MX13 Heavy Duty Truck Engine - 6 Cylinder Diesel Engine (Polygon mesh 3D model) is available on CGTrader for $199. Original author: markos3d. Specs: 23145456 polys, 11682000 verts.
STL (Stereolithography, filesize: 347 MB), OBJ (OBJ, filesize: 252 MB), MAX (Autodesk 3ds Max, filesize: 66.7 MB), 3DS (3D Studio, filesize: 92.8 MB), LWO (Lightwave, filesize: 75.9 MB), MA (Autodesk Maya, filesize: 111 MB), C4D (Cinema 4D, filesize: 182 MB), HRC (Autodesk Softimage, filesize: 336 MB), FBX (Autodesk FBX, filesize: 214 MB)