Tee Dee 049/051 Needle Valve Body - Testers Wanted!

MauricioB wrote:Here my experience then, first of all, I thank Mr. Matt this possibility that gave me to participate.
The first video shows the behavior with the original needle spring.
The second video shows how it behaves when the neoprene tube holds the needle, (in which case the spring was discarded for testing).

Video 1:

Video2:


These were your concerns .....
Approximate needle setting (rich, lean, etc.)
Driving range, 5 turns "fat" - 4 1/2 "fine". In 4 1/2 turns the motor works with the speed regulating ring between 7500 and 12700 rpm
Needle sensitivity (how difficult was it to dial-in)
The needle seems to have some play and is not thin at the time of adjustment. (It has micro movements) causing the engine to change.
Another problem that I detect, is that the spring when adjusting the needle, does not remain in the desired place, therefore can not be adjusted with that design perfectly.
Ease of use:
It would be interesting to make a factory mark on the needle to control the number of turns that open or close.
I had to make a mark on the needle with indelible ink in order to control the number of turns.
Anything else you wish to note:
I had to replace the original spring with a neoprene tube to let the needle set in the desired position. The original spring is discarded in this test.
The entire assembly fits perfectly to the engine even when a speed regulating ring is used. There are safe and sufficient spaces for everything to work properly. To see photos nr: 2444 and 2446.


Fuel Used:
25% Nitro
20% Ricino
Other Methanol
Propeller Used:
Cox Gray 6x4
Conclusion:
Mr. Matt with all my respect, I suggest you see how to hold the needle to avoid unwanted movements, which make the motor uneven march.
I also suggest making a mark on this needle so as not to lose control of turns when operating the engine.
(Note: information checked by Mr. Matt.)

getback wrote:Good Testing Mauricio , it is strange you had issues with the seal in the NVA when no one else said they did? Wonder if they're all not coming out the same off the product line ? I have had problems with the used and older nva's but not in new ones , may just bee me though.  

roddie wrote:

MauricioB wrote:
Roddie, I also placed some flat washers in some of my engines, but sometimes the neoprene is also necessary because in some cases there is air sucking.

It is seen that in many designs is an O'Ring to avoid air intake and also a steel tongue to hold the needle, that is still the safest.
The vibrations typical of the engine often means that if there is no steel tongue that locks the needle, the needle begins to move according to the RPM of the motor by vibrations.

Yes this is true. It would be very expensive for Matt to reproduce the original-style needle and steel-tab. I think he's probably using product-engine needles/springs/seals which he may already have in surplus-stock. The needle-valve "body", spray-bar and venturi are parts that needed to be made at his expense. It is a gamble whether enough modelers will buy these parts being offered, in-order to cover the expense of the machining-costs for an initial small-quantity production-run.

It is good that you and the other testers are giving some accurate and timely feed-back. This will help Matt to make decisions on how to proceed.

NEW222 wrote:Ok. So made a bit of time today to do some running in. Here are th estats as of the time of running the engine.
Temperature:
73.9°F
Dew point:
59.4°F
Humidity:
60%
Humidex:
81

Location is approximately 803 feet above sea level

Items used:
Really well run in and abused TD .051
Cox 5 x 3 Black propeller w/o safety tips
1 head gasket
TD glowhead
20% Sidewinder fuel with added castor
Homemade hotel shampoo bottle clunk tank
Balloon Tank

First, the installation of the new parts. All went well and smoothly except for one thing. The fitting of the venturi into its hole in the spraybar. On my test piece, the venturi only went in one way completely. If I put it in the other way, it would not completely seat itself and not be able to needle at all. I think if one was to drill it out ever so slightly, you could use it either way. So I had to live with mine having the needle set to the right side of the engine.

As usual, my engine was a bear to start. Then it started to easily flood. I had 'popping' almost instantaneously as I had set the needle at 4 turns (was kinda thinking of this as a starting point). Without any luck, I had thought I recalled a needle having to be open at 6 turns, so that is where I went to next. The 'popping' was actually better at this setting. But still no go. I then shut the needle completely and ran off all my excess fuel. Re-opened the needle to 3 1/2 turns and hook up the glowhead. It took off for a couple of seconds then stopped. I adjusted my tank height a bit higher and tried again. It again, fired right up. I then leaned out the needle slowly and listening. After it did not get any higher pitched, I backed the needle back out a couple of clicks for engine safety. When all was said and done, my final needle setting was set at 2 3/4 turns open overall. As well, my test RPM's were not taken as I do not have a tachometer and was all done by ear (wearing ear-muffs). Both tanks were about equal in respect of difference in needle settings. Needle settings were observed by marking the end of the needle using a Sharpie permanent marker. I cannot really think of anything else at this very moment, but if anyone has any questions in regards of my testing, I would be glad to try and help out to the best of my abilities.

Last thing to note is that I am a relative 'newbie' when it comes to running TD engines. I have only run TD a few times before this so there is probably some inexperience into setting up and starting these types of engines. Also this is my first real review of something, so if there was something I missed that you wanted to know please let me know. I had a lot of fun doing this and hope my results were what you were looking for.