.90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine

[Roger B]

By 'Brush Hone' do you mean a 'Flexi Hone'?

[strictlybusiness1]

Yes, Roger. They come in many different sizes & they will not damage the machined finish. I normally do several passes while rotating from end to end, washing in hot water until the cylinder & flexi hone are both clean.

JA

[Kim]

The items shown in your pictures don't look like a Flex-Hone.  They look more like what I'd call a 'bottle brush' or something.  Not for honing, just for cleaning.
Kim

[strictlybusiness1]

When I return to work on Tuesday, May 9,2017, I'll get the exact name & part number.

JA

[strictlybusiness1]

The honing device shown in post # 224 is a soft nylon deburring brush. The tool is impregnated with 500 grit aluminum oxide & is available from EngineHones.com.

JA

[strictlybusiness1]

I'm beginning the machining of a rubber isolated, cradle type tuned pipe mount for this boat. Both the tuned pipe & it's mount will be rubber isolated. The engine's steel exhaust flange & header has also been completed. No type of "O" ring or gasket is necessary for positive sealing.
 
JA

[Admiral_dk]

Two things immediately comes to my mind :

It looks like noise dampening isn't a problem where you race it - I know that the expansion chamber lowers the noise a good amount on certain frequencies and the rest can be lowered by quite an amount with a simple light absorption muffler at the end of the stinger ....

It looks like you use springs to hold the expansion chamber in place, if I "read" the last picture right - though they aren't there yet - or ?

And a bit of curiosity about the boat - is carbon fibre the normal material now ?

Is the hull a "catamaran" like a number of full size racing boats ?

Size and weight ?

[strictlybusiness1]

Noise is not a problem on the 30 mile long by 2 mile wide lake we use. The actual noise generated at WOT is a measured 110 DB's at 50 feet. A Muffler can lower this to 85 DB's at the same distance. I use springs as well as a machined teflon piece with hose clamps to hold & seal the pipe, header joint. The photo shows a similar set up as to what will be done for this tuned pipe, header connection point. Carbon fibre is not the normal material used because of it's high cost. This hull, a catamaran type, is an infusion molded type done with a vacuum pump. The hull weigh 6 LBS & is 48" long X 17" wide.

JA

[strictlybusiness1]

The tuned pipes flat section is not parallel to the top of the radio box, therefore a 7* angle is machined in the cradle as a first step. I rough cut the cradle & located it with the round plug on the rotary table. Custom made toe clamps securely holds the cradle for final machining. The adjustable clamp is held in place on both inside ID's  of the cradle with 3/32" OD pins which are located in pre-machined holes. These holes are driled after the cradle's  7* angle is machined & they are also drilled at a 7*angle. The 3/32" OD pins are silver soldered to the adjustable clamp pieces a small distance from their ends. Once they are inserted, they can only be removed by being driven out with a 3/32" OD pin. The final rubber isolation pieces will be glued in place with high temperature silicone rubber cement. The cradle will also have lightening holes machined in it's base.

Jim Allen

[Admiral_dk]

Noise is not a problem on the 30 mile long by 2 mile wide lake we use.

I see how lucky you are in that respect - here there's a mile maximum to the nearest house, no matter wich Danish lake we choose ....

Nice cradle 

[DRT]

 
Very beautiful watercraft and 2stroke gas pipe you have here James. What a stinger!! Doing all you own hardware too? Are you running a flex shaft or articulated drive...and how's the cowling like the pipe? Have you fitted it yet?

Also what have you put together in a new SAW pipe for the .90 nitro methane engine?

Yours Truly,
The puppy...

[strictlybusiness1]

The pipe fits perfectly under the cowling. There is a possibility I will use a solid drive with the ball & pin universals I have used for many projects. I haven't done anything with the nitro engine except to set up a troidal head. I'm wondering how you know about the articulated drive system that I used previously?

Jim Allen

[DRT]

Lol,
That's easy James. I have many of your prints, and the list of materials for toroidal heads, the tools that need to be made to turn the universals, connecting rods, double roller needle bearings etc. You sent them to me....and its all filed away for future reference.

I'm curious after you mount the pipe where does the cg sit on that catamaran from the transom? That will need to be worked out to avoid a blow over. I doubt the maker of that hull has mounted and run anything as powerful, or quite like the setup you have there with the pipes length and all considered. When you get it set up I'd love to come to falls lake to hear and see it run.

TTYL....

[strictlybusiness1]

The CG will be 17" to 17.5" from the bottom of the rear running surfaces going forward. This will be set up with everything in the hull, including fuel, special sparking coil (8 ozs), radio box with radio gear, fuel tanks with fuel, tach, all hardware mounted on the transom, drive train, etc., etc. This hull is long at 48", therefore if too much air gets trapped underneath, it will become a kite.

Why are you hiding your name "Mr. Puppy"? I remebered the title from another site.

Jim Allen

[DRT]

James you know this is Hubert or did you forget you directed me here to see the work you were doing. DRT stands for Daimler Robotics Tech! Definitely not hiding as I told you my handle through PM here when I arrived. Guess you forgot.