The project started around new standard size Mahle B23ET pistons and an overbored & o-ringed B21 block. The final itteration is a honed B23F, forged B21 crank, forged B21 M rods, B23ET pistons, and a lightened flat flywheel. All bottom end parts were balanced individually to 0.1g and then balanced together.

The B23 block was dipped, honed, and decked 0.016" to bring the pistons above the deck by 0.012" so I could use a 0.047" Elring HG for a piston to head clearance of 0.035". New main, rod, and intermediate shaft bearings, new freeze plugs, Elring gaskets top and bottom, and a new Melling M181 oil pump.