bconway

Hello, just thought I would share some picks of my build. I decided to go with an RCM drive after using a dbl. rudder set from Marine Specialties and drive from WHH for about 2 years. The RCM drive looks great even though it is a little big on the 46" hull. I have a wet pipe that I want to exit under the water line, so any tips would be appreciated. The motor mounts have to be moved to level out the motor, and might need to buy a different box for my servos. If you are reading (justaddwata) is it ok to solder the flex shaft to the top gear???? Have you had any luck with remote tilt adjustment with this drive??? Here are a few pics after getting the drive mounted.

JDFarmBoy

How did you polish the lower unit?? Looks great!!!

Flabum

Two things,,,,

1) I don't think I would want the pipe under the water line simply because if the boat stalls, you risk the chance of water ingestion into the engine.

2) Soldering the cable to the drive might melt a seal.


hey.... I like the drive. Can't wait to see that one run.

xxxboatworks

bconway,
You can solder it, but you could also use loctite to glue it in place. You can also run the stuffing tube through the radio box. More than likely, the box will sit too high if you try to put it over the tube.

jdfarmboy,
You can polish the lower end of the RCM drive with a polishing wheel and polishing compound.

flabum,
Why would the engine ingest water? As long as the exhaust port is above the water line (which it will be), I can't see how. I do agree though....an exhaust out the transom would be better in this boat.

Justaddwata

My Feedback: (3)

Just be careful not to overheat the input gear as this may damage the temper of the gear. This is why it is recommended to use Loctite 648 retaining compound. With either method. Install the input gear into the bearing assembly after it is bonded to avoid bonding or heating the bearing assembly.

crazyotto

My Feedback: (2)

yeah be carefull doing the shaft , i soldered mine but was real carefull , and make sure you check the oil in it often

bconway

I used:
400 sandpaper & water
800 sandpaper & water
1000 sandpaper & water
Then used Mother's billet polish & dremel

Yea, the gear would not be in the bearing carrier until after soldering, but I was afraid the heat might be an issue. If using locktite works under the power of bigger motors, I'm sure it will work with my Zen, just never thought it would hold up!

Still need a prop....anyone know the difference between 2 & 3 blade props???

Flabum

Qoute: flabum,
Why would the engine ingest water? As long as the exhaust port is above the water line (which it will be), I can't see how. I do agree though....an exhaust out the transom would be better in this boat.

Quote from bconway: I have a wet pipe that I want to exit under the water line


I never like having an exhaust under the waterline on any boat (I work on full scale ones for a living), it just gives too much chance for ingestion. I just don't like creating a weak point in any build.

bconway

Flabum, I guess the real reason for wanting the exhaust under the water is for keeping the sound down. It is quite loud for such a small motor. The end of the tuned pipe is about 3-4" from the hull, so I am not sure if I should have a 90 degree hose down, or an "S" shaped hose out the back. So actully this will not even be under any longer when up on plane.....hmmm

Flabum

yep...... gonna be noisy after 5mph anyways LOL, unless you tube it out the bottom............ don't you dare

bconway

Well, out the back where it was....

Justaddwata

My Feedback: (3)

I have seen Loctite bonded 1/4" shafts handle 14hp so a Zen wont be much issue.

"Difference between 2 & 3 blade props" - without being a wise ass - 1 blade But really there is not a huge difference performance wise. It is just important to select the right prop to run. I have seen 270 prather 2 blades and 6717/3 blade prop shop props working well with a stock zenoah and the RCM.

Nice job with the polish. More patience than me. I have painted one which came out nice (baked the paint which made it pretty tough).

I would think that a wet pipe would not be as loud as a regular pipe anyway. If you do manage to get water in your stalled motor it will be an easy fix anyway - the number of times I have seen a zenoah getting fully submerged - not a big issue

Keep the pics coming !!

bconway

Thanks, it looks like the big difference in props is the price! As for a water logged motor, I've sank a boat before so not too worried about that part. I tried to install the flex into the gear but took too much off the cable! Now there is alot of play....I had to order another cable.

One more question, JAW. I plan on getting 2, maybe 4 of the exhaust tips from Bonzi, and want them functional. I need some kind of water box (like on a Seadoo) that will split the exhaust up and through plastic or rubber hose to the tips. Will it kill my performance even if the tubes and exits are large enough?

Justaddwata

My Feedback: (3)

I dont think having an airbox to distribute the exhaust gas will be a real performance killer. I am doing similar on one of my builds. As you mention - just be sure not to create any major restrictions (hard to do with multiple tips anyway). It certainly adds to the look on the water

bconway

I will see what I can come up with, and continue with some pictures. If you get a chance, let me see what your working on.

Flabum

WHH makes a quad exhaust, but I had one and the water does not come out equally as Just said. Maybe with four engines it would.

bconway

Yea, its looks great but I think I could make something similar for less than what they charge. I just realized also, that the exhaust tips (flange) from Bonzi are 1.5" diam., so I think it would be too much to fit 4 on the back of the hull (14.5" wide)

Flabum

the pipe outputs on the quad from WHH is 1/2", so that is the size you would want to make yours. I work on real boat for a living and they usually use either tips ir the pipe comes out the transom and a beauty ring is intalled around the pipe. The beauty ring is basically a big washer with 4 holes drilled thru it to secure it to the transom. You might be able to make your exhaust pies, bake on a good paint job then make beauty rings out of 1/2" stainless washers.

bconway

Good info, I will look into this for sure!

wayneuk

i no u already purchased your outdrive but i have seen a outdrive on the net with a built in exhaust it looked real cool il try and find it

Brett230SX

Why can't you just find an appropriate sized pair of Grommets to fit into the hull and then pass the tips thorough and then install a beauty ring on the outside to clean it all up and finish it off nicely. There sure isn't much airgap around my real boat's thru hulls and being watercooled I can lay my hand on the risers as it's running without even getting close to burnt. I would imagine a true full wetted rc exhaust would run as cool.

bconway

Yes, it is cool to the touch from where the water is injected (2" past exhaust port), all the way back.

bconway

Worked on the boat a little today. I decided to add a swim platform, or whatever you call it for some sclale look. I used 3/16 balsa and 5 minute epoxy. I will attempt to cover it all in fiberglass after I shape it all up, not much experience so I hope all goes well. Here are the rough set up pictures.
Brian

bconway

Started glassing, after a little shaping.

CadillacDTS2001

Nice . now it looks like a real 47 fountain lighting.