What prop for 19' cuddy?

[chris0061]

Hello all, I've gotten a 1986 Regal Sebring cuddy cabin, 19' long and weighs about 3000 pounds loaded with the Mercruiser 170 and alpha one out-drive. I'm currently getting 4300 rpm at 40 mph. I've got the clymers coming for rmp range and gear ratio to do a analysis but my question is were do I want to start testing props. I'm looking for the most mph at the best rpm range as we do not pull skiers or tubs just fish and cruise. I believe my current prop is a 19 pitch and its alum. I will go with a stainless. Any suggestions on what kind of prop, 3 blade, 4 blade exc. Thanks in advance, Chris

 

[steelespike]

Re: What prop for 19' cuddy?

Your presnt performance seems pretty good.I'm guessing your max rpm is 4,600 and you are certainly within operating range.
I would try to find a dealer that will exchange props.There is an exchange program here at iboats.I would start with a 3 blade stainless in the same pitch.My limited experience has been that when going from AL to SS it can be a little un predictable some SS lowering rpm but raising speed and others raising rpm and speed.Perhaps the experts will chime in with some specific suggestions.

 

[tarheelebbtide]

Re: What prop for 19' cuddy?

The above advice is good. In my experience, you'll most likely see a slight decrease in RPM with the same pitch stainless as it doesn't flex as much as the aluminum and is a heavier wheel to spin.

 

[Turbo1]

Re: What prop for 19' cuddy?

The weight of the prop has little to do, if anything with how the engine will turn it.
90% of the increase in weight is close to center in the inner/outer hub.
Alum does flex more giving better hole-shot, but SS's lack of flex is not the reason for speed gain....blade geometery and extra lift from such is the reason.
18P would be good in a 4bld, I "think".....and give better hole-shot but some loss of top-speed will occure over the 3-bld.