# Webster NGEZ-1



## aircraftmech2 (Dec 20, 2016)

Finished building my engine that I started about two years ago, but it doesn't run... It's a .056 diesel and I'm not sure how much it should be making. Like how hard it is to flip over. Any help or tips would be appreciated, should I warm the engine up before trying to run it?


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## foxmusfast (Dec 20, 2016)

Are you getting fuel to the cylinders?  Have there been any "pops" or smoke coming from the exhaust.  Diesels can be hard to start until you find that sweet spot on compression and fuel settings.


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## /// (Dec 21, 2016)

Hi AM2, welcome.
Sorry, I can't help with getting it running, but just wanted to say nice work!
This is one I've wanted to make for a while, the whole EZE series actually.


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## aircraftmech2 (Dec 21, 2016)

foxmusfast said:


> Are you getting fuel to the cylinders?  Have there been any "pops" or smoke coming from the exhaust.  Diesels can be hard to start until you find that sweet spot on compression and fuel settings.



No pops or smoke. It's pulling fuel through the line and there's fuel all over the wall behind it... &#55357;&#56834; [ame]https://m.youtube.com/watch?v=OVSeduRfG54[/ame] Here's a link to a video of me trying to start it. I kinda felt like it was low on compression and when I put alittle straight two stroke oil in the cylinder it made way more compression.


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## aircraftmech2 (Dec 21, 2016)

/// said:


> Hi AM2, welcome.
> Sorry, I can't help with getting it running, but just wanted to say nice work!
> This is one I've wanted to make for a while, the whole EZE series actually.


Didn't know there was a series... thought this was the only one.


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## aircraftmech2 (Dec 21, 2016)

Ok, so I played with it some more this morning and I have fuel blowing out the exhaust when I turn the mixture out about three turns. Im not sure that it's making the compression it should. When I turn it slowly to TDC it is fairly stiff, about like a cox.049 that I have, but when I hold it there it slowly leaks out past the piston. Is that normal? If not would putting a finer finish in my cylinder Help it seal? I have a 400grit laping compound finish in the cylinder and a 1200 wet/dry paper finish on the piston. 
Thanks.


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## /// (Dec 21, 2016)

aircraftmech2 said:


> Didn't know there was a series... thought this was the only one.



It has evolved a bit over the decades.

From Webster:
"This basic engine design goes back several generations, first appearing in 1950 in Model Airplane News as Roy L. Clough Jr.'s  "Little Dragon", and appearing again in late 1998 / early 1999 as Tom Crompton presented three variations in Model Engine World.  Having already built a side-port diesel, I wanted to try my hand at a front rotary valve engine, so Tom's "EZE-2" was chosen as the basis of my design, and in 2004 The Next Generation EZE was born (for the obvious lack of a better name). "

And the late Ron Chernich
http://www.modelenginenews.org/lildragon/index.html

http://www.modelenginenews.org/eze/index.html

:thumbup:


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## Mechanicboy (Dec 21, 2016)

Bad fit between cylinder and piston. Compression must be good to generate heat to ignite fuel mixture. 

You need new piston and relapping to correct fit between piston and cylinder.  

To create tapered cylinder: Piston create tapered piston when the piston is lapped into the cylinder at final stage. 
To test fit is correct: Dry piston/cylinder ---> tight to enter into cylinder. Oiled piston/ cylinder ---> The piston is loose fit in BDC cylinder and tight in TDC.


Lets take a look at a typical lapping job - that of producing a fine finished bore and piston for an IC engine. In fact, piston and bore are both lapped in separate operations (NOT both together). All of these operations will be carried out in the lathe (and I need hardly mention the importance of keeping lapping compounds off the machine, particularly the chuck and slideways). For the bore an expanding lap is ideal, and this should be some 3-4 times the total length of the bore. The first grade of abrasive would be mixed with light machine oil (10W or lighter) and liberally coated on the inside of the workpiece. Similarly, the slurry would be added to the outside (and inside assuming it is of the ventilated type) of the lap. The lathe would be started at about 300rpm (for a nominal 1" bore) and the lap passed rapidly through the bore, keeping it moving back and forth without it coming out the bore. How to hold the lap? well, perhaps the best way is with a 'floating' tailstock holder, and failing this holding with the hand is a method as good as any. Be careful when holding the lap by hand as it's possible it may jam, hold it lightly and expect the unexpected. Remember also that unless the lap is maintained dead parallel with the bore (an almost impossible task) it will tend to bell-mouth the bore a little - hence the reason for making the work a little longer than finished size and trimming to length later. When the inside of the bore has achieved an all-over grey appearance, with the fine scratches appearing even and criss-crossing both ways, and with no evidence of any deeper scratches (as might be left by the reamer) it's time to move onto the next finer grade. The work will have to be removed from the chuck to clean it properly, and this should be done with clean paraffin oil followed by hot soapy water. The same procedure applies to the lap and all traces of the abrasive must be removed. The process continues until you reach the 'flour' grade of abrasive by which time the finish on the workpiece should be very fine indeed. A final polished finish, should this be deemed necessary, can be achieved using metal polish (diluted Autosol, or some liquid chrome cleaner). The lap should be a separate 'finishing' lap so there is no chance of contamination with the coarser grades of abrasive which might be embedded in the main lap. The piston is treated in a similar way except of course the lap is female. Work will continue with the coarse abrasive until (using the un-trimmed bore as a gauge) the piston will not *quite* enter the bore. At this stage finer grade abrasives are used and work continues until the piston will just enter the bore tightly. At this stage, it is usual to finish mating the two parts by using metal polish and briefly using the piston to lap the bore directly. Great care needs be taken but this method ensures that the fit is good for the entire length of the bore.


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## aircraftmech2 (Dec 23, 2016)

Thanks mechanicboy! I started re-lapping my cylinder today, got down to 400 grit. Rather slow but I should finish and maybe finish the new piston tomorrow.


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## Mechanicboy (Dec 23, 2016)

aircraftmech2 said:


> Thanks mechanicboy! I started re-lapping my cylinder today, got down to 400 grit. Rather slow but I should finish and maybe finish the new piston tomorrow.



Go up to  800 grit or use fine lapping paste for valvegrinding for automotive car at lastlapping.  Surface muct be smoth and crosshatched dull grey before last lapping  with piston into cylinder with chrome polishing paste.


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## aircraftmech2 (Dec 23, 2016)

So here a photo of what it looked like after disassembly, after 280 grit valve grinding compound, and the final lap prior to lapping in the piston. Working clockwise from upper left. Not sure how well this is gonna upload but if you zoom in on the original it shows the progress pretty well.


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## Mechanicboy (Dec 24, 2016)

Much better! Difficult to see in photo, are there crosshatched surface in cylinderwall? With crosshatched cylinder means a lot of oil pockets in cylinder wall who give the engine long lasting running. Aso not as "mirror" surface.  Lap the piston,  wash piston and cylinder clean in kerosene and check the piston is entered into the cylinder near half of the length of piston until it stop by tight fit. Lap piston carefully into cylinder from bottom side with chrome polishing paste until the piston is stopped by tight fit in cylinder. Remove piston and wash clean, then check fit is correct. If not, repeat to lap piston into cylinder until piston is stopped by tight fit. Stop to lap the piston when fit is correct as here: To test fit is correct: Dry piston/cylinder ---> tight to enter into cylinder. Oiled piston/ cylinder ---> The piston is loose fit in BDC cylinder and tight in TDC.  Note: Tight fit in TDC ---> near where the contrapiston is there, also never past the site where the contrapiston is in the cylinder.


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## aircraftmech2 (Dec 25, 2016)

Mechanicboy said:


> Much better! Difficult to see in photo, are there crosshatched surface in cylinderwall? With crosshatched cylinder means a lot of oil pockets in cylinder wall who give the engine long lasting running. Aso not as "mirror" surface.  Lap the piston,  wash piston and cylinder clean in kerosene and check the piston is entered into the cylinder near half of the length of piston until it stop by tight fit. Lap piston carefully into cylinder from bottom side with chrome polishing paste until the piston is stopped by tight fit in cylinder. Remove piston and wash clean, then check fit is correct. If not, repeat to lap piston into cylinder until piston is stopped by tight fit. Stop to lap the piston when fit is correct as here: To test fit is correct: Dry piston/cylinder ---> tight to enter into cylinder. Oiled piston/ cylinder ---> The piston is loose fit in BDC cylinder and tight in TDC.  Note: Tight fit in TDC ---> near where the contrapiston is there, also never past the site where the contrapiston is in the cylinder.


 Yes, very fine cross hatch though. The last piston got scratched really bad from the rougher finish so i went to about 1500 grit cross hatch on this one.
 Got my piston ready for parting and honing. won't make much more progress due to the holidays.


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## aircraftmech2 (Dec 27, 2016)

So i finished the piston and new contra. The fit is a little snug and makes some drag at TDC but is fairly free below the exhaust port. The increase in compression is significant, my little starter motor I used in the previous video can barely turn it over. If flipped to TDC you can hear it very softly leaking out but it takes a while before it stops. Still couldn't get it to fire, even though the cylinder got pretty warm when using the motor.
Heres a link to a video on youtube of me slowly flipping it over. If you turn the volume up the leak is barely audible. https://youtu.be/4BX_eEKPurY
Im running out of time (gonna be moving from my machine shop for school) to tinker with this motor, if i put a glow plug in the head and pull the contra out will it run? I would love for it to fire from compression but...


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## Mechanicboy (Dec 27, 2016)

Set piston TDC and turn contrapiston screw until it touching the piston. Then unscrew the contrapiston 1,5-2 turn back depending on size of treads on contrapiston screw. Flip engine fast, it will fire up engine.


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## aircraftmech2 (Dec 27, 2016)

So I got it to fire with the starter motor. Pops and smoke but it won't sustain running without the motor. I played with the compression and mixture quite a bit and it seemed pretty sensitive, 1/4 turn on either one seemed to be the difference between firing and not. Are there any tuning tips? Also on video going frame by frame it fires 4-5 time after the motor comes off, and then goes from close to full speed to stopped in one frame. (60FPS) Is it possible I need a heavier prop? That's a 7x4 plastic prop.


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## aircraftmech2 (Dec 27, 2016)

Mechanicboy said:


> Set piston TDC and turn contrapiston screw until it touching the piston. Then unscrew the contrapiston 1,5-2 turn back depending on size of treads on contrapiston screw. Flip engine fast, it will fire up engine.


I'm running about 1/4-1/2 a turn off the top of my piston with 10-32 threads. With a .376 stroke and 1/2 a turn is .0156... So that makes .376/.0156 compression or 24.1/1. A quarter turn would be twice that.


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## Mechanicboy (Dec 28, 2016)

aircraftmech2 said:


> So I got it to fire with the starter motor. Pops and smoke but it won't sustain running without the motor. I played with the compression and mixture quite a bit and it seemed pretty sensitive, 1/4 turn on either one seemed to be the difference between firing and not. Are there any tuning tips? Also on video going frame by frame it fires 4-5 time after the motor comes off, and then goes from close to full speed to stopped in one frame. (60FPS) Is it possible I need a heavier prop? That's a 7x4 plastic prop.



Enough ether in fuel? Dieselfuel will lost ether if the cap is not well sealed on container. 

35 % ether, 35% kerosene, 28% kerosene and 2% Isopropyl Nitrate (difficult to buy Isopropyl Nitrate, use glass fiber hardener fluid in the bottle who has Methyl Ethyl Ketone Peroxide. The peroxide/nitrate fluid is to reduce ignition lagg).

Are there any tuning tips? ---> http://www.eifflaender.com/instruct.htm

Is it possible I need a heavier prop? That's a 7x4 plastic prop. ---> The propeller is big enough for the engine.


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