Technical Blown French Flathead - Question about lubrication and engine ventilation

Hello everyone

I'm currently fitting my French Flathead with a 471 blower. I still need to modify and adjust the blower. Is it advisable to lubricate the blower gears with fresh oil (engine oil) or is a closed oil reservoir better? If closed reservoir, what type of oil and how much should be used?
I also have a question about crankcase ventilation – should I build it the cl***ic way with a road draft tube and breather, or with a breather and a PCV valve? What are your experiences with this?

Cheers, Matthias

 

90 wt gear oil in the reservoir works well. The oil level should be below the shafts.

Most guys use sealed rear bearings, that do not require oil.

Either draft tube or PCV valve will work. PCV might help the engine last longer if you actually drive it a lot of miles (or KMs, if that's all that is available where you live)