DART- TD .09

Thanks, Brad,

where do you think is the MRP of the tuned pipe with no intermediate silicone extension between the pipe and the exhaust? (My exhaust aluminum pipe protrodues right into the end of the tuned pipe)...around 25k?

If I mount it on a non-SPI TD050 RC, and use a small prop to simulate unloaded runs in the air, will the TD050 be capable of reaching the 25k MRP speed? My muffled common TD050-s seldome run over 20k with a 5x4 prop on them...will the tuned pipe really pull the rpm up by 5+k or so?(I think TD-s were reccomended for less than 24k to avoid crankpin damage...any experience on that?)

In your case of engine preservation propping to keep a safe rpm

1675 x 140 timing / 9.5 inch (MRP) for 24,684 rpm

The engine will operate well from 23.6k to 25.6k good throttle response is a benefit.
Oil spray will be controlled, will make a nice sound and of course look nice.

Just set up the pipe and fly it vid the results and observe the rpm with audio tach.
When done flying for the day place the plane facing up with a paper towel to catch
any leftover oil in the pipe it normally take about 20 mins or so for all the castor oil
to migrate out the pipe.

MRP is center of piston to red dot.




Here is a vid of a stock TD flying with a 4.1x4.1 prop.
Breaking the crank pin requires a heavy plane or big prop or low oil or lean run or
out of balance prop or draggy plane or sloppy ball socket or high compression any
combination can cause a break. I have flown the Lil Speedy at these rpms for quite some
time now and no broke pin because the plane and prop is not stressing the pin. Low stress
has kept the ball socket in good order no reset needed yet. It may have been reset
prior on another plane I can't recall. Normally after the first reset they last a long time.



Published on May 7, 2016

TD .049 /SPI / Throttle Sleeve Ports Allow SPI function / Prop 4.1 x 4.1N / 30% Nitro
Static 24,790 rpm / 7.4oz thrust / .127hp / 94.74w / 96.2 mph
Unloaded 30,492 best on Vid 1 / 118.4 mph per prop calc.
Doppler reading has it at 117mph per pass at 1:47mins into the vid.

1/2A Nut wrote:In your case of engine preservation propping to keep a safe rpm

1675 x 140 timing /9.5 inch

Brad, I checked with a TD050 non-SPI and 4,5 x 3 prop but the engine still did not tune in. I guess the silicon cuff between the exhaust manifold and the tuned pipe is too short thus the setup is tuned for high resonance MRP that the TD050 can not approach when loaded on a bench, approximately 20,5k as just measured.. I know when unloaded this rpm will be higher i.e. nearer to the tune pipe MRP but may still be lower than the 24,68k you mentioned, and maybe the engine will not tune in when airborne and unloaded.

For my easier reference, where is your 9,5 inch length measured between the tube tip and the engine exhaust? Can you please give me instead the distance of your setup between the tube tip and the cylinder centerline?

This tip to cylinder centerline distance on my setup is exactly 10 inch.

Thank you.

Brad just noted in your previous post the 9,5 inch to be measured between the red dot and the piston centerline. This on my setup is way shorter, about 8,6 inch, meaning I have to elongate the silicone cuff by around 1,3 inch i.e. 23mm. Thank you, I will fly the modified setup and check unloaded...

Great please post a video if you will sir = )

The pipe shape is broad and will not be too peaky to set the needle this allows greater speed range
for different props. The window for max power is about 2.5k rpm up or down. Note my set up is made for minimal restriction
smooth gas vapor / air flow helps. Look close at the photos note I use a pressure tap also helps to lock in the pipe extension.

It would be great if we can find someone to make smooth flow header pipes for now now this will have to do.














Try to find in your collection of cylinders a None SPI cylinder that faces the exhaust like this one shown once tight.



I have some new props I want to try so will Bench test the engine set up shown and post a vid.
Remember this: Nothing is a deal breaker with your set up if it is enjoyed!

Published on Aug 3, 2016

Cox TD .050 / Profi Tuned Pipe / 25,193 Static / HQ Prop 4 x 4.5
Static 7.3 oz thrust / .132 hp / 99w / 107.3 mph
9.3in MRP / 140 deg timing / Pipe set for 25,215 rpm!

Fuel line was a bit big for 1/2A use / pressure line was correct.
For flight prop HQ Prop 5x4.5 will unload near MRP and produce
est. 11 oz thrust. Non SPI / 20% oil / 30% nitro.

Bra being a 051 is this an SPI engine?

https://www.youtube.com/watch?v=k7YbAwFvQ7s&feature=youtu.be



Published on Aug 4, 2016

Late at night had to keep the noise down good time to set up the idle.
I did run it up till it caught on the pipe to show good transition back to idle
Noise had to be kept down it was after midnight. When bench testing best
to keep the pipe pointing down to avoid oil build up. Will be making one more
bench test vid showing best possible tuning for low and high end during
regular daytime hours. This is the cleanest running Cox engine to date
with 90% oil going out the pipe!

Tarno Carb from Canada with air bleed. 20% castor / 30% nitro.
I used proper 1/2A fuel line and didnt need pressure it draws just fine
with the smaller line the Tuned Pipe acts like a pump drawing fuel / air in.
I recommend not using pressure with a RC carb.

Just did another bench test HQ Prop 4x4.5 carbon composite

Best peaks average 25.9k to 26.2k
Static: 8oz thrust / .149hp / 111.2w / 112 mph
20% oil / 30% nitro unloaded est. 31k / 132 mph.
Too much rpm for the pipe setting best use a 4x5 at 26k / 147 mph.

Very good considering the timing being just bearable to even
use a tune pipe power is up well beyond stock.

Also tested my Queen Bee .074 with a HQ Prop 5x4.5
New engine broken in with 2oz of fuel thus far here are the results
Static: 18,195rpm / 9.5oz / .122hp / 91w / 78 mph
I think there is another 1k rpm after some more tweaking
Throttles well and should unload to 22.2k / 95 mph  



Now here is something interesting the exhaust timing is 155 deg ok for tuned pipe use!!




Ok update couldn't help myself slapped a Profi pipe on to test cut down 6x4 to 5x4
Static 19,379 rpm / .133hp / 99.22w / 10.7oz thrust / 74 mph
Est. 23.7k unloaded 90 mph / with a HQ 5x4.5 next should get 100mph
not bad for a Queen Bee 1.2cc / .074 cu. in.

Brad,

is your TD a non-SPI or SPI design? In one of your posts you mentioned a stock TD049 that is SPI, in another you wrote non-SPI...


Thank you.

Published on Aug 3, 2016

Cox TD .050 / Profi Tuned Pipe / 25,193 Static / HQ Prop 4 x 4.5
Static 7.3 oz thrust / .132 hp / 99w / 107.3 mph
9.3in MRP / 140 deg timing / Pipe set for 25,215 rpm!

Fuel line was a bit big for 1/2A use / pressure line was correct.
For flight prop HQ Prop 5x4.5 will unload near MRP and produce
est. 11 oz thrust. Non SPI / 20% oil / 30% nitro.


Published on Aug 6, 2016

Picco P-0 .0519 Cu. In. /.85cc / APC 4.2x4 / 28,585 Static
11.9 oz thrust .209 hp / 156w / 108.2 mph
- Mecoa Toki / Fuji Muffler APC 4.2x4 / 26.570k Static
If tested with the lean carbon HQ Prop 4x4.5 the rpm would bust 30k

Here is a Picco P-Zero .05  in action scratch built outrigger micro hydro small size
but is pushing 50 mph on the straights 33k average pass best pass 36,014 rpm
uses stock pipe ran with a Octura X427  prop  1.4in pitch x 27mm This is the only
known 1/2A size outrigger documented on Youtube very very rare treat.












I have already mounted mine on the DART will be the next engine to be tested with this plane
Expect best speed option with a carbon 4x5E at 34k down wind 161 mph potential. Will test fly with
a standard known APC 4.2x4 to compare power out with other engines I have used this prop
with. Should unload about 35k / 133 mph for starters.

at Outrigger is hauling some butt and the Picco just looks mean , you can hear the engine just revving with out any resistance to the water

Nut, I thoroughly enjoy watching you building and wringing out your machines. "1/2 A Nut" is an appropriate forum handle for you. I love the Hydroplane. Beautiful equipment and great work. Thanks.

Rusty

[quote="1/2A Nut
It would be great if we can find someone to make smooth flow header pipes for now now this will have to do.

[/quote]

Brad,

my car exhaust header does not fit gas-tight on the non-SPI TD 050 cylinder. Even if I plug the small hole opposite the exhaust extension, when I blow into the extension (with the piston closing the exhaust ports on the cylinder) there is a significant amount of air escaping the header, probably at its contacts with the crankcase and the lowermost cylinder fin..

Did you use any gasket on the top and the bottom of the exhaust header to prevent leaking of gas/losing pressure from the car exhaust header? With these significant leaks I guess the pipe will never tune in with the engine, simply because the pressure waves inside the pipe will be blown out through the leaks..

Thanks, András

The top will seal the bottom doesn't.
The Norvel with the sportwerks header and gasket seals very well reference those pics.
You will get wave action still just will be weakened. O ring or plumbers silicone tape might help.
Internal flat rubber gasket pushed down to the base of the muffler tight fit with some oil to
help slip over the cylinder would be a worth trying.

I have been busy building my own Outrigger Hydro with a Picco P-Zero 1/2A engine.
Used window paint program to design around my hardware then made it happen
With the Profi tuned pipe the rigger is going to boil some water and should boost
more torque / rpm than the RC car type mufflers. Will post a vid of the maiden run.
Down to setting up the servos and such next, then bench test / break in. Unlike in
the drawings I cut off 3 of the cooling fins and reduced the water coils should be
plenty of cooling and profiles much better with less external drag.

1/2A Nut wrote: For TD .09 fans I am working on a project for this engine called the DART

Engine has many custom performance enhancements  

- High speed performance crank
- Valentine Turbo Plug Head / OS Turbo Plug
- Kustom Kraftsmans 128 tpi NV
- KK big bore venturi
- Throttle sleeve - cut for SPI
- SPI Cylinder - dual bypass ports (not the RC version)
..............................]

Brad, is that throttle sleeve on the TD09 home made or sold by someone?

Thanks András

It is made by Cox, sometimes they come on Medallion .09 engines. In my case I bought
a Medallion engine off eBay just for the throttle sleeve.

Clarence Lee once commented that R/C boat engines operate under very severe conditions. Well, they are properly cooled and not subject to dusty conditions, but when you hear the engine revving randomly as the prop achieves and then loses bite, one can see why he said this.

Hi Jim,

Today's modern high performance engine can hack the abuse much better thankfully, Mr. Lee would for sure enjoy testing them.
Some amazing efforts to bring the very best to the table for us all to enjoy. From the video I posted I was rather shocked to hear
the engine revving up so high (44k +) on the dock it was just not necessary. Maxim from France has achieved a momentous 1/2A
offering for all of us to enjoy loaded state 36k. Nearly 50mph for a 1/2A boat is impressive. The revving will calm down when the
user becomes more concerned of the engines tolerances and life span should be cared for. If you have ever been to a dirt track
for RC cars when they jump them the engine can rev up to crazy numbers too if the driver is not tending to the changes, guess
it's just par for the course.

Glenn Quarles from Texas managed 40,386 rpm loaded for a two way pass record of 103 mph with a .12 size
outrigger hydro engine. Amazing that displacement in a loaded condition can hold a steady rpm that high.
With no load as you can imagine the engine would hit 45k+ wow! Crazy revolutions per second.

My design build is all set to run Jim,

Found this on International Waters another Picco 1/2A build.

https://www.youtube.com/watch?v=2K-k58SeXU4



Uploaded on Dec 31, 2015
Dr. Paul's outrigger, stretched out JAE .12 plan.
Octura X430 / best pass 38.4k rpm / 1oz tank.