Cylinder head, Cylinder head screws, <a href="https://garage.wiki/opel/engines/diesel/straight-4/25-l/4-ja1t/75-hp-at-3800-rpm-160-nm-at-2100-rpm.html" title="Opel diesel straight-4 2.5 L 4 JA1T 75 HP at 3800 RPM, 160 N⋅m at 2100 RPM engine DIY maintenance and service manual">Opel diesel straight-4 2.5 L 4 JA1T 75 HP at 3800 RPM, 160 N⋅m at 2100 RPM</a>, Bi-hexagon, First stage

by Roman Paulov