WoodCutter

My Feedback: (8)

Hello all....

This is my first post on this forum since registering. I have been a modeler (RC and CL) for over thirty years, but up to now, I haven't been one to participate in "online" anythings.

I design and scratch build mostly small (under .25 size) airplanes. Currently, I'm working on a plane for an Enya .09 RC (bushing)engine I have. It is off of another model that I retired about ten years ago. The engine has about a gallon of Omega 10% fuel thru it. I know I should have added a bit of extra castor to the fuel but I figured it would be o.k. if I just ran it a bit extra rich.

Well now I have it out of it's box to measure it for the mounting beams and I noticed that if I grab the crankshaft and push from side to side, the shaft has a little movement in it. The amount of side to side slop is too small to measure really. If I were to guess, Id say about 1/2 of a millimeter or a little less. There is also a bit of into and out of the case movovement of the crankshaft but I believe that had allways been there.

The compression and rest of the engine's condition are almost like new and I don't remember haveing any running "issues" with the motor when I used it last.


My question to any of you would be if I should consider this a "mid-time" engine that is still serviceable and go ahead and mount it anyway. Or, is side -to -side play an indicator of a worn out bushing that will give running problems in the near future.

I guess I really don't know how much play in the crank bushing is "TOO MUCH" on these engines.

Thanks for any responses, I'll check back later after work


Robert
(WoodCutter)

Mr Cox

A little play doesn't matter that much, in fact it helps to reduce the friction and gives you more power.
If it is really sloppy though you might get problems near idle on an RC engine.
Just run the engine and see how it performs, use plenty of all castor oil (20-25%) in the fuel (you need that for the piston anyway) and it will help to reduce the slop of the crank.

gcb

Robert,

The reason for more lube on these engines is partly for the main bearing. I would suggest upping your lube a bit.

The loose crankshaft should not be a problem unless it is losing too much fuel out the front. This is referred to as wet nosed. It ran fine in the previous plane, it should be the same in this one. IMHO, the Enya .09 is an excellent engine. When the time does come that you need parts, I believe Enya is still making them.

Go for it.

George

cutaway

Bushing engines don't want to be broken in super rich for extended periods. It screws up development of the wear pattern on the bushing creating a (slower running) 4-leaf clover pattern rather than a (faster running) oval pattern.

Mr Cox

I had to look up Omega fuel since we don't have it here, is it 18% oil content and 30% out of that being castor only?
Seems a bit low to me, I always use 20-25% all castor oil in my lapped technology engines.

WoodCutter

My Feedback: (8)

Thank you all for the replies.
I'll just buy a little Castor oil to add to the fuel. I don't know what the local hobby store is carrying these days, but I'm sure it's probably only 18 % total oil.

I will carry on building around the Enya engine as planned then.

Robert

mtntopgeo

My Feedback: (12)

If the crank snout side play is truly 1/2 mm, then I'd say that the front housing is "gone". You're talking nearly .020" of clearence here when you should be down to .001" or .002". If the crank can wobble around that much, I would suspect that the big end bushing of the rod is probably getting in bad shape (any vibration noticed when running the engine?). These engines have a lapped piston (means lots of castor); the piston is a cast iron unit (means lots of castor); AND, as discussed, the crank runs in a bushing (means lots of castor). As MR COX stated "20% - 25% castor". I have been running these old enyas (.09, & .15 size) on 15% Omega. (17% total oil, & 30% of that is castor) I add 1 OZ of castor /qt, & this brings the total lube to 19.5%, with nearly 41% of that being castor. However, for peace of mind, "more castor is better". ............ I've got some parts for these old relics. Check the rest of your engine, (especially the big end of the rod). If all is well, PM me & I'll send you a front housing. (used, but in good condition) N/C. ...... George K.

rcuser004

My Feedback: (287)

Make sure the crank is actually moving side to side and NOT fore and aft. Sometimes it is hard to tell when moving it in your hand. You can also disassemble the engine, push the crank half way into the bushing from the front and check the side play. Enya engines are very well made with excellent metallurgy and I would find it very unusual for the bushing to wear out with the limited usage you indicate.

WoodCutter

My Feedback: (8)

Hello again...
Yeah it's hard to tell how much play there really is. I'm sure there is some beacause I can see and feel it. I was also carefull to note weather it was side to side or fore and aft.

I really don't know if it's 1/2 of a millimeter. That was only a guess. When the engine was last on an airplane, (about10 years ago) I don't remember any running problems or vibration. It wasn't until I examined it closely while building a model around it that I noticed the "slop" in the crank. It is quite possible that it will run o.k. on another plane so I think I'll give it a shot.

I had always known that I should have been running more oil content than I had back then. Truth was that I didn't have any castor and was just too lazy/cheap to mail order some.

Back then it seemed that any good hobby store sold glow engines including small ones like this old Enya.
Now I could kick myself for not taking better care of it before. Compared to what is available today, That Enya is a really great motor.

Thanks
Robert
WoodCutter

rrragmanliam

My Feedback: (1)

Well then, just build the plane, mount the engine, and and run the SOB. It's an Enya and will probably run forever. Slop schmop your thinkin about it too much.

rrragman

Tom Nied

I'm not familiar with that engine but would have to totally agree with rrragman. I bet it runs just fine once you get it going.

gcb

Here are some Enya .09's. Note that the one on the lower left is a IV. That's when they moved the exhaust to the other side.

George