Ah, this is good to know. I ended up getting that parts catalog off e-bay which seems to confirm what you all are saying. Very happy to have this book in physical form! The pony motor is on hold until I can find someone capable of boring out the cylinders to accept dry sleeves. I'm running into the same problem Squatch was having in that all the machines in my area are set up for v-blocks which can't handle the height of this opposing cylinder engine. If anyone knows of a solid machinist in the pacific northwest area, I'm all ears!
Currently working on the fuel delivery system which should keep be busy for a few weeks.

Dirtbiker have you looked into getting over size positions? In South Australia they make them I think the place is called JP pistons?Im sure someone will give correct name of the place that make them for the pony so you can take minimal out of the block and possibly not fit sleeves? RAX or TrainsKid may know, cheers Jamie

Hi Buss020 and Dirtbiker,
Yes the company is called JP Pistons there contact details are attached they do several sizes in the d2/d4 pilot motors and also the d6 pilot motor, a member just brought a set of standard pistons with rings and gudeeon pins for approx $140au each.

 

i got them to make a piston for a bsa staionary engine i did up. i have three of them driving a common shaft. they got christened miss bits, miss stuck and miss anywhere

what you need is a machine shop with a horizontal borer. portable line borer could work but it would be "fun" getting it lined up.
if you could find a shop with a sip no6 hydroptic jig borer that machine can do the job. i know the location of one of these machines in queensland but the freight would kill you.

thinking a bit more a radial arm drill might work too.
you only need to bore to a size as oversize pistons are available.

cat have most parts still available for the pony anyway. you can search parts.cat.com if you have part numbers. note the system work on six charters minimum so some need to be "upgraded" with a zero after the first two characters to get six characters.