Any Dieselphytes have the specs for an Irvine .40 Diesel, I was comparing mine to an old series Irvine .40 glow and they do not have the same bore and stroke. The Diesel appears to have a 1.5MM smaller bore but a 1MM longer stroke than the glow. The crank in the Diesel is stamped 46. Also the Diesel head has the contra piston in it like a Davis head does but there the similarity ends.