Ram Jet

Just havin' fun with you Hobbsy. I can't spell Alison - I probably would spell it Allison but I can't spell to save my life. I''ll tell you one thing though, my dad could take apart a 1,710 C.I. Alison V-12 and reasseble it in his sleep.

Best regards,
Bill

blw

My Feedback: (3)

Bill,

I don't know if mine worked on those or not. I remember him working on Corsairs but I was too young to remember much of what he said about it.

Ram Jet

The Alison would be a piece of cake compared to the Corsair power plant.

Regards,
Bill

Ram Jet

The F-4U had dual Pratt and Witney Wasp engines (18 cylinders). Imagine doing a valve adjustment on that beast. When it was placed in service it was the most powerful fighter that existed. The inverted "gull-wings" had nothing to do with areodynamics. The plane was built that way so the enormous propeller could clear the carrier decks and landing strips. I have a 1:18 scale static model with Pacific colors hang over my head right now.

Best regards,
Bill

Taurus Flyer

Gents, for who is interested,

I read some posts about carbs,

Ever heard of the recovery of pressures of measuring orifices and venturi’s?
My attempt to realize a better sucking pressure recovery and lower carburetor resistance of my ENYA 60 4C engine. Enlarge the bore of air inside and outside of the barrel, equal to the bore/diameter of the carb housing and reduce the surface of the nozzle.
Maybe you think, the turbulence is needed to mix fuel and air, but too much turbulence is resistence, drag.

As normally I use a separate fuel pressure controller to supply the carb. So ratio of fuel and air mixture is no problem.

You see some pictures of the normal barrel and modified one.
I also did give the modified barrel a direct fuel connection to have a better control of the right flow direction, one way, to the nozzle tip.
Result is of course the fuel hose tube does rotate the degrees of the barrel but that’s no problem The separate needle valve is mounted on a place I can handle easy.
Engine runs fine for many flights now.

I use the 30 years old engine in a modified Orion, see last picture.
The plane is in the repair shop to fix the wing. It had a date with a Spruce Choose spar in the field, nothing to do with the engine.

Cees

martin_solo

Ed,

Please accept my appologies, I was bad[:@].

I never thought about transfer ports sizing. But now I am curious, how smaller is the Enya 61CX transfer ports compared to a regular 61?

I think the stock carb is too small for this engine, it is the same used in the Enya 32CX. It could run much stronger with a bigger one, like the G8.

Martin

martin_solo

Cees,

I like to hear this modification stories. A friend of mine also made different venturi for his 4S engine, but for use in C/L, and his aproach was also in the direction of a cleaner and less turbulent passage. Regular Venturis for C/L has the Spray bar crossing right in the middle of the venturi, he made one with the NVA tangent to the venturi inner wall, purtruding about .020" inside the venturi, it work better then other venturis.

One experiment I would like to see you try is to make the nozzle shorter, so it is just about of the venturi wall, that should make even less turbulance.

Martin

NM2K

My Feedback: (14)

Since I do own the Enya .61 CX engine, it would please me to no end if the transfer ducts were as large as those of a full size 10cc engine, but, alas, that is not possible in such a small crankcase.

I realize that Enya is subject to the laws of engineering and economics, just like every other engine manufacturer, but I really wish that they had kept using the AAC piston/liner technology that was employed in their .40 & .45 CX engines. They are my favorite engines of all time. Of course, if the .61 CX had been made using an AAC piston/liner, the gas passages would be considerably smaller than they are in the present version, due to the liner thickness having to be much greater than when using ABC technology.


Ed Cregger

downunder

I think there's a bit too much made of transfer port sizes restricting the breathing of an engine. The real bottle neck would be in the carb itself because it's surprising just how little area there is for air to get through it. While an 8 or 9mm carb sounds fairly large you have to take into consideration the area blocked off by the spray bar which naturally passes through the centre of the carb which only leaves the two crescent shaped areas either side. I just measured an ST carb which has an 8.9mm barrel (.35") so it's area would seem to be .0964 sq inches. The spray bar though is .155" diameter across that .35" bore so its area is .054 sq inches so the effective area of the venturi is .042 sq inch or less than half what at first glance it would be. By the same token, a slight increase in bore size gives a relatively much larger increase in effective area which in turn gives a much larger airflow but with reduced fuel draw ability. The Enya carbs where the spray bar projection can be wound in or out of the barrel allows for changing the effective area for either more power or better fuel draw.

Now I don't have an engine stripped right now to find the total cross sectional area of the 3 transfer passages but I'm fairly confident that their area will be a bit more than .04 sq inches even in an engine based on a small crankcase.

Maybe I should add that replacing a conventional CL spraybar with the tangential as Martin mentioned is why the engine gave more power. It most likely at least doubled the effective area. One small problem with having a tangential spray bar is that with the outlet being very close to the venturi wall it's in the boundary layer area where airflow is much lower so there's less drop in air pressure. The fastest airflow giving the greatest pressure drop is in the centre of the venturi so what some guys do is to use a cut down spigot made from a hypodermic syringe needle that projects into the centre of the venturi. That gives best fuel draw with the minimum airflow restriction.

Taurus Flyer

Martin,

The engine of your friend probably did not have a throttle, because you write C/L, "control line".
For me a constant fuel air ratio over the power range is more important than max power so also in idle position I need an airflow over the tip of the nozzle which I give a special shape. For this reason I have to position the tip in the centre of the venture and barrel. When I make the nozzle short it will be in a dead corner of the barrel in idle position.

Cees

NM2K

My Feedback: (14)

As Cees has pointed out, in so many words, the way we think about our engines is different for R/C than C/L. C/L tends to think in terms of constant speed with no concern for tractability.

One further point I will make, regardless of transport size is that a .40 sized engine will have a .40 sized crankshaft with an appropriately sized bore in the crankshaft beneath the cut made for the rotary valve. All of the transfer volume and carburetor size in the world will do you no good if the hole through the crankshaft is small.


Ed Cregger

Taurus Flyer

Ed,

You write:As Cees has pointed out, in so many words

For 4 stroke engines we need twice the amount of words to tell the facts.

For a 30 years old 4 stroke engine I am only interested in simple modifications the make the engine run better. Giving the barrel a better shape will reduce the contraction and turbulence of the airflow of the carb in the easiest way I show. Important is to watch the in and outlet areas of the barrel in nearly closed position. It seems the carburetor of an Enya 60 4C is of a smaller 2 stroke Enya (your 0.40?) and maybe this modification was too time consuming for a manufacturer in that period.
For my 60 4 C next step can be, reduce the drag if the inlet of the carb by mounting a well shaped inlet runner, but for that I do have to modify the flapper valve that is made to shut off the engine. Project for the future?

(Of course we all know, total sucking pressure is sum of drag (is pressure) of inlet and carb sucking pressure)

Cees

martin_solo

Ed,

You better get your Enya 61CX out of the box and start using it to make a better evaluation of its performance. I actually thought you had measured the transfer ports, so again I am going back to say you are making false statements

I don’t have any 61 here to measure against the 61CX, but I have an OS 55AX, the transfer ports in the Enya 61CX looks about the same area. The crankshaft in the OS 55AX has a 8.7mm bore and the Enya 61CX 10.6mm.

The 55AX carb is 7,6mm and the Enya 7,4mm

A bigger carby with 8.00mm should work fine on the 61CX.

There is a lot of metal left to machine a bigger transfer port in the Enya 61CX, but why Enya didn’t make it, is it really necessary?

Martin

captinjohn

Hey Guys...when is Enya going to get the new Glow powered gas engine on the market. Seems like by now somebody should have one to tell us about how they run. Photo below. Capt,n<hr />http://enya-engine.com/180XGS_E.html<hr />

NM2K

My Feedback: (14)

Your example engine, the OS .55AX, was also derived from a .40 sized crankcase, so comparing its passages to the Enya .61CX proves nothing. I have a couple of these too, still NIB. You are right about one thing. I'd better get busy and begin running some of these engines.


Ed Cregger

drube

Does anyone know the size Prop Nut my Enya 60 lll 7033 takes? Search seems to be down.

Thanks

martin_solo

it is 7mm

Martin

drube

Thanks Martin

captinjohn

More>>>>>> http://www.engineeringtoolbox.com/or...uri-d_590.html Capt,n

captinjohn

I am still wondering if thr Enya 1.80 Gas engine is going to be available?????? Capt,n

http://enya-engine.com/180XGS_E.html

earlwb

Looks like it is still in the "Coming Soon" mode. So maybe it will, maybe not, hard to say.

earlwb

I actually have several Enya engines I have acquired in the past. I think I have three or four Enya 35 RC engines, four Enya 15's, a couple of Enya SS 40's. Years ago I had two of the Enya 35's on a twin engine plane I made with a left over Contender wing when the fuel tank ruptured and soaked the fuselage up badly (the plane was pretty well used by that time anyway).  The Enya 15's are all different models though. I ran a couple of them on some small planes way back then. One of the SS 40's was on a Kaos 40 for a long time.  Like Fox engines you just can't wear out a Enya barring a crash or something.

Enya 15III TV


Enya 15 IV TV still NIB.

drube

I finally got around to taking the exhaust off my 60 lll thatwas strapped on with a hose clampand was surprisedto see two holes. Ican't figure out what they would be used for. This would also explain why the engine was covered in fuel after a day of flying. Wouldn't the holes being there cause less fuel pressure? Can the holes be plugged somehow with JB weld or something?

Thanks.

Holes in third pic

earlwb

it is a exhaust baffle, it rotates in conjunction with the throttle to control the engine's low speed.
Way back then no one used mufflers and neither did anyone use muffler pressure either.
You either used a muffler that had a large flange on it to cover the holes or you used a couple of small aluminum plugs to block the two outer holes. The muffler clamp kep the plugs on. it is ugly but some people have used JB weld to good effect. You'll need to use some masking tape to keep it from oozing out. You will have to do one hole wait for it to cure some and then do the other hole.

Here is a example of an exhaust baffle:


Here is a example of using aluminum plugs with the muffler clamp holding them on:

Mr Cox

Looks like it was meant to have an exhaust baffle rather than a muffler. It can be solved with a rod for instance, just like on the Veco .19 in the later versions.