Are Outboard Engine Wells a 'Drag' ?

[Capt.Fred]

Cormorant, I sure appreciate the info on the Sharpie. A very nice boat by the way and his modifications worked for him. My RR23 is configured differently,so.....I gotta go a different road. Thanks for the response and input, it was interesting. Capt.Fred

[Dockhead]

Capt Fred -- and anyone else having problems posting photos:

1. In the "Reply" window, click "Go Advanced"
2. Click the little paperclick icon above the message body -- "Manage Attachments"
3. The "Manage Attachments" popup window will appear.
4. Click a "Browse" button, and navigate to the image on your computer you want to upload.
5. When you see the path to your image in the "Upload File from your Computer" window (there are several of these, and you can do several images at once if you like), then click the button "Upload" which you will see to the right of the window.
6. Close the "Manage Attachments" window.
7. Now you're back to your post. NOW, if you click the little paperclip, you will see filenames of the images you uploaded. Click the one you want to position at that point in your post.
8. Voila.

I admit that is is not the simplest thing in the world, but I think everyone can do it with a little practice!

[sarafina]

Our Cal28 has an outboard well in a lazerette. There is a fiberglass plug the size of the well that can be inserted when the outboard is removed, to create a smooth seamless hull.

There must be some clever way when you are next hauled to make one. I don't work in fibreglass but from what I've seen it's a pretty easy medium. Maybe someone with more expertise could chime in here on how that might be accomplished.

[cal40john]

Probably hard to reproduce, but the best system I've seen is on the Hobie 33. There's a place on the backstay to attach a block and tackle that connects to the engine or mount, I don't remember which. The engine and mount slides up, you drop in the well plug, start lowering the engine. The top of the well plug has a ramp shaped to guide the engine skeg aft as the engine lowers, and when it's down the engine is resting on the plug holding it in place.

John

[pressuredrop]

Originally Posted by Bash

yes, outboard wells significantly degrade sailing performance.

more, less then, or equal to dragging a fixed inboard prop? considering that the outboard is not in the well when sailing...

[jpfx]

I have a rob roy 23. I'm happy if I get over 3.5 kn and 4 is a rare treat. it does heel at the tiniest puff but I'm becoming more used to this. it must be comparatively light because it's a bit of a stretch to touch the water to leeward (I don't normally attempt this when it's heeled).
also, the helm only starts to head up at about 6-8kn wind. it's not far off neutral and it does make steering by adjusting the sheets not too difficult as long as you don't move at all. moving around readily changes heading.

[jpfx]

forgot the main point!
at the speeds I've been sailing, the motor well hasn't been an obvious disadvantage. there's the odd gurgle and slop to let me know it's there but it's not like I'm looking into the eye of a maelstrom. I'm pretty certain that the roughness of ablative paint is as much an issue if not a bigger reason for my rr23's sedate pace. I do however have an idasailor rudder which makes light work of the tiller. I do not have experience to offer a comparison though.

[Capt.Fred]

A reply to Sarafina
There must be some clever way when you are next hauled to make one. I don't work in fibreglass but from what I've seen it's a pretty easy medium. Maybe someone with more expertise could chime in here on how that might be accomplished.__________________
Sara
ain't what ya do, it's the way that ya do it...

and FPFX...

Sara, I did build the 50' sailboat Daedalus, so I've pretty much got the fiberglassing down to a science. Please see my photo album.
FPFX, When I first saw a Rob Roy 23, I thought now there is a handsome boat with some potential. When I acquired one, I recognised several major weaknesses. The boat was too tender, the open triangle in the under weight centerboard actually created a vacuum type drag and the center of effort under certain circumtances was too far aft. If you look at my album, you will see some of my modifications. Now, I can get up to and a hair above 7 knots. See photo of my knot meter.... BTW, what kind of rudder do you have? Capt.Fred

[sarafina]

Would a picture of our plug be helpful?

[Bash]

Originally Posted by pressuredrop

more, less then, or equal to dragging a fixed inboard prop? considering that the outboard is not in the well when sailing...

Hard to say. I would NEVER drag a fixed inboard prop. Not behind a sailboat, anyway.

I think NOELEX said it all when he claimed, "The plate was essential for racing against identical boats, but only really only made a small speed difference of about 5%."

Only?

Hey, as far as "more or less" is concerned, 5% is a HUGE difference in one-design sailing. Give me a 5% bonus, and I'll deliver you a national championship in just about any one-design class out there.

[Capt.Fred]

Sarafina, thanks for the offer, any info would be interesting. BTW, working with fiberglass inside the mold wasn't the healthiest thing to do. It has caused me to look and feel about 77 years old.....Oh...wait, I am 77 years old. It probably burned out some brain cells, which was good, attracting me many more friends....lol..


xpfs, try adding 300-400# of lead ingots temporarily as ballast and see the difference in performance. Locate them centered forward of the centerboard hump under the sole. Also, try lowering your centerboard only 18" instead of the full 36". The original hull draft of 20" plus 18" gives you 3'-2", which I found to be adequate for the RR23. Doing that will eliminate that open triangle drag....Let me know....somebody.....Capt.Fred

[Capt.Fred]

jpfx,...I apologize...It's jpfx..!

[jpfx]

capt fred, no worries.
thanks for your insights. I have thought about adding some ballast and I'm not sure (because I haven't had a look) but the centerboard might've been changed on this rr23 already. However, it's not appreciably heavier than I'd expect when raising or lowering.
idasailor (have changed their name) but the web site is still Rudder Craft
my outboard, (to remain on topic) in the engine well, is a short 6hp tohatsu/nissan with a charging circuit added. Hull speed seems to be 5.5 kn and the ob will manage that between 2/3 to 3/4 throttle. I have managed 6.9 kn under sail but I was rounding up when I should've been running downwind during a particularly nasty gust that had enough rudder out of the water to loose steerage. That's a lesson I'm happy to learn just the once though it proves the claim that whatever you do; the boat can take more than you (I) can.

[Capt. Rob23]

Thanks! Can't wait to check out your photos. Concerning the motor mount. I did not raise the center portion of the mount so I have the same clearance between the engine top and the cover/seat. My issue was when the boat healed, the water from the motor well would come through the gap between the mount and the vertical foot well bulkhead. I cut some Starboard sheet "board" to fill this gap. The cut angle is from about 3 inches at the foot well bulkhead to the height of the motor mount. With the drain plug in the center of the bracket that stops any water from washing up on the cockpit floor. I used 3M 5200 quick cure to secure the Starboard to the fiberglass. I will attempt to upload photos of my Rob Roy 23 and the cockpit modifications in the near future.