Building the Prototype AMD Series Engines

The months since the last update have been spent machining the crankcases for all five engines.  This has taken a fair bit of time as there was a lot of metal to remove and everything had to be set up accurately.

The single cylinder crankcases are built in two pieces, vertically split.  The in-line four has a main central section with end pieces which are exactly the same as the 5cc singles.  The halves have a register machined to align them accurately.

With the crankcases now largely complete, except for some final drilling operations, attention will now turn to machining the cylinders.  When the cylinders have been bolted to the crankcases, the bores will be machined through both parts.  The cylinder liners will help to hold the cylinders and crankcases in alignment.

I have done some preliminary machining on the cylinders, but the fins will be cut later once the bores have been machined.

As a reminder, I am building five prototype engines as follows, to test the design in its basic configurations:

• Engine 1.  AMD5S,  air cooled SOHC, glow ignition, lubricated by oil mixed with fuel
• Engine 2.  AMD5S, water cooled, DOHC, spark ignition, oil pump
• Engine 3.  AMD10S,  air cooled SOHC, glow ignition, lubricated by oil mixed with fuel
• Engine 4.  AMD10S, water cooled, DOHC, spark ignition, oil pump
• Engine 5.  AMD20IL4, water cooled, DOHC, ignition method TBD.

Boring the inside of a 10S crankcase half.

Setting the crankcase centrally in the lathe ready for boring.

Boring the 20IL4 crankcase centre section.

A 5S crankcase viewed from the front.