Evo 52 development

[Dave Adamisin]

Hi guys. Just thought I'd put this up to keep you up on what I've been working on. A couple of you have asked Pete about maybe following up the 36 with something a little bigger. We have put in a summer on this and here are a pic and some video footage. The engine is very easy to handle and very powerfull. I have at least 50 flights on the one in the video and it still feels new. I had the head off to change the clearence at around 35 flights and it was completely clean. The plane is the same old white practice tug I showed in the very early testing: high AR 675 sq's, 69 oz., 12x6 Zinger thinned out (I took off about 0.080" along most of the length) with raked tips. The fuel is Cool Power 10%. I have been running a lot of different tanks in it. This flight is with an 8oz Dubro rectangle set up as uniflow (more about this in another post). The engine doesn't need all that fuel (about an once a minute) but I like the big tank while testing to add flight time to help loosen up the engine. The needle was set a bit fat on this run but it pulled fine. The engine REALLY likes a 12.5x5 Eather 3 blade set a little faster but I don't run expensive carbon props on lumpy grass fields...... It spins anything you put on it. It has the rear mounted valve and it's easy to set. The venturi ID is 0.234". Engine as seen weighs 13.7oz. Muffler is 0.7 oz.

Youtube video:

[Greg L Bahrman]

sounded bad like it was going to quit. Not confidence inspiring?

[johnbyrne]

Wow 

[Ralph Wenzel (d)]

Something was causing the engine to be unhappy in the inside-to-outside transitions, especially "uphill". More than just a "fat" needle. Could have been the tank or plug??? Otherwise, a very impressive-sounding run . . .

[Rudy Taube]

Hi Dave,

Thanks for the cool video. If that is your "tug" plane flying that nice pattern, then you must do a 560+ with your "good" plane!  

The engine sounded very good. My guess is the times it sounds like it wants to quit is more to do with the directional sensitivity of your audio mike, not the engine??? ... or maybe the tank???

I really like the "safe" NV placement. IMHO, we need more of these. 

It looks like Horizon has another winner, and in a perfect size too. 

[Dave Adamisin]

sounded bad like it was going to quit. Not confidence inspiring?

Yes it was burping on the transitions. You were paying attention to the video. The tank is a bottle type and I haven't got it to stop balooning yet. We learned in rc pylon that you need to constrain the tank somehow. I have it wrapped with glass reinforced packing tape, just not enough of it yet. It blows up as the engine accelerates on the inside loop and then the excess pressure as the "baloon" deflates causes it to go rich for a split second. I mentioned that I would have a seperate post about the tank. It's also non-traditionally vented.

[Dave Adamisin]

Something was causing the engine to be unhappy in the inside-to-outside transitions, especially "uphill". More than just a "fat" needle. Could have been the tank or plug??? Otherwise, a very impressive-sounding run . . .

You're right on that one. The plug's fine I think. See my reply to Greg about the tank. I have a fairly normal metal tank that works just fine. I have been playing around with a different approach to the uni-flow vent. More later after I figure it out...... I just wanted to get a post up before the snow flies.

[Dave Adamisin]

Hi Dave,

Thanks for the cool video. If that is your "tug" plane flying that nice pattern, then you must do a 560+ with your "good" plane!  

The engine sounded very good. My guess is the times it sounds like it wants to quit is more to do with the directional sensitivity of your audio mike, not the engine?

I really like the "safe" NV placement. IMHO, we need more of these. 

It looks like Horizon has another winner, and in a perfect size too. 

You're too kind about my driving Rudy....... The engine is close, we have a couple little things to try yet.

[wwwarbird]

 I've been waiting for this one, when can I order mine?

[Dave Adamisin]

Another note. The mounting pattern is the same as a Max SF. The thrust washer sticks out about 0.100" farther than the SF.

[Balsa Butcher]

Another note. The mounting pattern is the same as a Max SF. The thrust washer sticks out about 0.100" farther than the SF.

As I have an airplane powered by a .46 SF that refuses to run consistently, that is music to my ears. Stand by for retro-fit!

Modified: Request either a traditional 4/2/4 run or fast 4 cycle...and since it is still in development - a little better fuel economy would be nice.

[John Paris]

Dave,
Even with the burp this one seemed to haul the airplane around with authority.  Do you plan on going with a traditional style run (sort of sounded like it in video except for wind up and burp from the insides) or more of a wet 2 stroke that I am hearing the guys are running on the 36s?  Good to see your dad out there with you.  Tell him the crew from Clio says hi.
John Paris

[Randy Powell]

So, when and where might these jewels be available?

[Dave Adamisin]

So, when and where might these jewels be available?

Pete was showing one at the Chicago show. Pass any thoughts about this his way. I can tell you that it is a brute, really well made, easy to handle and I'm building a new plane for it. He can get them made. 

[Dave Adamisin]

Dave,
Even with the burp this one seemed to haul the airplane around with authority.  Do you plan on going with a traditional style run (sort of sounded like it in video except for wind up and burp from the insides) or more of a wet 2 stroke that I am hearing the guys are running on the 36s?  Good to see your dad out there with you.  Tell him the crew from Clio says hi.
John Paris

I was focussing more on a traditional run. A wet two would require a short pitch or a big plane. So you noticed my pit crew? The whole flying day was his idea. We flew the electric Brodak Vector that day too. My first time drive of an electric. Video credits go to my son Mike. He launched for me as well as doing the video so we joined the flight at the loops...........

[wwwarbird]

Pete Bergstrom just sent me a message saying that they expect the .52 to be available about mid-April.

[elizio]

Hi Dave:
It's impressing the sound.
I worship the "choke" in corner maneuvers.
Congratulations!
elizio - Brazil

[Richard Oliver]

Hi Dave, Good to see you with a handle in your hand (instead of a transmitter!!). My impression of the run is that the engine is just to rich. The venturi is a bit large and if it was a bit smaller it would cause you to run a bit leaner to get the same RPM. 5% nitro would also help. This would clean up the run a bit. I also only run plastic tanks and have not had any ballooning problems. You might also need to run a hotter plug if you stay with the richer type run. Modern technology (like the EVO) also will not need as much oil content and will probably be just fine with little or no Castor. This will also clean up the run some. Standard RC 10% castor mix will run just fine in my opinion. My personal choice is all synthetic but that is just me. I like the engine and airplane being cleaner after flying.
Thanks to you and Pete for getting Horizon on board.
Richard Oliver