Ceramic engines?

Are they durable enough to be put into cars designed with performance in mind? Does the engine have to be 100% ceramic (valves, crankshaft, heads, etc.)? Are there gaskets?

I've heard that some engines were made completely of S2, but I was wondering how well the ceramic crank stood up to the forces put on it.


P.S. Is it true they don't need any lubrication or cooling?

As far as I know (which isnt very far), its not so much a ceramic engine as it is an engine made of plastic coated with ceramic for heat protection, and yes, its true that they dont need cooling or lubrication.

1 (http://www.geocities.com/CapeCanaveral/1614/)
2 (http://www.geocities.com/CapeCanaveral/1614/ceramic.html)

I've never heard of a ceramic engine til now

Some of the major manufacturers were playing around with them last decade, I remember the concept engines which used ceramic blocks and were primarily two strokes (with direct fuel injection). Nothing ever came of them, but I suppose it was more just a fad than anything else.

That site certainly sounds interesting, and I suppose I can believe some of their claims, but it sounds too good to be true IMO. If there were that many advantages why isn't anyone using ceramic engines for any purpose? I mean if they haven't even gotten block development down and in production, how are they going to make a whole engine out of the stuff? I don't know, I just need some corroborating evidence before I buy into the idea it's so superior and has only a few minor drawbacks.

I think newer technologies will not be adopted because car mfgr's are lazy and stupid.

With all of those benefits so "obvious", and car makers spending enough money to make god cry tweaking engines and still not using ceramic, I'm tempted to agree with texan.

okay, perhaps someone can tell me where I've gone wrong, but on site 1 from 454's post, the author claims

We have an engine here that has 2.5 times the power of a metal engine of the same size using 1/4 of the fuel. It never uses oil or water and will run almost forever without servicing

If that were true, then wouldn't the engine be 10 times as efficient? Or are they talking about the fuel consumption and power output at different operating points (one at peak power, the other at peak econ)?

10 times as efficient = not thermally possible, unless they're comparing their engine to a ridiculously poor conventional engine

Even if their engine was 100% efficient (100% of the energy in the fuel was converted to mechanical power), they'd be only 2.5 times as efficient as the best IC engines out there. What's more, they'd have to have exhaust that came out at the same temperature as the incoming air, without letting it cool anywhere along the way - something I have a REALLY hard time believing.

he also mentions a VERY high price for crude oil ($100+ / barrel price by 2003) - if he's going to be right about it, the prices had better start soaring soon! As of April 12, 2002, the price was $19/barrel.

http://www.bry.com/prices.htm

Another interesting note - one of the sites that this guy cites as a reference only claims an 18% improvement in fuel economy... I wonder where the inconsistency comes in?

new to the website, looks like thers a ton of good info on here :cool:
ceramic is fairly brittle from what i've read, the crank is an especially big problem due to the jerking it recieves, rods as well i'm sure are causing problems, i wonder why that website makes no mention of it while showing the cons of metallic motors. and i find it extremely hard to believe they can machine pistons/bearings/crankshaft/rods/cylinder heads/etc in 3 minutes, especially being the piston to cylinder wall clearence is only 2 microns.
"Now any engineer will tell you that if piece of machinery looks good, it is good and this demonstration model is a beauty"
I dont know of a single engineer that will tell you that a piece of machineries quality can be based upon its exterior appearance. they also imply here "- Ceramics do not rust. This improves the life expectancy of the engine. It also means that corrosive fluids can be burned safely and cleanly" that metallic motors rust. i wasnt aware corrosive materials meant rusting, i had placed corrosive with the likes of acid which breaks metal down, not rust it. also i dont believe aluminum pistons rust, nor do aluminum heads or blocks, assuming stainless steel valves are used the only thing that could rust would be if the motor contained an iron cylinder wall. if the things they say are true it looks like its a great move forward, but i dont know how credible the can be called saying things like this.

I think he meant to say when he said that cermics dont rust, is that they dont respond to corrosive substances such as acids like metals do. Because a lot of corrosive things are contained by ceramics - glass, porcelin, and silicon if i remeber correctly, is very hard to break down chemically.

also i dont believe aluminum pistons rust, nor do aluminum heads or blocks, assuming stainless steel valves are used the only thing that could rust would be if the motor contained an iron cylinder wall
Depends on your definition of rust.

Originally posted by Steel
I think he meant to say when he said that cermics dont rust, is that they dont respond to corrosive substances such as acids like metals do. Because a lot of corrosive things are contained by ceramics - glass, porcelin, and silicon if i remeber correctly, is very hard to break down chemically.

ah, didnt think of that, does make a bit more sense

and 454, i dont quite follow what you mean :confused:

What is your definition of rust?

Originally posted by 454Casull
What is your definition of rust?

the metal oxidizing and breaking apart.

Sorry, I'm talking out of my ass again.

However, aluminum DOES oxidize - but does not break apart.

On that page they really seemed to overrate ceramic engines.

As I remember Renault had tried with ceramic pistons (just the pistons) in F1, but without any good results. The basic problem is the ceramics sensetivity, yes they're strong and hard, but hard usually also means sensitive.

Ceramics are difficult to machine, almost impossible, instead they are usually sintered (or similary).

Ceramics, just like metals expand in heat, this is a limitation of the tolerances.

Also, ceramics like all materials have friction (which we should be happy for) when they get in contact with another material. No wear.. good joke.

Ceramics can't oxidize, this is because they already have.

A higher combustion temperature means that much more can burn (just like mentioned on that page), but this isn't always a good thing. Since air contains about 70% nitrogen, NOx can easily be formed, this is one of the problems in todays lean burn engines.

It is easy to got carried away with the talk about ceramics, but it should not be forgotten that ceramics isn't always the best construction material, in engine applications it's probably metals that is the best material.

Take a look on aero engines, you don't find so many ceramics huh, and here is money usually no problem (since an engine can cost $3M).
Today, many of the "supermaterials" used in cars come from aero or space technology... so if they will get these type of materials to work that is probably the place where we'll find it first.

Originally posted by 454Casull
Sorry, I'm talking out of my ass again.

However, aluminum DOES oxidize - but does not break apart.

ahh, didnt know that part, i was under the impression it couldnt be rusted/corroded by other materials, like water,oils, etc, save for acidic substances of course

A number of ceramics were tried for engines, one being Sialon for Si Al O N or silicon, aluminum, oxygen, nitrogen which is the original silicon nitride dope (small amount added) with aluminum oxide. This ceramic had the hardness and flexibility to make some parts but ceramic has to be made in pieces to allow for heat expansion. Sialon has an excellent thermal shock resistance (resists strength of material objectit when one piece changes size and another doesn't) and glass for instance has little. Glass is essentially a solution of silicon doped with many different other elements and is actually a liquid. Silicon has to be almost totally pure to crystallize and thus not change shape. The tiny amount of doping in silicon solid state materials are just enough to creat holes in anb actual crystal while glass is very impure. Silicon, if pure, will take a lot as long as it is heated throughout but engines is not one of its uses.
If thin enough, its flexibility might approach its strength such as in exotic deposition (ion transfer in a vacuum making films of several atoms thickness) which are not brittle because the displacement of bonds across that distance are too small to matter. The only ceramic engine available would be some ceramic made up of bubbles that had walls very thin so the flexibility would exceed the strength.

Sialon is silicon aluminum oxynitride - I feel nitpicky. :)

Glass is not a liquid (at room temp), but rather an amorphous solid.

... What did you resurrect this thread for, anyway?

Check out Ford's SHO's, the newer ones have ceramic parts. It's lighter and runs cooler, I guess, makes me wonder why we still have cars that are under 100 miles per gallon, I mean come on, we're in outer space (not well, but we're there) for Gods' sake. It's all about the money.

(This is stuff I remember from college physics. If anyone can point out errors in my logic, please feel free to do so.)

Assume a 3000 pound car gets 25 mpg and is 10% efficient (worse case scenario). That means that 10% of the energy in the fuel system is used to move the car, and 90% is lost due to incomplete fuel burning, friction in the drive train, and heat.

For that car to get 250 mpg, it would need 100% efficiency. 100% of the gas would have to be vaporized and burned. The shifts of the transmission (where gas is wasted while the engine runs but no gear is engaged) would have to be instantaneous and friction free. You couldn't possibly use cylinders in the engine itself, because energy is lost in the constant up-stop-down-stop cycling. You couldn't possibly use valves in the engine itself, because the up-stop-down-stup movement of the valves saps energy too. Bigger valves, which permit more air and fuel into the cylinders and increase power, also burn more power because they are heavier. The pollutant control systems in the exhaust would have to work without slowing exhaust fumes at all, because that reduces efficiency. The exhaust would have to leave the car the same temperature it was in intake, and all of the heat energy it contained would need to be recycled. Now, heat energy can be converted to electrical energy, so that adds efficiency to the car. However, the conversion process would sap power by slowing the exhaust and adding mass to the car. The wheels would have to weigh nothing, because the energy from the engine pushes the car by spinning the wheels, and a lot of the energy is lost fighting the angular momentum of the wheels. 100% of the energy from braking would have to be recovered by the engine. The engine would be off whenever the car wasn't moving.

I think a 50% efficiency vehicle would represent positively amazing technology.

Some marine diesels approach 50% in total efficiency.

Some marine diesels approach 50% in total efficiency.

Marine diesels don't have drivetrains, transmissions and/or torque converters, complicated exhaust systems, tires to spin, idling at a stop light, or braking to worry about. I would think that makes a big difference in total efficiency.

Still, that's an impressive percentage. I didn't realize they worked that well.