When talking about any Diesel, like the LA in question, I would say propping it about 1,500 RPM shy of the calculated HP peak, would be the best way to do it.

Propping any engine to spin significantly below its torque peak, is bad for any engine, Diesels and converted Diesels included.
I believe, Dave, you would agree to this.

The question is how much the conversion lowered the HP peak and the torque peak, in RPM terms.


So, before trying several props, to plot a HP curve, none of us would really know the best power RPM to prop the engine (first paragraph).

The torque peak on a two-stroke Diesel is usually about 3/4 of the way to HP peak (my estimate), so if this converted engine has its peak HP at 12,000 RPM, I believe propping it for less than 9,000, even from Martin's and Brian's POV, is useless.


I believe 9,500-10,500 is OK for the .46LA. Lower RPM would probably be usable for larger engines.


As I wrote, I could not yet run my .49.
Barkai will be coming for a visit soon, with fuel that can work and we will work on this...