LEGO IDEAS - Educational Piston Engine model diesel or gas
LEGO part 3652 - Light Gray Technic Engine Piston Square 2 x 2 - Old at BrickScout
Technicopedia: 858
Amazon.com: ZOSTER Technic Crankshaft Accessories Kit Engine Connecting Rod Parts Individual Mechanical Technology Educational Parts Compatible with Lego Technic (67 Pieces) Random Color 517114QY20LURWYN : Toys & Games
LEGO® 2851 - ToyPro
LEGO MOC Piston Engine V6 by AKM-Sky | Rebrickable - Build with LEGO