Paul M

WOW!! I would love to see anyone of the three run. I know my Casa runs the 27# MTI with authority and I think it's somewhere in the 7-8 HP range. I can't imagine twice the hp much less almost 3 times. Weight going to be under 40 pounds in any of them?

Delinport

Hows things going Matt? Made any good progress this week?

Justaddwata

My Feedback: (3)

Ok - so I have been slow to update the thread.

the aluminum rails are glassed in with carbon fiber to help stiffen the hull a little more. I also added a little carbon in a few other areas for a little added support.

The pipes are painted with auto exhaust header paint which is rated at 1500f+. To properly cure the paint it is recommended to bake it. Rather than all the smoke in the house from baking pipes (especially used pipes with all the old oil build up) I did it on the BBQ with good results.

The exhaust tips I made up with two different diameter aluminum round stock. I would not be happy with the large diameter tips exiting the hull so made up a comprimise where a smaller tip is surrounded by a series of holes in the larger pipe. It flows plenty of air and I hope it will end up working fine. The mufflers are also water injected and I was thinking of injecting a ltitle water to the tips. That can happen later. I am still not happy with the angle the tips exit the hull at though. I would rathe rit square to the transom but the pipes follow this angle back from the motor so it is just a continuation of this line.

The alloy radio box has a pair of 805bb servos to handle the drives. These servos are rated at 343oz/in each at 6volts. The radio box also has the stuffing tube running through it. I also plan on attaching tuned pipe supports to the side of the radio box as the pipes could use a little central support.

I still have to rewire the electronic ignition for the motor and have batteries coming for it (it has a separate module for the ignition - not a coil).

I added a few pin stripes and some XXXBoatworks decals to the hull which will suffice until it is running. I will likely get her painted up but for the moment - white with stripes will work.

I still have the hatch to mount, Radio box to finish, motor to get running, find a 5/16 flex cable (or some option to make it work since it is not a 1/4" drive on the motor), add some floatation, do the plumbing, add a tank and then see if she floats !! I will probably post more pics before that all happens.

madgti

just curios how hard is it to tune 2 motors in a hull?

Justaddwata

My Feedback: (3)

The one shown above is a two Cyl so it is a single motor tune. The other GTX hull is looking like having a pair of twin Zenoahs in it. Tuning on a pair of twins can take some time and effort. The fact that the motors are stock standard should make it a little easier (likely be close to stock carb settings etc).

But as a rule - twin motors in a boat are going to be 3 times more work to get them running right.

Delinport

Hey Matt....looking great. I have been out of the loop a bit lately, work has been crazy. I suppose I am going to have to come up with an idea for my next project. Any thoughts? You make it hard for a guy to come up with a new idea with all your cool projects.

Del

littlebuick8

matt lookin good! making progress. cant wait to see her rip!!

ZCOPTER

MAT,

THE WATER PICK UPS ARE GREAT! YOU DID A NICE JOB ON THEM! THE BOATS LOOK GREAT TOO!


KEEP THE WET SIDE DOWN!!![sm=drowning.gif]

inlinezenoah

matt any new pics ?

Flabum

Stupid question here.... on full size boats, we toe the drives a bit..... do you toe the drives on these scale boats?
Stupid question 2. Is there any advantage to running the drives inboard (towards eachother) as opposed to outboard as they are (away from eachother) or has anybody even tried that?

Justaddwata

My Feedback: (3)

No new pics (and not much new work to show either [&o] ) Spending too much time online (though did take the Apache out again today ) and trying to make room in the shop for yet another project (or two).

I will make some changes soon and keep you all in the loop.

I aim for the drives to be parallel. I have not run twin stern drives yet though the boats I have seen running them have not given consideration to the drives other than parallel.


I have seen the props swinging both ways. In reality it would not be that difficult to reverse the rotation of the drives (either swap the drives or rotate the gearbod 180 degrees) and props. I have heard that rotating down in the center can create lift at the transom and up in the center can pull the transom down.

I guess it really would depend on how the prop contacts the water at the transom while the hull is moving through the water as to which would actually give or remove lift.

Ultimate48

My Feedback: (1)

Matt

how does that paint hold up on the exhaust system?

Justaddwata

My Feedback: (3)

I have had mixed results using high temp ceramic based header paints. Most common complaint is that they will crack and flake / peel off. The blue paint I have not run on a motor as yet. It was they best paint that Autozone had (but that may not be saying much). End of the day - I am confident that powder coating will be significantly better and JET coating is hard to beat. (But I had to try this stuff )

Ultimate48

My Feedback: (1)

I,ve used this paint on my real cars and boat headers with very good results, will handle high temp.
web site to paint

http://www.jegs.com/webapp/wcs/store...10002_19023_-1

Flabum

Cracking and flaking is due to expansion and contraction from the heat/cool cycles. The thinner the header material is, the more it will expand/contract. Not much you can do about it.