Cool scifi idea: is there an engineer in the house?

[Cheshire]

On the way back home on the scooter today, an idea crossed my mind. I was behind a Prius, and the notion started when the engine shut off at the light and started up when they accelerated.

Wouldn't it be great if there was a hybrid scooter/motorcycle engine? I'm not talking about electric/gas. The thing I love about my scooter, but is almost a bittersweet kind of love, is it's amazing efficiency. The tradeoff of power and top speed can't be gotten around. Okay, enough building up to and rambling!

I think it would be intriguing at the least to have a twin-cylinder engine that could be run on either one or both cylinders. Run on one, you have the equivalent to a 125, 150, or 250cc thumper, with the fuel efficiency thereof. Run on both, you have an interstate-capable 250-500cc engine with plenty of power. Oh, the versatility!

Discuss.

[Cheshire]

Ooooh...or maybe an triple-cylinder engine, kinda like Triumphs to give a 125, 250, and 375cc range, all in the same scooter!!

Hmm....

[Portland_Rider]

Chesire my friend, how much coffee have you had today?

[Syd]

Not as much as most Mechanical Engineers, I'd wager.

[Cheshire]

Umm...just a small peppermint mocha at 9 this morning...why?

[UnionZac]

yeah, i think its the peppermint mocha filling you with hope of wild, unreachable dreams. i like that drink too.

It is a cool idea, just seems like the cost to develop that would prohibit its creation.

[Portland_Rider]

Umm...just a small peppermint mocha at 9 this morning...why?

hahaha.... don't give me that sad look!

It's cool idea. I'm no expert on scooter body designs and weight, yet I wonder about flipping a switch and going from a 125cc to a 250cc that might cause a lighter weight scoot some stability problems ie keeping the rubber tires from going airborne a bit and causing a wipe-out.

That's just me worrying of course and still never having fully recovered emotionally from my own crash last year.

[Cheshire]

The frame would have to be larger. Maybe not switch-operated, though that was my first thought. Cars have locks that engage once you reach a certain speed, and the hybrids like the Prius engage the gasoline engine once a certain power output is reached or needed. Why not something like that for this engine? It stays on a single cylinder at speeds up to xx, maybe 50-55 mph then let off the throttle and goose it to engage both cylinders. That would prevent the engagement of full power from making the scooter lurch.

Or, in the spirit of 4-wheel drive vehicles, a power mode that can only be changed at a complete stop. You've been running errands and commuting all week in-town, but need to go across the state to help a friend or visit someone. With the brakes engaged fully, engine off, maybe key in a unique 4th position, switch from single cylinder to twin or triple for long-distance interstate travel!

[bigbropgo]

Many of the things you love about your scooter would change. Light, nimble, small. Easy to control and work on. No to mention the cost would be crazy high. Not completly shooting down your idea. After all the scooter itself was probably a crazy idea.

[Portland_Rider]

This is out of my league. I think commentary here now requires the Insight and Wisdom of Eric Alm.

[gr8dog]

OK, lets look at energy consumption. Nothing comes for free. An engine with two 125cc cylinders would weigh more than a single 125cc cylinder, therefore requiring more energy to move and reducing your efficiency when running on a single cylinder. When running on one cylinder the other piston will still be moving, thus stealing more energy. You simply would not get the high mileage from running half a twin cylinder engine that you would get from running a single cylinder. This idea has been done in cars and never really worked well.

[jfrost2]

It's possible, atleast in car engines right now. Honda makes a SUV that can run 4 or 6 cylinder to save gasoline. Not sure if this will ever flow into working in motorcycles and scooters though, by the time it does, there would probably be much more fuel efficient and greener engine styles that would be better fit for a scooter.

[Elm Creek Smith]

The power to the wheels of a hybrid comes from the electric motor; the gas engine runs to recharge the batteries and to provide extra current to the electric motor as it demands it. There would be no sudden surge of power to the drive motor since the throttle doesn't control the gas engine.

Modern passenger diesel locomotives have used what they call "head end power" where the diesel engines run at full power all the time. The traction motors only use as much as they need with the excess being used to power all the electrical stuff in the passenger cars.

The problem would be the weight of the batteries and the cost of the electronics.

ECS

[Kaos]

It's possible, atleast in car engines right now. Honda makes a SUV that can run 4 or 6 cylinder to save gasoline. Not sure if this will ever flow into working in motorcycles and scooters though, by the time it does, there would probably be much more fuel efficient and greener engine styles that would be better fit for a scooter.

Yeah, Chrysler did it with the first re-run of the Hemi's(the 5.7) It could be a 6 or 8 cyl depending on your driving habits.

[Roose Hurro]

yeah, i think its the peppermint mocha filling you with hope of wild, unreachable dreams. i like that drink too.

It is a cool idea, just seems like the cost to develop that would prohibit its creation.

The tech is already available in autos, why not scooters?

Personally, I'd rather have that Idle Stop feature I've heard about (though, unfortunately, when that scoot comes to America, it won't have that feature... the one feature that would make it unique and desirable).


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[BeachBuzz]

I think it's a fine idea that deserves some thought and development and it could have legs in the future. It's interesting what we dream up while we're scooting along lifes open roads

I wonder how much increased fuel efficiency you would expect to get, or how much of a difference it would take to make it even feasable. People that drive hybrid cars dont really expect to recoup the added expense over the life of the vehicle do they? Mrs. claims that she would pay the price even if over the life of the vehicle the additional cost would never be reclaimed, but she would be doing her part to save the planet
I would rather spend my money (like I already have) on a variety of scooters than one hybrid that would probably cost near the same as 2 standard scoots.

The range in MPG I see currently from the scoots in my stable is not that different based on engine size. My 400 (58-64) does a little better than my 50 (around 60) but my 150 (mid 70s)does significantly better than the 400. Wife's 125 is the leader at 80+, havent checked the Met yet, it's not fully broken in but I expect it will be between the 50 and the 125. The numbers all change though when the application changes. The 150 is my daily commuter and seems to be in it's element. If I took the same daily route on the 400 it would definately drop in efficiency. The 150 jumped into the high 80s on an open road trip to the beach.

my $.08 ($.02/cylinder)

[Tricia]

Hmm. I think there was a Mopar MDS- multiple displacement system. An 8,6, or 4 cyl. Basically, it closes the appropriate valves based on your RPM speed- no gas, no spark, no go.

Ha- just yelled over to Zac to ask. "Yeah, and they were real pieces of sh*t!....(grumble gruimble grumble)" I guess there were all sorts of problems with the valves sticking open or closed, or halfway.

That does seem like it would take a lot away from what the scooter is now and make it......not a scooter. This would require a computer, and be cumbersome, and possibly dangerous, but still a cool concept.

[UnionZac]

yeah, i think its the peppermint mocha filling you with hope of wild, unreachable dreams. i like that drink too.

It is a cool idea, just seems like the cost to develop that would prohibit its creation.

The tech is already available in autos, why not scooters?

Along with what others have already mentioned, it seems like the money it would cost any company to develop that technology for a scooter would not end up being a profitable investment for them. The high cost to develop it would mean a high sticker price for the buyer. Building a prohibitively expensive scooter would in the end only attract a very small niche, in an already niche market.

Not saying I don't think the idea is rad, just unlikely to be pursued by anyone.

[yeauxkneauxit]

Wait a min....hold on there...you my friend are bumping up against big brothers pocket books and suggesting something that goes against all logic...I mean its hard enough to get 50 miles per gallon out of prius

What are you asking for 500 miles/per gallon out of a scooter? Big Brother will not go for this

[bigbropgo]

Wait a min....hold on there...you my friend are bumping up against big brothers pocket books and suggesting something that goes against all logic...I mean its hard enough to get 50 miles per gallon out of prius

What are you asking for 500 miles/per gallon out of a scooter? Big Brother will not go for this

This is a good point. There is no modivation to be the safest, most fuel efficient vehicle on the market. Everything is just safe enough an efficient enough to meet a certain standard. If a scooter (or car) was designed like this and made bulletproof, others would have a problem with it. They would cut them a check to purchase the product and shut it down. Ya know just the man keepin it down.

[Portland_Rider]

Wait a min....hold on there...you my friend are bumping up against big brothers pocket books and suggesting something that goes against all logic...I mean its hard enough to get 50 miles per gallon out of prius

What are you asking for 500 miles/per gallon out of a scooter? Big Brother will not go for this

This is a good point. There is no modivation to be the safest, most fuel efficient vehicle on the market. Everything is just safe enough an efficient enough to meet a certain standard. If a scooter (or car) was designed like this and made bulletproof, others would have a problem with it. They would cut them a check to purchase the product and shut it down. Ya know just the man keepin it down.

True. Too much change is not wanted unless it is less change for us. I think that I just wrote my first Japanese Zen Koan.

[Cheshire]

Hmm. I wonder if there were a way to engage/disengage the cylinders so they would either move together (like a normal twin-cylinder) or have just the one cylinder moving with the other taken out of the loop. Maybe a parallel twin cylinder engine for the setup?

[Tricia]

With the MDS, all (2, 4, 6, 8, etc) pistons do move. If one doesn't, that means that crankshaft isn't working, and the engine is seized- the "unused" piston has to move, or each piston would have to operate independently on it's own crankshaft.

[Roose Hurro]

yeah, i think its the peppermint mocha filling you with hope of wild, unreachable dreams. i like that drink too.

It is a cool idea, just seems like the cost to develop that would prohibit its creation.

The tech is already available in autos, why not scooters?

Along with what others have already mentioned, it seems like the money it would cost any company to develop that technology for a scooter would not end up being a profitable investment for them. The high cost to develop it would mean a high sticker price for the buyer. Building a prohibitively expensive scooter would in the end only attract a very small niche, in an already niche market.

Not saying I don't think the idea is rad, just unlikely to be pursued by anyone.

Point taken... a small-displacement engine most likely is not a good thing to use this tech on. Too little return for the investment.


HOWEVER!


I have links to tech even more of interest:


http://thekneeslider.com/archives/2009/ ... ke-engine/

http://kugelmotor.peraves.ch/index_en.htm

http://peswiki.com/index.php/Directory: ... YT)_Engine

http://www.greentechgazette.com/index.p ... -comeback/

http://www.youtube.com/watch?v=kGlUZg2pC0Q ... YouTuber vid...

http://video.google.com/videoplay?docid ... 4976235267# ... Another vid...

http://pesn.com/2009/01/13/9501512_Mass ... roduction/

Hmm. I wonder if there were a way to engage/disengage the cylinders so they would either move together (like a normal twin-cylinder) or have just the one cylinder moving with the other taken out of the loop. Maybe a parallel twin cylinder engine for the setup?

Actually, I came up with the idea of hooking two independent engines through a shared transmission. Run both engines when you need the power, or shut one engine down, decouple it from the trans, and run on just the one, for better economy. Though I'd actually designed this based on the idea that an engine breakdown would most likely only effect one of the two coupled engines, so you could shut one down and run on the other... in other words, eliminate the danger of being broken down on the side of the road out in the middle of nowhere (or somewhere dangerous).


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[Tricia]

Actually, I came up with the idea of hooking to independent engines through a shared transmission. Run both engines when you need the power, or shut one engine down, decouple it from the trans, and run on just the one, for better economy. Though I'd actually designed this based on the idea that an engine breakdown would most likely only effect one of the two coupled engines, so you could shut one down and run on the other... in other words, eliminate the danger of being broken down on the side of the road out in the middle of nowhere (or somewhere dangerous).

Thats FUN!

[Drumwoulf]

Methinks a small, switchable turbo charger would get you the same effect, w/o all the engineering and added weight penalities of additional cylinders?
Works on motorcycles okay, and I think I did see a turbo-charged scooter in Scoot mag once or twice?

My single cylinder GT200 now gets atound 70 MPG. If it had an option where you had two 100cc cylinder engines and could switch over to a single 100cc cylinder engine at times, would you really save much fuel? The vehicle's body would, for safety, have to be built to the specs of a 200cc machine, so when you ran it on 100ccs the smaller engine would have to work harder than the double to push the same weight around!

Smaller engines can become less efficient than larger ones if they're overworked by having an inefficient power-to-weight ratio, no? You need some fancy design gimmicks to get around this problem, and that usually raises considerably the price of a vehicle!

[Roose Hurro]

Actually, I came up with the idea of hooking to independent engines through a shared transmission. Run both engines when you need the power, or shut one engine down, decouple it from the trans, and run on just the one, for better economy. Though I'd actually designed this based on the idea that an engine breakdown would most likely only effect one of the two coupled engines, so you could shut one down and run on the other... in other words, eliminate the danger of being broken down on the side of the road out in the middle of nowhere (or somewhere dangerous).

Thats FUN!

But those engines share a common trans WITHOUT the ability to flip a switch to remove one engine from the driveline, while shutting that removed engine down... while still under power on the road.


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[jrsjr]

I think it would be intriguing at the least to have a twin-cylinder engine that could be run on either one or both cylinders. Run on one, you have the equivalent to a 125, 150, or 250cc thumper, with the fuel efficiency thereof. Run on both, you have an interstate-capable 250-500cc engine with plenty of power. Oh, the versatility!

I wouldn't really be hard to make a test of your concept out of, say, a Suzuki Burgman 650. The 650 Burgman is a twin. It wouldn't be difficult at all to put in a switch that kills the spark to one cylinder and simultaneously shuts off the fuel injector to that cylinder. With a little work, you could test your concept. Unfortunately, I'd bet that you'd learn to hate the result. It would be terribly underpowered and overweight with the second cylinder shut down. It's one thing to shut down two cylinders of a V8 and quite another to shut down one cylinder of a two-cylinder motor.

The thing to remember is that a properly engineered CVT transmission is a model of efficiency because it can be tuned to keep the motor running at its most efficient virtually all the time. It's really a mechanical marvel for such a simple machine.

As it happens, I am an engineer, though I don't play one on television. Engineers are taught to believe in the KISS principle - Keep It Simple Stupid. Applying the KISS principle to the real underlying problem, I suggest leaving the superbly-engineered CVT in the Buddy scooter to do its job and, if you insist on being more efficient than that, simply turn your scoot off while you're waiting at long redlights, in slow-moving lines (like the ATM), and so on.

KISS - it's a way of life, especially for engineers.

[JeffersonJ]

Running a 2-cylinder engine with only one "power" piston is A LOT different than running a 6-cylinder with only four "power" pistons. It MIGHT work for a 2-stroke engine in which the spark fires with every upstroke, but I don't think it would even run (let alone efficiently) on a 4-stroke.

By the way, an MS of Mechanical Engineering speaking here.