dnepr and single diesel engine

arnaud · Post by **arnaud** » Thu Oct 23, 2008 4:21 pm

Hi, on this site; http://www.dieselbike.net/Hamm08/Hamm08.htm
is a pic of an dnepr with, i believe a single cylinder china diesel.
since the length of the engine(especially the flywheel) and the outlining with the gearbox and final drive would be a problem, many people who installes 2 cylinders were forced to adjust the frame.
But this one, despite the vague pic, seems original??
Maybe is it something I can do if it is unaltered!
however, a small twin (would a 483 kubota fit) would be better since the final drive takes far more power then a chain..

oilburner · Post by **oilburner** » Thu Oct 23, 2008 11:19 pm

The frame on the bike has definitely been modified. I edited a part of the picture, adding lines to show:
(A) the modified tubes under the seat (now curved upward. The backbone appears to be almost horizontal.
(B) the engine has been installed on an angle which allows the base to rest on the downtubes.

FYI

arnaud · Post by **arnaud** » Fri Oct 24, 2008 9:21 am

indeed, now i see.
The gearbox is far away from the engine. maybe the builder did not chose the shortest crankshaft output, wich will make it shorter?
I wonder if it is possible to fit such an engine without altering the frame.
it would be great for the average hobby builder..

andrewaust · Post by **andrewaust** » Fri Oct 24, 2008 9:29 am

It would also be cool to see someone convert the boxer twin to a diesel like was done to the Harley screaming eagle engine.

As you mentioned Arnaud, a heap of space could be gained by shortening the flywheel section if a suitable clutch system fabricated.

I once looked at the Chang Jiang motorcycle as a diesel project which has a similar box engine etc. Pistons and head design are big engineering feat, bottom ends in some engines are very strong, some not so strong. A lot of factors to consider I guess.

arnaud · Post by **arnaud** » Fri Oct 24, 2008 9:55 am

i think the most simple thing to do, is buy the one with the shortest axle(you can choose from several types with a china diesel) and mount the dnepr flywheel and clutch on it, or maybe a smaller one would fit, if the clutch operates the same, for instance the one from a honda CX500?
the most difficult to make will be the mount between the gearbox and engine which have to line out exactly

johnfireball · Post by **johnfireball** » Fri Oct 24, 2008 6:41 pm

Hi,
the Dnepr frame crossbar is very low where it meets the frame at the saddle and will I believe require cutting and welding for allmost any upright diesel engine.However it's easily done and I think you would not have to lengthen the frame if one of the smaller 2 cylinder engines was used with a bellhousing made to minimum width.
John.

roverthetop · Post by **roverthetop** » Sat Oct 25, 2008 5:57 am

i had to stretch the frame and raise the backbone on a dnepr to accomodate the lombardini 25ld-425

poelbize · Post by **poelbize** » Wed Oct 29, 2008 8:59 pm

hello forum,

on the dieselbike.info page is a bike shown that
follows a easy concept, please take a klick
http://www.dieselkrad.info/dieselmotorr ... +1B40.html

this bike based a a dnepr with singel cylinder hatz engine, it looks easy to build.
i remenber a post of the owner taht he used a some real axel sprocket (tooth wheels) to have a longer gear, he import them direkty from russia.

i didn´t see the bike on the meeting this year in hamm.
so i hope it works well.
it´s a simple thing to build drivewind cooled engine, then the flywheel (perhaps designed for that) moved to the gearbox side. if the adjustment is well, i think it will work properly. it looks like a good concept.

regards helmut

ps: first note without a detailed introduce...

will follow soon this some details of my diesel bike project.

pss: sorry for simple englisch

arnaud · Post by **arnaud** » Thu Oct 30, 2008 8:34 am

yes, it is a beautifull bike, but i wonder, since the cooling fins of a forced blow engine are smaller, if it won't get too hot

stormcoat · Post by **stormcoat** » Tue Dec 30, 2008 10:29 pm

Both Dnepr and Chang frames have insufficient space for most upright engines, and Ural has even less, so in most cases, the frame needs some alteration. V twins are more suitable, of course, but we are limited to Chinese engines.
I sized up a three cylinder D662 Kubota to my frame, originally. It needed only an extra six inches or so, not allowing for the radiator, but to save weight and plumbing , I opted for a Petter twin for my contribution to the DIY section of the Diesel Bike Scenario. Frame modification is drastic (see picture), but its "industrial" looks should attract some attention.
As for converting the original engine to diesel, my opinion would be that, even given a stronger crank (last estimate obtained for this was £500), it is unlikely that the Dnepr cylinders would hold up. Chang cylinders look meatier, but, again, the strength is unknown. One thing in favour of the Dnepr crank is the one piece plain bearing design, so if someone would like to find a way to beef up the crankcases, bearings and cylinders it could be in with a chance. I have a dismantled engine for sale........anyone???

Stormcoat.[/img]

arnaud · Post by **arnaud** » Wed Dec 31, 2008 9:26 am

since the compression ratio in a diesel is about 3 times as high, i don't think an russian ural or dnepr crankshaft is suitable for diesel rebuilding..

Nanko · Post by **Nanko** » Wed Dec 31, 2008 11:00 am

arnaud wrote:since the compression ratio in a diesel is about 3 times as high, i don't think an russian ural or dnepr crankshaft is suitable for diesel rebuilding..

Is it the compression or the combustion stroke giving the biggest stress on the bearings?
i.m.o. its the combustion , check max torque from both engines if there is no hughe difference and dneprs dont have crankshaft bearing issues , its worth a try

arnaud · Post by **arnaud** » Wed Dec 31, 2008 11:09 am

Both! and the knocking of a diesel is a lot worse!
compare the big end from a small single dieselengine with a xt500 big end and see the difference..
But, you don't have much dnepr experience i guess

Nanko · Post by **Nanko** » Wed Dec 31, 2008 1:04 pm

arnaud wrote:But, you don't have much dnepr experience i guess

True , zero experience , I forgot the word if , if dneprs dont have crankshaft issues

numuzmar · Post by **numuzmar** » Wed Nov 14, 2012 9:41 pm

i am also interested in this bike

this is 4 or 9 HP engine ? its enough for heavy bike like dnepr ? (dnepr without sidecar weights 220 kg.)
what speed can achieve this bike?
oh many questions =)) maybe some one knows how to contact creator of this bike?

coachgeo · Post by **coachgeo** » Thu Nov 15, 2012 3:01 am

numuzmar wrote:i am also interested in this bike.... this is 4 or 9 HP engine ? its enough for heavy bike like dnepr ? (dnepr without sidecar weights 220 kg.)
what speed can achieve this bike?
oh many questions =)) maybe some one knows how to contact creator of this bike?

Most success with Dneper that can hit success full highway speeds (safe highway speeds) have been 3cyl engines with minimum 18hp. Smaller engine and you can cruise the backroads at a smell the roses 45mph or so.

Search this site for the various types of bike you are interested in and you will find discussions that will lead you to the answer you seek.

DieselBike.net

dnepr and single diesel engine

dnepr and single diesel engine

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Re: dnepr and single diesel engine