MR Flyer57

Thank you for all the information so far, but it seems I still need to tap the knowledge base here again,,, if I may.

I have a enya 1.20 that is giving me fits, I got it used on a large airplane and it ran but not well. I mothballed it for a while and now I need it for a large Cross Country Contest.

My Question is this: Is there a head gasket used on this engine?

I have completely disassembled it and cleaned it, checking all the parts. When I put it back together I noticed that the intake valve is striking the piston at top dead center when beginning the intake stroke.

I was worried that it was the valve timing, so with help from folks here, I got that set correctly. I have checked and rechecked everything and I don't think anything is out of time.


I believe that the clearance problem can only be due to a missing, though very thin metal head gasket that has been lost sometime before I got the engine.

If this is true then I really do need a little help! Does anyone have or know of someone who could sell me one?

If not could anyone measure their head gasket for thickness and post it here? With that information I could have someone in our club mill me one.

I would also need to know what it is made of, if you can tell.

Does anyone know if there were different thicknesses, for changing the compression ratio?

If there is no head gasket used on this engine, does anyone have any ideas as to why there would be a clearance problem?

I am not sure what vintage the engine is, I didn't see any markings except the 1.20 4c on one side of the cylinder and Enya on the other.

Thank you all in advance for any help with this engine.

MR Flyer57

TimC

MR Flyer57, I notice in the text of the section of the manual I posted in the other thread that the 1.20 is shipped without a head gasket, but one is included with the engine for those wishing to use higher nitro. I wouldn't think the lack of a gasket ( if it is missing) is causing your clearance problem. I have the manual for the non-R engine that I could email you if you wish. There are some members here at RCU that are very skilled with Enya four strokes and maybe one can help you with the valve clearance problem. Does your 1.20 look like this?

William Robison

My Feedback: (3)

Flyer:

Most Enya engines have the cams made in a manner such that the inlet and exhaust cams can not be switched side to side. But not all are made that way.

If you have a valve strike condition, and you are SURE the timing is correct, you may have switched the cams. Otherwise the inlet cam has to be out of time – properly assembled and adjusted, the valves will not strike the piston, even without a head gasket.

Bill.

MR Flyer57

Thank you again for the information.
I think that I might have gotten it fixed. My guess is that the cams are not exactly the same, or maybe I got the timing off a tooth. What ever the fix was it seemed that when I opened up the engine for the photos, that I reversed the cams or got the timing adjusted because I cannot hear or feel a contact now.

Here are the pictures of the little demon, well I hope it has been tamed now. Or should I say, I hope I have learned enough to allow a great engine to run!

Please look at the pictures (such as they are) and see if you agree with the cam timing. Also I could not see or feel any difference in the cams, but when I exchanged their places, the clearance problem was gone.

There is a picture of the cams at 180 degrees off to show how the marks line up also.


Thank you very, very much for all your help. I will be putting this engine on the test stand and will update you on what I find out.


MR Flyer57

William Robison

My Feedback: (3)

Flyer:

If you have the cams installed with the timing marks as shown in your first picture I can almost guarantee the two are switched side to side. With the marks aligned the lobes should be positioned approximately as shown in your second picture.

Bill.

William Robison

My Feedback: (3)

Flyer:

This is roughly what they should look like when timed properly. Ignore the overlap of the gears, yours is an older model.;

Bill.

MR Flyer57

Hello Bill,
The pictures are of the 1.20 at tdc on the power stroke and tdc 180 off at the end of the exhaust stroke. The timing is set the same for each picture, I just turned the engine over until it was at tdc and took a look at the timing marks. It seemed that the marks were at a place where some knowledgeable sage might be able to tell if I had missed the timing marks.

The lobes on the cams look a little off from the timing marks (one looks a little more advanced) in the picture, as you pointed out. That might be the answer to why I had contact even with the marks set correctly. Having one of the cam lobes off by a few degrees would cause the strike that I had encountered.

I had been looking for a hight difference not a timing difference, but I still didn't see any markings that would designate one for the intake and the other for the exhaust.

I have included the cam timing information the TimC had so kindly send me in my last cry for help. (thanks again Tim)

Thank you for your interest and help, I'm sure that this is not the end of the story or the last of my questions.

You guys helping is what this hobby is all about, and being on the receiving end makes me very humble. I am deeply in your debt.

Thanks again for everything.

MR Flyer57

MR Flyer57

Hello again Bill,
That's very interesting and I will try that setup to see what happens.
I was not aware that they would have two completely different cam timing setups, one newer than the other. This engine is indeed an older one, but I have no idea just how old.

Thanks again for the information.
Marshall

William Robison

My Feedback: (3)

Marshall:

You have what I used to call the “Fat box” Enya, the version in which the gears do not overlap. All of them could have the cams switched if assembled carelessly.

And TWO settings? Not so sir. Even on the later ones with overlapping gears there are three different timing mark sets for normal rotation. You have to know exactly which engine you have to know the right way to put it together. Then add that all Enyas can be timed in another different way to reverse the rotation. Much fun.

Your engine, with the marks aligned and the piston at TDC, should have the lobes pointing out and down as seen in my drawing. After one full turn of the crank, and the piston at TDC again, the lobes should be in the position shown in the drawing you got from TimC. The marks though, will not align again until the second full turn.

Bill.

MR Flyer57

Wow!
So much more than I had bargained for!
I wonder what a guy would do if not for some experienced folks that could be reached here on-line?
My guess it would run as before and go into mothballs again, maybe for good. Thanks for the lesson, and if there is anything else you think later, please fire off a line or two.

I will test this engine a little later today, so I'll keep my fingers crossed!

Thanks again,
Marshall

MR Flyer57

Just a quick follow up on the 1.20.
It still won't run correctly, but it is an inconsistent run that makes me think that there is an air leak. I will tear down the carb again and see if I can find anything.

About the Cross Country, I had to go to a back up plane. It was tragic, my battery failed and it destroyed it's self in a crash.

This is the first time I haven't finished, but I was the only one who lost a plane in the event, so I guess you win some and you loose some.

Marshall

William Robison

My Feedback: (3)

Marshall:

Your engine should have a paper gasket between the intake pipe and the cylinder head. In the earlier picture you posted I see no sign of the gasket. If it’s missing you could easily have a leak there. You can cut one from thin gasket material, or possibly a smear of silicone seal would do the job it the flange is flat where it bolts up.

Also, as you insert the pipe into the carb you should feel the o-ring in the carb body sliding on the pipe. If you don’t the o-ring there could be leaking as well.

Bill.

NM2K

My Feedback: (14)

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I had an Enya 80-4C that could not run an OS Type F plug without an extra plug gasket in place. The piston would strike the glow plug tip without the extra gasket. Could this be the problem?

bla bla

Oh yeah Artisan... you've definately hit the nail on the head here.
The F type protrudes far further out than an Enya Nr3.
I'm putting my money with the old man on this one.
Come and tell us what plug you're using beause the cam gears look fine.

William Robison

My Feedback: (3)

Ed:

Look back in post #4. What he shows there is definitely a valve strike. It's not in the right position to have been the glow plug.

Bill.

William Robison

My Feedback: (3)

Bla-bla:

Look at this picture. It's the same one I mentioned in my last post, but I've added arrows pointing the the clearance cuts for the push rod tubes. The glow plug goes in the opposite side of the cylinder, if it had hit the piston the mark would be somewhere around where I put the red hatching.

Bill.

bla bla

Yeap... looks like I've just lost the holiday money Honey!!!

MR Flyer57

Hello Bill,

Thank you all for your help.
This engine has been running weird for a long time and the list of things that could be making it run badly is long and it will take some time to run them all down.

I have been through a bunch of glow plugs, and keeping them from striking the piston has not been my main concern, though it will be now. My concern was making sure it stuck down far enough to be in the compression chamber. I have been watching the length of the plugs, and I don't think I have had any strikes there.

I do have an original paper gasket between the intake manifold and the head, I just didn't include it in the picture. I also have made new gaskets as replacements for the other places needing gaskets, but none of these seem to be critical as far as needing to be air tight.

I am concerned about the intake manifold to carburetor "O" ring. This looks like there has been a lot of pressure applied to one side of it. By that I mean that while looking into the carburetor you would be able to see a difference in the way the "O" ring was sitting, suggesting that the manifold may not be centered and might be (my worry) off set beyond the rubber "O" rings ability to seal.

The part I don't know and would like advice on is the carburetor. In some of them the spray bar is not solid and is moved to adjust the idle rich setting. This is an air bleed so that should not be a problem. My questions are:

1. Is there any way for air to enter incorrectly, other than the needle threads, or the barrel end?

2. Is there a chance that the spray bar is not sitting correctly? Is it even possible to put it in incorrectly?

3. is there something I'm over looking that would make this engine run inconsistently on the top end and refuse to idle, and just die when it is idled down?

Thanks again for your interest and help,


MR Flyer57

PlaneKrazee

My Feedback: (14)

Your engine cams are the same as my Enya 155. You have the larger R-120 not the small one and it is not timed the same. I believe it is like the copy Bill posted. I will get the timing info and scan it.

Your carb is a very special metering carb and the engine will run best with the low end richer than you would think it should be set. There should be a small black rubber seal around the needle, if not you can get one from MRC for about $.98.

You set the "bleed screw" half way open, start the engine, let it warm up, throttle up and set the high speed needle. Bring it down to a idle, set the low speed screw to give good transition abd raise the idle trim if required.

I always run a Enya #3 in a Enya four stroke.

If you are afraid of an air leak clean the parts with alcohol and use a tiny amount of high temp copper silicone to seal the joints. You can wipe a little silicone around the carb to intake pipe joint after it has been assembled.

PlaneKrazee

My Feedback: (14)

Also the cams are interchangable. When working on an older engine I'll lightly highlight the marks by taking a little 400 grit paper to make the punch marks more visible and then use a good light source so I can see what I'm doing to set it up.

How is the compression? Do you think you bent the intake valve?

William Robison

My Feedback: (3)

Marshall:

It is entirely possible for o-ring in the carb to have hardened with age, and not be sealing properly. I don’t know how old you are, but unless you’re an old duck the engine (and the o-ring) could be older. Thankfully, most larger hardware stores stock a good supply of o-rings so replacement shouldn’t be hard.

A thin smear of RTV on both sides of the pipe gasket might help also.

Sky has some good suggestions in his post, but I prefer a new o-ring if it’s in question. I agree with his suggested #3 plug.

One thing many “New” Enya owners mess up on is the fuel. Use zero nitro, or no more than 5% nitro blend. And get a fresh jug to try. Old fuel also gives many strange problems.

Bill.

PlaneKrazee

My Feedback: (14)

Bill,

Good call on the need for low nitro also.

NM2K

My Feedback: (14)

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Yep, can't argue with that photo. I must have skimmed and missed it the first time.

MR Flyer57

Hello Skypilot_one,
Thank you for the information, I will try the sealer and take a look at the timing info if you get it scanned.
I did use Bill's timing information to set the timing for the cams, and it does look like that should be it.
I read RC Report, and the guy who writes the "oily hands" column had timing four cycle engines as his theme this month. It really helped, because even though I know a lot about four cycle engines (the larger kind) it was a great refresher to get to read his column.

Thanks again each one of you who have taken the time to respond, it is very helpful.
MR Flyer

eclecticant

My Feedback: (10)

william Robinson
I have to used but gone thrue Enya 120 & R 120 can i use them with know pressure lines in large gas tank planes

KEN