Enya 61CX

[Martin Quartim]

Since this is an engine a few people know I thought it would be worth to start a topic and share my little experience with it.
 
The plane I am using to test and get the ultimate performance out of this engine is an 75oz Strega.

My initial setup was
8.0mm venturi (Stock one is 7.5mm)
Randy Smith Tube Muffler with a deflector installed
About 5.5 Oz fuel ( filled the 6.0 Oz tank up and removed one turn w/ fuel pump)
10% Nitro 10% castor 10% synthetic
Enya 3 Plug
APC 13x4 prop
Lines with  69' center to center
Launch at 10400rpms to keep it under 2-2-2
Laps 4.9s

Although fast, I had no problem doing the pattern. The plane flew very firmly from start to end keeping the lines tight and speed under control.

When I launch richer to go slower, it went into 4-2-4 mode and I felt the speed control was not as good as with 2-2-2.

Then I tried the Bolly 13x4.5 3 blades with the pitch set to an actual 4.5 (it comes from Bolly with 3.5) Launch rpms was around 9400rpms and laps at 5.2s running in 2-2-2 but it seems it loaded the engine a bit much. Although I could fly the hole pattern with some good wind blowing. It didn't gave me the same firm feeling as I had with the APC 13x4.

I was surprised how slow the plane flew the down leg of the hour glass, this is the first time I tried a 3 blade prop and sure enough they really slow things down. Perhaps I got so used to flying fast with 4S engines that now I feel is too slow.

My feeling has always been that this engine produces more torque above 10000 rpms, so I reduced the pitch to 4.

With the reduced pitch I could launch at 10100rpm to get 5.1s laps and it indeed produced a lot more torque then when with 4.5” pitch. Now I feel the model as firm in my hands as with the APC 13x4 but with better speed control going down hill. However I noticed pre ignition in the overheads. I changed to a 8.5mm venturi and added more castor oil to fuel mix to bring total oil content to 22% (yeah I know I should have used more castor since the beginning ). The pre ignition diminish a lot but not totally and the engine start working in 4-2-4 mode.

I thought about using a head shim but thought why not call Randy up and see what he tells me. As always Randy is super nice guy and suggested using a colder plug before anything else.

So for today’s flight I just replace the Enya 3 for an Enya 4 and kept all the same. The engine ran a bit smoother and with a bit more power. Pre ignition is almost all gone, just in the final 3 laps I can hear just a little bit of it.

The engine works in a 4-2-4 with this setup and it is speeding up a bit when I do the inside loops, I believe it is the tank height. I had set the tank about 5/32” lower then the NVA, which worked fine when the engine was running in 2-2-2 with the APC prop, it kept the same pace on the horizontal 8, maneuver for which I set tank height to work even.

I would like to find a way to make my engine run 2-2-2 with the Bolly 3 blade prop, and sort it out which is truly the best way 4-2-4 or 2-2-2 for me to fly this heavy bird.

I will try to reduce the pitch from 4.0 to 3.8 and see what happens when running in higher rpms.

The way the model/engine is performing now I feel I can beat some friends I have never  beaten before, will see May 1st hehe

Martin
p.s the Strega ARC although very heavy is making some very nice and tight corners. I had this model built just for testing this engine and sell it later but it is growing on me.

[john e. holliday]

Good report on the engine and set up.  I think the LA 46 is about as big as I will go.  It's on my version of the Bill Simon's P-39 kitted by Walter Umland.  At 62 or 64 ounces after three flights the arm says stop.  Looks like you have a winning combination.

[Mario Verol]

Hello, Martin! I saw you flying in Piracicaba and Prudente and I cling to the bravery of 61 to pull a plane of almost 2200 kg. I think your set up is perfect, congratulations! You just have to solve the problem of tank capacity. Maybe you'll have problems flying at sea level, ok?
Regards,
Verol

[Joseph Devenish]

I saw Martin fly his Strega/Enya61CX in a competition in Limeira (SP) last Saturday. Very impressive too with the Enya61 really pulling this big model around very well. This engine really sounded really smooth, and has that beautiful throathy note with lots of power on tap. Clearly, the three blade Bolly helps with the 8mm venturi in this heavy model - again quite impressive!

Well done Martin!

JoeD

[Eric Viglione]

WOW! Sounds pretty powerful to me! Makes one wonder what the rear exhaust Enya 61 would do on a pipe... 

EricV

[jim welch]

The enya 61pro rear exhaust is one bear of a motor on pipe or off.I'll have much info by the next weekend since mine is in development stage and will be in my T Rex by the weekend for some airtime playing.On the test stand its a stump puller of a motor................Jimmy

[Martin Quartim]

Thank you for the compliments guys.

The other positive thing about this engine is that it doesn't have a sensitive needle. I can launch from 9800 to 10400 rpms and the engine will  drive the Strega with no problem. I can fly as slow as 5.6s or as fast as 4.9s laps. When I launch very rich it seems it kicks harder to go up and I have no trouble on the overheads. The only problem I found when flying very slow is a bit slack lines in the 8SQ.

There has been a contest every other week and I haven't had the time to experiment other things, like reducing the prop pitch a bit more.

The only thing I changed since a last post above was the tank height. I moved the tank up, now it's about 1/8 below the NVA and I have not experience any speeding during the inside loops or other manuvers.

Also, the Engine starts up side down very easily, I choke with 3 flips and it starts just twisting the spinner.

Martin

[Martin Quartim]

 I start using a new Enya 61CX  and this one is bit different then the first. The first one is an engine that has been used for more then a year with different people, who insisted in trying to make it work like an ST 60, using the same props and all, it didn’t work right of course. Anyway this engine end up in my Strega and ran mighty well as I have reported above.

My second engine is brand new with about 1 gallon of fuel and it is not running as strong as the first one. For trying the new Engine I used the same setup, exact same venturi, glow plug, fuel and prop. On the bench it was about 600rpms less in the exact same configuration, having tested both one after another.  I put it on the Strega and I noticed a big difference in power. It was not as loud, it run mostly 2-2-2, and I had to round more in the corners. The engine is still new so probably it will get a little better with more running. I had bit difficulty making the first loop of the clover leave with moderate wind, the rest seems ok.

To get more power, I replaced the low compression button head for the high compression and it indeed worked better and it seems it did a bit of 4-2-4, but it still doesn’t growl like the first one.

Not noticing any sign of pre ignition I replaced  the Enya 4  plug for the Enya 3 and it worked stronger and better, no sign whatsoever of pre ignition. The first engine with the lower compression head would not work with the Enya 3 plug.

With the R/C high compression head and the Enya 3 plug I got better power and it is  burning  less fuel then the first engine.

The only internal difference I could find between the two engines was  the deck height, the second one 0,0043 deeper. That could mean that the liner in the first engine is mounted a bit lower on the block, or the liner lip is a bit thinner, thus more compression.

This is a video of Second engine running with low compression head and Enya 4 plug. Not bad actually for the engine, now for the flying well it was me at the controls.

With the 1st engine I can make a bit tighter corners, and plane seems to fly a bit more firmly too.






Martin