Streamlined gasoline-ICE microcar/tadpole trikes

[amberwolf]

Imagine taking an old school Coleman lantern and wrapping solar cells around it. It would be similar to this.

Funny, when I was a kid that's how I thought they would do fusion power. :lol:

 

[Logic11]

Personally, If I were to build something like this(which I may, someday)

I would use one of Honda's GX series mini 4-stroke engines(or similar):
honda 4-sroke mini engine at DuckDuckGo

Honda Engines | Mini 4-Stroke Series

4-strokes have some advantage for land based motation:
Usually much quieter.
No 2-stroke oil mixed gas.
Usually lower emissions(see final point)
Usually longer service/lifetime intervals.

Final point, I would convert the engine to run on propane, advantages:
Massively lower (toxic) emissions, can be operated indoors/enclosed spaces with adequate ventilation, no carbon monoxide.
Lower maintenance, no gummed up carburetor from old gas.
Propane does not get 'old', absorb water from the air, rust out your fuel tank(aarrrghhh)
No liquid fuels to handle/spill/stink up your hands.
Longer engine lifetime, near zero carbon buildup, have you ever seen the innards of an engine only run on propane? they look like they just rolled off the assembly line!
You can buy dirt cheap off the shelf propane kits for slightly larger engines(I have been researching this lately for my Honda 3500w generator)

Possible disadvantage to propane:
Fuel sourcing,
If you ran your own propane cylinder, you would have to find a refill location, not that hard, but less common than gas stations.
If you ran a common 20lbs BBQ exchange cylinder, I'll bet there are more exchange locations than gas stations.

Fuel energy density:
I have heard/seen figures around 20% less than gas, don't have exact figures.
EDIT: looks like 27% less on a gal. to gal. basis, source:
Propane: An underrated fuel of the future | Fuels Fix

Just my 3cents.

While one cant beat the power to weight ratio of a 2 stroke, these advantages are compelling.

One thing you haven't considered is that normal gasoline or diesel or just about anything can be pyrolysed into mostly methane and methane like gasses by using the (normally waste) heat of the engine.
Further; some of that methane can be/is turned into Hydrogen by the same 'reactor' using the Steam Reformation and Water-Gas Shift reactions.
I'm sure you're aware of how beneficial adding a bit of hydrogen to propane etc is.
I think I have included links to how this is accomplished with a couple of plumbing fittings and some piping here.
Maybe it was elsewhere, but its late so let me know if your are interested in links etc.

That gives the advantages you listed but adds multi fuel use which Toecutter wants and lighter more compact fuel storage.

There's one more thing one can do to improve the power to weight ratio of a 4-stoke. Especially a single cylinder:
Air into the crankcase via a reed valve.
Air out via another reed valve, into a holding tank/oil centrifuge, attached to the stock intake.
This gives you 2 (crankcase) induction strokes for every 1 std intake stroke, turning the crankcase into a supercharger with very little added weight and size.
In single cylinder engines as would be used here to keep heat loss/efficiency as high as possible, pumping losses are a major drawback negated by this.
Such engines are in fact on the market, but they run on a 2-stoke oil-fuel mix. That I don't like. (more on that below)
What is Crankcase Supercharging? - RCU Forums
Hybrid 4 Engine Technology for Trimmers, Blowers, Brushcutters, Edgers and Multi-Tools | Hybrid4Engine.com
(Glad something came of my provisional patent on this. Stupid of me to think I'd make any money out of it though. I was young...)


2-Strokes have the advantage that the frame of the velo can do double duty as the exhaust and muffler without rust issues thx to the oil.
At constant rpm they can be made much cleaner than most realize.
That is linked here.

Problem is they need a separate oil mist injection system to lube the crankcase. (and sleeve)
That means the above Pyrolysis cant be used with them unless the engine uses a separate fuel and oil injection system.
You did/do get such kits. I need to see if a kit is still available when its not 3am in the morning!

 

[classicalgas]

Personally, If I were to build something like this(which I may, someday)

I would use one of Honda's GX series mini 4-stroke engines(or similar):
honda 4-sroke mini engine at DuckDuckGo

Honda Engines | Mini 4-Stroke Series

4-strokes have some advantage for land based motation:
Usually much quieter.
No 2-stroke oil mixed gas.
Usually lower emissions(see final point)
Usually longer service/lifetime intervals.

Final point, I would convert the engine to run on propane, advantages:
Massively lower (toxic) emissions, can be operated indoors/enclosed spaces with adequate ventilation, no carbon monoxide.
Lower maintenance, no gummed up carburetor from old gas.
Propane does not get 'old', absorb water from the air, rust out your fuel tank(aarrrghhh)
No liquid fuels to handle/spill/stink up your hands.
Longer engine lifetime, near zero carbon buildup, have you ever seen the innards of an engine only run on propane? they look like they just rolled off the assembly line!
You can buy dirt cheap off the shelf propane kits for slightly larger engines(I have been researching this lately for my Honda 3500w generator)

Possible disadvantage to propane:
Fuel sourcing,
If you ran your own propane cylinder, you would have to find a refill location, not that hard, but less common than gas stations.
If you ran a common 20lbs BBQ exchange cylinder, I'll bet there are more exchange locations than gas stations.

Fuel energy density:
I have heard/seen figures around 20% less than gas, don't have exact figures.
EDIT: looks like 27% less on a gal. to gal. basis, source:
Propane: An underrated fuel of the future | Fuels Fix

Just my 3cents.

I have a couple 30 cc ( maybe 50cc?) propane powered four stroke weed whackers that I picked up on sale a decade ago, never been run. Set up for camping size propane tanks. A 4 stroke set up to get the best out of propane needs its compression bumped up from the gasoline version.

 

[neptronix]

Boy would i hate to hear and smell a weedwhacker on a recumbent.
Would just ruin the quiet, easy ride, as well as any semblance of stealth.
Different strokes for different folks i guess :O

 

[amberwolf]

Boy would i hate to hear and smell a weedwhacker on a recumbent.
Would just ruin the quiet, easy ride, as well as any semblance of stealth.
Different strokes for different folks i guess :O

That's the biggest reason why I went electric; originally i was going to go gasser for the range and the pretty low cost...but after i heard people riding those little "china girl" gas engines on teh canal paths....and seeing them broken down all the time....

 

[Hillhater]

Boy would i hate to hear and smell a weedwhacker on a recumbent.
Would just ruin the quiet,

The stock Honda 50 “Cub” type moped/scooter bikes are very quiet and practically inconspicuous ..most likely because of clever Japanese muffler design and development.

 

[marvin78]

The stock Honda 50 “Cub” type moped/scooter bikes are very quiet and practically inconspicuous ..most likely because of clever Japanese muffler design and development.

The GX30 ( or is it 31) clone I got suffers from mechanical noise a lot, it's air cooled and doesn't have a thick cilinder wall. Even with a better mufler and better airbox for intake sounds, you will never get it quiet.

I've seen one of those larger one's, maybe a GX340 or bigger, which had an extended exhaust which he routed under water. I asked him if the backpressure of the water was an issue, and he said no but it might be an issue with my smaller displacement engine if I tried the same. And it had much thicker cillinder walls, reducing mechanical noise.

Pretty sure those engines also run half the rpm of the smaller one's so that will certainly help.

Boy would i hate to hear and smell a weedwhacker on a recumbent.
Would just ruin the quiet, easy ride, as well as any semblance of stealth.
Different strokes for different folks i guess :O

I bought my outboard thinking: surely that video in the add is right, and the noise won't be like a normal weedwacker I'm sure they done something to make it more tollerable... as you don't see people wearing hearing protection in their advertising.

Yet everyone I see operating a weedwacker for 'work' .. seems to be wearing hearing protection... go figure

Compared to Weedwackers tho... RC plane engines are even worse. There is a reason they get better power to weight, open pipes are common.

 

[classicalgas]

That's the biggest reason why I went electric; originally i was going to go gasser for the range and the pretty low cost...but after i heard people riding those little "china girl" gas engines on teh canal paths....and seeing them broken down all the time....

I got into powered bikes through the "china girl" route. Even with glass pack mufflers on the end of long pipes, and all sorts of efforts to make them civilized, the first ebike I owned ( a horrific DD front hub motor with rack mounted SLA batteries) was so much better that I started disposing of my gasbike parts that week.

I still think about building a propane powered serial hybrid...but not for very often or long...

 

[Logic11]

This is a really interesting, Aero, Tadpole trike build.
It's a shame we don't get to see the end result.

 

[Logic11]

Boy would i hate to hear and smell a weedwhacker on a recumbent.
Would just ruin the quiet, easy ride, as well as any semblance of stealth.
Different strokes for different folks i guess :O

Hear:
We are talking constant rpm Series Hybrid here, where Helmholtz and Quarter Wave Resonators (anti noise waves) are hugely effective at damping specific frequencies. Frequencies that remain constant at constant rpm..!
They work in engine enclosures, exhausts (extensive anti drone use), and intakes (in use).
Thx to the oily exhaust they can be part of the frame/structure, saving weight and space, without rust issues: A Quarter Wave Resonator is just a T'd in, tuned length (capped), piece of pipe.

For me; anything above a low hum would be unacceptable and scientifically cancelled TF out!

Smell:
Again; constant rpm means 2-strokes can be very clean, and cheaply!
(Do check the link to see whatTF 'The Nutter's' on about! )
This comes down to:

• A Tune pipe (@ constant rpm)
• A small reed valve/s in the transfer ports
• A centrifuge to recycle the smoke and oil. (much heavier than gas)
• A bit of onboard hydrogen production, for emissions more than economy. (but maybe mostly from waste heat)

ie: If 'the cops' can hear or see it from further than 20 feet away; it's out!
With a handy cut-off switch, they wont.

 

[Logic11]

The GX30 ( or is it 31) clone I got suffers from mechanical noise a lot, it's air cooled and doesn't have a thick cylinder wall. Even with a better mufler and better airbox for intake sounds, you will never get it quiet.

Ye; water cooled is way better and you do get water cooled RC engines nowadays.
Then there's no reason not to put it in a 'Helmholtz designed' box.

I've seen one of those larger one's, maybe a GX340 or bigger, which had an extended exhaust which he routed under water. I asked him if the backpressure of the water was an issue, and he said no but it might be an issue with my smaller displacement engine if I tried the same. And it had much thicker cillinder walls, reducing mechanical noise.

Water's one way to do it and exhaust is full of water once you cool it down enough.
There can be other advantages too.
But rust, weight and aero is a challenge.

The trick to silencing an exhaust without losing performance is a Pressure Wave Termination Box. (David Vizard)

No reason a Tune Pipe cant feed into one.
(Many do ...kinda. And NB that Tune Pipes at optimal rpm are quieter than when the engine is at other rpm's)
After that you can basically go nuts with resonators and mufflers, as long as they aren't the cheap, highly restrictive BS one normally sees on Weedwackers etc.

Pretty sure those engines also run half the rpm of the smaller one's so that will certainly help.

Lower rpm generally = lower frequencies. (and also more weight and space)
Lower frequencies generally take thicker damping materiel (= bigger stuffed enclosures) and longer or bigger Helmholtz and/or Quarter Wave Resonators.
Higher frequencies also attenuate with distance sooner than low.
ie: If you've blocked your ears with a pillow due to a party close-by, it's the 'Boom-boom-boom!' that gets through, so high frequencies are easier to silence.

That means small, light, high (but CONSTANT) rpm engines are easier to quiet than big, heavy, low rpm engines, IF you go to the trouble...
RC planes and weedwackers etc don't bother because of varying rpm, weight and cost.
Weight and cost is close to zero if the vehicle chassis/frame's doing 'Double Duty'!