Author Topic: An absolute beginners journey to restore a Viking 2.5cc Diesel  (Read 7581 times)

Offline Admiral_dk

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I should probably start with a quick intro of myself even though I’m one of the first members here.

Right out of primary school I started at “Århus Tekniske Skole” (Aarhus Technical School) at “Svagstrømsteknisk Værkstedsskole” (~ Electronic Workshop-school) in 1978. This was the first step towards an education for either “Elektronik Tekniker” (Electronic Technician) or “Svagstrøms Ingeniør” (a Master degree in Electronics). This was three semesters from August to June. In each semester we alternated between a week in the electronic workshop and the next in the metal workshop. On metal weeks we had Wednesday doing drawings, how to write to correct types (font) on the drawings by hand, etc. and the other four days working on metal. First semester where how to correctly mark and measure on metal, hand file a straight or curve, use a hacksaw correctly and choose the right blade for it, use a drill press and how to sharpen the drill bits, use a brake on sheet metal and finally how to hard solder.

Second semester where “mastering the lathe” and third semester “mastering the mill”. In all three semesters we had to make tools and professional enclosures to the electronic projects – I still have all those tools and some of them I still use often 

So why do I call this : An absolute beginners journey to restore a Viking 2.5cc Diesel ?
Well I haven’t used any of those skills in the years between and as the Yanks say – Use it or lose it – so I have lost most of it (hopefully not including all my marbles – though I’m brain damaged after a MC accident in 94). I was also born dyslexic – so writing has never been something I liked to do, but ….

It was not my intension to start with the Viking, but one of the more simple worn / damaged model engines I acquired over the last seven years or so, but I came into contact with Luis Petersen, multiple World Champion Team-racer / engine builder and he gave me some of the parts I needed to get my old Viking (1950) running again +  I more or less promised him that this would happen in the not too distant future.

Luis told me that he used grade 10 high tensile bolts, for his cranks and pressed in “lokke nåle” (punch needles) a la : http://power-tools.dk/Resources/Files/pdf%20norm%20snitstans/Posaunen.pdf for the crankpin.

We agreed that the Viking crank is too thin for a pressed needle. I found and ordered 10 M22 bolts from eBay.de at €1 a piece.

For those who wishes to read the story of Danish model engines and the Viking in particular, have a look here :

http://adriansmodelaeroengines.com/catalog/main.php?cat_id=107

Here is the engine in question – or more correct how it should look :



Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #1 on: July 24, 2016, 09:59:52 PM »
Sorry I had intensions of posting the next two instalments now - only to discover that I need a place for the pictures ....  :wallbang:
« Last Edit: July 25, 2016, 09:59:20 PM by Admiral_dk »

Offline Jo

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #2 on: July 25, 2016, 07:46:33 AM »
I do like the look of the little Viking 2.5cc Diesel.

Per I hope you realise I will now have to go and have a look through my model aero engine casting sets for something equally nice  :embarassed:

Jo
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Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #3 on: July 25, 2016, 10:00:06 PM »
Quote
I do like the look of the little Viking 2.5cc Diesel.

Per I hope you realise I will now have to go and have a look through my model aero engine casting sets for something equally nice  :embarassed:

Well I'm almost sorry for you Jo .... but then again, you might need to do something other than making three times the number of parts for an engine  ;)

First I put the hex end of the bolt in the three jaw chuck and center drilled it so I could use my dead center, only to discover that there was no way that was possible  :rant: . For one, I had placed the Y-axis glass-scale between the “main-sledge” (I have never seen anybody name it here) and the headstock.



I tried to turn the bolt anyway, just to see if the result might be useful anyway – nope – I had to move the glass-scale. That took a few weeks before I had the new parts to do that. Only to discover that it was still not possible, for two reasons. The original tool holder took up too much space and the dead center did the same in the other dimension.

The first problem was solved by Niels Abildgaard, who very kindly lendt me his Tangential tool holder + some tools from Arc Euro Trade, I ordered a mini live center, a half- dead center, some diamond paste for lapping and a few more items.



I haven’t got a picture of the first operation. I removed the thread with a new HSS tool that got blunt from trying to cut 0.3 mm per pass and the bolt wobbled quite a bit afterwards as I could see on the center hole that was not on center anymore.
First picture is the bolt after I have rebuild the glass-scale mounting and have received Niels tool – you can see that I just skimmed the corners of the hex.



Niels tool worked fantastic – I took 1 mm interrupted cuts at more than 30 mm diameter – No worries   Result can be seen I picture two.



First major UPS before I got the half- dead center can be seen on picture three - I forgot to lock the ram of the headstock. I started out fine, then the cut got deeper and deeper and sounded bad !   :facepalm:



Lesson learned : Do not try to figure out why things are going wrong while cutting !!!
HIT the stop button immediately !!!! – this might have prevented the marks on the crank web and almost certainly prevented the embarrassing marks on Niels tool – I now owe him a new one + you have plenty of time to contemplate after the lathe is shut down ….
Oh well – you can only gain experience by making mistakes – first one on the list .
« Last Edit: July 27, 2016, 10:26:07 PM by Admiral_dk »

Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #4 on: July 25, 2016, 11:30:02 PM »
I got my tools from Arc Euro Trade, and in order to try them, I thought ; Why not try to continue with the “scrap part” – after all it might still be a runner, even if it won’t be a pretty one. First picture is the crank turned down to the diameters for the last operations on the shaft side.



I had planned to use my single point tool to make the M5 thread, only to discover that I needed two 80 teeth gears for the box and I have only one  :cussing:

I therefor took my cheap M5 die and pressed it onto the crank axel with the headstock ram, in order to have it square so to speak, while I turned the chuck with my hand. It cut the thread but it looks horrible. I’m sure that the problems can be traced down to the fact that I did not turn backwards every turn or so. That has never been necessary since I got those great Zebra Taps, so I did not think about using the technique on the old style die – oh well, another one for the books. Forgot to take a picture.

For the next step, I had to go back to the standard tool-holder and HSS tool. There was no place for the dead center either, as I had to do an angle taper from the 5 mm to the 6 mm part of the axel where the prop-driver. I used this great little tool to calculate the angle http://www.magafor.com/841/uk.htm

And as close as I could measure the diameters + length of the taper, I got a value from the calculator that was very close to 5 degrees. Since all values on my drawing are some very nice numeric number, I decided to try 5 degrees on my compound and give it a go. As Fools Luck goes, it was a perfect match to the prop-driver. Sorry no picture either here.

Third operation on the crank-shaft, is lapping. I had made a tool for trying fix the old crank a while back and it didn’t work. For once it couldn’t clamp the shaft hard enough to do any work and it was too short to hold a crank with this much throw (3/4” ~ 19mm) as the shaft is against the chuck. It is the middle fixture in the picture and the hole furthest away was the one that was supposed to be used. I decided that it could be reclaimed as the lapping tool. I placed it in the vice on my drill press, took a ½” wood router bit and cut out the recces (?) for the bolt. Drilled a 4.2 mm hole all the way through followed by a 5.5 mm half way through and cut a M5 here. Turned the part 90 degrees and drilled the 5.5 mm hole almost in the center and reamed it with a 6 mm reamer. Charged it with the 12 um diamond paste and now it looked as in the picture.


Offline Niels Abildgaard

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #5 on: July 26, 2016, 09:19:00 AM »
Lesson learned : Do not try to figure out why things are going wrong while cutting !!!
HIT the stop button immediately !!!! – this might have prevented the marks on the crank web and almost certainly prevented the embarrassing marks on Niels tool – I now owe him a new one + you have plenty of time to contemplate after the lathe is shut down ….
Oh well – you can only gain experience by making mistakes – first one on the list .

Hello Per

Glad You find toolholder usable and do not worry about replacement.It was a gift.
Breed is improving all the time and I keep the best myself.
For the job shown You will be better of with a 2 times 2 almost square tool with a nose radius of .1mm.

http://i.imgur.com/jqkRKCB.jpg

The jig shown  used on my swing grinder, gives parallellity within 0.005 mm but I have not figured how to make nose radius

Keep cutting and good luck
« Last Edit: July 26, 2016, 10:12:17 AM by Niels Abildgaard »

Offline Jo

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #6 on: July 26, 2016, 09:43:18 AM »
Well I'm almost sorry for you Jo .... but then again, you might need to do something other than making three times the number of parts for an engine  ;)

 :lolb: Well Per you will be pleased to know your little build has me casting fondling again and I have found three cuties that may need further investigations: a AHC Diesel, Pepperall and a Sugden Special  :embarassed:

Tip wise I find the Sumitomo tips will even cut induction hardened steel  ;) I have had one of their little 6mm boring bars (triangular tips) for over 25 years and have only just had to replace the first tip after many years of abuse  ::) 

Jo

P.S. someone gave me a box of 10 more Sumitomo tips for my little boring bar so I am expecting them to out last me  8)
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Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #7 on: July 26, 2016, 12:34:05 PM »
Quote
Glad You find toolholder usable and do not worry about replacement.It was a gift.
Breed is improving all the time and I keep the best myself.
For the job shown You will be better of with a 2 times 2 almost square tool with a nose radius of .1mm.

 :praise2: Well in that case - thank you very much   :whoohoo:

I'm guessing that this is a newer design
and I can certainly see one improvement or two - you moved the tool "spanner bolt" and that must also make the tool easier to make  :praise2:

Is the holder still just as immune to vibrations / chatter as the one you gave me ?

Jo - I'll be looking forward to see you do another Aero engine.
« Last Edit: July 26, 2016, 05:38:27 PM by Admiral_dk »

Offline Niels Abildgaard

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #8 on: July 26, 2016, 07:24:30 PM »
Hello Per
My Boxford lathe sits very firmly on a block of granite and is  rocksteady as a Schaublin or Hardinge.
Chatter is not a common problem for me so I do not know if the new type is more prone than Your example.
Main problem has been the screw.
f You thigten up Yours really hard carbide breaks and if to loose tools slips down with the swarf cross sections I want.
For the time being I use a modified countersunk 3/8 UNF screw as metric fine seems unavailable.
When ready for making an almost 2 times 2 square holder let us know on my tangential thread and I will gladly supply carbide and advice with pictures.
Need an excuse really.

http://i.imgur.com/WvKsXOd.jpg
« Last Edit: July 26, 2016, 07:47:59 PM by Niels Abildgaard »

Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #9 on: July 27, 2016, 11:55:44 PM »
The original crank measures 5.955 mm all the way and it’s a perfect match that runs smoothly and with no measureable tolerance, so that is what I’m aiming for.
I tried to do as Ramon describes how to lap a cylinder – except this is easier, as you can adjust the lap without stopping the lathe. I got a almost perfect shaft in my first try (actually, lap, clean, measure, repeat). The shaft is 5.960 mm except for next to the web, where it is 5.951 mm. Sorry forgot to take a picture again.

Holding the web in the chuck I placed my angle meter against one of the jaws and turned the chuck until it showed zero degrees.

Then I cranked the Y axis so the tool just marked a thin line on the web, turned the chuck 45 degrees :

And cranked the Y axis again, turned the other way to -45 degrees, repeat cranking. I wasn’t totally happy with the result, so I did the same with + and – 60 degrees. Next I placed the tool @ 10 mm from center and marked a circle on the web. Removed the fixture and crank from the chuck – decided to use the 60 degree marks and the circle. Over to the drill-press and drill the intersects with a 2.5 mm drill bit – not all the way through, but deep enough to see them after the crank throw is “cut”.

Back in the chuck and make sure all is aligned again. Start on the interrupted cut for the crank throw – would it work with just the M5 nut to prevent the crank from rotating in the fixture ?
I started by removing 0.3 mm with a feed of 0.05 mm for the first 10 mm.

Increased the depth to 0.4 mm for the next 10 mm and finally 0.5 mm until there was less than 0.5 mm oversize. Next I tried to do the side of the web, but it didn’t go too well – reason – well I forgot to tighten the contra nuts on the gib when I adjusted it after moving the glass-scale  :Doh:

In order to “cover the fact” I contoured the side of the web and took the finishing cuts of the throw – the result could be a lot worse for a first time.


« Last Edit: July 28, 2016, 10:55:32 PM by Admiral_dk »

Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #10 on: July 28, 2016, 10:46:06 PM »
I see that I have some who have looked in – great – at least the fact that the hours I take to write this isn’t lost  :)

I had made the fixture for the crank throw earlier, but only have one picture of making it. Here you can see that I have the fixture in the 4 jaw chuck and that it is offset – in this case 3/8” => 3/4” throw.



I drilled it with 3 mm bit first, followed by a 5.5 mm and a 6 mm reamer. Next I used a 12.2 mm (biggest sharp drill bit I got) and drilled some 5 mm to make space for the M5 nut that holds the crank while turning the crank throw. My plan was to follow it with my boring bar, until I tried to put that in the holder and noticed that it will not “flatten” the bottom of the hole. So I modified the first HSS tool I have ground so it looked like this :



Not perfect, but it worked fine and my first attempt. Next I placed the fixture in the 3 jaw chuck and faced both ends and then tried it with the crank only to notice the I had most of the web 0.1 mm from the fixture  :facepalm:  …. Why – well I “improved” the web as I went along, so only the center part would “rub” against the crankcase – hence the 0.1 mm offset. I really couldn’t be bothered to put the 4 jaw back on, so I took a countersunk and removed the center part by hand until the rest was flush with no light between them.

Back to the “sequence” – I’m sorry that I’m such a scatterbrain, but that is related to my damaged short term memory ….

I had to make a lap for the Throw, so I found a bar of aluminium and put two marking lines on it – one @ 7.5 mm and one @ 15 mm.
Placed in in the vice and drilled a 3 mm hole in one end and a another  25% in from the other end on the 7.5 mm line – just eyeballed it – followed by a 4.5 mm and a 5 mm reamer.


Move the bar in the wise a cut it with a hacksaw @ the 7.5 mm line – through the reamed hole and to the 3 mm hole. Next cut along the 15 mm line all the way through. Remove all burs with a file, place it in the vice again, so the “end” was up. Mark and drill a 4.2 mm hole 6 mm from end and in the middle of the narrow side, all the way followed by a 5.5 mm hole half way through. Next tap it to M5 – se picture :


and remove the last burs. Charge the lap with diamond paste and try to get the rest of the smear onto the Throw


Ready to lap – or NOT  :slap: …. Remember to cover the bed  :noidea:


After a few runs of lap, clean, measure – repeat – I had a Throw measuring 4.975 mm and the used conrod I got from Luis was a perfect fit. The brand new rod I bought from Jens Geswender (Luis partner in Crime  ;) ) would have required that I went down to about 4.955 - 4.960 mm – but that can wait to I master a “perfect” crank.

Remove the fixture from the chuck, loosen the M5 nut and turn the crank so one of the balance holes where in the middle of the fixture. Place the fixture in the drill press vice and drill the hole to size, turn the crank to the next hole and drill it to size too.


And here we have a family picture – the new and old crank next to each other.


I’m very good at procrastination – the rest of the bench shows what I really ought to be doing – making a new home on the wall for some of all my maternal grandfathers tools and restoring my off-roader bike (although the engine is only partial in the pic).


« Last Edit: July 28, 2016, 10:56:06 PM by Admiral_dk »

Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #11 on: July 29, 2016, 08:53:53 PM »
I discovered that I had to turn the web down to a smaller diameter – not really a surprise – so not shown, I took a piece of sheet metal from a Heineken Beer and wrapped around the crankshaft and placed both in the chuck and tighten it slightly. I reduced the overall diameter to 26.2 mm – smaller would have taken something out of the “side-bearing” part of the web – so I didn’t remove more. The original was put into another offset fixture to remove the “offending” part of the web that interfered with the bottom of the piston at BDC.

So what to do ?

 I had from the start when I acquired this engine promised myself that I wouldn’t change any original parts that where fine.
Now a lot later in time I had an OK crank that has quite a bit of interference with the piston and I was anxious to see if it would work so I completely forgot about my promise to myself.
Next thought ; well the inlet timing is extremely “narrow” with a duration of 86 degrees and the piston is 21 mm – longer than need be. The mopeds of my youth had a more or less conservative inlet duration of 120 degrees when legal + the fact that the Viking has an exhaust duration of 145 degrees and transfer ports around the 120 degrees – the latter two, can hardly be thought of as docile, but more in the sport territory. Why not remove 1 mm of the bottom of the piston, that would bring it to a inlet timing more consistent with the rest and hopefully be enough …!

Well it almost did – there were only a few degrees of interference now, so I did the same again. Place the piston inside a bit of “Heineken-wrap”, chucked it very lightly and this time I removed 0.6 mm.
Hurray – now the engine turned over smoothly  :whoohoo:

I took a piece off furniture “wood” and cut out enough for the engine + tank to be mounted snugly. Used a C-clamp to hold it onto my work bench, found the fuel and a syringe, filled the tank and a drop of fuel on top of the piston.
First pop came on the third flick and surprised me, since I had not turned the compression screw enough to get to the resistance I would expect for it to do so. Increased the compression some more, still no go, so I put a finger on the carb to choke it and now it started – but as can be seen – it can’t run without choking :

I had assembled the carburetor in such a way as to get maximum airflow and realized that this might not have enough venture effect, so I removed the needle and the locknut in order to screw the needle-holder further into the carb. All back together and it will run without chocking :
I’m not sure if I should laugh or cry – it is certainly mixed emotions
Most of the members here like their engines to run as slowly as possible and if that was my goal, I hit Jackpot – but I was hoping to see it fly sometime, so I need to find out why it won’t really suck fuel well enough. I expect that I have a leak since it will run when my finger blocks the carb completely.

I am a bit mad with myself for changing the original piston – even though I have an inlet duration of 106 degrees that still isn't in the sport territory.

I need to find some cast iron before I can continue.

Offline Jo

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #12 on: July 29, 2016, 09:13:56 PM »
Well done, that does seem very slow for a diesel.  :noidea:

Per we can't see your second video as it says it is private.  :'(

Jo
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Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #13 on: July 30, 2016, 07:25:41 PM »
Thank you for your nice comment Jo and sorry about the second video - should work now.

I consider the RPM it is running as idle and a very nice low one at that - next step ought to enable it to fly too.
« Last Edit: July 30, 2016, 07:29:30 PM by Admiral_dk »

Offline Ramon

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #14 on: July 30, 2016, 09:00:16 PM »
Hello Per, First off congratulations on retrieving an old vintage engine - always a satisfying experience to 'bring them back'  - you've done a good job :ThumbsUp:

Regarding the very low speed - looking at the videos it appears to me that it is well 'over propped' hence the very low speed. At 2.5 cc capacity and on the bench running a 10" x 4" (250mm dia x 100mm pitch) should be tops really and a 9" x 4" (225 x 100mm) should perk things up considerably without it over revving. Overloading on diameter puts a big strain on the crank bearing and on pitch 6-8" (150- 200mm)  a heavy load on the engine which usually leads quickly to overheating.

Just my thoughts - hope they help  :)

Regards - Ramon
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Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #15 on: July 31, 2016, 02:07:14 PM »
Hi Ramon

Thank you very much for checking in and giving advice to a novice  :praise2: and your kind words from an expert are appreciated too  :)

I new you where right - I couldn't find the prop I really wanted to try it with, so I took the next best (or not). One reason for using a big prop came from an advice from Ron Chernich - I have a nice old FOK 15 sport diesel and I had no luck running it with the 7/5" (if memory ...).
Every time I tried to start it, I got a heavy hit on my finger when it fired - it's so fast that the normal smart flick isn't fast enough to get your finger out of harms way. Next step was to try starting it with a stick - that just smashed the prop, since it is more solid than my finger  :censored: (there really ought to be a scared emoticon too) - with parts of the prop flying fast all over the shop  :help: - This is why Ron advised me to learn to handle the FOK with a much bigger prop and a 9/6" work wonder on that engine. This was actually the prop I was looking for to test the Viking.

Your comment made me go down to the workshop and look for all my props (not that many) and in the box with engines I found a 1HP 7.5 cc glow with the same size prop that I had on the Viking - OK, that is really in the very heavy over prop territory  :slap:
Soon after I found the FOK and the 9/6" was still on it - took it and drilled it up to 9.5 mm so I could mount it on the Viking and tried to start it again. A little harder to start than with the bigger prop - smaller flywheel effect being 2" smaller in diameter - it ran quicker, but not enough. Found a 8/4" and tried that too - much better, but still no joy in regards to get it up to flying speed.

I'm sure the 8/4" is the right prop (or very close), but it still can't "clear it's throat". It runs fast enough to easily see that there is a big spray back out the carb - bigger than what can be seen leaving the exhaust. This kind of confirms that size not always scales down well and that I really need to get my hand on some cast iron for a new piston, so I can make a new much closer to the original inlet timing. I do also think that I might need to make a new carb or find a way to cure the original of any leaks - though that will only happen if a new piston can't cure the problem.

Offline dieselpilot

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #16 on: July 31, 2016, 03:30:25 PM »
To me it sounds like that engine is not running but oscillating. The exhaust note is very weak.

Offline Ramon

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #17 on: July 31, 2016, 05:40:46 PM »
Hi 'DP' -  yes that was my first thought too on the initial viewing but having watched it several times concluded that it was actually running but as said obviously well overloaded. That said it does actually have that look about it but I have a feeling something is awry with the timing as well I would say .

Per - just a consideration - are you certain the liner is in the correct way round? IE the exhaust is on the correct side. Many have been caught out on this (yes, guilty as charged  :-[)  particularly on the Mills .75 - the piston has a step which if re assembled the wrong way leads to some very poor and erratic running and difficult starting.

The fact that you removed some material from the piston skirt has probably contributed to the leakage of fuel out of the venturi - if the port is just not closing - if only fractionally - then not only will that happen but you will be losing crankcase pressure too which will also contribute to the running characteristic you have.

The engine, being a side port will have conservative and even porting - not the kind of engine that is really suited to high revs and fast running but you should be able to get a nice steady beat out of it with an 8 x 4. If not, assuming your fuel is okay (I would say it is given it does start and run after a fashion) it's definitely something 'internal'

Good luck with the next stage  :ThumbsUp:

Regards - Ramon
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Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #18 on: July 31, 2016, 10:11:38 PM »
Hi Greg and Ramon - thank you for your thoughts, much appreciated.

I feel rather confident that it wasn't oscillating and it is running faster with the smaller props, but I can't guaranty that this is the case. I still does not sound right at all - it runs rough, speed increases with higher compression, but it sounds worse if I increase it over a certain amount. Leaning it makes it run very smooth but also quite a bit slower - though it is still faster that way with the 8/4" than it was with the 11/6" (rather logical).

As to the piston vs. cylinder - The Viking and most old Danish two-stroke model engines are inspired by a fellow Danish Engineer - Jørgen Skafte Rasmussen, the man who constructed the German DKW car and motorcycle engines - so they are Schnürle ported with flat piston crowns (or in this case, chamfered). I might have the cylinder a few degrees wrong - but I can see the right ports aligning with the holes in the block.

They where when I assembled it. When writing this I when down to the shop to check again and the cylinder has turned itself some 5-10 degrees, so I corrected this and tried again. It didn't really run any quicker, but the cylinder has turned a few degrees again - they where known for some of them to have this problem  :facepalm:

If the cylinder liner is 180 degrees out, both the exhaust and inlet is completely blocked.

As to the fuel - this is the stuff I bought a year or two ago and solved my problems with the FOK together with the bigger prop on that. It's in a steel container with seals - so I'm hoping that the ether hasn't evaporated - but if it is less good than as new, I would expect starting problems and I have none.

Offline Neil-Lickfold

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #19 on: February 18, 2019, 04:40:05 AM »
I suspect in both videos the engine is over compressed and is oscillating rather than running. I have never heard a running engine sound like that in your video. That to me is clearly an oscillating engine.  Try backing off the compression and restarting, slowing increasing the compression until it starts and runs.
A basic fuel is 1 part ether, 1 part castor oil and 1 part Kerosene or low odour kerosene. Then if you have any, add 1% to 1.5% of diesel ignition improver. It can be bought as diesel fuel cetane improver.  In the old days it was IPN or Amyl  Nitrate.
An 8X4 prop sounds right for a 2.5cc engine. 

An update if you got it solved would be nice to hear.

Offline Admiral_dk

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Re: An absolute beginners journey to restore a Viking 2.5cc Diesel
« Reply #20 on: February 18, 2019, 11:28:37 AM »
Thank you very much for your input Niel  :ThumbsUp:  but do not forget that my mistake modifying the piston gives the engine a way too long inlet duration, so a big part of the fuel is pushed back out the carb  :-[

I write this from my lunch break at work, so I can't go look at the tin, but the fuel comes from a respected supplier of modern CI engine fuels and includes 1.5% ignition improver

Oh, I forgot to mention that I did try to lower the compression, but the engine just stops when I do.

Best wishes

Per