Prop selection question

[dukewichers]

Ok get ready, lot's of info. Reading through other posts I think I have my set up about right.<br />I have a 21' Reno wide body (www.renoboats.com), with a 93 Johnson 200 attached to a 6inch set back manual jack plate. Cav plate 2.5 inches above the bottom any higher it blows out in turns. The boat came with trim tabs. Tabs down boat jumps out the water 15 yrds max. This set up is heavy, close to 3500 lbs full of fuel, gear, etc. Engine turns 5750 (photo tach) speedo says 54. I am running a omc stainless 15x17 in great shape and has never been worked. I am shooting for 6k and a little more speed (can never have enough). Now I am stumped...Which prop is best. I have talked to the boat maker and local shop about prop selection but very few boats are set up like mine, most are work boats.<br />I was thinking 15x15 SST but which brand? I have looked on iboats but very little technical data is given on the props. Please help I have worked on set up to long to stop so close to my goal. Thanks for any suggestions,<br /><br /><br />Bayou Thunder

 

[walleyehed]

Re: Prop selection question

I think you're best to stay at 5700-5800 with that engine. 54MPH is incorrect for a 17P at 5750. It's running 42-45MPH at best. With 12% slip figured at 54MPH your RPM would have to be around the 7000 mark to achieve that speed...that engine won't rev that high unless mods have been added.<br />The OMC 15X17 is a good prop, but you can gain some speed with some higher quality props, and blowing out in turns is part of it...ya got to drop the trim a bit when planning a turn.<br />Is the prop in real good shape at the tips???

 

[dukewichers]

Re: Prop selection question

The tips are in "good" shape. The leading edge could use a file. I do trim down before turning and if my engine turned 7K I wouldn't need more speed or be wanting 250 more rpm!!

 

[walleyehed]

Re: Prop selection question

That's why I'm saying your speedo is way off.<br />If the STD 15X17 is venting trimmed in in turns, we need a higher tech prop that will handle the running heigth you have.<br />It's going to take something like a Raker, Turbo Lightning, Solas Scorpion-(here at iboats).<br />I just finished running several of these props for test data and the Scorpion has it's place in high engine heigth conditions and bites well.<br />I own several props from testing, and the Turbos perform day after day, very well...I can't in any way point you away from a Turbo..they are some of the fastest I run.

 

[dukewichers]

Re: Prop selection question

Ok one more questiion... I run offshore alot, with my engine height would a 4 blade say Turbo Ultima 4 in 14.25 15 or 17 be better than a three blade turbo 1 14.25 x 17? I do have more room to raise my engine height to get the 4 blade out of the water more. Thanks in advance,<br />and your prop test is awsome. <br /><br />Thanks,<br /><br />Duke

 

[walleyehed]

Re: Prop selection question

Yes, if you can raise the engine some, a 4bld may work fine. I've looked at the boat and it doesn't appear that the 4bld would cause any problems with the way the hull is designed, but each is a tad to a bunch different.<br />I wouldn't be afraid to try a 17 Turbo in 4bld, as you can still raise some to get some R's back...as long as water pressure isn't an issue, you might as well swing all you can.

 

[dukewichers]

Re: Prop selection question

Thanks Kenny for the advise I'll let ya know how it works out.<br /><br /><br />Duke