Diesel Bike Diary

[alexanderfoti]

Should be doable I think, Its very dependant on the type of riding you do I think as well. If I wasnt in a city mine would do 150+ as I would be just keeping the same speed the whole time.

[Tetronator]

The netherlands are as flat as a pancake and the roads don't do much corners so I think I'm good, aside from the interior of Amsterdam ect.

[Tetronator]

# 2 - The road to success is always under construction!
Date: 9-10-2014
Status: Further Research

Righto, Allmost 6 months have passed since my first message. But I haven't been sitting still! Been to the Hamm Rally and the automotoren treffen on Texel. Also looked at a few Dnepr's and Ural's and I'm sure enough that I will be using a Dnepr or Ural bike. As for the engine, because I need to have as little frame modification as possible, preferably none at all. I'm stuck to either the small one cilinders, (Hatz 1b40, Kubota Z482, Yanmar L100), or a V-twin Kipor which are neigh impossible to get with any kind of spare parts backing in the Netherlands...

...But there is hope for a more powerfull option!...

If I take a look at this bike ;


Which has an Hatz 1b40.

Look at the dimensions of said Hatz 1b40.
http://www.hatz-diesel.com/uploads/tx_h ... -22_02.pdf

It might just be possible to fit any of these kubota multicilinder engines in there... Thinking the sump will find it place between the lower frame bits. (Might need to shorten the sump if it all possible due to road clearance.)
Z602 15,8HP http://www.prinsmaasdijk.nl/motoren/2/k ... -Z602.html
D722 19,0HP http://www.prinsmaasdijk.nl/motoren/2/k ... -D722.html
I will also have too remove the waterpump, fan and alternator to make that fit. Repalcing the water pump with an electric one and attaching the alternator somehow somewhere else.

Added bonus of using a Kubota is that apearantly a BMW R80 Gearbox is mostly bolt-on.
Stated here; https://www.dieselbikeforum.com/view ... ota#p12706
Now does a bmw R80 gearbox just bolt in place of the Dnepr/Ural One? (Doubtfull.)

So, Unmodified Dnepr/Ural frame with a BMW r80 gearbox powered by a Kubota D722/Z602?


Research aside, still no place for me to work on the bike or metalworking tools to do so... Nor funds...
Anyway thats all for now that I can think of. Share your tougths please! You're all more experienced than I am afterall.

[Blunt Eversmoke]

If you are stern on going the Ural/Dnepr or old-school BMW way, there's also the possibility to walk this way; just watch the vid and read the topic.
Not saying it is THE easiest way to go; just that if you chose to, you would not need any frame mods because the engine pretty much stays put; no need to adapt an engine to the gearbox; and little to no gearing changes because the revs of a fore-chamber diesel are the same as on Ural/Dnepr(if not even higher).
You would have to modify the engine itself extensively, of course, but the vid proves it can be done.

[Tetronator]

If you are stern on going the Ural/Dnepr or old-school BMW way, there's also the possibility to walk this way; just watch the vid and read the topic.
Not saying it is THE easiest way to go; just that if you chose to, you would not need any frame mods because the engine pretty much stays put; no need to adapt an engine to the gearbox; and little to no gearing changes because the revs of a fore-chamber diesel are the same as on Ural/Dnepr(if not even higher).
You would have to modify the engine itself extensively, of course, but the vid proves it can be done.

That would be awesome, but I do not think I've got anywhere NEAR the technical expertise or metalworking skills to accomplish such a feat. Nor anyway to get them sadly enough... And there still is the reliability issue.

[Tetronator]

# 3 - Westenberg Special
Date: 12-11-2014
Status: Designing

Another month bites the dust. But a lot has been accomplished in that month. For I now have an actual idea on how I'm going to put this together!

Donor bike
A Dnepr K-750 or Ural M-72.
Preferably the Dnepr because the gearboxes in the Dneprs seem to be off a stronger build and I have found the ratio's & replacement gears online.
Why the Dnepr?:
-Lower noise regulations
-Tax Exemption if I do not stretch the wheelbase more than 60mm (Not planning on stretching) because I get to keep the original license plates.
-The wheels are all the same, thus interchangeable.
-Cheap parts.
-Cool looks
-Gearing changeable
-Cheap on purchase
-Sidecar



Gearbox & Clutch
I'm thinking of using the Dnepr gearbox and machining the diesel engine's flywheel to accept the Dnepr Clutch assembly. Keeping it all in its original position by lobbing the flywheel cover off of the Dnepr engine and using it to mate the diesel engine to the gearbox.

Using the Dnepr gearbox geared for Solo use it will need some ratio changes to make full use of the diesel powerband.
So I found this: http://www.dneprside.dk/dnepr_k750_gear_tabel.htm

Slight edit later, we get this:




As you can see above a top speed of 130km/h is obtainable using off the shelf gearing with an maximum RPM of 3600.
If you see anything wrong in the table above, please let me know... I did just 'borrow' it from what looks like a Danish site.
Eitherway said gearing will require quite some power so on to the next point!

Engine
Getting that top speed of 130km/h means that any single cylinders engines are not adequate enough for the job. These machines, (...and me... ) aren't exactly lightweight, especially when adding a sidecar.
So the engine needs enough power & be able to fit into the Dnepr frame without stretching it...

Dimensions of the original engine:


Therefore I have selected these engines:

(Preferred) Kubota D722
http://www.prinsmaasdijk.nl/motoren/2/k ... -D722.html
Advantages:
-Parts readily available worldwide, this engine has been in production since the 80's apparently, and still is.
-Reliable Japanese quality
-Smooth 3 Cylinder power delivery, will save the transmission and final drive.
-Cheaper than the alternative due to secondhand availability
-Multiple versions avaiable

Disadvantages:
-Size constraint, might not fit, will likely need to modify the lower frame parts.
-Little less power than alternative
-Water-cooled, will need radiator.
-No-one has fitted this engine into a Dnepr before.

(Backup) Kipor KM2V80
http://www.rotek.at/a000/002/000002287_00_RT_A_de.html
http://www.kiporpowersystem.eu/product/KD2V86F.htm
Advantages:
-Will fit in unmodified frame.
-V-twin power... (More powerfull than Kubota)
-Has been done before

Disadvantages:
-Parts not available on demand.
-Less fuel efficient
-Chinese quality
-Limited to no availability, might need to pull it out off a NEW generator.
-Water-cooled, will need radiator.


(2nd Backup) Kipor KD2V86
http://www.rotek.at/a000/002/000002287_00_RT_A_de.html
http://www.kiporpowersystem.eu/product/KD2V86F.htm
Advantages:
-Will fit in unmodified frame.
-Has been done before
-Air-cooled, no radiator, maybe oil cooler.

Disadvantages:
-Parts not available on demand.
-Less fuel efficient
-Chinese quality
-Limited to no availability, will need to order from abroad.
-Has less power than Kubota


Now the next step is actually purchasing, (beg, borrow, steal,) said components. Although I will need a way to obtain said budget...
In other news Jeroen, (Boutje on the forum), from VVMracing has agreed to help me out with the machining and welding bits!
And I've got a name for the bike, at least for the work in progress...

The Westenberg Special!

As always please share your tougths!

[pietenpol2002]

Regarding the Kubota D722

Little less power than alternative

In fact the most conservative rating of the turbocharged 722 is 22 hp. And I do love the sound of your planned build. Frankly, I'd be happy with any one of the engines you're considering. Best of luck with your build.

[Tetronator]

Regarding the Kubota D722

Little less power than alternative

In fact the most conservative rating of the turbocharged 722 is 22 hp. And I do love the sound of your planned build. Frankly, I'd be happy with any one of the engines you're considering. Best of luck with your build.

Thanks, I'm going to need that luck!
But I do not think that I can fit the turbocharged version or even get that here in the Netherlands.

http://www.marktplaats.nl/z/kubota-d722 ... increasing

[coachgeo]

...But I do not think that I can fit the turbocharged version or even get that here in the Netherlands....

Supercharge it for tighter space fitting? Either Turbo or Super; either from what I've read, is not hard to do with a D722, thus not necessary to find/purchase a turboed version to install

[pietenpol2002]

Supercharge it for tighter space fitting?

Not cheap (the shipping is what kils you), but about the simplest way to generate a good deal of additional power. Could be driven from the "front" of the crankshaft and hung from either side.

http://www.kemotorsport.com/
http://tinyurl.com/ntvegmj

And in use just down the street from you in the Netherlands (albeit petrol)

http://www.brommerforum.nl/showtopic/45321/4 (scroll down)

[Tetronator]

...But I do not think that I can fit the turbocharged version or even get that here in the Netherlands....

Supercharge it for tighter space fitting? Either Turbo or Super; either from what I've read, is not hard to do with a D722, thus not necessary to find/purchase a turboed version to install

Supercharge it for tighter space fitting?

Not cheap (the shipping is what kils you), but about the simplest way to generate a good deal of additional power. Could be driven from the "front" of the crankshaft and hung from either side.

http://www.kemotorsport.com/
http://tinyurl.com/ntvegmj

And in use just down the street from you in the Netherlands (albeit petrol)

http://www.brommerforum.nl/showtopic/45321/4 (scroll down)

Good to know, I've seen it done before with the D722 but I didn't know if it was hard to do or not.
https://www.youtube.com/watch?v=GgFOt-aUG7o

I will first try to fit the engine into/measure if it will fit into the bike.
After that process if I find it lacking in power I will try to add a turbo/supercharger.
But first comes freeing up a budget as that's a real concern, sadly enough.

Thanks for the info!

[Tetronator]

Tread Hijack prevention. https://www.dieselbikeforum.com/view ... 371#p21371

Nice! Very similar to what I'm planning to do, just a different bike and no CVT. What Carrier/Reefer unit did you pull it out off? I'm looking for sources where I could get a D722.

Cool to hear, what bike do you plan to use? Unfortunately mine was always seperated from the reefer unit when I purchased it so I dont know what unit it came out of. I can tell you that thermo kings use almost exclusively yanmars with some exceptions and carrier transicolds use almost exclusively kubotas with some exceptions. So focus on carrier reefers.

Allright thanks, I'm hoping to get me a Dnepr K750 and just mating the D722 to the gearbox. Maybe turboing it...

Check the details here: https://www.dieselbikeforum.com/view ... =31&t=2873

http://www.sunbeltcarrier.com/wp-conten ... 593608.pdf
It appears that these units may use the D722 based on page 1-9 and some of the pictures showing three injector lines, not 100% sure though. I was going to mention that there is a Supra644 for sale near me for cheap, until I saw how far away you are located.

http://www.sunbeltcarrier.com/wp-conten ... 593608.pdf
It appears that these units may use the D722 based on page 1-9 and some of the pictures showing three injector lines, not 100% sure though. I was going to mention that there is a Supra644 for sale near me for cheap, until I saw how far away you are located.

Haha, I appreciate the effort nonetheless. But the engine in that thing doesn't produce the 14 kW the D722 produces so I'm kind of doubtfull.

I noticed that too but, if you look closer that is at only 2200 rpm, not the 3600 rpm they are usually rated at.

I noticed that too but, if you look closer that is at only 2200 rpm, not the 3600 rpm they are usually rated at.

You know what, I think your right. The displacement actually matches up too.
http://www.prinsmaasdijk.nl/motoren/2/k ... -D722.html

Sorry, the manual i posted says 10.3kw at 2200rpm, which matches up with this graph perfectly.

http://www.m-k.com/pdf/D722.pdf

Also on closer inspection of the pictures I can see that the coolant port on top of the engine is the exact same as on my D722

Not that it matters just thought it was interesting, but I looked at the picture in the link you posted to see the coolant port and it appears that they have used the incorrect picture and used one of a Z482 instead (2 injectors). Just a precaution, dont use that particular picture as a reference for a D722. I may be mistaken. The dimension pictures at the bottom of that page are however correct. If you need any particular dimensions for the engine let me know.

And yes, they did use the wrong picture. But they are the main Kubota Supplier in the Netherlands I believe.

[garbs]

Just a thought id like to throw out there:
It seems you are set on a ural/Dnepr frame for the sidecar application, I actually very much like these as donor bikes as well. It seems that one of your main problems is getting a powerful enough engine to fit. Like you said in one of your posts, the Kubotas have a very narrow, long and tall profile. Although mounting the engine to the stock transmission is in my opinion, one of the best ways to do a conversion, I think it may be limiting your engine choices too much. I ran into this exact issue with the engine that would give the bike the capabilities I wanted, being too big for my frame. I did overcome this but not really practically and will be changing that engine out for a smaller one. Then building a second bike with a much larger frame which will hold a big enough engine and be able to accomlplish what I set out to build in the first place. I think my revamped first bike will perform fine, but basically what I'm getting at is that I should have built the second bike in the first place, instead of the bike I did build. When I realized it was going to be such a tight fit, it would have been more practical to either 1.Settle for a smaller engine 2.Use the same engine but use a larger frame or 3. Find a way to mount the engine differently to create more space. I think shaft drive bikes are plagued by the engine size limitations when trying to use a stock frame and transmission due to the nature of diesel engine shapes (long, tall, and narrow). This doesn't apply to smaller engines with slightly lower performace obviously, but your application seems to require a bigger engine. While I fully believe you could pull it off, you may be ahead to consider option 3 partly for ease and your lack of engine specific engine availability. If you were able to change the rear swingarm to a chain drive style you could then take advantage of the diesel engine shape and mount it sideways. The engine will obviously stick out the sides a bit, but shouldn't matter much on a sidecar bike (no leaning), and give you ample space behind the engine to mount a transmission due to being narrow. A simple cvt system comes to mind. Being able to use a larger engine should increase the selection available to you while ensuring that you will have enough power for a sidecar equipped rig. Having a chain drive rear end is much more forgiving in terms of placement of the engine and transmission as the chain can simply be lengthened or shortened. If you're set on the stock swingarm and tranny I fully believe you could make it work, just trying to give my two cents based on having built a shaft drive bike.

[garbs]

I don't know about engine availability in your area but I have always had an easier time finding engines in the 20hp and up range. Maybe something such as a Kubota d902 would be easier for you to find. I also see a trend where the harder they are to find, the more expensive they are. I can find larger engines all day for 300-500, but am hard pressed to find something like a Kubota z482 for anything under 600-800. That's just in my part of the, your area could be very different for this.

[Tetronator]

I see exactly what you mean all of this. That's why I am so specific on my engine choices, because I believe the D722 will fit and is available in such quantities that it has become very cheap second hand. Compared to a new one at least.
http://www.marktplaats.nl/z.html?query= ... ode=1024VZ (Dutch Craigslist/Ebay)
If its really necessary I will modify the upper frame as well, all tough I think cutting a corner out of the valve cover will work wonders in clearance.
I've got a very skilled machinist whom is willing to help me. (Shout out too boutje!)

But if I can get one of those Chinese V-twins... No worries, been done before.
https://www.youtube.com/watch?v=mBjpckJ ... yle_pVrJtE

I've also tougth about using a HD frame with a HD Ultima gearbox with belt drives... That be a special kind of expensive... Harley expensive. So no luck on that.
Besides I've got my mind set on my next motorcycle having a shaft drive as I've had enough of the chain malarkey. (That's how the british say it right, malarkey?)

But yeah, its gonna be tight allright. (That's what she said! )

Also turbo's
https://www.youtube.com/watch?v=6oX9xqDSCTc

[coachgeo]

...Also turbo's...https://www.youtube.com/watch?v=6oX9xqDSCTc

That D722 turbo is in a bike of a member here.

Another good thing about the D722 is it has close to the best HP by weight of the small Kubota. For example the D902 is around 60lb heavier and not that much more HP than the upper ranges the D722 has been used. Granted the Z has not much less HP than the D722 and is again much lighter.. lot lighter if I recall correctly.

[garbs]

The weights are actually much closer than that. Based on Kubotas site the d902 is only 19 pounds heavier than a d722. The difference between the z482 and d722 is about 22 pounds. But along with more weight comes bigger dimensions as well and size and every little bit of size and weight counts as it seems to add up faster than you think. The d722 does have close power figures to the d902 in most applications I have seen and I agree that it seems to be the best combination of size, weight, and power for a motorcycle application. I was mainly suggesting the d902 based on the 5 or so more hp it has for a heavy sidecar application but I definitely think a turbo'd d722 would have the best of both worlds and is the best option for sure. Something I think has a big impact on the overall weight is the oil pan. A good source of these engines is truck reefers, however, these engines most often come with the reefer style oil pans. Not only does the extra large oil pan add some weight, you have to factor in the weight of a couple extra liters of oil. I believe the oil pan on my d722 holds 4 or 5 liters. Id recommend to anyone to who attained one from a reefer to use the regular oil pan.

[coachgeo]

... I was mainly suggesting the d902 based on the 5 or so more hp it has for a heavy sidecar application

ahhhhhhh... very good point!!

... but I definitely think a turbo'd d722 would have the best of both worlds and is the best option for sure. Something I think has a big impact on the overall weight is the oil pan. A good source of these engines is truck reefers, however, these engines most often come with the reefer style oil pans. Not only does the extra large oil pan add some weight, you have to factor in the weight of a couple extra liters of oil. I believe the oil pan on my d722 holds 4 or 5 liters. Id recommend to anyone to who attained one from a reefer to use the regular oil pan.

Yep.... this is one area I almost screwed up. visual by picture I was thinking the carrier/reefer oil pan I had was actually wider but not as deep making the overall engine height lower than typical oil pan. Once we got a standard pan to look at first hand and compared.... we discovered the typical pan gives the best overall height by a few inches.

[Tetronator]

...Also turbo's...https://www.youtube.com/watch?v=6oX9xqDSCTc

That D722 turbo is in a bike of a member here.

Another good thing about the D722 is it has close to the best HP by weight of the small Kubota. For example the D902 is around 60lb heavier and not that much more HP than the upper ranges the D722 has been used. Granted the Z has not much less HP than the D722 and is again much lighter.. lot lighter if I recall correctly.

Lets off know-how here about the D722 it seems.

The weights are actually much closer than that. Based on Kubotas site the d902 is only 19 pounds heavier than a d722. The difference between the z482 and d722 is about 22 pounds. But along with more weight comes bigger dimensions as well and size and every little bit of size and weight counts as it seems to add up faster than you think. The d722 does have close power figures to the d902 in most applications I have seen and I agree that it seems to be the best combination of size, weight, and power for a motorcycle application. I was mainly suggesting the d902 based on the 5 or so more hp it has for a heavy sidecar application but I definitely think a turbo'd d722 would have the best of both worlds and is the best option for sure. Something I think has a big impact on the overall weight is the oil pan. A good source of these engines is truck reefers, however, these engines most often come with the reefer style oil pans. Not only does the extra large oil pan add some weight, you have to factor in the weight of a couple extra liters of oil. I believe the oil pan on my d722 holds 4 or 5 liters. Id recommend to anyone to who attained one from a reefer to use the regular oil pan.

Exactly, but first I will see if the D722 can handle the custom gear ratio and if I'm pleased with the acceleration. If not, turbo. Both the Z482 and D902 are more expensive/harder to get than the D722. As you can see there are mostly standard D722 available, and I was even thinking about shortening the sump to make more road clearance. The speed bumps here in the Netherlands are horrendous.

... I was mainly suggesting the d902 based on the 5 or so more hp it has for a heavy sidecar application

ahhhhhhh... very good point!!

... but I definitely think a turbo'd d722 would have the best of both worlds and is the best option for sure. Something I think has a big impact on the overall weight is the oil pan. A good source of these engines is truck reefers, however, these engines most often come with the reefer style oil pans. Not only does the extra large oil pan add some weight, you have to factor in the weight of a couple extra liters of oil. I believe the oil pan on my d722 holds 4 or 5 liters. Id recommend to anyone to who attained one from a reefer to use the regular oil pan.

Yep.... this is one area I almost screwed up. visual by picture I was thinking the carrier/reefer oil pan I had was actually wider but not as deep making the overall engine height lower than typical oil pan. Once we got a standard pan to look at first hand and compared.... we discovered the typical pan gives the best overall height by a few inches.

I thought so too, but apparently normal one is smaller.

[pietenpol2002]

My argument is still for the 902. Admittedly, 19 lbs heavier. However, on a power-to-weight basis it performs better than the 722. The 902 has a ratio of 6.4 lbs per horsepower while the 722 comes in at nearly 7 lbs per horsepower. The 482 is even worse at nearly 8.8 lbs/hp. Additionally, the 902 is shorter than both the 722 and the diminutive 482. The 902 is 21.42 inches overall while the 2 smaller engines (horsepower wise) are 22.21 inches. The reduction in height with the 902 is due largely to a redesigned pan.

[Tetronator]

Hmm, you say its shorter but...

Z482


Z602


D722


D902


Other than that, if I can get one for reasonable price and it fits, I'm all for extra power.

[garbs]

Yes hes correct, it is shorter. The confusion comes from mistaking which specific dimension he was referring to. If you referance the specific numbers he mentioned, he was talking about top to bottom not front to back. This may slightly help with having to modify thr valve cover like you mentioned. As you noticed, it is slightly longer.

[Tetronator]

Whoops, yeah it is less tall. But there's also a lengthwise issue going on. The only way to make sure that it will fit is buying/measuring the motorcycle I want it in.
I'm afraid that's going to have to wait till I have moved and have collected to funds to start this project. (Getting underway tough!... But not fast... )

If anyone has information on this build:
https://www.youtube.com/watch?v=NkbEwQAe3aQ
Please share.

[pietenpol2002]

If anyone has information on this build:
https://www.youtube.com/watch?v=NkbEwQAe3aQ

Below are the links from a thread posted here back in 2009 on this Estonian bike. BTW, the Yanmar in this Dnepr would be very simiar in size to the Kubota D722. And like some of the Kubotas, it was liberated from a refrigeration unit.

http://www.youtube.com/user/miilits001
http://www.youtube.com/watch?v=XZQnN6qP0Ao
https://www.youtube.com/watch?v=8wrZzZCrf2c
https://www.youtube.com/watch?v=bwQ3Ci-kvAQ
https://www.youtube.com/watch?v=sEFt5LfzUfA

http://pilt.delfi.ee/show_original/4837115/
http://pilt.delfi.ee/show_original/4837119/
http://pilt.delfi.ee/show_original/4837117/

[Tetronator]

Mucho's thank yous. Know what kind of yanmar engine it is?

[pietenpol2002]

Know what kind of yanmar engine it is?

There's reference made to 650cc. So, likely Thermo King's TK366 which I believe shares many, but not all parts with the original Yanmar 3TN66 . Manual below from the John Deere application.

http://golftechs.us/Manuals/JD220dieselengine.pdf

-

[Tetronator]

Ah, thank you. I was hoping to find some schematics of the engine for size comparison but I can't seem to find any.

[Tetronator]

# 4 - 3D Models!
Date: 20-1-2015
Status: Designing second stage

Well then I thought it time for another update, I still have not moved to a new house but all in due time. In the mean while,
I've gone about making a 3D model of my yet-to-be diesel motorcycle to check if it'll all fit inside the frame and what I would need to change to make it fit...
Here are my results!

Technical Drawings
To make said detailed 3D models I'd need something to base them off, so I went on to search for technical drawings of the Dnepr K-750... I couldnt find any,
but I did find drawings for the Ural M-72 where the K-750 is based upon. Thus meaning that they are VERY similar in construction and dimension. So similar that
you can exchange engines and gearboxes. There's a catch tough... They're written in russian... Needless to say, I tried anyway!

Examples!



What came out of that is this, keep in mind the wheels are the "worst" possible scenario of 4,00x19 and the front forks are a placeholder.



Now I needed to get some technical drawings off the engine I'd like to use... Couldn't find any online... So I paid a visit to the main supplier of Kubota in the Netherlands!
Much to my surprise, after I explained what I was treeing to do, I walked away with technical drawings AND a detailed 3D model off the D722...

Score! With compliments from Prins Maasdijk in the Netherlands http://www.prinsmaasdijk.nl/



Next up, rough gearbox model with proper placement in frame.





Design

So... Time to stick that mean diesel in there... Leave some place for a modified clutch assembly...


Good news, it clears the lower frame parts. Bad news, it's too long for an un-stretched frame and the valve cover clips the upper frame as I feared.


Stretchin' time!
Keeping in mind the limit of 50mm extra wheel base length I decided to move the front wheel 45mm forwards, hoping that it will give me enough space to make this work.
I had a couple of stabs at designing something but please share any ideas you might have. Also tell me which you find most viable in terms off contructability and strength.

First try: Kinky, Because it has a kink in the upper frame bit.


Second try: Lowrider, lowered engine, transmission, wheels. Don't know if this would work due to drive shaft clearance...


Third try: The Split, Split upperframe whats more to say?



So on to the next problem, flywheel and clutch. I'd like to keep the Kubota electric starter so that means that I will have to keep the starter gear ring on the flywheel.
Again I've had a couple of stabs at it, please give me your input.

Kubota flywheel, starter ring highlighted in red.


Kubota Front, those bolt holes are going to get in the way.


Kubota Rear, those balancing holes, they looks to big to just be balancing the flywheel. Do they balance the engine aswell? Also they get in the way


Ural M-72 Flywheel



My attempts:
First try, machined from Kubota flywheel. Holes drilled for springs and clutch "pegs" welded to front. Realized clutch "pegs" whould hit the starter housing and holes would reach the balancing holes on the back.


Second try, machined from Ural flywheel. Starter ring removed from kubota flywheel and rewelded to Ural flywheel. Actually the first time I encountered the starter clearance issue.


Third try, machined from kubota flywheel. Turned off too remove pesky bolt holes, holes drilled for springs and clutch "pegs" welded to front then again turned off too clear starter housing.


Fourth try, double whammy, total overkill. Machined from both flywheels. Kubota flywheel turned down to remove bolt holes, removed as much weigth as possible from Ural flywheel then welded to Kubota flywheel.



Hope its clear to you all and I didn't forget something but don't fret to ask anything, I'll make some more screenshots if needed.
As is customary now, please share your thougths.

Massive post is MASSIVE.

[pietenpol2002]

those balancing holes, they looks to big to just be balancing the flywheel. Do they balance the engine aswell?

Yes, the engine is balanced externally. And the holes in the flywheel are crucial elements in that balance.

[Tetronator]

those balancing holes, they looks to big to just be balancing the flywheel. Do they balance the engine aswell?

Yes, the engine is balanced externally. And the holes in the flywheel are crucial elements in that balance.

Hmm, good to know. Is it still wise to remove material from the flywheel then? Provided I leave the holes untouched and mount a balanced "secondary" flywheel?
Lets say instead of welding like my 4th attempt bolting it to the kubota flywheel. Via means of new treaded holes in the kubota flywheel?