23' CC with Suzuki DF175

[SeaPlusPlus]

Been toying with an idea, wanted to get some opinions.

I have a 2008 Suzuki DF175 25" on my 20SF with pretty low hours. My 23 that I'm restoring does not have power.

I'm thinking about moving the DF175 to the 23' and if I'm happy with it, picking up a similar year DF140 for the 20SF.

Now I know the general consensus is 175 HP is under powered for the 23, but here are my reasons for considering this:

• Trying this will basically be free, it's out of warranty so I'll be doing the moving/rigging myself.

• I already have a second set of controls/gauges for the DF175 (had planned for a second station on the tower in the 20SF that I never installed) so no need to buy a binnacle, tach, etc or spend hours derigging/rerigging my 20SF if this doesn't work.

• Need to do more research but just about everything I have on the 20SF tach/control wise should just hook right up to a DF140.

• The DF175 is a lot of motor for the 20SF, she would perform just fine with a DF140 (as proven here) and would benefit from a lighter engine on the bracket

• Bigshrimpin has proven that a 150 HP power plant will perform admirably on this hull

• I think a DF140 will be easier to sell on the 20SF than the DF175

• If it works it will save me a boatload of money, if it doesn't I just move the motor back to the 20SF and get a similar year DF250 for the 23 using the same binnacle/tach

I'm not looking to go 50+ mph in this boat (did plenty of that in the 20SF), just get from A to B safely and efficiently.

Here are some numbers I've been running, first the estimates:

Full restored weight (with the DF175) around 4476.4:



And that 2323.1 estimated restored hull weight number comes from this estimate on composite vs original and removing the liner (which I am making a guess that its around 300lbs):



Take that full restored weight and add 500lbs of persons, 100lbs of gear, 100lbs of boat jewelry, and 50 lbs of ice to give a fully loaded weight of 5226.4lbs.

Plug that into a calculator using Crouch's formula to give a max theoretical speed of 46mph (using a constant of 250 for "Fast V bottom High Drives, boxes, notched transom, good bottom"):



I currently have a 3x16x23p prop on the DF175, plugging that into a Prop Slip Calculator with 9% slip and I'm seeing the same max top end speed at 5700 RPMs:



These numbers seem to align pretty well with Bigshrimpin's numbers who saw 38 mph WOT at 5700 rpms on that 150 HP, and I'd be happy with top end in the low 40s and cruise in the mid 20s.

In my opinion I'm only wasting my time if I fail right? Even if it works at first and I hate it after using the boat for a while I could still sell the DF175 and repower. My biggest concern is safety in snotty conditions and if the DF175 has enough umph to push the boat through the snot.

What do you all think?