Prop Selection Question

pwiseman

Petty Officer 1st Class
Joined
May 4, 2005
Messages
207
Just bought a new boat. Lund Rebel 1450 with a 30 HP Honda. I did get the Power Trim with this.<br />Boat is 14' 11" and hull weight is 600 lbs with a 75" beam. My best guess on weight including the motor is 1400 - 2 people with some gear, gas and a battery. Max the boat is rated for is 1100 lbs capacity or 1700 lbs. Hull is a deep v with staking hull.<br /><br />The Honda comes with a 9.25 x 12 pitch three blade aluminum prop. My gut feel is that this may be a bit too much pitch. I am looking at eeking out everything I can by going with 3 blade stainless or a 4 blade aluminum. The ones I looked at were 10 x 11 I don't know how much difference the stake will have on performance, but I suspect it will help some getting on plane and giving a good clean water supply to the prop.<br /><br />Reasons for a 4 blade might be getting on plane better when loaded up and I often end up in windy choppy conditions. I value cruising stability more than top end speed, so this might be a good choice.<br /><br />The other question I have is positioning the motor. Transom is a standard 20" and the Honda has 21.7" listed as the height. It won't be easy to adjust once it is mounted. Wondering if I should match up the cavitation plate with the hull or let it sit down under the water an inch or so. Owners Manual said up to 2" under the water is ok. Thinking the trim might compensate if neccesary. <br /><br />The only reference I have is my old boat. 16'8" Lund with 80" beam, and 950 lb hull without the strakes. I ran this with a 2002 Merc 50 EFI and a 12 pitch. This was a decent setup, could have gone up to 13 but the 12 was giving me as much speed as I needed (33 mph on GPS). My calculations ended up with .15 slip as I was getting 85% of the Thoeretical Max (RPM * pitch)/(1056 * Gear Ratio. New boat should be similar or slightly better.<br /><br />Looking for advice. Thanks in advance.
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Prop Selection Question

This may sound stupid, but the only way you are going to know is test, test, test....get the max RPM and bring it back and we can tell ya which way and possibly what to do about engine height, but I would think it should be flush with bottom for a starting point.
 

pwiseman

Petty Officer 1st Class
Joined
May 4, 2005
Messages
207
Re: Prop Selection Question

Originally posted by walleyehed:<br /> This may sound stupid, but the only way you are going to know is test, test, test....get the max RPM and bring it back and we can tell ya which way and possibly what to do about engine height, but I would think it should be flush with bottom for a starting point.
No question that testing will be required. Looking for a good place to start. I am thinking flush is a good place to start as well. Bugs me for some reason that the motor has 21.7" clearance instead of 20". I have seen a few Hondas rigged flush, one guy had a stick on top of the transom to create the extra space. I won't try that. The owners manual talked about the new system that does not require drilling holes through the transom. Not sure how this works yet. Boat is not here yet. Trying to think this stuff through ahead of time and get everything setup without spending too much time jacking around when it does get here. I plan to try a few props out. These little guys are not outragous in price. Solace has some stainless and 4 blade aluminium that list at about $125<br /><br />I will ask lund about this transom thing. I know they offer factory prerig for honda.
 
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