Enya .09 II Questions

The .09II probably my favorite Enya along with the original .09 pot bellied engine.

I have never seen one with a muffler and your's is the first one with the later carburator. All my throttled versions (early style carb) have springed needles.

Thanks George for the detailed thoughts and links to reviews on the Enya …. I look forward to read thru those when I get a chance….Interesting thought on starting with a wood prop…. My knee jerk reaction would be with a heavier nylon to help flywheel thru….But, many of our small engines take on their own best procedures so I’ll keep the wood prop in mind…. Maybe one of each when we get the size dialed in….I have 15% fuel on hand I use for my .049’s…. Maybe this would be appropriate…. Wouldn’t want a rocket, Just sport performance…Yes, I’m hoping Mike will chime in…. Quite knowledgeable with Enya’s…..

Well thank you for the nice little engine Bob, We need a project for it…. Meaningful, that it’s on of your favorites …. With all this Jim Walker stuff going I was looking at his
FreeBee….A control line T-28 with throttle … I have a plan for a little larger T-28 for .09….
Maybe I could convince myself I wouldn’t dizzy out if the speed could be controlled….. Thinking it thru anyway….

rdw777 wrote:Thanks George for the detailed thoughts and links to reviews on the Enya …. I look forward to read thru those when I get a chance….Interesting thought on starting with a wood prop…. My knee jerk reaction would be with a heavier nylon to help flywheel thru….But, many of our small engines take on their own best procedures so I’ll keep the wood prop in mind…. Maybe one of each when we get the size dialed in….I have 15% fuel on hand I use for my .049’s…. Maybe this would be appropriate…. Wouldn’t want a rocket, Just sport performance…Yes, I’m hoping Mike will chime in…. Quite knowledgeable with Enya’s…..

Well thank you for the nice little engine Bob, We need a project for it…. Meaningful, that it’s on of your favorites …. With all this Jim Walker stuff going I was looking at his
FreeBee….A control line T-28 with throttle … I have a plan for a little larger T-28 for .09….
Maybe I could convince myself I wouldn’t dizzy out if the speed could be controlled….. Thinking it thru anyway….

Did I send you that engine Robert?  I seldom remember my give-aways.  Perhaps you have it because it has the later carburator..................   Curious, if I sent it to you it should have been as a complete engine....

Let's see what Mike has to say, he has studied these Enyas a lot deeper than I have. Love the Enya's, have over a hundred including several very rare examples.

Yes Sir, You did Bob, Kind of a surprise…. It’s been on the
to do list to get up and running….. I had one many years ago only with the plain venturi so this will nice to handle another one….. No problem for me to chase down a part or two for it

rdw777 wrote: I was looking at his
FreeBee….A control line T-28 with throttle … I have a plan for a little larger T-28 for .09….
Maybe I could convince myself I wouldn’t dizzy out if the speed could be controlled….. Thinking it thru anyway….

OooOOO! I just have to see this one upon completion. For some reason trikes strike a nerve for me much like my love of twins. Please do a build log...from thoughts to flying, pretty please!

If you need three-wire notes, I have a few. PM so I can find them and hand them off.

rdw777 wrote:Yes Sir, You did Bob, Kind of a surprise…. It’s been on the
to do list to get up and running….. I had one many years ago only with the plain venturi so this will nice to handle another one….. No problem for me to chase down a part or two for it

Let me see if I can scare up a needle for it Robert.

Just for fun I took a trip down memory lane looking at some of my give-aways.  You participated in both of these.


https://www.coxengineforum.com/t15599p25-contest-contest-contest-version-2-0-big-brother?highlight=contest

https://www.coxengineforum.com/t15585-contest-contest-contest?highlight=contest

We need another contest. As Eric once said it brightens/spices things up a bit around here. Or words to that effect.

Yes I remember those…. Light hearted fun provided by a generous and kind organizer ….. Fun to see the group guessing and discussing the potential answers …, The “stuff” is great but more so the good will

rdw777 wrote:Yes I remember those…. Light hearted fun provided by a generous and kind organizer ….. Fun to see the group guessing and discussing the potential answers …, The “stuff” is great but more so the good will

Jason started it with a "Guess how many Cox engines are in the bottle". Pee Wees I think but they could have been Babe Bee's. Great fun, I think both of us had more fun putting the contests on than the winners had in receiving the prizes.

I would do another one, perhaps guess how many Enya's are on my two Enya trees...............but then I would have to count them, and probably make a mistake doing so.

I got it, guess the displacement of a Cox .049 engine.

Now I remember..........The Enya .09II - appreciation and thanks for for the Stensils, or was it the Surf Skimmer, or was it for..............

944_Jim wrote:OooOOO! I just have to see this one upon completion. For some reason trikes strike a nerve for me much like my love of twins. Please do a build log...from thoughts to flying, pretty please!

If you need three-wire notes, I have a few. PM so I can find them and hand them off.

Hi Jim, Sorry I missed this yesterday….. Yes, trikes are cool…. Nose wheel up first, up on the mains and away you go!…. Yes, would like to see what you have on three line stuff, sounds interesting….. I’ll send you a link to the plan I’m looking at…. Got to get an engine running before going much further though

Difficult to say if it's the right needle valve for this carb but yes it really looks like it I must have one With the same needle to compare and yes the silencer works well but steals performance slightly I like the carburetor less the response is slow i tends to want to enrich the mix a lot when idling the engine and makes the response of the accelerator slightly slow But with the correct adjustment of the air blead valve helps but I always have difficulty adjusting it I much prefer the models with two gas needles

My Enya .09 was running the 7X4 or 5 can't remember for sure not a throttled one though .. I think its at the shop on a test stand rite now cause i can't find it 15/19/29s but no .09 HummmmmI get a think about it when i go out i will look 15% should work fine ,,, Here is some info right here on CEF >>> https://www.coxengineforum.com/t10362-enya-09-ii

Hello All,
Had a busy day yesterday doing a bunch of "spring" cleaning.

Nice to see an old Enya .09-II in such good shape.

Here are photos of my .09-II R/C later version with muffler.
It took me a while to get an original "after-market" muffler as the engine was not really originally designed for use with a muffler by Enya.

This is the last version of the .09-II with throttle valve control.






The 1st original R/C carburetor for the .09-II had a 90° wire (and the U-control springy needle valve) and it was really for throttle cut-off and not really for radio control (yet)
It was hooked up to a mechanical timer and after a set time, the timer activated the throttle barrel and rotate to close off the intake and turn the engine off. [/b]

Below are the original Enya instructions for the U-Control and R/C version of the Enya .09-II engines.

U- Control instructions:



R/C instructions:





Now for the 1st question that Robert has about the needle valve (NIP) Enya Stock #09220-Z
That is for the U-control and the needle valve really won't work with the R/C carb.
Even though the needle valve will thread into the carb, it might not be the correct length.
Unscrew the needle valve from the U-control assemble and screw it into the R/C assembly.
I'm pretty sure that should work since the original needle valve is missing?

Now the Question:
The "later" R/C carburetor fitted to this Enya .09-II
Indeed, it is an Enya .09-III carb modified to fit into the venturi area of this .09-II.
I been able to modify three of my .09-II engines to have R/C throttles fitted.
It was rather simple to do. I just had to turn down the throat diameter size by 1mm to make it fit into the venturi of the .09-II

I did think originally to use a reamer and open up the venturi on the .09-II engine but then I thought of how the modifying the diameter of the venturi intake would change the "original" properties of the engine. 2nd thought, I opted for the carb modification.
So, If I remove the carb and turned it back to a U-Control engine --- nothing changes. Now "if" I bored out the venturi, then the larger venturi would suck more fuel, make the engine a little harder to start and needle adjustments would be different.


Below are three of the Enya .09-II that I modified .09-III carburetors to fit the .09-II venturi size.





Now for the prop sizing.
Well 1st thing it look at is the bore and stroke.
The Enya .09-II is a "square" engine ---- what that is the bore and stroke are closely the same.
Higher (later) engines were over squared (bore was larger than the stroke)
If you look at the earlier engines they were longer stroked and smaller bore.

With a longer stroke you can run a larger prop at a slower speed
Short stroke engines are happier with a smaller prop running faster.

Last question ---- muffler?
If you have either an Enya .09-III or a later version of the Enya .09-IV (strap on muffler) they will work out fine.
The .09-II with muffler ---- there seems to be no change in the performance as it is a happy slower running engine with a larger than usual prop over the new faster running engines.

The Enya .09-IV earlier version muffler with clamping band (on the left in the photo) and the Enya .09-III muffler (rare to find) on the right in the photo.


Additional muffler photo:



One last thing:
The Enya .09-II Robert has --- has been rebuilt because the head screws and other screws are not the original JIS (Philips style) screws as on the original that of rsv1cox engines or mine.

As for the prop --- I used on mine was the 7x6 Top Flite Power wood props.
The .09-II was happy using what I call paddle props. Some fliers call them paint stirrers.

Nice thing with the square or long stroke engines are they run longer at the slower speed with the bigger props over the oversquare faster, smaller prop engines.

And yes, I tried to retrofit an Enya .09-III front housing onto the crankcase of the .09-II to see if they could fit together and they didn't. That is why I had to turn down the throat diameter of the Enya .09-III carburetors to fit the venturi of the .09-II engines to make them R/C.

I think I covered everything (questions)?

A very nice, comprehensive write up on the Enya II, @sosam117 , with all bases covered.

Robert, on the fuel issue, what nitro level to use, my Enya .09-III was happy on 15%. Warring used fuel from 0 nitro to 30% without any problems.

I think you have a lot of flexibility on what fuel to use. Fuel you are using for your Coxes may make logistics easier, especially with multiple planes at the flying field.

@Greenman38633 , there's nothing wrong with a IV. Although I don't have one, impressions are it is a right hand exhaust III. Some later versions incorporated a ball bearing with its crankshaft. It has the same bore and stroke as my III.

The II is not as common. Some interest has been stirred, as a few here own them.

I found my III slightly more powerful over my 1965 OS Max .10R/C, which helps to compensate for its additional ounce in weight.

You have the earlier Enya muffler. The rotating cover was to make it easier to squirt fuel into the combustion chamber, to make priming the engine easier. This was back when hand starting was the norm. Later, more were using electric starters. Plus, I have found that by priming through the carburetor opening was just as easy.

Greenman38633,
I am in agreement with GallopingGhostler that there is nothing wrong with your .09-IV.
Though, I have a couple of things I would like to point out to you on your engine/muffler.

You have an Enya .09 with a "red" prop driver.
If built as original with the "red" driver, then it was an easy giveaway that it was a ball bearing .09-IV.
Later on, Enya just used the "red" driver for all of the Enya .09 engines.

Here is a photo of my Enya .09-IV with the "red" prop driver:



BUT ---- this one is the Ball Bearing version ----- BB stamped on the front housing.
And there is a slight performance difference as well.




Next is the muffler on your engine.
It is the earlier version for the Enya .09-III which is a good muffler for the .09-III (left hand exhaust) but is a little restricting for your .09-IV (right hand exhaust) as the muffler you have is for the slower running "square" (bore and stroke) Enya .09
The valve on the side of the muffler is to be used for priming the fuel into through the exhaust port (if needed)
Then closed off when flying. But I guess you can use it to reduce the back pressure?

As you see in the later versions of the Enya mufflers, they don't have that valve opening on the mufflers.

Yours is an over bored, short stroke (higher revving) engine and need the have a larger muffler volume.

Below are the different mufflers for the Enya .09 engines over the years.
The original 1st muffler (stock #M100) was for the left exhaust .09-III ( though it will work on the .09-II)
Next is the 2nd muffler (stock #M102) it was ok to strap onto the old .09-III but was designed with more volume for the .09-IV engines coming out. As you can see these mufflers had "straps" to clamp the muffler onto the exhaust port.
Next version was Enya stock #M120 muffler --- this muffler was for the later version .09-IV that had "ears" cast onto the crankcases to do away with the clamping strap. Though, "IF" you can either find a strap from the older mufflers, you can use this muffler and clamp the M120 muffler to the .09-III and IV engines without the "ears" and it will work.
Last is the universal muffler Enya currently has (stock #M154 and stock #M153) which fits many different engines. I'm not really fond of this muffler as it is a "one size fits all" but for the .09-IV and (.09 Quicky) it is too big and on the other end is too small for the Enya .19-VI






So Greenman38633 ---- take a look to see if you have a plain bearing or ball bearing (BB) Enya (I think it is a plain bearing).
And the other is to find the correct muffler for it for better performance.

Much thanks Mike for the detailed information, photos, and instruction sheets!!!
I had no idea that mine had the TV - (carb) from the later 09-III series …. That will be helpful info for tracking down the correct needle….Do you have instruction sheets for the
09-III TV with part #’s?…. There’s a seller on the bay with some Enya needle assemblies but asks buyer to specify the engine…..Maybe a part# would be helpful as part of the description ….Thanks!

FYI, actually Mike, the III is slightly over-square, same dimensions as the III.

Enya .09-IV shown is earlier non-ball bearing one. Example, "7x8-6x4" prop means range 7x6 to 8x4.

Yet, it still benefits from using steeper pitched / larger diameter props. Seems typical of the cross scavenge with baffle (fenced) piston engines of the day.

I remember the late William "Bill" Winter, a well known chief editor of several model airplane magazines, last the AMA's Model Aviation, back in the latter 1970's in an AMA editorial article, decried manufacturers abandoning cross scavenge engines for Schneurle technology. He flew a lot of old timer aircraft, where they benefitted from larger diameter props. His point was, "Why can't they call these torque engines?"

(Bill was a neat guy, I mailed him two NOS Jetex 50 engines complete with packaging as a gift, since I could not obtain fuel pellets for them in Hawaii, early 1980's. He sent me a very nice, hand typed thank you note, with his Buzzard Bombshell flying experiences. Got it somewhere, when I find it one of these days, will post.)

(Example, the old Brown Junior .60 ignition engine was rated at 0.25 BHP, but could easily haul an 8 foot (2400 mm) wingspan cabin free flight with ease turning a 14 - 16 inch prop, but same horsepower modern day .15 turning an 8 inch propeller would not cut it. Couldn't put the thrust air past the fuselage.)

Was the earlier Enya .09-III muffler with priming port a carry over from the Enya .09-II ?

For sport use, I gather that unless one was going to higher nitro levels, wouldn't the earlier muffler with slightly more back pressure provide a more reliable idle for the III ?

Some plug the muffler priming port holes with silicon sealant caulk. This was to reduce the amount of exhaust residue splatter for a cleaner appearance.

My hunch is with mild nitro, the earlier more restrictive Enya .09-III muffler may still be OK, if one is sport flying and resorting to larger diameter / steeper pitched props, which would put the engine closer to its HP curve in flight with better fuel economy.

Your thoughts?

rdw777 wrote:Yes Sir, You did Bob, Kind of a surprise…. It’s been on the
to do list to get up and running….. I had one many years ago only with the plain venturi so this will nice to handle another one….. No problem for me to chase down a part or two for it

I apologize for my foggy memory on that engine robert.  At the height of my Enya phase I was getting them in 3 or 4 at a time buying them cheap as parts engines or just worn.  I went through all my old ebay files and can't find anything on it, also my picture files and the search function here on the forum.  Nothing.  Also, I can't locate a needle for it in all the obvious places, now to check the less obvious.

But I did run across these photos that you might get a kick out of.

GallopingGhostler wrote:FYI, actually Mike, the III is slightly over-square, same dimensions as the III.

Enya .09-IV shown is earlier non-ball bearing one. Example, "7x8-6x4" prop means range 7x6 to 8x4.

Yet, it still benefits from using steeper pitched / larger diameter props. Seems typical of the cross scavenge with baffle (fenced) piston engines of the day.

Yes, I know of the bore and strokes of the .09 engines.
If you are rounding up the numbers it is a "square" engine. If you don't then not exactly a "square" engine.
Sometimes you'll see the bore and stroke the same at .500 inches.

Example of exact bore/stroke:

.09 model #3001 = bore:.496 / stroke .498
.09-II = bore: .500 / stroke: .498
.09-III = bore: .512 / stroke: .480
.09-IV and Quicky .09 = bore: .512 / stroke .480

Actual bore/stroke dimensions are from engine test/reviews.