checkered wrote:Good thinking Belatti, you
anticipated my emerging question! The manufacturing process sounds quite energy intensive, though. I'm just wondering how that compares to any savings in fuel economy/engine durability vs. more "primitive" engines. (Naturally, I'm kinda hoping it's not a zero sum game, or worse.) This as I've come to wonder generally about the attention paid to the energy consumed in manufacturing/recycling a vehicle vs. its operating energy expenditures.
Well, "direct" savings in fuel are usually because lighter pistons or a decrease in friction (both due to materials developments)
Here you can see the fatigue strenght evolution through years that made posible mass reductions:
Then, other "indirect" savings come when engine performance is increased by adoption of new technologies. With the raise in combustion chamber pressures you must adopt the cooling gallery, all that justo to get a better HP/liter ratio plus durability.
To make a proper energy balance between fuel savings vs. "cooled pistons" production energy increase, you must consider energy used to extract and transport the salt, the machine that manufactures the mould, the machine that dissolve the salt once the piston is casted and (as salted water is considered industrial waste) the energy to build and maintain a wastewater treatment plant.
Thats a hard job to do. Anyway, the market is moved by money and energy efficience is not considered as a whole. After all, many new jobs were given with the implementation of such thing.
One more technical aspect I forgot to mention: you can only have galleries in die casted pistons. In racing (thus forged) pistons oil is just directed to the underside of the piston, as djones said.
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