Phil Thomas Stealth Sport 20 FE Build

[mojoracer]

8/30/2011

Motor and Driveline Installation:

Time to make holes in the hull and mount the motor bracket. I used a simple bracket that was given to me, and modified it by Tig welding some side gussets to it. I used a # 28 drill bit of 0.140" diameter installed in the flex hex drive. This is used as an alignment tool. Slide the drill bit into the shaft liner and get the motor aligned straight to the shaft. Then mark the position of the motor mount on the deck of the boat with a pencil. Once the outline was marked, I removed the motor from the bracket. I marked the bolt slots, and laid out where the 4 bolt holes are to be drilled. Just so happens the #28 drill bit is also a good size for the #6 button head bolts I will use. Drill your holes, and insert the bolts through the bottom of the boat. Set the motor mont on to the bolts and install nuts. Snug them, but do not tighten! The motor is then installed back onto the bracket.


Now get your drive shaft out of the package. I am using a 3/16 shaft with a 0.150" flex cable. I would recomend Hughey brand flex cable. They are high quality parts! I have had numerous failures with the Aquacraft shafts sold by my local hobby shops. Hughey shafts have a reputation of being the best quality, and I have had great sucess with them.


Push the shaft up and into the boat, and check the alignment. Move your motor mount until you get perfect shaft alignment. Now tighten the motor mount bolts down.


Now determine your shaft length and cut it using some quality diagonal cutters.

[mojoracer]

Debur the end of the flex and apply some solder on the tip so the flex will not fray on you. Determine your drive dog location by mocking it up with a prop and nut. Scribe the shaft behind the drive dog to help locate the set-screw flat spot that needs to be ground into the shaft. Use a motor tool and grind a flat spot onto the shaft.



Now insert your shaft into the motor flex hex and tighten. You should have a gap between your drive dog and the rear of the strut like this:


I threw in the batteries and speed control to test the motor. It spins and works like it should! Now tomorrows project will be to install the cooling system.

[mojoracer]

8/31/11

Finishing It Up:

Time to install the cooling water plumbing. I used a Octura fitting for the water outlet. I cut the threaded portion down to save a little weight. I put the outlet at the back of the left side sponson.

I made a hole in the motor well side and glued in a short piece of aluminum tubing. This will connect the motor out water to the brass exit fitting. Use a small piece of hose to connect the tube to the discharge fitting. Access the hose installation through the provided opening in the engine well. Once this was hooked up, I filled the sponsons with styrofoam and closed off the access holes with thin sheet styreen plastic.

I drilled a hole in the right side of the transom and passed aluminum tubing through. I glued the tube into the hull. Using a short piece of hose, I attached the tube to the speed control. As far as routing, I run the water through both sides of the ESC and then to the motor jacket. I also attached a hose from the rudder pick-up to the transom through tube. Check your cooling system for leaks by blowing through the outside hose rudder end. You should have air flow to the outlet point. Put your finger over the outlet, and blow through the hose again. Listen for any air leaks in your connections and water jacket.

[mojoracer]

Finishing Up

Strut to stuffing tube seal is done with a piece of shrink tube. I used 3/8" diameter black. Slide it on before you assemble the tube to the strut. I used a heat gun and shrank it.

Finished engine bay lay-out.

Weigh in:
I used my cheepo Harbor Freight scale to check the completed weight. Looks like 6.14 lbs. This is about 11 ounces more than my UL-1 weighed.

A few shots of the finished boat:

[ray schrauwen]

Make sure you tether you cooling line so it doesn't get cut like mine did on first run. Lucky I only did 2 laps otherwise It would have cooked.

The wind force at speed forced the tubing into my prop.

[ray schrauwen]

What did you use to close off the holes? is that cut foam flotation? or plastic covers glued?

I've read through most posts but, I must have missed it...

Thanks. Your boat is sweet! Can't wait to get my 2Kprimer and 2K gloss.

[mojoracer]

Ray, I made the covers from 0.040" sheet styreen plastic from my local hobby shop. I glued them on with Zap a Gap "goop" clear adhesive/sealer. How did you tie your water line down? Thoght about doing it, but do not have any good ideas yet...

[ray schrauwen]

Thank you.

I just tie wrapped it for now. I will think of something prettier later. It's time for me to paint.

I used a Carbon fiberrod/tube. The 2-56 rod threaded right into it nice & tight. One end is captive near the quick disconnect link.

For those hole I am going to cut closed cell foam the same shape but with a 1/4" extra so it fits snug. Water seal thats temporary. At least thats the plan.
Thats what I thought you did.

[Namba328]

I'd like to see video of this beast running

[mojoracer]

Hatch Flotation:

I used some re-cycled styrofoam from a tool package. I cut the foam to the rough shape, and then sanded to shape. I used 80 grit to form the foam to the curvature of the inner cowl. I tried contact adhesive, which was wrong! This stuff melts foam. I broke out the old hot glue gun and stuck the foam onto the hatch. I filled up my laundry tub to test it. The hatch did float!

[mojoracer]

A Gentler Bend:

Based on readers coments, and advice from my local club experts I decided to re-do my flex tube. I made a much more gentler bend in it. I heated the bend area with a propane torch and let it cool down slowlt. I taped over 1 end of the tube and filled it with salt. I bent the tube on my bench pattern. Once the bend was complete, I drained the salt. I re-heated the bend area and then immediately quenched it in cold water. This is suppposed to re-harden the brass. Thanks for the tip Mr. Davis! I also made the tube longer to go throgh the strut and also closer to the motor coupler.

[ray schrauwen]

MUCH better!

[mojoracer]

Test Session 9/5/11

The 1st test session was run on 8/31/11 next to my office. I tried a X 445 off of my Titan LSO boat. The Stealth Sport 20 got right on plane and turned well. Down the straights was un-impressive. The biat would accelerate to a certain point and then just fall on it's face. Lots of spray from the right sponson. The motor also was very hot. This pond was too weedy, and that may be part of the heat problem. I raised the stut to 7/8" to the bottom (not the center as my previous setting). I replaced the strut tube, propped down to a de-tongued X442 prop, and changed the skid fin angle.

Labor Day Monday Test:

Boat popped up on plane and ran great! Did a couple of laps and brought it in. There was some water inside of the engine well. I applied some more sealer to the motor mount bolts. Temperatures were very good. I am pleased with the performance of my new boat. I did notice the boat rides high on the right side at the end of the straight. I may want to tip the skid fin down to correct this. It was very windy, but the boat did not get loose at all! Much better than the boat I am replacing with the Phil Thomas.

DSCN3546.JPGDSCN3547.jpg

I will try to post the video tomorrow.

[mojoracer]

VIDEO TIME

Ok I had to get a You-Yube account. I uploaded the video from Monday afternoon's test session. Hope it works....

[ksm2001]

Very nice and smooth, great job