I've heard a few say that the 30 is a little underpowered under 20hp but have not heard of one as high as a 35hp that I'm interested in. Can anyone see any possible problems with a 35hp in a 30_74-83?
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Engine size
Joe, I previously owned a 79 H30 with a 15hp Yanmar. It would push the boat past 7 on my GPS. Unless your fighting massive tides and currents a 20hp is perfect. 30hp would be the largest I'd want to go. After that your burning excess fuel for nothing. Pat McCartin Inland Marine Diesel Buford, GA imd_ga@hotmail.com
Joe, I previously owned a 79 H30 with a 15hp Yanmar. It would push the boat past 7 on my GPS. Unless your fighting massive tides and currents a 20hp is perfect. 30hp would be the largest I'd want to go. After that your burning excess fuel for nothing. Pat McCartin Inland Marine Diesel Buford, GA imd_ga@hotmail.com
A little more kick...
Hi Joe, I've been considering a Beta Marine 28 HP for my eventual repower (same boat as yours). It's not so much that I want to push the hull speed, as to feel like I have a good amount of power if I need it. Like others have said, I don't want to go so big that it's a case of diminshing return, and 28 HP seems about right in terms of weight, fuel consumption, and a little extra kick when I need it. Good luck with the repower.
Hi Joe, I've been considering a Beta Marine 28 HP for my eventual repower (same boat as yours). It's not so much that I want to push the hull speed, as to feel like I have a good amount of power if I need it. Like others have said, I don't want to go so big that it's a case of diminshing return, and 28 HP seems about right in terms of weight, fuel consumption, and a little extra kick when I need it. Good luck with the repower.
J
John
Prop Size
The older H30 max prop size is 13 inches ( unless you want to start changing all the prop shaft and mounting angles ). My limited understanding is that running a 28 - 35HP engine on a 13inch prop is futile. You really don't get the the full HP from the engine because the prop is too small. Also, you will have a hard time getting a corrrectly pitched prop. I did the calcs a while back, and the HP required for "theoretical" hullspeed ( 6.7 ) on the H30 is 14hp. By calculation, to get about 5 knots (no outside forces ) requires only about 4 HP. Also ( just by calculation ), with a 20 knot headwind, you need about 15 HP to go 5 knots. To be prudent, you should add 10% to 20% to these HP estimate to account for HP loss to alternators and water pumps and engine maybe not running tip top all the time. So 15HP to 18HP is about right depending how much wind you buck, and how fast you need to go. To add 100% to 150% more than that for extra kick to battle headwind, you must be planning to sail into hurricane force winds and still keep hull speed. I have seen 2 different H30s on yachtworld.com with 3gm30s though....
The older H30 max prop size is 13 inches ( unless you want to start changing all the prop shaft and mounting angles ). My limited understanding is that running a 28 - 35HP engine on a 13inch prop is futile. You really don't get the the full HP from the engine because the prop is too small. Also, you will have a hard time getting a corrrectly pitched prop. I did the calcs a while back, and the HP required for "theoretical" hullspeed ( 6.7 ) on the H30 is 14hp. By calculation, to get about 5 knots (no outside forces ) requires only about 4 HP. Also ( just by calculation ), with a 20 knot headwind, you need about 15 HP to go 5 knots. To be prudent, you should add 10% to 20% to these HP estimate to account for HP loss to alternators and water pumps and engine maybe not running tip top all the time. So 15HP to 18HP is about right depending how much wind you buck, and how fast you need to go. To add 100% to 150% more than that for extra kick to battle headwind, you must be planning to sail into hurricane force winds and still keep hull speed. I have seen 2 different H30s on yachtworld.com with 3gm30s though....
R
Royce
20hp
I have a 76 h30 that I repowered with a Vetus M3.10 20 hp. You cannot increase the prop diameter on the h30 without major mods. You will need a new prop if you still have the Yanmar YSE12 as it is a left hand rotation engine and new engines are right hand. Good luck Royce
I have a 76 h30 that I repowered with a Vetus M3.10 20 hp. You cannot increase the prop diameter on the h30 without major mods. You will need a new prop if you still have the Yanmar YSE12 as it is a left hand rotation engine and new engines are right hand. Good luck Royce
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