Theoretical engine material efficiency improvements

[gone-ot]

Inserting different metals for the crystals within a structure?

[19bonestock88]

Originally Posted by Old Tele man

Polimotor experimented with a plastic 2.0L Ford engine years ago:

The plastic in question was Torlon, but all I’ve found(back when I had an old Ford 2.0) was that it was significantly lighter than even aluminum and the engine was made mostly from it except the rotating assembly and made some pretty big power for a normally aspirated engine...

If we could get Ti sleeves at the same hardness as steel, but save weight and have lower thermal conductivity, put them into a Torlon block... don’t get me wrong, we’d have a half million dollar engine but it would be remarkably efficient and powerful for its capacity...

[freebeard]

Originally Posted by Old Tele man

Inserting different metals for the crystals within a structure?

Weaving crystalline lattices into a composite alloy?

[Ecky]

My car already has a plastic valve cover and intake manifold. The dipstick is made from carbon fiber, the oil pan, magnesium. These materials seem to hold up just as well as their metal counterparts and save weight too.

One idea I'm surprised didn't take off sooner is the offset crankshaft. That seems to me really low hanging fruit for efficiency.

[Frank Lee]

Crank offset has been around for 100 years; I don't know the pros and cons of it or why or how much it is implemented.

[Ecky]

It started going into a lot of mass production engines in the mid to late 2000's. My understanding is that the forces on a piston are highest during the power/expansion stroke, so by improving the angle during that stroke you can cut internal friction pretty significantly. It also saves on piston ring and cylinder wall wear.

It doesn't show up in a lot of high revving engines, or those in luxury cars. My guess is that it's harder to balance, if that can be done at all.

[RustyLugNut]

But truthfully, the majority of the current materials work is not in making the engine that much lighter or the reciprocating mass lighter, it is reducing friction and heat loss. Those are what help you gain efficiency.

Ceramic coatings are already common and have improved to the point they are used in race and production environments. Simply coating the piston heads and combustion chambers of an engine gain several horsepower with no other changes if detonation is controlled. Coolant temperatures also go down.

I worked with a project where the wet cylinder sleeves of a Cummins diesel N14 were replaced with ceramic sleeves. Engine power increased by almost 20 horsepower with no other changes and engine coolant temperature decreased. Problems with piston ring life and wet cylinder sealing are still being worked on.

The single biggest contributor to internal combustion engine friction is the cylinder walls and piston ring interface. Material make up of the ring face as well as the cylinder surface can gain horsepower.

A practical engine we had prepared for the AutoXprize utilized heavily ceramic coated combustion chambers and piston domes. The piston rings had an exotic plasma coating as well as the iron cylinder liners. This reduced the ring to cylinder wall friction considerably.

None of this is so exotic and costly that it cannot be implemented today.