Catalina 30 with Atomic four with 3blade prop

Status
Not open for further replies.
G

Gary D'Amco

My boat seems very underpowered . I am uncertain if it is simply underpowered or if I could improve speed under power by returning to a two bladed prop. I just bought this boat and it came with a three bladed prop. I am not certain at this time its dimensions since it is in the water. Does anyone else have any experience and or suggestions with this? Please email me directly at : insured@snet.net Thanks very much GD
 
P

Pete

atomic 4 underpowered?

Gary, I think you will find that the atomic 4 is overpowered as far as hoursepower is concerned,the engine will move your boat at hull speed no problem,so the answer most likely is that you are underproped or have a built up groth on the bottom. Going back to a two blade would only make it worse unless the two blade prop was bigger then the three. I think the thing to do is find out what is the correct size prop, both two and three blade, from a prop shop(check with Kevin here on HOW in the prop forum)and then see what size prop you have.I do not know what speed you are getting now or what you expect to get but hull speed is as good as it gets ! Good Luck !
 
K

Kevin L. Woody

Add to prop

Hello Gary, If the motor is not undersized you could possibly increase the vessels powering ability by switching out the current three blade prop. This could be done by switching out the current prop completely or possibly just increasing the current propellers pitch. A propeller is simply a distributor of what power is available from what is driving it. If the propeller does not have enough pitch the motor produces to many Rpm’s. This will cause the boat to seem as if it has little power, which will cause slow speeds. Increase the propellers pitch and the load increases to the motor helping to limit Rpm’s, at the same time driving the boat faster through the water at the same given Rpm. Of coarse this is all predicated on whether the motor has the ability of handling the increased load caused by the additional pitch. It could be that the engine is not producing the power needed to propel it at the speed you are trying to achieve. This lack of power output can be caused by numerous things, including but not limited to, fuel integrity, engine sound ness and additional pulleys and equipment we are forcing the engine to run at the same time we are asking it to push the 10K lb. boat. I would first start by simply increasing the propellers pitch by 1”. See how the vessel and the engine respond. If you experience no problem, it worked. If you experience problems at least you have narrowed out the prop issue. Hope this helps. Kevin
 
B

Bob Uehlein

Prop

Had a Atomic 4 powered C-30 for years with a folding martec 2 blade prop. It was not underpowered. You have another proplem, either the wrong prop pitch, an engine with a performance problem, or growth on you bottom.
 
Status
Not open for further replies.