I need some basic info. on Enya .29 engine.
 

I was give a new in the box Enya .29 engine. It was purchased in 1962 for $21.50.

1. Is this a ringed engine?
2. Is this a ball baring engine?
3. There is no back plate to remove, the front of the engine can
be removed from the crankcase.
4. Do I need to be careful when removing the front from the crankcase?
5. What is the bolt between the crankcase and the prop hub on the bottom side for?[/color]

Any general information you want to add would be great.

RE: I need some basic info. on Enya .29 engine.
 

1. No it is a cast iron piston with steel sleeve, use 100% castor fuel, but other wise it operates about the same as and ABC engine..

2. No it is a bushing engine, but I have never seen one worn out.

3. Yes and it doesn't really need a backplate.

4. No not really, just be sure to get the crankpin into the connecting rod. Not hard to do if you position them at BDC.

5. That is for timed crankcase pressure. Each time the rotery valve passes over it crankcase pressure is used to pressurize the fuel tank. Not sure of the value of being timed. Regardless you won't need it.

RE: I need some basic info. on Enya .29 engine.
 

These engines came in either plain or ball raced crankshafts and it's easy to tell what you have. Just take off the prop driver and see if there's a ball race behind it or not. Chances are it's not ballraced though. Also they came in two versions. The early ones had a square intake while the later ones were round. I've got a later 35 with the round venturi but there's no pressure tap screw so I'll guess yours is the square venturi for now. There should be 3 venturis of different sizes ranging from quite small to a very large hole (assuming yours isn't the RC version :) ). If the venturi with the large hole is used then there's almost no fuel draw and that's when the pressure tap has to be used. As Sport_Pilot said, this is timed crankcase pressure and it's quite high, much higher than what a normal untimed pressure is. There should also be 2 cylinder heads with it....I'm not sure which one it's fitted with as standard but one is low compression (7.5:1) and the other is high compression (9:1). Unless you've got the ball raced version in which case it's 9.5:1. Confused yet??? :D

These Enyas take forever to run in but make sure you use 25% all castor at all times and it will never wear out!

RE: I need some basic info. on Enya .29 engine.
 

[sm=stupid.gif][sm=bananahead.gif][sm=drowning.gif][sm=spinnyeyes.gif] Not sure which of these explain my understanding of that last post best. I got a freebee .35 Enya R/C from someone quiting the hobby years ago. I didn't get all of the extra's.

RE: I need some basic info. on Enya .29 engine.
 

First let me thank you both for your information. Sorry I forgot to mention the egine is a model 29-IV TV, which is for RC. I did take off the prop driver and there is no ball race behind it. This version has the square intake (venturi). Yep I got two cylinder heads with it. The information that was provided with the engine states... the head that came on the engine has a compression ratio of 5:1. the other has a compression ratio of 9:1.

Thanks again. I hope to have it up and running soon

RE: I need some basic info. on Enya .29 engine.
 

Throttle,
A few more tidbits:
1. Break-in should start with a series of rich two minute runs on a bench. Each run should be followed by complete cool down. This is called heat cycling and enhances the fit between the iron piston and steel cylinder. Every few runs turn the needle a few clicks leaner. If during a run it starts to slow down, stop it, let it cool, then continue a few clicks richer. When it will run at a lean setting without sagging (slowing down), it is broken in. If you break it in properly, it will reward you with many, many hours of use.
2. They run smoother with the low compression head.
Good luck with it.

George

RE: I need some basic info. on Enya .29 engine.
 

Thanks gcb. I had read a previous post by you dated 12/1/2003 describing the braken procedure. I even printed it out. I was wondering if I use all Castor oil and if so what % should I use? I have herd some say as high as 25%. That seams like allot.

RE: I need some basic info. on Enya .29 engine.
 

Just run for a half hour or more at a full four cycle mode. Never break in this engine running leaner than a four cycle mode. If you are running that rich you don't need to let it cool down. You cannot temper cast iron or steel till it gets above 350 degrees preferably above 600, at that point the engine is burned up.

RE: I need some basic info. on Enya .29 engine.
 

Throttle....use a MINIMUM of 25% all castor and even up to 29% (Fox fuel). Don't let synthetics anywhere near it :) With the Enyas the chances are it won't be run in for several hours but then it'll last a lifetime. This is no joke, given proper treatment these Enyas have the reputation for being just about the longest lived engines ever made.

RE: I need some basic info. on Enya .29 engine.
 

Downunder is quite right about using an all castor based fuel. Do not let any experts tell you differently. I have several 50 year old Enya 29/35's and they are all running quite well.
One of the problems with the Enya was they were made out of some of the hardest material ever used in a piston and liner and really do take almost forever to break in the motor. Follow all the break in info that you have been given and take your time with it.
Incidentally these are old style baffled piston designs, as such they are not high revvers. They hit their best power at about 11k. best prop is a 10/6 use a HOT plug

RE: I need some basic info. on Enya .29 engine.
 

Thinking the 9-7 or 10-5 might be better for the .29.

RE: I need some basic info. on Enya .29 engine.
 

Most of my tech info comes from a .pdf file I've got which lists just about every Enya engine made up to the 60X. For the RC version the prop sizes recommended range from 10x4 to 11x6. Rev range is 2000-13000 and puts out .5HP but doesn't say at what revs although I'd suspect close to that 13000. If I remember right they've got a very small bore carb so muffler presure isn't necessary.

When used as CL though things were a bit different. The large bore venturi gave .8HP and the rev range was up to 18,000. They were used to good effect in class B Team Racing up against the ETA and McCoy racing engines. And I've just remembered that somewhere I've got a ball raced version...all I have to do is find it now :D

RE: I need some basic info. on Enya .29 engine.
 

Boy thinks again for all the information and post. I will get fuel with a mim. of 25% Castor oil. Will use a 10/6 prop because that's what I have at hand for break in. As for break-in procedure I will run sloppy rich (4 cycle) for an hr or so then start leaning out a little at a time if it sags I'll let cool down. I believe in compromise when there is a conflict of views. Since this is a RC engine it has a venturi with a very small carb. What a great hobby model planes are!

RE: I need some basic info. on Enya .29 engine.
 

Remember that you cannot just start it up and let it run rich for a hour that will do nothing and just count as one run in the break in procedure. It must be allowed to cool COMPLETELY between runs. This is tedious work and explains why ABC motors are popular. Unfortunately ABC motors are either breaking in or wearing out. They don't stay on top very long. Dennis

RE: I need some basic info. on Enya .29 engine.
 

This accomplish's nothing, except to evaluate the change in cold compression. I recall running a full quart of fuel on one run. It was broken in or very close to it. Ran like a champ. Still have that engine and ran it a few weeks ago. A Fox 35 Stunt. Breaking in is a matter of running it in without overheating it. Nothing more. All of the rest is just to avoid overheating it, or else of no added value.

RE: I need some basic info. on Enya .29 engine.
 

Actually thats not true. Yes the motor might have run like a champ but it's not broken it. If you have a more recent Fox 35[50th anniv model ] it's fit up a little looser then previous models and will hold a setting faster then the older ones. however it still needs a fair amount of careful running to realize maximum lifespan. And remember it dosn't take too many lean runs, broken in or not ,to ruin the fit.
In regard to the Enya though it does not have the luxury of loose fits and I've not seen one that would run well after one run on the bench.

RE: I need some basic info. on Enya .29 engine.
 

Sport_Pilot,

I mean no disrespect but I think you are wrong.
An iron/steel setup does not have to temper, it has to anneal. You are removing milling and other stresses imposed by manufacture. The heating/cooling process is called heat cycling. The amount of time accumulated is not as important as how many heat cycles. Two minutes plus cooling produces one heat cycle. Two hours plus cooling produces one heat cycle.
And yes, as you smooth the surfaces and progressively increase RPM you DO go into two cycle, being careful to not run over-lean.
There are other ways of doing it but this process has served me well since the 1950's.
ABC, etc is a whole nother ball game. They do very little heat cycling. That's why they break in so fast.

George

RE: I need some basic info. on Enya .29 engine.
 

Have you annealed steel or cast iron? Well let me tell you the process. You heat the metal in a furnace till it is red hot. You stick a pole with a swinging magnet on the end to the iron, if it is attracted to the metal you heat it up some more, if it is not attracted to the metal then that means it is above the magnetic line of 1450 degrees F. You prepare a box full of gypsum and lime and quickly place the metal in this box, add more gypsum, and let cool for a day or too. To harden metal you do the same thing except you quench the metal in water or oil. Then you temper it by heating it to 600 degrees and let it air cool. You will temper it several times. Our engines will be sitting in a pool of molten aluminum and brass if we heat the metal up enough to anneal the iron piston or steel sleeve. You wouldn't want to anneal it in any event, the steel sleeve and piston would become very soft, the steel may be almost as soft ar copper. It wouldn't last very long.

RE: I need some basic info. on Enya .29 engine.
 

The proper procedure for running in a cast iron piston and the reasons behind it were discovered by the CL team racing guys with their diesel engines where the fits have to be very precise. Unfortunately the web page no longer exists (or has been moved somewhere) so I'll sum it up.

Fresh cast iron is softer than steel so long as it doesn't get too hot then cooled. This allows the softer piston to lap the harder steel liner without wearing itself. Running slobbering rich keeps the piston as cool as possible and extra oil helps avoid localised hot spots from friction. After the lapping process is finished, shorter and leaner runs with a cool down begins hardening the piston and as it's hardening it also grows slightly. This growth may not be as noticeable in a glow engine where the fit isn't as critical as it is in a competition diesel but why not make use of it?

Cast iron will still do all this even when not subjected to heat cycling as happens in an engine although it takes far longer. High quality (older Rolls Royce for instance) raw engine blocks and rough cast surface plates will be left out in the weather for a year or so to stabilise them before machining.

RE: I need some basic info. on Enya .29 engine.
 

Downunder, I know that the ageing of cast iron is another myth started by auto machinest and junk yard salesmen. I suspect that cast iron growth is another myth. Sounds like some winning C/L racers guessed why their break in worked, then their word was repeated as gospel. Most likely the growth is a build up of oil varnish.

RE: I need some basic info. on Enya .29 engine.
 

downunder, try: http://www3.bc.sympatico.ca/dieselco...ut_diesels.htm
Remember that diesel fuel uses kerosene where glow engines use alcohol. The kerosene provides much better lubrication so I think it may not work exactly the same way...but close enough. I have used their process for diesels ever since I read it several years ago.
Back in the dark ages (1950's) modelers debated on whether an engine (iron/steel) needed break-in. Most CL guys said yes, most FF guys said no. The FF guys were starting their engine, peaking it out, and letting the model go. Run time a minute or so. They were essentially heat cycling the engine as described above.
I believe the cast iron is referred to as being "green" before the stresses are relieved. I've heard that in the USA, cast iron engine blocks are (or were) aged for two or three years before final milling and processing.

Sport_Pilot, you must work on some BIG model engines. :)
I know my break-in procedure works for me. Feel free to use your method on your engines.

George

RE: I need some basic info. on Enya .29 engine.
 

GCB,
The FF were simply not running the engines long enough for the heat from the friction of the tight fit to be a problem. I have run into several lapped engines that did not need any break in. Many of the newer lapped Fox engines need little to no break in.

RE: I need some basic info. on Enya .29 engine.
 

As far as the cast iron age strenghting, I guess I will have to eat crow on this one. When I was in school I recall studies showing that this did not occure or that the statistical data did not prove that it did. At the end of this article I see that some cast irons do not age and others do depending on the nitrogen content.

http://www.moderncasting.com/archive...402/99-191.pdf

FWIW doubt it's going to make a huge differance on how we break in our engines.

RE: I need some basic info. on Enya .29 engine.
 

gcb.....that's the link that got changed...thanks for that :D

RE: I need some basic info. on Enya .29 engine.
 

Exactly! For CL (my primary interest) you run them long enough to encounter thermal runaway when the piston expands faster than the cylinder. By starting the heat cycling process rich and progressively leaning out, you control the heat, which allows the piston/cylinder to polish the surfaces, including any stresspoints caused by iron growth.

Although they will run without break-in, by spending the time you may maximize the useful life as well as performance of the engine. I use this time to "get to know" how the engine operates, ie. how much to prime, the best way to start it, etc. I consider bench time well spent.
Some engine manufacturers use methods such as tapered bore, tapered piston, or both, to cut down friction except at the top of the stroke. These all hasten break-in time.
One of the older iron/steel engines (Orwick, I think) had break-in instructions to run it until it seized, let it cool, then run it again. When it ran without seizing it was considered broken-in. BUT, it used a sintered iron piston, not mehanite (hope I spelled those correctly).
Still, there is seldom only one way of doing things. Many have had great success with various methods. Whether you need to break-in an engine is a definite MAYBE. :)

George