooters is that they aren't that much more expensive anymore. They are much easier/cheaper to operate because:
- Not having to buy/add premix
- They take a lot longer to run the engine into the ground than 2T without any rebuilds

Easy and cheap to replace and maintain makes it attractive to people who don't want to spend any time or resources on the things.

Andrew H.
www.mototribology.com

RE: Annoying Engine Regulations

"The regulations you cite from Kentucky are also poorly written. Torque at 2,626 RPM (for example) is what defines speed and, assuming the wheel rotation speed is maintained by an appropriate reduction gear, an engine producing 2 HP at 5xRPM will produce 5xTorque at the wheel compared to the same 2 HP engine running at 1x RPM directly attached to the wheel."

Not if the second engine makes 2 hp at the lower rpm. It will also produce 5x torque.

Knowing engine torque without gearing/rpm is meaningless because it is POWER that defines the limits of a vehicle's top speed and acceleration. "Torque at 2,626 RPM" actually defines a power output.

je suis charlie

RE: Annoying Engine Regulations

So you are targeting the almost infinite scooter market then, but have realised that your engine's physical displacement is the measure that the regulators will use. Take a look at the arguments over how to measure the displacement of a (Wankel) rotary engine for comparison with a conventional reciprocating (4-stroke) piston engine.

Steve

RE: Annoying Engine Regulations

(OP)
LionelHutz,

I never said 4-stroke scooters *dominated* the market, only that they are quite common and will *ultimately dominate. Emissions concerns around the world keep increasing, and that will demand uncommon 2-stroke performance. That being said, *my* engine is a two-stroke, and my analysis indicates it will be low emissions. My largest concern is oil between the rings slipping out the ports, but I think I have that problem licked (using a technique similar to Wärtsilä's).

gruntguru,

Oops! I see my mistake! It takes work to move an object, and torque is rotational work, so I prefer to think that it's in the lead, in in reality, torque, horsepower, and RPM are directly related (HP=Torque*RPM/5252, Torque=HP*5252/RPM, RPM=HP*5252/RPM). In my experience, when people talk about gears, they are most commonly referred to as torque multiplers (or dividers as the case may be). Not to say it's never been said, I've never heard anyone say gears multiply/divide horsepower. If one wants to drive a wheel at 5252 RPM with 2 ft-lb of torque, the engine must have 2 HP (2*5252/5252). If one wants to drive the same wheel at the same speed through a 2:1 reduction gear, the engine would require 1 ft-lb torque at 10,504 RPM, and that's also 2 HP (1*10504/5252). Both provide the same torque at the same RPM and thus the same HP at the wheel. I should have thought through my statements more carefully and tested them in my spreadsheets before speaking aloud (I've never been good at math off-the-cuff). You're right to have called me on it.

SometingGuy,

I don't think I'll actually be in the scooter or small motorcycle business any time soon. My actual target is aviation because power/weight is king, the EPA is slowly pushing emissions onto piston engines that have had none, and the selling price of the engines has a nice retail premium that supports low volume manufacturing. I looked into scooters because I've decided to prototype a small engine to save money, and I was thinking I may lend out to scooter companies for evaluation to see if they'd be willing to invest the funds and epertise required to ramp up production for reduce costs.

Rod

RE: Annoying Engine Regulations

[The thing about 4-stroke scooters is that they aren't that much more expensive anymore. They are much easier/cheaper to operate because:
- Not having to buy/add premix
- They take a lot longer to run the engine into the ground than 2T without any rebuilds]

Premix ? The last bike I had with premix was a BSA Bantam, and I didn't premix, we could get 25:1 at the pump, or add oil and fuel to the tank and shake the bike. My current 2T 50cc scooter gets nearly 2000km to a litre of oil, not a lot more expensive than a 4T. My last 2T street legal dirt bike 10 years ago lasted 30,000km on a piston, a comparable 4T of the time with far less HP would be lucky to get half that distance for a far more expensive rebuild. The last of the 2 strokes were very good, they didn't disapear because they weren't reliable or didn't perform.

A 50cc 4T scooter is so gutless it's almost dangerous, and is in some situations. My 2T keeps up with traffic in my town, I sometimes have to slow down for the dawdling cars. It meets Euro 2, which doesn't mean much, but it does have a cat. And we can still buy a 2T scooter in my country.

RE: Annoying Engine Regulations

Quote (LadaTrouble)

Premix ? The last bike I had with premix was a BSA Bantam, and I didn't premix, we could get 25:1 at the pump, or add oil and fuel to the tank and shake the bike.
In the very same sentence, you say you didn't premix and then continue describing how you would use premix.

The point I was trying to make is; 4-strokes are pretty much dummy-proof and maintenance free, which is very attractive to people who don't want to spare a single thought about their vehicle. That demographic is an extremely large portion of the global population of scooter/small bike riders in my experience.

I'm not referencing the portion of riders who are caring for their bikes and using decent oil rather than the cheapest available stuff. I'm talking about the person who buys a cheap bike, runs it with the minimum care taken to keep the wheels rolling, and when they do stop rolling, they replace it with the next cheapest one and so on.

Andrew H.
www.mototribology.com

RE: Annoying Engine Regulations

No, I wasn't premixing, I was mixing fuel and oil in the motorcycle tank, and riding away. Premix refers to mixing fuel and oil in a container and then pouring into the bikes fuel tank...I do that with lawnmowers and chainsaws, and I've done it with off road motorcycles, but since the '70's most 2 stroke road going motorcycles have used an oil pump and tank. That makes a 2 stroke pretty much dummy proof and maintence free, far more maintenace free than a 4 stroke.

The 2 stroke hasn't been killed by any unreliability or performance issues, nor by rider preference, it's been killed only by government legislation.

RE: Annoying Engine Regulations

Grrr - semantics.
Premix - the oil and fuel are mixed before induction into the engine.
Not premix - the oil is held in a separate tank on the vehicle and metered to the engine by a system integrated into the vehicle.

je suis charlie

RE: Annoying Engine Regulations

The whole argument is rather moot anyways. I highly doubt the design would ever make it into a scooter. Being a 2-stroke and too complex pretty much sink it.

RE: Annoying Engine Regulations

(OP)
LionelHutz,

It’s a two-stroke supercharged HCCI engine with low emissions, high efficiency, and high power density (in theory). It doesn’t require oil injection or premix, and is about as complex as a four stroke. That being said, my primary target is aviation as it’s well suited to that market which will be the last market to be killed off by electrics.

Rod

RE: Annoying Engine Regulations

Annoying Engine Regulations! In my opinion all agenda based, and I'll stop there.
Would the crying stop if hydrogen was the fuel used? Battery power, ignored are the impact of the manufacturing process of the battery's.

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