Building a 21' cruiser with inboard diesel and auto

Finaly found the right surface piercing drive, the sea fury, it looks just how I wanted to design it except without trim variation, It's mostly sheet metal, and includes the rudder in the unit which mounts to the 45deg transom, under a duck board.
I've emailed for a quote, but seeing I found a 10 year old arneson drive on ebay for $8500 I doubt it will as cheap as it is simple.
What I really want is the right prop to use on my own design.

 

Surfac Drives without trimability have driven many boaties to.....hell and back.
You also may be dissappointed,although your choice is probably a better one.Why would some one sell an Arnson for $8500 if it was a good drive,may be moving on through a bad experience.The right prop for your boat will have to be many comprises especially if using S/P drives as you cannot choose a prop just to suit your hull and motor,but you must take into account how S/P drives work.

 

Tom, I was intending to make a similar surface/piercing drive to the seafury, (I had already visioned a similar concept,) but with a trim option It made sense use the seafury prop that they calculate to use on the hull. with their drive at 6 deg and the said clearances. As far as the props design, appart from what I've read up on in the principals of avoiding cavitation, I think if I'm 75% of the way to 100% of efficiency, I'll be happy for a first off boat.
I will learn alot in the processes of the whole design, and who to deal with, to get the right advice and the right price. So I guess I would be open to take any suggestions on who to get a prop from based on experience.
At least I'll have a good place to start, preferably someone who really understands the physics of their craft for propellers.
I also like to experiment with performance enhancing mods, making small incremantal mods to prop over time to get 100% efficiency is more than likely, with the final proven product the one I would on-sell.
I will also be building 2 boats at once with slight variations as a test as well, just to get instant comparisons on various mods, which will dramaticly speed up the development process.
Quite often in what I do, I take a process of a machine where there is more than one module the same and apply different theories to each, it's amazing what little intricate movements evolve within an action, to give subconsciously unforseen results.
The result is all the answers very quickly by crossing over the retrieved data
And the finshed and bullet proof product ahead of schedule and done right the first time !!!! Well third time, but who's counting
It's irrelevant when the overall time is shorter than doing it twice, which unfortunatley is how most engineering ops work.
It doesn't mean that I'll be spending twice as much, it means that one lucky mate will get a new 22' boat for $20,000.
Anyway ANY PROP CONTACTS PLEASE

 

You are spoiled for prop selection and built to customers specs,investment casting the lot.There are very efficient and competitive South Korean (supplying some NZ businesses) Manufactures,and Turkey, India,and of course many others.The usual big names for props have much competition now.If you have the time to cover them all that will keep you very busy,and take a lot of checking on reliable supply,although that does not seem to be too great of problem to a competent modern business man.

 

So far from the vast amounts of info I've bombarded myself with and the number of emails sent to have a prop size and pitch specified, I'm starting to think that given the step drive is 'new' that me stating I will have a final drive of 1:1 with a 3 speed auto, "so don't worry about acceleration" just the most efficient prop at 30 knotts seems to have them stumped, as I can't get reply.
I've found 2 local businesses that make and repair props, so I'll go and investigate to see if someone can actually give me the right 'oversized' prop.

On the engine side I've found some awesome new engines, one being the toyota avensis, with 2.2lt turbo diesel and 400Nm of torque, just released 2005, with fuel ecconomy that blows me away for the power. As I step back into importable engines from japan the power drops dramaticly as the technology decreases.
To get my 350Nm I might end up with a 3.0TD or higher. Which realy sucks out my fuel economy.
Funny enough I have a Mitsubishi Delica 2.8 TD which has 300Nm, which is the highest for it's age and size.
I often simulate while driving how it would push a boat, and considering it's a 2.5 ton car, it would work well, I guess then I should start with a bigger prop, and decrease it's size if the torque level doesn't hold the planing speed.
Does that sound logical ?

 

Ok decided on an engine today The toyota hilux/prado engine and 4 speed auto
Displacement, cc 2982
Engine model 1KZ-TE
Max.power (Net), kw(PS)/rpm 145 ps (106.65 kw) / 3600 rpm
Max.torque(Net), N*m(kg*m)/rpm 35.0 kg*m (343.23 N*m) / 2000 rpm

The prop will be custom made about 20" bronze, when I get all the details, for about $1600
The surface drive I'm about to start modeling, the files in dxf, or any solid edge file format will be available to download if anyone wants to copy it, as well as parts list.
I think If anyone has the skills to assemble their own surface drive and doesn't have $11,500 +prop for the smallest unit available. Then I'm glad to share the design for free, keeping in mind the intellectual property rights and non commercial use of the design, as without this forum and the people on it It would not have been possible to concept the idea in the first place.
Please email if interested and I will forward files when available.
As well as file format you can read.dxf,dwg for cad drawings, psm or asm for model to make your own drawing files for cnc cut/fold etc.
Simon.

 

Hi Simon, you have hit the nail on the head with this project, the consept of what you are talking about sounds fantastic and I'm looking forward to working with you on this project.

Regards Jason.
JT Fibreglass Products.

 

Hey Jason, I've been persuided by Neil (nigels brother) to dump the Glen L monsoon for the clark craft 26 crown cruiser, That will be another 3 foot of storage for kingy's
Go to Clarkcraft.com.
It takes more power to push it to 30 knots, quoted 250hp compared to 180 hp for the monsoon, but the write up's read well for ocean going
The Viking has the same hull design at 22' and one guy posted a 1.7 ltr diesel pushing 45mph
I think if the surface drive is set up right it should fly and be most importantly stable.
Don't have any other ideas on the hull, because I just ordered it.
And don't forget were adding another 3 - 4 feet for the duck board, that's 30 feet F&^%*%k !!

Should be good winding down through belgrave on the tight windy roads pushing tourists off the cliffs, hey now it has another good purpose.

See you soon, come on Muloways, I've been dreaming about hooking up giant 70kg mulloways.
Simon.

 

This is exactly what I mean about "Marine" rip off

Re pricing our current Trade price for 1 x SF22 Unit complete is NZ$ 31,130.00 unfortunately this price will increase as the world metal price does as seems to be out of control at present.

Materials cost $300 + prop (where's the justification in that?)

 

project

Its called ripping off the little guy who knows nothing about the industury.
It realy is a shame that some people are so greedy.

 

SeaFury

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Don't go around looking up peoples phone numbers with their profile information, with the sole purpose of harassment. It's Ilegal.
Courts don't see kindly to bully tactics.
The fact is your product is 10 x the price of one of your competitors

If you have a problem you also have my email address.

Simon

 

inboard car diesel for rubber duck 6.4m

Hi lucas,i have read some of your ideas and think they r gr8.im curently looking for a good diesel to push my 6.4m duck it only weigh in at 380kg hull only im also using a surface piercing prop direct drive at 3500rpm was looking at the 2c toyota turbo any tips would help prop size????