need help with prop selection

schalmat

New Member
Hey Folks,i'm stuck on which prop for my boat, Its a 18 foot steury v518,it has a 165 i6 mercruiser.when i got the boat ,it had a 15x15p prop but its chunked pretty bad.I bought a 14x19p prop..boat seems to have good top end,but lags out of the hole.wot is about 3800rpm.the boat weighs about 2100lbs .awhen i pull a skier or tube it lugs pretty hard and doesnt maintain very good in the corners..should i step back to the 15x15p? i know the rpmss will come up,what effect will the diameter have with the 15x15 vs 14x19.k.i would like to have some top end.what will i loose or gain with the 15x15 or should i go to a 15x16por 17?.im pretty new to the prop thing so any help is appreciated.thanks....matt
 

nathan

Active Member
the bad part of prop selection is every boat is different and the effect from a prop selection. going bigger should not hurt to end to much. but I would think with the smaller pitch your rpms should be up. you may also consider a four blade. trial is about the best way to find out.

here is a good write up for props
http://www.firstchoicemarine.com/t-propeller-basics.aspx
 

Sean

Well-Known Member
Ive done a lot of homework on this subjuct....
WoT on the Merc IL6 165 is 4,300 RPM.
Pitch is the main thing to look at. You want to match your pitch to achieve WOT with a light load (1/4 tank fuel, no gear, no extra passengers, etc.) it's okay to go a little above the max RPM in this configuration (100 - 200 RPM over).

You jumped 2 sizes from the 15p to the 19p. So, depending on the type of prop you are using... you might have missed the set up at 17p which should add a couple hundred more RPM to your 3,800. Or maybe you should consider a 15p 4 blade prop. That should spin up quicker, give you more hole shot and still push enough water for a skier....

See if your prop supplier has a "try 'em" first program.
 

schalmat

New Member
Thanks for all the input guys,Sean,,i think you hit the nail on the head,I checked with turning point
and he reccomended the 4 blade hustler in 17p .I think that will
get the rpm up and power in the turns and pulling a tube behind it,Along with the other good handling qualities.Thanks everyone for the input.
Matt
.
 
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schalmat

New Member
Will do,,gonna be a little while,when funds permit.lol.anybody wanna buy a michigan wheel
14.25x19 prop?
 

schalmat

New Member
its just a 14.25 x19 michigan wheel aluminum prop.i think i paid 115.00 for it. i'll get the part number off of it.its 15 spline on a mercruiser r drive.its the base model prop,,,,I'll prob use it the rest of the season then sell it.Would make someone a great spare.prob .i'm thinkin prob 90.00 bucks,thats if it's still in its current shape.i'll let you know when i get ready to pull it off. thanks Matt
 
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