Glen-L.com

Hi guys, the strut I got with the donor boat is a bit short and if I move it forward on the shaft to meet the hull I think the gap between the strut and the prop will be too big at about 3" another thing I could do is raise up the base of the strut on a bit of wood and taper it to the hull but that may work like a trim tab that I might not need,so before I splash out for a new strut any ideas on how I could make this work




Also I have seen these on the internet are they any good for speedboats as I think it would be easy to set up the shaft angle and then just fix the strut in place. Thanks for any help

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Malahini, SEAN-NÓS http://www.youtube.com/watch?v=Qd6vkPjEy4U
http://www.youtube.com/watch?v=8uDVzcVpdhc
crackerbox build http://s753.photobucket.com/albums/xx17 ... =slideshow

Question - If you mount the strut to the keel, how much clearance do you have with your prop?

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Dave

My Riviera build - the Midnight Cry Project

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Few things in the world measure up to the thrill and satisfaction of boating in a boat that you built.

It looks like there is loads of room but when the blade of the prop is vertical it's less than 2" from the hull as is, and if I sink the base of the strut into the hull there will be less than 1" clearance.

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Malahini, SEAN-NÓS http://www.youtube.com/watch?v=Qd6vkPjEy4U
http://www.youtube.com/watch?v=8uDVzcVpdhc
crackerbox build http://s753.photobucket.com/albums/xx17 ... =slideshow

We need more info ...

What is the strut drop and shaft angle as installed in your full size mockup with the rear of the strut touching the keel ? What diameter is the propeller ?

The dimension listed for "drop" is the distance from the strut base to the centerline of the shaft bore at the aft end of the strut.

The "angle" is the degree of the slope between the strut base and the shaft bore centerline.





A 6-3/4" drop strut will accommodate propellers to 12" diameter.

A 7-1/2" drop strut will accommodate propellers to 14" diameter.

If your strut drop is less than 7" and your propeller diameter is larger than 13", have it cut down or try a 12" diameter propeller.

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Paul Kane Chelsea, PQ

Building the Glen-L Hot Rod : http://www.boats.chelseacoachworks.com

My understanding is to keep the blade tips at least 1.5" from the hull. How thick would a wedge have to be between the strut and hull to get the proper distance you need?

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Dave

My Riviera build - the Midnight Cry Project

Video of Midnight in Action
Blog

Few things in the world measure up to the thrill and satisfaction of boating in a boat that you built.

Of course, Paul brings in technical heavy equipment But you cannot go wrong listening to him.

_________________
Dave

My Riviera build - the Midnight Cry Project

Video of Midnight in Action
Blog

Few things in the world measure up to the thrill and satisfaction of boating in a boat that you built.

The angle of this strut is 17 degrees I need it to be 13 the drop is 6" and I need 6 3/4" to 7" depending how deep I sink it in the hull to make it flush, the prop is just under 13x13 after been cleaned up.
Thanks.

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Malahini, SEAN-NÓS http://www.youtube.com/watch?v=Qd6vkPjEy4U
http://www.youtube.com/watch?v=8uDVzcVpdhc
crackerbox build http://s753.photobucket.com/albums/xx17 ... =slideshow

ok, one final question. What is the angle between your motor stringer and keel? On the Riviera, there is a negative 2 degrees, which means the keel is closer to the motor stringers at the stern compared to the bow.

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Dave

My Riviera build - the Midnight Cry Project

Video of Midnight in Action
Blog

Few things in the world measure up to the thrill and satisfaction of boating in a boat that you built.

take a common 2x6 and drill a shaft hole, bolt it all up and take a good look at it.
you can play with the shaft angle a little bit when you mount the strut to the keel. also you can set the strut flush to the keel and then use some fairing compound at the base for smooth contour.

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God Bless our Troops; especially our Snipers

The shaft angle is more or less set at 13 degrees I can't drop the engine any more as I'm just about sitting on the keel if I raise it up I would have to shave the prop to get good clearance from the hull and I don't want to do that unless I have to. I'm happy with the setup as it is and could get a strut made to fit for $$$$$$$


What do you think of the glass-in p bracket I can get one for £200 and think it would make things very easy for me
http://www.sillette.co.uk/brackets.html
http://www.shreegajanan.com/glass_p_brk ... age=page-1

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Malahini, SEAN-NÓS http://www.youtube.com/watch?v=Qd6vkPjEy4U
http://www.youtube.com/watch?v=8uDVzcVpdhc
crackerbox build http://s753.photobucket.com/albums/xx17 ... =slideshow

How do those mount?

If they are glassed-in to the hull,they would be a royal b--ch to replace if you hit something and cracked it like someone on here did a wile back

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Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

Fergal - If I am seeing all of this correctly you, the wedge you will have to build to hold the strut would not be very large at all. It should not be more than 3/4" thick with no more than a 4 degree (probably closer to 2 degree) pitch to the front. Thus the front would be slightly thicker. You should be able to taper the front edge to a clean tight light. The good part is this wedge will help with potential porpoising which you will probably experience at higher speeds.

dave

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Dave

My Riviera build - the Midnight Cry Project

Video of Midnight in Action
Blog

Few things in the world measure up to the thrill and satisfaction of boating in a boat that you built.

If his set-up is anything like Tunahelper's old Crackerbox,it won't be porpoising....when I drove it, it felt glued to the water like it was on rails

_________________
Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

This is how the wedge would be 1/2" at the back of the strut 1" at the front and about 1 3/4" at the front edge

_________________
Malahini, SEAN-NÓS http://www.youtube.com/watch?v=Qd6vkPjEy4U
http://www.youtube.com/watch?v=8uDVzcVpdhc
crackerbox build http://s753.photobucket.com/albums/xx17 ... =slideshow

Fergal - I am trying to insure the calculations. I don't understand the 1 3/4". Your strut is 17 degrees and your engine is at 13 degrees you will probably only have to make up 2 degrees. I am sure that your keel is not parallel to your motor stringer.

If your wedge is 1/2" thick at the aft side then your front edge will only be 7/8" (.904" to be exact) thick at one foot forward. Is the foot plate of your strut 4" wide? To me this is not going to be that big of deal for a wedge to mount your strut like you want. Remember, your wedge is going to be located behind your shaft which will have already caused a water displacement. Am I seeing something differently?

_________________
Dave

My Riviera build - the Midnight Cry Project

Video of Midnight in Action
Blog

Few things in the world measure up to the thrill and satisfaction of boating in a boat that you built.