Re-powering a houseboat - Stay with Stern drive?

I have a 50ft houseboat (~50k lbs), that currently has a dead 3.0 mercruiser with an Alpha One Stern Drive.

I am pulling the boat this Winter to get new Aluminum pontoons and engine pod. I was planning to replace the engine/outdrive as well. These Sterndrives seem great on boats that get trailered and can be pulled easily for maintenance, but not for a houseboat that sits in the water for years at a time.

My question...
Since I am getting a new engine pod built, should I consider transitioning to an Inboard?

BTW I'm not interested in an outboard (although they sound great), due to a rear deck/swim platform that I want to keep unobstructed.

 

You will have handling problems with an inboard motor, unless you choose dual motors, one in each pontoon.
Stern drives have a huge advantage there, as their direction of thrust is articulated.

 

What is the beam of your houseboat?
If you had a pair of outboards, one on each hull transom, then you would be much more manoeuverable, and the mid section of your aft deck would still be relatively unobstructed?

 

20ft, good point.

 

And you wouldn't have to build a pod, which absolutely is terrible for performance.

 

Would hanging an o/b off each new pontoon (designed for them) leave the swim-grid clear enough?
This would be a great set-up, build your fuel systems, etcetera into the pontoons.
A 20' beam on a 50' hull is a maneuverability challenge, no?
Directable thrust on widely spaced twins would serve you well.

 

This is not a houseboat it's a floathome or floathouse.
Did I miss something, how fast do you expect this to move under power?
How much power did you have in mind, or was that your next thread?

 

OP calls it a “houseboat”.
What’s the difference?
Does it have any bearing on how the craft is powered?
Maybe the OP should state travel range and speed requirements.

 

A 3.0 Mercruiser has 140 HP. The cheapest option would be a pair of 70 HP outboards. Pods add a lot of drag and not a lot of benefits. If the boat stays in the water for years and only moves occassionally, a jack plate will make it possible to raise the outboard completely out of the water.

 

The 3.0 used car reporting horsepower. It has 140 at the crankshaft. It delivered 100 hp at the prop, so the power demands are even less than that. But definitely need the performance numbers for the boat. In a boat like that the speed/drag curve is extremely non linear, and 25hp might move it almost as fast as 100.

 

There is no way it loses 40HP from the gears. Maybe 5 to 7. Further, claiming that 25 HP will move the boat at the same speed as the 3.0 makes no sense.

 

OP seems to have lost interest despite several Forum visits, so it's all a mute point.

Well, accept for the three pages of arguing that's about to ensue over nomenclature and HP.

BB

 

We can wrap up the argument in 2 1/2 pages.

 

“What we have here is a failure to communicate “
I see here a willingness to discuss this subject, but a lack of details and input from the OP making meaningful discussion impossible.

 

Yes, it does. And I'm starting to think you need remedial reading courses. You can't tell when I'm quoting someone else, and you can't tell the difference between close to and the same. The output at the prop is from their own documentation, and that includes all peripherals. Cooling losses, electrical generation, and the complex gearing path(1). Maybe learn a little about engines, while you're brushing up on your reading skills?

1- Ogorkiewicz, R.M. Janes Technology of Tanks
1991, 227