Changing prop from 3 blade to 2 blade?

[bumblefish]

Sometime ago I asked about my black smoke/unburnt diesel issue. thought could have been due to being over proped. My boat is in the yard and a friend of mine had a look at her this morning, he commented that prop was not only as big as his but his was only 2 bladed, on a 38 footer! Who do I ask for advice on the correct prop set up and if I did decide to change down any recommendations? Elizabethan 30, Bukh 10.

 

[Gin]

Would this help?

http://www.castlemarine.co.uk/pitch.htm

 

[cindersailor]

Don't forget to take the geabox ratio into the equation when comparing props with other boats. Suggest you download the Castle Marine Propeller Calculator from http://www.castlemarine.co.uk/pitch.htm and have a play with it. Should make everything clearer.

 

[cindersailor]

SNAP!

 

[bumblefish]

Just tried that but I am not sure what category to put my yacht in?

 

[Fergus]

Get an Autoprop - magic! Will be a 2 blader on your boat

 

[cindersailor]

Elizabethan 30 is definitely Full Displacement.