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My Dnepr engine

dnepr mt9 mt10

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#1 luca.stere

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Posted 25 October 2014 - 08:18 AM

I have now a Dnepr engine, I'm not crazy about them but I think they are not so bad as the people are saying. This is the first Dnepr engine I am repairing, I will analyze it and I will do everything is possible to remove the design and manufacturing problems.

Attached File  motor-dnepr-nipru-complet.jpg   129.54K   13 downloads

Attached File  motor-dnepr-nipru-complet-2.jpg   128.43K   14 downloads

I started with ckecking the cylinders and I found the reason why the engine was stuck, the water entered in the piston head through carburetors that were not sealed properly:

Attached File  piston-dnepr-nipru-cocsat.jpg   108.85K   15 downloads

Attached File  piston-cocsat-dreapta-2.jpg   135.26K   13 downloads

Attached File  piston-dnepr-nipru-cocsat-2.jpg   127.82K   13 downloads

Attached File  chiulasa-stanga-dnepr-nipru.jpg   137.57K   12 downloads

The same problems on both sides.

#2 rbike

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Posted 16 November 2014 - 06:34 AM

Considering it's not first Ukrainian engine that you are rebuilding, shouldn't be too difficult. Plenty of space for modifications on this engine.
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#3 luca.stere

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Posted 16 November 2014 - 01:59 PM

 rbike, on 16 November 2014 - 06:34 AM, said:

Considering it's not first Ukrainian engine that you are rebuilding, shouldn't be too difficult. Plenty of space for modifications on this engine.

I have already prepared some new pistons with a very good quality: Citroen GS 1299cmc pistons and Goetze rings. In fact this pistons were made in Romania for engines made in Romania under the Citroen license (Oltcit cars http://en.wikipedia.org/wiki/Oltcit ). This is an air cooled engine wich it was quite reliable.

Below you can see the Dnepr piston in the left and the Citroen piston in the right:

Attached File  comparatie-pistoane-Dnepr-Oltcit.jpg   121.36K   14 downloads

After I have milled the pistons, Citroen in the left and Dnepr piston in the right:

Attached File  comparatie-pistoane-oltcit-dnepr-rsz.jpg   15.47K   14 downloads

#4 SafetyBob

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Posted 16 November 2014 - 02:36 PM

As strong and as well designed as Ural engine.  I own both.  Properly set up and cared for, the Dnepr engine is a strong and long lasting engine.  Run as it was designed to do, you will have no issues.

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#5 luca.stere

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Posted 16 November 2014 - 02:48 PM

 SafetyBob, on 16 November 2014 - 02:36 PM, said:

As strong and as well designed as Ural engine.  I own both.  Properly set up and cared for, the Dnepr engine is a strong and long lasting engine.  Run as it was designed to do, you will have no issues.

SB#3

In Romania the problem are the parts, they are cheap (from Ukrain) but not reliable. I can buy two cylinders, two pistons with rings and pins with 120$ and I mean new parts. At this price you can not have quality.

#6 rbike

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Posted 16 November 2014 - 03:35 PM

What Citroen piston pin size is? Did you machined only valve cuts or some more places?
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#7 luca.stere

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Posted 16 November 2014 - 04:01 PM

 rbike, on 16 November 2014 - 03:35 PM, said:

What Citroen piston pin size is? Did you machined only valve cuts or some more places?

Pin size is 22mm, I have already made another bushes for pins and I have machined only the valve cuts (not me, the turner did it).

#8 lobofuego

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Posted 24 November 2014 - 07:46 PM

Thanks for posting Luca...Good work!!

#9 luca.stere

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Posted 25 November 2014 - 12:42 AM

 lobofuego, on 24 November 2014 - 07:46 PM, said:

Thanks for posting Luca...Good work!!

If you want to see more pictures with another Dnepr engine that I just repaired with Citroen pistons you follow this limk: http://motorist.ro/v....php?f=30&t=313 . You can translate romanian language with google translate.

My Dnepr engine it will take some time to rebuild and show here because I am very busey and also it is not a priority for the moment.

#10 arbalest

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Posted 09 December 2014 - 12:59 PM

Depending on the year, watch out for soft cams and poor machining of the heads. I had a 1983 OHV Dnepr. The valve spring seats were not machined concentric to the valve guides, and the rocker arm geometry was bad. With the lash caps on the valve stems, the rockerarms would go over center in their travel, putting a sideload on the valve stem in the valve guide. I had several valve stem seizures in the valve guides, before I discovered the problem.

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#11 luca.stere

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Posted 09 December 2014 - 03:11 PM

Yes, I know this kind of problems. The cylinder heads will be completely rebuilt with compatible parts from western engine. The rockerarms... I don't like the angle but I will try to compare with other engines to see if it is a problem with that.

#12 luca.stere

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Posted 11 April 2017 - 02:11 PM

He he, I started to rebuild this engine, pictures coming soon.





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