BerniModels

Project progress Update
The new test engine (IT2) as I call it, has been put together. Tests will start soon to adjust it and fine tunning.

Several parts were made from scratch, whereas all the head components were taken from the IT1 engine. In the next picture, you can see the machinning of the con rod in my CNC milling machine. A 2mm end drill is used to make the pocket in the body. The con rod is made of two separate parts, that are then bolted together. After this, the head drill is made and the bearings are press fit.

 This is the size of the block and piston. You can compare it with a caliper, the piston is 21.5 mm in diameter and the stroke is just 8.5 mm! it can also be seen in this picture the finished conrod, with its oil channel. Ball bearings are used to hold the crankshaft on the engine block.

 The crankshaft is some quite nice part to make. It is swaped from the lathe to the milling machine several times before it can be ready. This was the first time I used the new CNC rotary table. The journal shaft is quite thick, because it represents the real crankshaft that will be much longer and carry more power. The crankshaft counterweights are rather small, because I use a heavy alloy insert which is more dense than the steel.

 All main parts exposed. The liner is only 21.4 mm tall. The piston skirt is most of the time exposed also outside the liner. This helps the oil to cool it down. On the right hand side of the picture, there is the crankcase. The crankshaft cavity is round, machined to improve efficiency. This is meant for a dry sump system, which is not used now, but will be incorporated in IT3 or IT4.

 This is the bottom view of the engine, with the components from the picture above are assembled together. It is hard to see on the picture, but the clearances of the crankcase cavity, crankcase and piston are below than 1mm. This is why it is so small!

Finnally a picture of the complete engine. At the moment it is being adjusted meanwhile some details are finished. I will use a hand driller to start up the engine. The aim is that it reaches above 15000 rpm... I'll keep you posted!