Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Good thoughts on the ventiation. I have been thinking similr and will try leaving the cap off. I have also been thinking about cutting some larger openings into the crank case area.

As for the main bearings, they are needle bearings. I find that when I place a drop of synthetic clock oil next to them on them outside, it is wicked in immediately... at least when it isn't running. I believe this also works while it is running.

Running them slower and with plenty of oil in the fuel also goes a long way toward keeping them cool. WD40 is not a good lubricant.