Uctkam 2.5 cc MK 1 Rebuild Project

Uctkam 2.5 cc MK 1 Rebuild Project

Design History:
The UCTKAM Model 2.5 D was Designed and Manufacturer in the U.S.S.R. (C.C.C.P.) around 1968; was evolved from the Uctkam-1. 


Design Features:
classical configuration diesel;
steel cylinder liner;
cast iron piston;
fixed type carburetor (without speed control);
induction front rotary valve (crankshaft);
plain bronze bearing supported crankshaft; 
schnuerle scavenging engine of high quality construction


Specifications:
2.47 Displacement d.c. (0.151 cu. In.);
bore 15 mm. (0.591 in.);
stroke 14 mm. (0.551 in.);


Observations:

This engine was acquired from a friend living in Lithuania but there were a number of problems which resulted in it not being a very good runner

Condition as received: there was excessive radial play of the shaft at the main bearing; it also had very poor compression and, tuning at the inlet slot in the shaft resulted in timing errors being introduced 

Below: the reassembled engine is looking good after its extensive rebuild project; for full details on this project are documented in the eBook, check below for details on how you can get your own copy.

The engine in the test stand ready for that first run with a big propeller fitted and a rich fuel setting to flush out any loose particles and seat in the moving parts  

Below: pictured are the MK1 (our engine) and the MK2 'Powerhouse" (1 HP @30,000 RPM) which will be a future feature engine

* Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.

In comparison, bronze is principally an alloy of copper and tin. Bronze does not necessarily contain tin, and a variety of alloys of copper, including alloys with arsenic, phosphorus, aluminium, manganese, and silicon, are commonly termed "bronze". The term is applied to a variety of brasses and the distinction is largely historical.

Observations continued:

Again a warm welcome for this one.The Uctkam engines were made in the same Ukraine factory as the Meteor and Kometa engines......to name just a few. The Russians, especially the Ukraine, made a lot nice engines in the past. But the final quality control was not always as best as it should have been. However, if you stick to some golden rules about older Russian engines, and you are a bit handy too, you can get yourself a very nice runner....for a low price. The KMD and MK-17 have proved, that they are not all that bad. But either you love the Russian engines or hate them....Well, I always like to give them a second chance. And when I see my newly rebuilt Uctkam MK II....well that's a real engine!!! I got this old engine in what I would call, not so good condition. It was actually complete, but I was not sure, if he was a runner or not, in any case, it would be a real pain to start up. It had bad timing and not that much in the away of compression. With the leaking from the front bearing that also would make it hard to start. And I am not speaking about small things here: like a bad working spray-bar or loose fitting needle or some other minor thing. But I was surprised at how nice the cylinder looked. To speak about the openings in it you could almost imagine, it could be a Supertigre....well maybe the sent a spy to Italy....who knows?? But all in all I think when I saw the internal parts, I was thinking that this engine should be real performer, if everything worked out as it should. At the first start I ran into a bit trouble while trying to get him fire up, but as it turned out the engine was not freed up yet. I must find the right settings and I also drill out the original venturi from 3,80 to 4,50 mm. But I did not drill those microscopic small holes in the venturi ring bigger, where the fuel mix with the air. As it is now, I got now less vacuum than I need, so I must compensate for that too. The cone I made does help, but not enough. Well it will do for now, at least he runs and starts up right away. I Just can't wait for the 'big run" the one with a smaller prop. That should be very interesting! The engine is not yet completely freed up and now he runs at 10,000 rpm. But the Uctkam needs a smaller prop to use all his potential,as its not a long-stroke engine (bore is 15mm/stroke 14mm). Maybe even a 7x6 prop would be a good choice! I am very happy that I bought the engine from Pavel. Thanks!! And also this rebuild went perfectly, much easier than the small Jon 0,30 diesel that I did 2 weeks ago. When I had the Uctkam conrod in my hands, I thought...JEZUS what a huge conrod!! It looks like its right away from the Titanics engine.....so big!!....... but of course,.... its a upside down world.......the Jon was just Sooooooo small! :-) Thanks for your time and interest. I didn't show all of the necessary steps what I took, but only some big fragments here, its a long story anyway..... More stuff soon here,..... of course on my channel! Vallic000 *** Thanks for ratings and comments***


http://www.youtube.com/watch?v=f-K9i-5Atgg

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Uctkam 2.5 cc MK 1 Rebuild Project

Table of Contents

Item	Title	Page Number
1	Engine data	4
2	Making and installing new main journal bearing	6
3	Attempting piston expansion by heating	16
4	Finish machining bronze bushing for press fit	18
5	Making a new piston and wrist pin	24
6	Piston lapping procedure	27
7	Repairing engine timing	28
8	Cleaning parts prior to assembly	29
9	Running-in procedure	30
10	Final observations	33

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