So a little looking for Starwind 27 online shows:
LWL - 22.5'
Beam - 9.6'
Displ. - either 5200 lb. or 5500 lb. depending on keel
model-- I'll use 6000lb for full load conditions
Theoretical hull speed
- approx. 6.3 or 6.4 Kts.
Additional looking shows several for sale
, one with 1GM Yanmar
@9h.p., several with Westerbeke
10, one with Perkins
M-20. Probably the Westerbeke
10 was the std. engine and the M20 might have been a repower
A little calculation work
shows that 10 hp. should push the boat around 5.7 or 5.8 Kts in the full load condition, so if the W10 was the std. engine, the boat was a bit underpowered. There could have been several reasons for that, such as ready availability of engines, cost, engine room fit, etc. With 15 hp. the vessel should reach hull speed
in full load condition, and any power more than that is just money
in the bank....
My suggestion is to look for an engine in the 10 to 15 hp. range. Examples are:
D1-13, Yanmar 2ym-13, Beta 14 or 16 and there are probably others. Any of these engines will probably require a propeller
in the 13" to 14" diameter range with a 2:1 reduction gear
and three blade prop. So now is the time to measure how big of a prop you can fit under the hull while still retaining about 12-15% of the diameter for tip clearance. Going for more hp. might be tempting, but you need to be certain there is room enough for a prop that can absorb that extra power, and an engine room big enough to hold that more powerful engine.
So collect some dimension drawings for the engines that you might be interested in and start to compare those drawings to the engine room drawings that you already made, and you will soon see what's possible and what isn't.
From here on it just gets to be nuts and bolts, glass and resin.....
Hope this helps.