|Single cylinder deutz life boat engine
Post Number: 1
|Posted on Saturday, April 15, 2006 - 09:08 am: ||
i have a couple of 14 hp air cooled single cylinder deutz marine engines with marine gears that came from old life boats. i am planning on building a 21 foot launch to put one of them in. i would like any information you may have on prop sizing . these are really cool moters they run like sewing machines and turn up 3000 rpm
Post Number: 220
|Posted on Monday, April 17, 2006 - 11:04 am: ||
Assuming that you run the engine at 1500 RPM and you have a 12 in pitch prop with a 25% slip, you'll ( theoretically) will get about 11 mph. That is slightly over the terminal hull speed for a 21 ft dsplacement hull. So a 12 in pitch is a good place to start.
Assuming that your engine is rated at 14 HP at 3000 rppm, and knowing that (torque x speed) = HP and further assuming a failrly flat torque curve for the engine, you'll be getting aboutr 7 HP at 1500 rpm.
So you'll want a prop diameter that will absorb 7 HP and a 12 in pitch. A good guess is in the neighbourhood of about 12-14 in diameter.
There are plenty of references about how to estimate proplellers, but it comes down to the assumptions and how acurate they are ( and there are a lot of them) .
Propleller sizing is ( or can become) an endless discussion and experience is about the only thing that settles it.
Post Number: 2
|Posted on Wednesday, August 26, 2009 - 01:50 pm: ||
We have SABB DIESEL,YANMAR, BUKH, VOLVO PENTA, LISTER,PROMOMER(Argentina) for sell, HP: 22 to 68 HP all are water cooled and in running Conditioned. If you interested please give us an email. please dont send any email for asking if seriously like to buy then please contact. we collected the engine from the demolition ship we also have used lifeboat for sell too. firstname.lastname@example.org