Efficiency Improvements for Internal Combustion Engines

[autoteach]

Originally Posted by NeilBlanchard

Two things: the exhaust flow is nearly constant because it is a 2 cylinder opposed 2 stroke, and the turbo could be sized appropriately? The RPM's are low, so there is some time. Also, each piston is pushing the other through exhaust, and there is no throttle, so pumping losses are low.

What is it about compression that is required for favorable combustion? Is it heat only, or is the pressure required? I was hoping to avoid the "work" of compression.

Your point about the offset causing low power on the upstroke is key -- the whole aim of this is gain the downstroke advantage, and not really need the upstroke power. Otherwise, it would seem that a crankshaft design for ICE is inherently and fatally flawed in that it cannot achieve any better efficiency than it already has?

(It was invented for steam power after all, which has a large back pressure reserve, so the piston is pushed nearly constantly through the whole stroke; instead of a burst at the very beginning.)

Efficiency goes up with compression, but I guess you could stand to reduce the chemical reaction efficiency as well as mechanical efficiency (I believed that I linked it) to gain back some mechanical from the non compression stroke. I would say that compression is important. Here is some more reference on this for another "less mechanically" efficient engine.
http://www.cast-safety.org/pdf/3_eng...ndamentals.pdf

I NEVER said anything about low power up stroke. What I did say that there was a significant thrust issue with your cylinder arrangement. Forcing a piston up against the side of the cylinder will use some of its life and some energy up.

As for mech's link on efficiency, the audi and vw engines putting up 41 and 44% efficiency (50% never being achievable by our antiquated modified steam engines) are 2.5 and 3.3 liters. It would seem that these would fit in cars.

And, so you know, they have gotten 2 stroke DI engines up to 20mpg in snowmobiles.

[user removed]

Originally Posted by dcb

dude, you gotta get that thing running on gas or some kind of fuel first. And CVTs are not in the "most efficient transmission" column.

Post 1

[user removed]

Originally Posted by dcb

Test your theories on a working model? Opinion != fact.

Post 2

[user removed]

Originally Posted by dcb

a flywheel and a piston cost 70k? I just wouldn't present theory as fact without testing. While I get the benefits of your proposal, I think you all might have missed a few considerations that could put this engine in the realm of seriously impractical for improving the efficiency of vehicles, i.e.: reliance on an inefficient cvt, large amounts of rotating mass , lots of extra weight, unproven delicacies in the crank area, unknown volumetric efficiency, rotating exhaust seal, articulated stroke has exponentially worse compression ratio in response to changes in displacement (unless the cylinders are made to be moveable too).

If you are going to present CVT as an efficiency improvement, you gotta back it up with real data. Number of patents and PHDs and a flow diagram doesn't mean squat. The real data I've seen has CVTs sucking air.

Post 3

[user removed]

Originally Posted by dcb

I listened It's well past time to stop thinking and start verifying though.

and 60%?!? you know that's too good to be true, like electricity, hydrogen is not a "primary fuel", and the books have been cooked in the 60% example certainly.

Post 5

[user removed]

Originally Posted by dcb

My point in comparing hydrogen it to electricity is that you are ignoring all the losses in making the hydrogen in the first place.
...



No, what I missed is the practical application of your ideas. The piston flinger is massive for it's power output, and the variable stroke is in lock step with dramatic changes in compression ratio, and an unproven valving/manifold/ignition/lubrication system. I give you credit for thinking out of the box, but I must stop giving you credit when you talk in absolutes where no validation step has occurred.

Post 6

[user removed]

Originally Posted by dcb

Look, I don't really care about patent/money problems or how many VA tech students looked at it. I've given some specific items and you chose to not address them directly and gave me the "I need a grant" spiel again. I think the whole patent system is screwed up to begin with, and is simultaneously self-serving and a mechanism of technology obstructionism (along with an unhealthy dose of bureaucracy). So I'm only focusing on the design, to no monetary gain of my own, the rest is just noise.

re hydraulic cvt: I think there is a serious over-estimation of the efficiency in cruise mode, same thinking that is currently plaguing the series hybrid crowd. While the "positive displacement" aspect is ideal, it does come at a cost and limits peak efficiency. If you are on the hiway, you don't have that nice big blue arrow jacking you up to 94% efficient transmission.

This is also going to be a constant power drain on your flywheel assembly, no?

Post 7

[user removed]

Originally Posted by dcb

unfortunately that doesn't really answer the question... when the pistons (and some fraction of the connecting rods) are accelerated and decelerated energy is lost, question is how much. I did figure it out on the valves once and it was a trivial amount of power, assuming you aren't approaching redline.

Id that 8 it's getting booring.

Not a single one was constructive or directed at anyone but guess who.

Dude indeed, talking about defensive.

[user removed]

Originally Posted by dcb

Dude, don't be defensive, I'm already driving a tdi, which they list as 41% efficient, and drive it more efficiently than most people realize is possible (there are many boxes that bind us).

I did research the hydraulic transmission a bit more, in this real world example it is ~85% efficient.
Torvec, Inc. - Message from the CEO ", reflecting an overall operating efficiency of 85% (92% x 92%). " which isn't real good for long distances. Sprockets are the best I've seen so far, achieving up to 98% transmission efficiency.

You should stop the personal attacks immediately and deal with the technical issues and invalid assumptions you are making.

Do I need to link the 93% efficient quotes from the University of Michigan, Ford, Eaton, and the EPA, or are you smarter than all of them combined.

[dcb]

I posted the links, and the reasons, you don't read my posts, as evidenced by the non-sequitur stream of responses.

If I said "Everyone should use a 2 speed powerglide because it will be more efficient cuz they are too dumb to operate a stick shift", and you said "Umm, I don't think so", would anyone accuse you of being non-constructive?