Can someone help me with a prop setup

Re 'raising the propeller' - it might be easier to instead have a water jet propulsion unit?

This is the smallest unit from these folk in New Zealand, but the minimum power is still 50 hp -
Scott Waterjet - Jet units, Jet pumps, Water Jet drives, Jet boats, Trim nozzles, Impellers https://www.scottwaterjet.com/products/jet_612.html

Maybe something like this - a small jet unit designed for a surf-ski or kayak?
https://www.aquanami.eu/models

 

Not harsh at all but I think you are misunderstanding what I trying to accomplish with this. The picture was to the show the prop and prop shaft arrangement so you all had an idea of what I was asking for in this post...places that source them so I can price up.

 

Michigan propeller is probably your best source.

 

For a start you might browse thru the products of what used to be Buck Algonquin, now known as Hydrasearch,
All sorts of stuff for drivetrain installations.

 

West Denny 33,

jehardiman's post is probably the most helpful but you have a lot of engineering work to do before you can even spec out anything. The boat you picture reminds me of the old Garwood's or Chris Craft runabouts. Most basically you'll have an engine and transmission in the boat. The size and weight of the boat as well as the hull shape will go a long way in determining how much power you need. Behind the engine is a coupling (maybe $200) that connects your transmission output to the propeller shaft. You'll need a shaft log, and the modern and IMO better packless shaft seal that keeps the water from pouring through the shaft log and into the boat. A small packless shaft seal runs around $250.00. A shaft log for a 1" shaft maybe $150.00. Of course you need to determine the proper angle for the shaft log. You need a prop shaft. Depending on the quality of the material and the length these can price out all over the place. For a small boat like that lets just go with $300.00. You'll need a strut to support the shaft. Again the proper angle must be determined. I can't even see a price on a strut for your application. You'd need to contact a prop distributor and get a quote. Then there's the prop. Let's figure a 1" shaft and a 12" diameter wheel. That's a pretty small prop and is probably close. About $400 - $550 for one of those. So somewhere around $1,300 to $1,500 should be in the ballpark, but the ballpark is pretty big. You also need to know how to install the running gear and get the whole assembly running true. Of course before you do ANYTHING, you need to have done a proper analysis. The engineering and mathematical formulas required for an accurate design aren't too terribly difficult. I'd say that if you've passed some college level calculus and can work with fractional exponents you'd be able to apply the engineering formulas. You have a scientific calculator, right? It will take a considerable amount of study though, so be ready to put some time into this. Naval architects and engineers have spent uncounted hours figuring this all out, testing and developing the engineering that goes into designing a drive system that works.

A good place to start might be Deep Blue Yacht Supply, General Propeller and Getaprop.com.

In my opinion, if you're only looking at a 4 knot boat I'd consider electric power.