18 x 21 3 blade is stock. But I think your speed numbers seem low. How did you check those?Off topic of the generator discussion. Looking to see what prop size and 3 or 4 blade combo works best for the 1995 370 sundancer. My engines are re manufactured long blocks (Gen 5 with roller cam) built to 310hp specs. Running 18 x 21 (3) blades now (Nibral), Cruise at 3200rpm is 16knt. / W.O.T. is 4400rpm / 26knts. Read thru all 214 tabs in this forum searching for an answer and really not clear.
Numbers about right for this ?
I originally has 17 x 21 4 blades and while speed was ok, rpm’s were low. Went to 18 x 19 4 blades. Here are the results I posted a few pages back.
“Got new props over the winter. Acme 18 x 19. Did a short shakedown today.
WOT was about 4100 RPM, Gps @31.5 mph. (vs. 3800 RPM, 28-29 mph)
Good cruise at 3000 RPM, Gps @ 22.8 mph (vs 3200 RPM, 22-23 mph)
Did 2600 RPM while still on plane, 15.1 Gps. (vs. 2900 RPM, 16.5 mph)”