Oddball engines and prototypes

[Frits Overmars]

Seems I have either made a profound statement ..... or just total bullshit? - either way there seems to be no answer!

You might also conclude that it was indisputable .

[WilDun]

You might also conclude that it was indisputable .

Well, I might and it's very kind of you to say so, but ...... that means that the conversation is closed - and that's not really what forums are about! - especially on this particular thread, an indisputable conclusion is not recommended!

So....... this is the most interesting development I have seen lately, it's actually working and perhaps if combined with HCCI, it could be the biggest change in the internal combustion engine for some time!
https://www.youtube.com/watch?v=gNVnvptNJqM

[tjbw]

Well, I might and it's very kind of you to say so, but ...... that means that the conversation is closed - and that's not really what forums are about! - especially on this particular thread, an indisputable conclusion is not recommended!

So....... this is the most interesting development I have seen lately, it's actually working and perhaps if combined with HCCI, it could be the biggest change in the internal combustion engine for some time!
https://www.youtube.com/watch?v=gNVnvptNJqM

Well I like that, even though it looks heavy and expensive.

I've often thought of using something like a rack and pinion, with a piston on each end of the rack, didn't think of variable compression with that concept though.

Something like this:
https://www.youtube.com/watch?v=ScB6Wd4r9Jc

Here's more info on mce-5:
http://blog.caranddriver.com/vary-in...ession-engine/

[WilDun]

Well I like that, even though it looks heavy and expensive............. didn't think of variable compression with that concept though.

A very significant thing about the MCE5 engine is that the piston assembly moves in a straight line - the side thrust (which will always be generated when rotary motion is transformed into linear motion) is taken up by a rack/gear/roller combination, preventing any side thrust on the piston - maybe this could be a step towards an "oilless" system (possibly being considered by some people)?
It's also a very tidy solution to achieving variable compression.

[OopsClunkThud]

wouldn't the pressure angle of the rack/roller still result in side thrust on the piston? Further, the thrust would always be to the same side.

[190mech]

How is the rack and pinion going to look after 250,000 miles???

[WilDun]

wouldn't the pressure angle of the rack/roller still result in side thrust on the piston? Further, the thrust would always be to the same side.

As I see it, sidethrust is contained by the rollers (which are incorporated in the gears) and the roller tracks (incorporated in the racks).

How is the rack and pinion going to look after 250,000 miles???

Who knows? but how is any engine after 250000 miles? that might give us a clue!

[190mech]

250,000 miles is quite common with many more to go!I have a friend with a 1982 Ford Ranger that has 420,000 miles on his engine and still runs well.He's replaced 2 heads due to cracks,but the bottom end is still original!

[ken seeber]

Well, it looks like an elegant way to achieve linear motion combined with variable CR, BUT at the costs of:

• A much larger parts count
• Lots of overall and reciprocating weight
• Some really complex tolerance stack ups to achieve minimum clearances of the gears
• Dunno about the life of the gearsets given the high cyclic loads they must see
• I reckon with a very small amount of gear wear, it’d be pretty rattly

This was in 2010 and now nothing commercial I am aware of. Reckon I’d put my money on a smart 2 stroke, the Mazda HCCI or electric first.

[Frits Overmars]

Well, it looks like an elegant way to achieve linear motion combined with variable CR, BUT at the costs of:
• A much larger parts count
• Lots of overall and reciprocating weight
• Some really complex tolerance stack ups to achieve minimum clearances of the gears
• Dunno about the life of the gearsets given the high cyclic loads they must see
• I reckon with a very small amount of gear wear, it’d be pretty rattly
This was in 2010 and now nothing commercial I am aware of. Reckon I’d put my money on a smart 2 stroke, the Mazda HCCI or electric first.

I'm afraid your definition of elegant differs frome mine, Ken. I'd rather call it the KISS-violation of the month.
And yes, in time we'll al go electric. I was hugely impressed by a Tesla car. But then I'd pass it each time it has to recharge.
So I think we've got some internal combustion time left, until we'll see cheaper mass-produced fuel cells that can be fed with a liquid energy-carrier like methanol.

[ken seeber]

I'm afraid your definition of elegant rather differs frome mine, Ken. I'd rather call it the KISS-violation of the month.
And yes, in time we'll al go electric. I was hugely impressed by a Tesla car. But then I'd pass it each time it has to recharge.
So I think we've got some internal combustion time left, until we'll see cheaper mass-produced fuel cells that can be fed with a liquid energy-carrier like methanol.

Frits, yeah it surely does violate the KISS principle, but I was trying to be generous.
Same as you, there is some time left for the ICE to have some innovation prior to the first big swing. Clearly the first swing will be battery, one only has to look at the global inertia towards this. Whether fuel cells be the next swing, be they liquid fed (as you suggest) or hydrogen fed (can’t see this myself) will be decided by the trade-off of energy density (methanol would win over batteries I think) vs the costs/emissions of production. The latter I would think would favour batteries that can be charged by wind/solar electricity direct whereas methanol production would require a fair degree of processing, whether or not the stuff was derived from agriculture, petroleum or electricity generated.

Sadly though, whatever the next swing might be, it won’t make a noise that we know and love.

[Frits Overmars]

....batteries that can be charged by wind/solar electricity direct whereas methanol production would require a fair degree of processing...

You're right about the processing requirement of methanol. But think a bit further: the required processing time will already be passed at the plant; it won't bother us. And we could refuel at any petrol station; the complete infrastructure is already there.
Battery charging on the other hand will eat into our time each time we need a recharge. And I have yet to see a battery match the energy density of a tankfull of methanol.

[lohring]

Electrics do have a problem with long trips, but in normal use some exceed the range (around 300 miles) of my gasoline car. I very seldom take a longer trip than that and my home is 100 miles from my work. An interesting video explains why fuel cells aren't being used in place of batteries. The pressure is on and we'll see how the Tesla model 3 does. In the high priced sedan area the Tesla model S is outselling similar IC cars.

Lohring Miller

[Frits Overmars]

Electrics do have a problem with long trips, but in normal use some exceed the range (around 300 miles) of my gasoline car. I very seldom take a longer trip than that and my home is 100 miles from my work. An interesting video explains why fuel cells aren't being used in place of batteries. The pressure is on and we'll see how the Tesla model 3 does. In the high priced sedan area the Tesla model S is outselling similar IC cars.

If I'd never have to travel farther than 100 miles a day, I would gladly go electric. But I need a car that will go four times that far between stops.

That video is a great example of a biased view, hammering on the disadvantages of hydrogen fuel cells. But it's not the fuel cells that are to blame, it's the hydrogen. "Hydrogen is the energy carrier of the future and will probably remain so forever", my own words. That is why I prefer methanol-fed fuel cells. The methanol is first split into H2 and CO2 in a reformer at the cost of some efficiency, but the process is still far more efficient than burning the stuff. And unlike hydrogen, if you fill up your tank with methanol, it will stay full until you start using it. A hydrogen tank will loose 50% of its content in a couple of weeks through diffusion, even if you don't use any of it: the hydrogen molecules are so small that they escape right through the tank walls.

Another nice quote from the video:
"Battery packs don't produce a lot of heat because they're pretty efficient at turning chemical energy into electrical energy.
Fuel cells are less efficient and produce a lot of waste heat, requiring large radiators to keep them cool."

Yeah, right. Not a word about the efficiency of generating electrical energy for charging those batteries.

[WilDun]

Some interesting theories on the future I must say - I believe that electric will win through ..... eventually!

The MCE5 is overcoming sliding friction with its rack and pinion, producing straight line only piston movement without sidethrust and much reduced friction - isn't this what we were all seeking just a few months ago in connection with going "oilless"??

The gears could actually be adjusted to be quiet by having two racks independently movable but both in contact with the same gear and automatically controlled to take up any slack when the force changes to the other side of the lobe. .... and yes, I know .... more parts and not in line with the (PC) K.I.S.S. principle !

To be honest, I still believe that the future will be electric, whether it's produced by a normal piston engine, free piston engine, gas turbine engine, wind power, water power, solar power, any kind of power station or methanol fuel cell, (I reckon the latter should be the focus here), but this still has a long way to go in it's development.
Electric motors with smart controllers which make them infinitely variable are a much cheaper option than any working or practical truly infinitely variable gearbox (if there is such a thing) that I have ever come across!

However, all this will depend on the world's lunatics with their nuclear bomb playthings! - it's sad to see that all this potential energy is being used to make bombs when it could be used to make power for everyone and all the research could have been put into that (and into what we are discussing here!).