I have a 14x48 jon boat with 15 deg vee. I am going to outfit the homemade mudmotor frame I have with an 11hp briggs. Which prop here would you guys recommend?

http://www.hillmarine.net/Weedless-Propellers-s/30.htm

9X9 or 9X7 is a good place to start.

that would be a 7x5 or an 8 x 4 for that size motor, the info above is for big block motors

Thanks All !

^^^ Depends on if it will be a surface drive with reduction or a longtail. A 10 hp with a 1.5: reduction would turn a 9X9 surface piercing prop nicely.

his link takes you to long tail props

I have a slightly modded 8hp that spins a 7x4 really nice, an 8x4 might be a little much for that engine, I think a 7x5 would be about perfect.

"his link takes you to long tail props"

Actually the props from the 9X9 on are all surface piercing props... have to give good data if you want a good answer.

whats the real difference between the two?

what i was meaning, the physical differences.
hill marine 9x9 and larger look to be SD props, they look different. the prop blades dont have much "tucked in", they spread out and act like a paddle blade.

i found out mine is a 7hp. if the engine does not sell today, i will put a 9x9 with a 1.4 reduction and see what happens.

CRC, you are correct the quickest way to visually ID them is how the blades extend from the hub. The sub-surface props will have more of an auger look and an overlap in the blades to the hub when viewed from face of the blade. A surface piercing prop will have a blade that is more extended. Of course, there are many more differences in diameter, pitch and how they are cupped so that they correctly ventillate and pull air into the blade face as it re-enters the water.

its amazing how a little bit of difference in the prop makes a huge impact on speed.
think a ron hill 9x9 is too much for 7hp with 1.4 reduction?

I think you would need to be closer to 10+ hp and 1.5:1 reduction to turn a 9X9.

The props seem to have a little difference in design, but they operate on 2 completely different theories.