Zdz

[Sibola]

https://youtu.be/MdX4qP7w6R8

[Cosmith]

Wow...incredibly smooth!

What do the engine gurus think of the ZDZ112 vs the DA120 for the 120 class of 3D planes???

[Sibola]

Wow...incredibly smooth!

What do the engine gurus think of the ZDZ112 vs the DA120 for the 120 class of 3D planes???

How about the new ZDZ 140 for the 120 class.

Thats my plan, going in a AW 260 Free Style.

[Cosmith]

Ken, how does the 140 compare in terms of physical size? Looks like the 112 is about 2 inches longer than the DA120 which means major surgery on most ARFs unfortunately, unless I'm missing something.

[Sibola]

It's actually about the same size. All though will have to punch a hole in firewall for carb.

Scan0015.pdfScan0016.pdfScan0017.pdfScan0018.pdf

[Sibola]

Hope that worked.

DA 120 159mm prop hub to mounting plate.

ZDZ 140 154 mm prop hub to mounting plate.

[tbrum]

Cory... the 112 is actually a bit shorter than the DA or GP

[Cosmith]

Cory... the 112 is actually a bit shorter than the DA or GP

Yep...feel like a tool...the 3 view on the AMR website must be for the wrong engine, it shows a prop hub to mounting tab length of 203mm...but now I went straight to the source and I see 156mm.

Don't necessarily like the idea of the carb in the motor box, but I can see that has some advantages as well. How are these engines for spitting fuel out the carb??? Does the rotary valve have any effect on that???

[itizme]

Rotary valve opens on upstroke and closes at tdc. Also the seal of the valve is so important that they don't start unless the rotary valve is wet, nothing blows back like the old Quadra days.

[Cosmith]

Rotary valve opens on upstroke and closes at tdc. Also the seal of the valve is so important that they don't start unless the rotary valve is wet, nothing blows back like the old Quadra days.

Are they a little different/harder to start then?

I just love the idea of a super smooth engine with as clean a mid-range as possible. I'd gladly give up some top end for a smooth engine with a clean mid-range and great transition.

I went to a stock exhaust on my Mamba/DA70 because I was having some transition issues with the can I had on it, now she spins a Falcon 24x9 carbon at 7350rpm all day long! The motor is awesome and transition is great, but that mid-range sounds nasty! But, point is, when it spun 6850rpm on the can it still had gobs of power...I would give up that extra top end to clean up the mid range in a heart beat. (This is not a bash on the 70 at all, I love this engine...smooth, idles awesome, stupid top end, etc...but it still runs like a two stroke with a Walbro carb!)