Ok all I think an important point has been missed here. Greg, Jens, Andy, and most likely a few others out there that do not post on the forum. have the skills and machine tools to "fix" the Enya 4 stroke diesel ( well maybe not 100%) for most operating conditions and convert other 4 strks . Most modelers expect to take a product out of the box and it works. Enya did not do this with the 41CD having the compression high enough to start with and using adjustable compression instead of a blocked off glow plug really is a little hard to believe for a $300 engine. It should arrive that way; really should be out of the box and go without you horoscope being right and the stars lined up in the right position
and Mr Davis does deserve a lot of credit for his efforts over the last 32 years or so take a decent glow engine 2 stk,
remove 4 or 6 head screws bolt it (conversion head) an instant diesel no hassel, and yes there is always some that cannot properly adjust a compression screw let alone a carb but most figure it out reading directions help too any engine gas, glo or diesel
As I stated before have lots of Davis heads, irvine diesels, MVVS diesels. PAWs, and the enya 11,15,25 diesels which are great
bottom line they screwed up on the 41
martin
and yes some of the classics paw. small MVVS do have a contra in the cylinder which will sometimes hang up
but loosenig the screw of the top it will pop up as it runs and you can adjust, only proplem I had was my MVVS 15 that was so stuck had to take engine apart and drive out with a dowel and hammer after I got it back together it did not repeat
the problem contra in head still a better idea

Good news!!!

I has raised the compression ratio to 1:18.97 and the Enya 41-4CD ran much better and faster as normal diesel engine will do it.

Maked special tool to keep the cylinder head then fastened to face plate at the lathe and used the scriber to find center of cylinder head before removing of material.

I has removed so much material until the surface are in same height as edge of the valves, measured combustion volume with syringe without pump (the pump jammed) and a plexiglass dish with hole. Measured to 0.17 ml (only in cylinder head), total volume in combustion camber 0.35 ml (before 0.29 ml , total volume in combustion was 0.47 ml).

Tried with 2 gasked, the engine ran a bit better, removed all 2 gasked and tried again, the engine was much easier to start and run much better and fast. Nothing hard sound as knocking or engine are oscillating of overcompressed compresion. Also the engine are normal running with improved compression adapted for the fuel formula from Enya instruction.

Tested both in +20 degree and +8 degree in case i need more or less comression if i am using same fuel formula, nothing problem to run the engine with compression ratio at 1:18.97, idling ran well (before idling was impossible with compression ratio at 1:14). Checked cylinderhead for carbon build up, there are very thinn carbon who are indicated the combustion are good.

Tomorrow i take the movie of the engine running and will be posted in Youtube..

Mr. Ken Enya has much to learn of me (Motorboy), Greg (gkamysz) and Brian (Capin) how to make better 4 stroke diesel engine with adjustable compression.

Here are picture..

Excellent Jens, what prop did you use and what rpm did you achieve, Thanks, Dave

Jens congrads on this one, Brian and Greg and you have spents lots of time on this and of course a few years back
Bob Davis makes a lavona cell for an over compressed saito 80. worked fine I understand Laser had a 4 stroke diesel that WORKED
but it is no more too bad. All of you like challenges and solve the problem. The basic fact still remains the 41 in its present state should not be on the market. Ken Enya does indeed have a bit to learn something to be said for USA\and European know-how. martin

Martin, do you think Bob would part with the one he has? Thanks

Will ask him tomorrow I just got the OS 108 tonite 9PM looks in great shape Bob has a head for me just turned out 2
he had a sale for one and figured I would get it he guessed right after messing around with the smaller stuff this thing is big compared to my ST90 which is as large as I went
who out there in diesel land is running one of these conversions prop size you are using??

Great Jens! Did you get a new lathe? It looks bigger than you pictures from a couple years ago.

Martin, that ought to be good for a 15x8 to a 16x8.

Seems like they mis-machined Jens engine. Lucky for him he knows how to remedy the problem at home. His combustion chamber volume measures out about the same as I mine, as far as I am able to measure . (Mine looks like 0.33ml using one thin gasket.)

It may be just luck, but my new Enya 41CD TN continues to start easily and run well. It loves the 15x4 I tried on it yesterday.

Bone: Thanks for the magazine article! THe only thing I think he got wrong is claiming that the cylinder is not tapered. When you rotate it feels just the same as turning over a new lapped 2-stroke. It is tight at the top and "notches" past TDC.

No, Bob won't part with the decompression chamber thank you, if he had back 20 years ago it would have been put on the market as a product. Again, I am try not to put down the spirit of invention as that is what got me started, but fella's this forum is getting to look more like a machine shop course on how to make an engine and that is not its function. This forum is to encurage models into trying diesel as an easy more reliable system to power their plane, boat or truck. Remeber anytime you have less parts there are less parts to go wrong like in modeler parlence the best glow plug is no plug. This forum is to help models succeed with their diesel engine and to share good expreiences with fellow diesel freeks. The reason we never brought out a four stroke diesel kit is because you could not just bolt it on, the Saito 80 was a mistake in disign so I made the decompression chamber to make work because I bought it and did not know what it was I was getting. It was latter cleared up by Saito with a extra gasket to put under the jug. In this case were Enya put this thing on the market it should have been rejected by the reviewer as a bad idea who's time should not come and it would have been pulled from the market, remember the products you buy are expected to work with minimum effort and are not put there to turn you off or to make you resort to becomming a machinist. Nuff said on this subject those that must write private emails to each other.

Something was brought to my attention the other day regarding a booklet sold on Ebay about how to start and run your diesel. My friend read me the first few parts to the book and I was very troubled by the miss information. In the book the writer tells the modeler to set the carb. just above idle then proceed with the needle and the compression. If you put your diesel at just above idle you could spend the rest of you life trying to start it you must always set the carb. at 1/8 to 1/4 open just like glow. Another statement was to backoff the compression after you are finished for the day. The reason we did not put a handle on our system is so once you set it the idea was to try to forget it for as long as you had to. Diesel is supposed to be as close to set and forget has possible. For those that have lost their directions or don't read the foreign language their written in please don't guess our offer always stand send us $1 and a self-addressed envelope and we will send you our diesel operating instructions, which have evolved over these past 32. years.

P.S. LM Cox sold millions of control line airplanes each year through department stores toy departments. what they did was turn off millions of potential modelers and make people think that all model airplanes and their engines were toys. If a potential diesel user were to com on this forum he would think you would have to be a machinist to redisign your diesel engine to make the dam thing work and he would move on.

Personally I love the machine shop photos and think they are great for those who are interested. The begginers don't have to look at them if they don't want to. Actually thease people on this forum are the best place for a begginer to come to learn. That is what I did...

DDD quote "Nuff said on this subject those that must write private emails to each other. " What does this mean? Is this post being closed? Why does it bother you so much that there are people modifying and building and sharing engine info? Isn't that what you did? Seems to me that since it is called EVERYTHING DIESEL that all of this stuff is fine.

Bob, why does an individual need to buy instructions from you for something you already made money on? All the engine manufacturers put their operating manuals online. Buying an engine and converting it to diesel isn't exactly turnkey. Why didn't you never bring out your own engine line?

Fact is that most people who run diesel can do their own machining. And many people who can build model engines, build diesels. Diesel IS tinkering. Many modelers are tinkerers and those that aren't, stick with the simple stuff. I honestly think one attracts the other. Jens once suggested a model engineering forum here, I would be there if they added one.

I tached the engine with 13x6 at 7380 rpm, 0.492 hp and static thrust LB at 4.40 and other propeller 14x8 5010 rpm, 0.276 hp and static thrust LB at 2.73

Fuel are without MEKP.

The pic. of blindplug show the carbon build up who mean the combustion are good enough.

Here are all 3 movies of the Enya running..

http://www.youtube.com/watch?v=lCSGvyUnU68

http://www.youtube.com/watch?v=FTmmTLAsEas

http://www.youtube.com/watch?v=XmnMW52WUbk

gkamysz, yes, i has bigger lathe, bed to center 250 mm and from chuck to tailstock 550 mm. Made in China, well made lathe.

Jens Eirik

Jens, thanks for the video on the Enya 4 stroke diesel. How long will the Enya run on 28 cc of fuel with the 14x8 prop? Jack

Wow... amazing work Jens!

But do they all come from the factory the way Jens got it, or did they really just slip up on that one? Strange...

MikeG4936 wrote:

As shown in earlier posts, my engine measured out differently than Jens, and runs great right out of the box. Beginner's luck?


Some expert diesel modelers seem to fear that a bad first experience with a diesel will sour a modeler to glowplug-free flying. It seems to me if newbies come to forums like this one and see senior (take it either way) modelers rant, flame and "foam at the mouth" against a new model of engine that they have not even tried first hand, well that could also be a turn-off. Time will tell if this new Enya diesel is a lemon or not. Why get so upset? I come to these forums to learn more about diesels and enjoy the fellowship of flyers and other engine fanatics. We are all in this for fun, are we not?

I took the head off mine today. It measures 20.05mm. The recess for the liner is .5mm. The combustion chamber volume is as before.

One thing I did notice is that it is extremely tight at TDC with the head installed with the plug removed. Without the head on there is only a slight pinch. How are your engines?

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This is exactly what I was thinking, since at least one other poster said that his worked fine right out of the box.


Ed Cregger

Same here i get tight at TDC, the sleeve are little to soft to be formed of pressure of cylinder head. But it must be a little tapered sleeve to keep compression when the engine are cold. When the engine get work temperature, the sleeve will expand more, there are very little leakage. It is neccesary to get oil lube to go between sleeve and piston, text way are to lube moving parts in crank case.

Jens Eirik

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Because paper, printer ink and postage cost money. Does anyone seriously think that Bob is getting rich from his DDD efforts?

While I understand your sentiments from the intellectual property side of the issue, generating, handling and postage are very real costs to any business.

Yes, posting the instructions in PDF form on his website would be an excellent idea - depending upon whether he does his own web page maintenance or not. If not, again, expenses enter into the picture.


Ed Cregger

www.quigleyquotables.com

This has been quite an interesting thread.
I am both a designer/manufacturer of model products, and a diesel aficionado. From the information in this thread, it appears that Jens' engine has been assembled with the wrong head, or the head was mis-machined (did someone at the factory mistake 21.0mm for 20.1mm?)
My questions now, in view of the spate of autocongratulation in this thread, which more or less drowns the opinion of those who are happy with the engine :
Has anyone fed this information back to the factory, with sufficient detail that the mistake will not happen again?
Has anyone asked Enya what the design head size is?
I mean that, in Jens' position, having fully ascertained the cause of the problem, I would certainly already have contacted the manufacturer.
I for one at least sent an email to Enya with the URL to this thread.
As a designer, prompt and proper feedback is something I seek avidly, especially when a new product is launched (By the way, my "day" job is about technical support for maintenance engineers, repairing printing machines).
This is how any mistake can be corrected early in the product life.

www.jmp-solutions.com

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I'm with you, I like the machine shop photos and talk too, but we should periodically post non machinist material to the site in order to prevent it from looking like a machinests' haven.


Ed Cregger

If the vaue of the paper and time to put it in an envelope is $1 to support a product that one has already profited from (simple support would normally be included when pricing a product), then well I guess that explains the hours long phone calls that provide the same support. When you have a captive audience you can charge for things like that, DDD has no competitor in the US.

I've worked for companies like that and, well, I don't work there any more.

JMP, I didn't know you were that JMP. I could call Enya and help them fix their errors. I don't know why I would do this. It's just my past experience with vendors that had problems. They already shot themsleves in the foot. They aren't likely to recall engines, and I wouldn't send mine back to Japan at my expense for the repair/upgrade. If they were to contact me, I don't know. We should be calling them and telling them that we expect engines that work and are user freindly? That's a no brainer! Glorious, but technically inaccurate reviews sell a few engines and they prove themsleves in the field. If they work word spreads, if they don't, it also spreads. Engines sit on the shelves and they have to figure out why. If Enya isn't googling 41-41CD every day to see what is happening with their product, they are way behind the times and I wish them luck. In my opinion product testing should not be the responsibility of the paying consumer. If people who don't design engines can figure out what is wrong with an engine, then Enya didn't do their homework.

Yes, we could post non machining posts. For me, taking an out of box product and using it isn't exactly interesting at this point in my hobby. Outside of the recent topics there has been no activity. This forum was mostly "look what I just bought" and bench running. Virtually everyone in the diesel forum has much experience and already knows about diesel, whether or not they actually fly them.

If you look at the posts such as "how many diesels do you own", what was your first diesel" etc etc. It is quite clear that for the last 60 years or so paw, ed, mills and tons more
had adjustable compression, 32 year ago Davis comes up with conversion heads to make 2 strk diesels Peter Chinn ,a glowing review on this advance so not my own personal opinion Enya did screw this one up and having to go into your shop and redesign their engine is almost beyond belief ( and yes a couple of you have the skills to do it and did it)
Enya does have some great engine their new 2 stks stks great, have the 11,15 and 25 diesels. I am willing to bet that had OS done this it would have been right to first time
with adjustable compression. Had Mr enya senior been involved it would have been right the first time ( I do not know if this gentleman is still around with us or not)
for quality and price the best example I can think of in a 40 size engine is the ST 40 $50 davis head $60 thus $110 for a hasselfree bulletproof diesel.
If 2 enya 40 4stks work out of the box and two do not not a good ratio.and you still have to change head shims for prop and fuel combos???? martin

and yes there are folks out there that do NOT FOLLOW or LOOK at the INFO and then they wind up on the posts asking questions
The late Paul landels of just Engines comented that he has had engines come back glow and diesel and the instructions were still sealed in ther plastic envelopes Mr Davis made the same comment and most likely quite common, trying to run high nitro fuels in glow engines desinged for 0 or 5% nitro without adding head shims (why not run them as designed)
I am refering here to sport appications not hopups for competition