Does anyone here have any experience with the Webra Dynamix carb on the .32 Speed? I have a NIB Speed .32 ABCD with the Dynamix and just wanted to know if there are any gotcha's to look out for.

Thanks in advance,
John

Read the directions, the big thing is not to go fiddeling with the needles too much the factory settings are a good place to start. If you mess with the needles too much you will get the main spraybar out of wack and then you will not be happy. There was an article in RCM probably 10 years ago about the correct initial set up. I got a copy and filed it away so far I haven'tr needed it. The high speed is normal unscrew to richen.
The low speed works backwards unscrew to lean and the idle mixture affects the high speed needle, so go back and check it after every idle mixture adjustment.
I have about 5 gallons through mine and love it.
Sparky

Thanks Sparky,
I did note in the instructions that the idle mixture behaves like an airbleed. Any favorite props? The engine is going in a small, clean, fast model. I think my engine was missing part of the instructions when I bought it and I don't have a prop table to refer to. I was thinking about a 9X6, but if you have any other suggestions, I'd more than welcome them.

Thanks again,
John

The 9x6 prop will work fine. I might also think about 9x5 as well. I use APC almost exclusivly on my planes. I have found that you can get about 1000 more RPM if you run the webra mini tuned pipe from the Pylon/Quickie .40 engine. I had to drill another hole in the muffler for the smaller spacing of the exhaust holes and I used a plug in the outlet to increase the back preasue. I am running this on a fun fly plabe and it screams! I am running a APC 10.25 x 3.5 or something like that at over 15K.
Sparky

I run APC's myself. I'd like to turn as much pitch as possible to get the speed up. Maybe an 8X7 or 8X8? The plane will weigh about 3.5 lbs. ready to fly. I currently have a Webra quiet muffler, but have thought about one of the Jett mufflers if it's too restrictive.

Thanks again,
John

John,
I don't have any experience with the Jett exhaust but the Performance/nelson mufflers do work great and would be a great alternative to my set up mentioned earlier. You might be able to find one on the want ads at RCU.
Sparky

If you need more power and speed get the Webra Speed 35 aircraft engine with the easy to tune TNII carb. Webra lists the power of the 35 at 1.4 HP.

Thanks, but I already have the Speed .32 and don't want to buy another engine. I just want the most power out of this one. Also, the Dynamix aren't difficult to tune, they are just different. You know, some of us are on a budget

John

Here is a guy that needs it.

I had to take my dynamix apart to clean it, now wondering where a good place to start is with the spraybar. Take a look at the pics.

The first pic shows you whats going on with the way the spraybar is V-Grooved and drilled out.

The second pic shows where I think wide open throttle mix will be, with the hole near the edge of the bore.

The third pic shows were I think wide open throttle mix would be on paper, or should I say the ideal placement of the fuel orfice.

Can someone help with this initial setup?

The motor being 25 years old itself has never been run, I had to disasseble everything to clean it...I never had a clue about what was going on with this carb when I took it apart and couldnt see much in there so now I'm lost. I would hate to fire this thing up the very first time and cook it with a lean mixture, or have it peak out right away.

David,


Anywhere you set it to start is a good place, if you know your engines well enough to know if it is running too rich, or too lean.

I seem to remember the instructions that came with the Webra Racing #1030 that had this Dynamix carburettor installed, said to use a fuel pump... Exhaust pressure was stated to be somewhere between borderline and insufficient.

...But there are others using the exhaust to pressurize the fuel tank, without too many problems.

Maybe this photo of the external linkages between the parts, would be good to help you find a reasonably good starting position.


And BTW, the low speed needle is a classic fuel metering system. The only thing it has in common with an air-bleed low-speed mixture adjustment, is that it is turned in the closing direction to open it further and vice-versa.