Problem breaking in Enya

Hi

I'm breaking in an enya .15. It's taking a while.
Set up a 500ml bottle as a break in tank. Ran rich
for 20 min or so and have been leaning it out ever since.
The engine has done around 3 hrs now, 2 hrs as lean as I can go without the engine quiting. Problem is, after a few minutes at peak revs it still gets tight, looses power and quits.

Someone told me enyas took a lot to break in and only break in fully in flight. I'm reluctant to put it in a plane yet as it's likely to quit as it leans out.

I'm using a 8x4 prop, should I try to get the revs up with a smaller prop, maybe 7x4 for breaking in?
What are the expert suggestions?

Also I notice some bubbles collecting in the back of the head gasket slot. OK before jumping to conclusions, the head bolts are tight and the compression is better than any engine I ever owned hot or cold. Put it on TDC and come back whenever you like, it still has compression. Havn't left it overnight though.

Could the bubles be oil collecting in the gasket slot and boiling or should I be worried?

First question to be asked - what fuel are you using?

Tony

Fuel is 20% caster 80% methanol, the old FAI 4:1

>I'm using a 8x4 prop, should I try to get the revs up with a
>smaller prop, maybe 7x4 for breaking in?
>What are the expert suggestions?
>
>Also I notice some bubbles collecting in the back of the
>head gasket slot. OK before jumping to conclusions, the
>head bolts are tight and the compression is better than any
>engine I ever owned hot or cold. Put it on TDC and come
>back whenever you like, it still has compression. Havn't
>left it overnight though.
>
>Could the bubles be oil collecting in the gasket slot and
>boiling or should I be worried?
>
>
>Regards,
>Ken

Hi Ken, The 8x4 is fine... REPLACE THE HEAD GASKET NOW! Okay, I
won't scream again...also as Tony E. implies, use an appropriate fuel
that is, a fuel with some Castor oil in the lube formula. You likely
have enough run time on the engine to use an 8x6 or a 9x4 prop for flying. Best Regards; Tony G.

What model is it,mark 3 or 4.

Ken:

Put the engine on a plane and put it in the air. Back the Needle off from full lean about a quarter turn, this should allow the engine to run out a full tank without overheating. Might even be too rich once the engine unloads, if so lean it a click or two for the next flight. The engine won't be producing maximum power but should be able to fly a 15 size plane without any problem.

With 3 hours run time you probably have less than a gallon of fuel run through the engine. Depending on the fuel and how tight the engine is I wouldn't expect it to be fully broken in until it has burned 2 to 5 gallons, last one I did needed more than 2 gallons. Since this is a lapped engine with bronze bushings the ideal fuel during the break in period would be Fox Superfuel, afterwards I'd run at least 23 % oil, mostly if not all castor, and high nitro won't be a problem.

Real nice engine, once broken in it'll last forever, as long as you use plenty of oil. With 16 - 18 % synthetic oil as is common in a lot of fuels the engine will sag badly.

Typical Enya. It's like trying to wear out a Toyota Camry.

If you think breaking in an Enya 15 is bad, try an old sandcast Enya 60. Many hours...

I'd go ahead and mount it, run it rich, and with, say, a one to 1.5 ounce tank.

Ken,
If you still want to break it in on the bench, run it for a series of two minute runs followed by complete cool down. It is the heat cycles that break it in, not continuous running.
Enya once ran a new Enya (.19) for something like 300 hours continuously. After that they broke it down and re measured it. The only wear was from breaking in prior to the extended run.
Of course in actual flying conditions we have dust, lean runs, crashes, etc. that wear them much faster.
I like Enyas.

>Ken,
> If you still want to break it in on the bench, run it for a
>series of two minute runs followed by complete cool down. It
>is the heat cycles that break it in, not continuous running.
> Enya once ran a new Enya (.19) for something like 300 hours
>continuously. After that they broke it down and re measured
>it. The only wear was from breaking in prior to the extended
>run.
> Of course in actual flying conditions we have dust, lean
>runs, crashes, etc. that wear them much faster.
> I like Enyas.
>
> George

I think that I posted this before but it's always interesting tidbit about Enya durability.
A friend of mine since departed bought a new Enya 29 5224RC and put it on a suitably sized ugly stick with the intention of breakin it in his way. His way was to start it up and set it to running speed fly it till it siezed and stopped. He did this for quite a few times and I figured the motor was toast. Anyhow the thing ran for years and was a consistant one or two flip starter. I still have the motor and it is still a consistant performer. Go figure. Says volumes about the durability compared to other motors particularly OS, Oh yes Fox too.
Dennis

LAST EDITED ON Mar-15-04 AT 08:02 PM (CDT)
 
Heat cycling, 2 or 3 minute runs with cooling between, will get the breakin done quicker, per George's post. Is this what you are doing? I hope so. Steve

>Hi
>
>I'm breaking in an enya .15. It's taking a while.
>Set up a 500ml bottle as a break in tank. Ran rich
>for 20 min or so and have been leaning it out ever since.
>The engine has done around 3 hrs now, 2 hrs as lean as I can
>go without the engine quiting. Problem is, after a few
>minutes at peak revs it still gets tight, looses power and
>quits.

It is the shaft tightening up and it never is going to break-in, no matter how many gallons of fuel you run through it. Sorry.
Get someone who knows what they are doing to hone the bush out a little so there is a slight rock in the shaft.
with regards

Hi

Thanks for all the replies.

It gets tight at TDC so I guess it's the pistons getting tight.
I took the plug out immediatly after it stopped to confirm this.

I think I'll try short runs on the bench and see if that improves matters.

On the head gasket, I guess it's best to replace it just in case but I don't understand how it can hold compression for more than an hour if the gasket is leaking but then again, how to explain the bubbles?

It gets tight at TDC so I guess it's the pistons getting tight.\

Ken,

It is meant to get tight at TDC!
The problem is still the shaft fit and this is not unknown in Enyas.
Here's the test:
Run the engine on an 8x4 (max) prop on a good fuel with minimum 20% castor. Lean it right out.

Stand behind the engine and reach under, placing your index finger under the front housing.
If you can keep your finger there and the engine still overheats and stops, it is not the shaft!
The engine is never going to be any good, so do yourself a favor and bin it!
If you can't keep your finger on the housing, it is the shaft bushing.
Get someone to rectify the fit as I have suggested. Pity GMA is no longer with us, as he would hone it for you.
If you can't find anyone to do the job, contact me offline.
regards