KIWI Mk2

I/C ENGINE BUILD

Part 9 By Vince Cutajar

There are four oil passageways holes to be drilled in the crank. Drilled and tapped 3mm the first hole through web, from the top of the web to the crank centre line (photo 1). Set up to drill the second hole through the crankpin (photo 2). Used a wiggler to align the spindle with the hole mark (photo 3) and drilled till it broke into hole 1. Tapped 3mm. Also used a jewel screwdriver in hole one to see when I break into the hole. Good thing I had the extra long drill for this operation (photo 4).

Hole 3 was drilled in the crankpin until it broke into hole 2. Used the same screw driver to know when I reached hole 2.
Fourth hole finished and tapped 3mm. Used a steady rest to support the crankshaft. Started the hole using a normal size 2.5mm drill then continued with the long drill. I need to get me some 3mm grub screws to plug the holes that were tapped. One more hole needed in the crankshaft. This will be the oil feed hole but will do it at the same time when drilling the crankcase.
Made the oil inlet hole in the front crankcase casting. Held the casting in a vice and milled flat the boss of the oil inlet. Drilled through a 2.5mm hole and then drilled and tapped 5mm.

Next the oil inlet hole on the crankshaft which should meet the previously drilled hole in the crankcase. With the crankcase still in the vice, inserted the crankshaft and positioned it at TDC. With a transfer punch through the crankcase 2.5mm hole marked the crankshaft. Drilled a 2.5mm hole in the crankshaft and filed it with a small round file as per instructions.

The bronze casting for the bronze counterweights for the crankshaft came with the kit. Milled the bottom to give me a flat surface and then milled the top.
Brought down the thickness of the casting to dimension on the lathe. Then mounted the casting on the milling table (photo 2). Used a 12mm endmill and milled the slot to the required depth of 3.175mm.
Using the DRO (thank God for them) I widened the slot to 12.7mm all the time using a piece of the excess material I had hacksawed off when making the crankshaft as a gauge. I do not want the slot to be a sloppy fit in the crankshaft webs.
Hacksawed the casting so that I could separate both balance weights. Milled the flat at the top on both weights and then marked them so that next time I will mill the 15 deg. sides.
Milled the angled sides. The rest will be turned in the lathe when the balance weights are fixed to the crankshaft.
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