So according to what I can find, aluminum gets substantially weaker at operating temps, at a peak operating temp of 350 Celsius 6061 drops to 21MPa in strength, while stainless steel 304 drops to 60% of its strength.. while cast steel is still 100%
So cast steel will still be 248 MPa
And stainless 304 will be 621 * 0.6 = 373 MPA.
Cast steel should be 3.9x stronger than 6061 aluminum at 350 Celsius. While stainless 304 will be 5.8x stronger.
Now if we made pistons the same weight as the aluminum pistons, they’ll be thinner, so if we account for the approx 3x higher density.
If our goals outgrow stock pistons, why are we paying for forged aluminum pistons again? I know stuff like nickel coating pistons are supposed to lower temperatures of the piston etc, since it has lower thermal conductivity than aluminum and more heat would be pushed out exhaust, but I’ve never found by how much. But steel has half the thermal conductivity of nickel and that would be the whole piston so would lead to lower temperatures for piston and cylinder head if nickel coating aluminum pistons works.
>noooo that’s ultimate tensile strength
So is for the 6061, even if we compare the ultimate tensile strength to the lowest figure for yield strength for 304 /and/ adjust for density and assume they’ll reach same op temp, then that yield strength is still double the ultimate tensile strength of 6061
>muh thermal expansion
6061 has a linear expansion per degree 35.2% higher than stainless 304. Stainless could run tighter tolerances.