by Jim Thomerson » Thu Mar 09, 2006 3:45 pm
I've blown blades off two Cox grey 8 x 4's at around 14,000 on an ST G20-15 diesel. On the other hand I've run them up to 17,000 with no problem on a Cox 15 special. The 7 x 3.5 is fine at 15,000 on a TD 09 and I've run them at 17,000 for short periods without failure. I think diesels and glow engines put different stresses on props, but that's opinion rather than fact. I don't know if there is published limit data.