Well I was able to get out today and do a second test on my twin Honda 2.3 engines. I have to say this has worked out way beyond any of my expectations and I am tickled that everything actually works. Actually beyond my wildest dreams.
I replaced the 10 inch pitch propellers with the same 7 inch pitch propellers I've been using for the last 4 yrs, and boy what a difference that makes. The ten in pitch props were just too much for these little 2.3 hp motors. I haven't double checked the fuel economy yet, but after measuring my fuel usage today, I'm thinking my fuel economy will remain close to what I was getting with the single engine, with duel engines (around 75-100 mpg).
I started out today with no sails up and pulled away with the motors running just above idle, the boat was going 5-6 mph (If you recall with the single engine the boat would go 3-4 at that throttle setting).
I opened the throttles up to just below 1/4 throttle (just below the normal setting I have always used) and instead of 4-5 mph the boat was traveling 6-7 mph (without sails). As soon as I opened up the wing and main sails the boat took off in around 7 mph winds I was quickly doing 8-9 mph ( used to be 6-7 with the single engine), actually I'm pretty sure the dual engine setup can operate efficiently at a lower throttle setting as compared to the single engine setup, and the resultant speed is much higher.
Basically everything I described (in theory) has worked out in reality, and I really feel I have a setup that I can really use. The only problems now are:
1. I can no longer smoke while underway because I cannot get the cigarettes lit with my lighter (true story today)
2. I have to now get a new sailing hat because the bill on the hat flies up, this never happened before today.
3. My spray skirts were useless today, I made them a year or two ago from heavy duty patio screen material, and never had any spray problem before, the spray went right thru them and I got pretty wet. With the natural wind 7-8mph plus the forward motion (9-10mph) the wind on my face was about 18mph (breezy), the water coming thru the screen shot right back at me.
4. I now need to plug all the scupper holes and mirage drive holes as the water squirts up thru them about a foot like a geyser now (never had any problems before), in the video you can see the water geyser in the rear mirage drive opening (would be directed at rear passengers face and chest, (note to self, must fix before taking wife out, or she will never trust me again).
5. I will have to pull the mirage drive because it was fluttering quite badly today if I stopped pedaling in the water (may get damaged), never noticed that before either. (Note ( I still pedal most of the time up to around 10 mph, I think above that speed I need to pull the mirage drive). But then again I have no reason whatsoever to go faster than about 10 mph, I'm fine and very happy with continuing to pedal the boat.
At the very low throttle setting that I use (typically less than 1/4 throttle), the engines are very quiet, you can easily talk over them, definitely not annoying at all. The sound from twin engines running is totally unique and distinctive (cool factor 10 plus).
I have the urethane foam on order to re-shape the rear of the TI hull (get rid of the point), and will have that mod done within a week or so, I expect my speeds to increase quite a bit once I get the hull planning, and eliminate the huge wake at the back of the boat (as seen in the video below).
Because of the lift created by the wing, and the weight of the extra motor (27 lbs) the bow and AMA fronts now ride continuously 3-5 inches out of the water which is perfect (in order to plane the bow front will need to be completely out of the water. (planing on the big flat bottom of the boat)
[youtube]http://youtu.be/jO1uuzBLBec[/youtube]https://www.youtube.com/watch?v=jO1uuzB ... e=youtu.be
Here is a pic of both the 7 inch pitch prop and the ten inch prop side by side:
The 10 inch pitch prop even after reducing the dia down to 7 inches is still too much for the motors (the clutches worked fine, but I could get any rpms out of the motors), I'll put those props away for now, and only try them after replacing the main sail with a rigid wing sail (phase 3).
In the video if you look at my pirate flag on the mast you can see I am sailing almost directly into the wind (about 15 degrees off the wind) at around 9-10 mph (the wind was around 7-8 mph at the time).
I can't wait to do further testing, and get that hull re-designed.