Prop set back from face or transom

[Darren Kinvig]

   Is there some sort of formula for the distance from transom face to closest prop. blade?   How do I know how far under the hull the prop should be?   The picture shows the prop blade being 2 1/2 inches from the face of transom. In this position I can take the prop off without removing the rudder. The rudder is a transom mount rudder.   I am more concerned with being too close to the transom face.  How do I know where the prop should be positioned?  Anyone have an idea? I am trying to layout gear, shaft, shaft log and strut.  Any help would be appreciated.  Thanks

Topic

[Tony Athens]

Darren,   I really do not think there is a cut & dry answer to your question.. All has to fit, allow clearance for the prop to R&R it ( hopefully without pulling the rudder), all tip clearance, allow a minimum space between the prop hub and a cutless bearings, etc. Every boat is different..   I grabbed of few pics –As you can see, the mountings/setups  are all over the place. 

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Darren Kinvig

[Darren Kinvig]

Prop set back

    The question is how far the prop should be under the boat from the face of transom.  Not how far from bottom of hull or how far from strut.  The picture is difficult to take because the underside of the boat is very close to the floor of the shop.  thanks.

 

   Darrren

[Darren Kinvig]

Prop set back

   My question is how far back from the transom face.  Not how far from strut or how far prop from under the hull.  Sorry if the picture is not the greatest. It’s very tight under the boat. The picture shows that the closest prop blade is 2  1/2 inches under the boat from face of transom.

 

 Thanks

 

[donald roth]

Prop should be about 1 shaft width behind strut, and that’s all you’re going to get without a major rework.                                                                                          Is that a blackfin?  They are usually outfitted with a swim step to keep human parts further away from the works.

[Clark Leighs]

I am going to add that the one photo is in so close that there is no context.  

 

Shoot a couple more from somewhat further back  so we can see better what the total arrangement is.

[Clark Leighs]

If I remember correctly the MINIMUM distance between the hull bottom and the prop blade is 15% of the prop diameter.   

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