Brad Tucker wrote:After running the 13x12, I found that it would allow the engine to exceed the max WOT of 4400rpm. I'm not sure by how much, because I didn't allow it to happen. I had more throttle left, and was running mid-upper 30's mph at 4400 rpm. Test run 2 was with an Acme 13x13. Max attainable rpm was 4200 with 42mph. Interestingly, I was getting around 28mph at 2500 rpm. The Speedo is a Faria GPS Speedo and I did not cross check it with any other GPS device. I'm thinking I will keep her propped with the 13x13 Acme, although the 13x12.625 they offer may be the perfect prop. Engine is a mid 90's PCM 351 rated at 240hp with very few hours.
Sounds like you got a 42mph boat, pretty good.
You mentioned 2 different Acme props, what was their stated cupping for each prop?