ZDZ 90, Install into new EF 94" MXS

[Terryscustom]

So I was talking with Joe at zdzusa.com about some other stuff and he brought up the 90 single now being in stock. I had previously read several reports from @tbrum on the canadian forums about the smoothness of these engines. Joe confirmed this after doing a re-build of one and running it on a test stand.

So this summer I was on the lookout for an airframe to try out one of these bad-boys for myself. Since the trend for many airframes is going larger and larger, I started running some numbers on wing loading and comparing to my experiments this past summer. "Some of you may remember I built new wings and converted an 88" Edge to a 91" with an 85cc power plant."

After traveling to the Taildragger Extreme 3D event, I knew I had found the perfect plane to test this engine. The 94" EF MXS is perfectly proportioned for a larger engine but it takes a little planning and for-thought to make it work properly. The only thing I would change is to have dual servos in the wings, which can be done but I will test it as is first before going in for surgery.

Here are some un-boxing pics from the 90 and comparing to the engine that is meant to go into this plane. And.....just for fun the weight of a DLE111 that funny enough would also fit in this plane, the cowl is huge:

 

[Terryscustom]

Pics of engine install and start of plane assembly. Pretty much electronics and ready to roll at this point. I forgot that I had to order a new prop because it has to be indexed for this particular spinner so with luck that will show up by the weekend for some test flight.

 

[Terryscustom]

More from today. Very important on this type of cowl to get proper air flow at the cylinders (baffling is not even a question, it MUST be done!!), whether running the 70 or a large single. I did a partial baffle to make sure that ALL air coming into the front hole is going through the fins. I also decided that since the muffler on this engine is large, I made some cylinders from foam and aimed the air coming in back at the muffler to cool it, and also get that air aimed towards the exits.

 

[Terryscustom]

I forgot the terryscustom disclaimer:

NOTICE: This setup is not for everyone. I consider the warranty as null and void on any ARF airplane that I build as soon as I open the box and check over all the parts to be damage free. This engine is spinning the same prop as a DA100 at about 50rpm's less according to info I've been given. This means that it has power enough to cause structural damage if not flown with a good understanding of how and when to use this power!

 

[ericb]

Looks awesome. Can't wait to see that engine running.

 

[1932]

I have had problems with air flow with the big mufflers behind engin not letting air out of fins.

 

[Terryscustom]

I have had problems with air flow with the big mufflers behind engin not letting air out of fins.

Yup, notice what I did on the top two snorkel holes. Air blown directly at the muffler and aimed directly at the can tunnel to promote air flow. Also notice the 3/4" tall low pressure lip on the belly side. This creates a venturi effect and actually pulls air through the system. With these two things, I expect air to accelerate as it gets through the engine.

The one thing I do foresee is re-starting the engine after a run. It will have to sit for a bit, because with the large can in there heat will build up after shut-down. I've had this with other singles with large pitts mufflers though and it's not a huge deal unless you anticipate flying back to back.

 

[crashflow]

 

[Snoopy1]

Very interesting Terry was taking a long look at this plane at joeNall. Will be following this thread.

 

[Flyrcjoe]

It is looking really good ! The power to weight ratio of this airplane is going to be fun !!!