How small is "small displacement"? I have PSA's (Citroën-Peugeot, also installed in Fords as the 1.6l TDCi) HDi turbodiesel: 1.6 liter, aluminum block, 4 cylinder, 16 valves. I believe the newer 2.0l 2.2l also has a 4v/cyl version.
I don't know about the 0.8l 3-cyl CDI diesel in the Smart ForTwo, but I think the 1.2l 3-cyl TDI, of Audi A2 and VW Lupo 3L fame, had 4v per cylinder.
EDIT: Checked on
Wikipedia: The VW 1.2 TDI has only 2 valves per cylinder, but it is aluminum and weighs only 100kg (220lbs).
EDIT#2: The
0.8l CDI also is aluminum and has 2v/cyl, but no info on how much it weighs.
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e·co·mod·ding: the art of turning vehicles into what they should be
What matters is
where you're going, not
how fast.
"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell
[Old] Piwoslaw's Peugeot 307sw modding thread