Prop pitch?

[clancy72]

I just purchased a 24' cobia caribbean with a "400" hp 350 chev paired with a v/p 280 outdrive. The boat is 3950# and the previous owner was running a 17 pitch v/p OEM prop. He stated that he was getting 45mph at powell with a load (9 adults and 70 gallons of fuel). He also stated his hole shot was "great" and the boat comes right up on plane. Any suggestions on prop brands/size/pitch to optimize the HP for top-end speed without losing too much hole-shot? I will only occasionally pull a tube with 5 and 6yr olds so a 4 blade really isn't necessary... And YES I'm getting a new trailer....

 

[Silvertip]

Re: Prop pitch?

You've given us lots of information but unfortunately its useless because it is all heresay and not actually observed by you. Speed, hole shot, the number of people, size weight, is all relevent only when you include engine RPM at wide open throttle. Why is that important? Because you may already have the best prop! Wide open throttle RPM with average load is what determines whether or not you have the best prop. If the engine cannot reach it's maximum recommended wide open throttle rpm (4600 - 4800 rpm in your case) you already have a prop with too much pitch and are lugging the engine (it doesn't like that). Conversely, if the engine exceeds that rpm band you have a prop with too little pitch (it doesn't like that either). Speed is what you get when the prop pitch is right. So -- do some wide open runs with an average load and note engine rpm. "About" xxxx is not a good answer. We are talking within 100 rpm here. Come on back and perhaps we can help.

 

[clancy72]

Re: Prop pitch?

Thanks for the info....