That is the problem with most diesels and affordable building in the
performance range that suits me. To date this is the lightest I can
find. At least no PSRU would be necessary.

One problem with affordable designs and materials is added weight.
Fir for spruce, heavier wall mild steel tubing for 4130, heavier
engines, PSRUs, etcetera. This steady stacking of weight is a serious
issue with building cheap. My definition of affordable includes
buying materials locally. If shipping, particularly from the US, or
purchasing from Aircraft Suppliers are involved affordable is a lost
goal.

The most affordable option in North America remains buying a flying
airplane like a Fly Baby after an educated inspection. In my case I
bought a Fly Baby in Oregon and brought it back to Canada. If I price
out 8:00x4 Cub wheels and tires, tailwheel, strong A65, McCauley
metal prop, fuel tank, covering supplies, Sitka spruce, ..., my plane
cost total landed in my garage was cheaper than a set of A65
cylinders.


For fun I found Kubota specs for a small diesel.

http://www.engine.kubota.ne.jp/engli...4_v1505_36.pdf

Thanks for the research! But weighing 110 kg DRY for just 39HP it
doesn't seem very useable, does it?