So I've become very very interested in diesel powered motorcycles of late. Google turns up very little on them, and I'm very interested in acquiring one, or fitting a diesel engine to a gas model. I'm in the US, and it's already pretty damned hard to find an original diesel model anything for under $15,000, so the decision is leaning towards converting an existing frame to use a diesel. Google turns up little information about converting a gas cycle to diesel, or much info at all about diesel cycles in general.
So tell me Veeky Forums, how difficult from an engineering standpoint would it be to do the conversion, and fit a diesel to the chassis? I don't know much about motorcycles, or automotive mechanics for that matter, but how hard could it honestly be? I've got the time and intuition to learn and work at a slow pace. From a layman's viewpoint, the most difficult part seems to be finding a transmission that will work with it, since most motorcycles seem to have their current one built into the motor. I'm not really concerned with how fast the thing will be. I actually really like the advantages a diesel engine gives in the form of a motorcycle. I want to build it just because I can, and to see just how fuel efficient I can make it, while keeping it's top speed at around 75mph.
What would be some good places to start looking in America? I really do like the post-war aesthetic of Royal-Enfield bikes, and would like to find a similar chassis, or acquire an actual sommer chasis. Ultimately though, I'm just concerned about making a fully functioning product, and am willing to throw out all forms of aesthetic to make a working piece as my first venture. I'm thinking my total capital available to put into the project would be about $4,000-$6,000.
How feasible is this project with my budget and being located in the US? Where can I start looking for good models that are easy to convert over with my budget? What are some good resources I can use for learning more about converting a gas automobile to diesel?
Jose Butler
Bike and general mech here.
Throwing engines not designed for motorcycles into motorcycles leads to bad motorcycles. I suggest hunting up a recent diesel military motorcycle. All your problems solved in a useful package.
from what I understand, not many of those were made, only around 500 were made, at least for the first order, and none have been ordered since 2010. I've seen them go for sale, but for astronomical amounts for what they are, like in the neighborhood of $10,000 dollars. Believe me, I'd love to outright buy an old Royal-Enfield, or one of the newer converted Royal-Enfields, or perhaps some decommissioned war-bike, but those are way out of my price-range. I wouldn't honestly be thinking about getting one at that price, since it defeats the purpose I originally set for acquiring one, learning a modicum about auto-mechanics and diesel mechanics, and creating a long-term fuel saver.
I here an issue diesels too large for the bike cause a lot of vibrations, loosening parts. But I'll state again, I'm not really concerned that it will create a motorcycle that isn't comparable in performance to other gasoline models. I'd just like it to perform reliably and efficiently as possible.
Levi Phillips
diesel bikes suck.
Juan Parker
That's like, your opinion man.
Leo Diaz
>diesel in a motorcycle, why not more?
Law of diminishing returns. A motorcycle, compared to a car, is so light weight it doesn't stand to gain much from a diesel power plant as opposed to conventional gasoline. What you lose in the trade-off is either roughly equal or more valuable in utility than what you gain. That being said:
This never got a lot of attention, but it combines two seemingly atrocious concepts (hydrostatic drive + diesel in a motorcycle) and works fantastically, from what I read. There's another one made by the same guy, but it's somehow twice as ugly as the original.
I know the marines have a diesel motorcycle, but that's only so it can drink from the same fuel supply as literally everything else in the military's inventory. I've never really heard about it performance wise, but the conversion for their bike is horrifically expensive. It's basically a Kawasaki that gets gutted and refitted with a new engine.
At the end of it all, I can say this: If this is the first time you've swung a wrench on a bike, and you're looking to retrofit this much crap to have a novelty, I strongly suggest you take the time to find other projects. It's not a dumb idea, but the net gains might be a lot less than you think, intrinsically and otherwise. This is coming from the guy who thought the coolest bike he ever saw was someone's nigger rigged backyard project with a snowmobile engine.
Owen Torres
A Dnepr with a 1000cc Hatz diesel engine
is a diesel trike with a t-34 engine installed. I think it still may hold the world record as heaviest diesel motorcycle.
Evan Morris
1 do you even ride 2 do you even have a diesel 3 do you wrench
Tyler Turner
I wanted to acquire something like an old Dnepr, or Royal-Enfield specifically for the reason that it might be a real son-of-a-bitch to fit one to most other bikes. I've read that not nearly as much work goes into converting them.
I will say any of those alien hydrostatic drive bikes are way beyond my foreseeable skill. I'll be damned if they aren't ugly as fuck too.
I'm thinking I'll either buy a gas Dnepr or RE and do more book-learning and resource gathering in the meantime so I can a Yanmar or Hatz diesel to it at a later date.
Parker Butler
nope, nope, and nope. But who's to say I can't learn? It's not like I've failed at doing anything I've sunk the time and effort into before, no sense in that changing now.
The reason I came here was to ask for places to acquire diesel bikes or parts, acquire books and resources in line with my goals, and seek advice.
Ayden Brown
If that hydrostatic getup is beyond you, so's refitting a frame to take an engine it was never imagined to hold. You've got a long way to go, I'd save your money and work on something easier for now. There's no shame in taking baby steps. Having outlandish, silly goals is what makes the automotive, and especially the motorcyclist community what it is. Shit, some guy made a radial engine from 9 single-cylinder Honda engines. But jumping waist deep your first time around is a quick and easy way to blow a shitload of money and end with a pile of scrap.
Mason James
hey OP, nice thread, I am also interested in diesel bikes. I got into it ages ago, my $0.02:
First, small diesel engines are designed for like, generators and bilge pumps etc. So they tend to be really loud and heavy for the power they make. Compare the specific output of like a yanmar 500cc diesel to the specific output of a diesel golf and be horrified. So it's going to be hard to find an appropriate diesel engine with say, more than 30hp that will weigh the right amount.
Second, the transmission issue. Most of the conversions I saw on the internet used some CVT unit and did actually function well. However in my opinion, CVT would be fucking boring and ruin the whole experience of riding a motorbike in the first place.
Third: it's not what you want to hear when assessing a possible project, but something like a dr650 is more dieselly than most diesels and it's a beautifully engineered stock bike/complete package. But that's kind of irrelevant IMO, the concept of a diesel bike is cool enough that it needs to get built.
So where does that leave us? Some positives and possibilities. Working on motorcycles, especially steel framed/carburetted ones, is dead simple. It's a great way to learn how to wrench. I think if I were to go a diesel motorcycle, I would go: small car based turbodiesel (out of some europoor shitbox), harley seperate transmission and belt drive, and put it in a large framed motorcycle so the suspension and frame can already handle the weight.
Owen Hernandez
Enjoy, guys.
(BTW does anybody know what motorcycle this originally was?)
I can't imagine why you'd want a smelly, heavy engine that sounds like a bag of broken hammers and makes about three horsepower at 3000rpm in a motorcycle.
You can get ridiculous fuel economy with small bikes, you can get good torque from petrol singles and twins, I just can't see why you'd want a diesel boat anchor in a bike.
Also, if you have to ask it's probably out of your league, just saying.
Chase Morgan
looks like some Ural frame.
Connor Young
Look up Dieselwiesel, import one of those for 8800€
Dominic Mitchell
I advise you to learn on something a bit simpler because your use of a diesel conversion as "benchmark" act is going a bit far. If you must, you should find the ENGINE you want first. In clean, running condition or damn close to that with no engine problems. (Donor vehicle can be fucked, and "wrecks were running until they rekt".
There is a way to have a relatively easy time producing a diesel trike which you can outfit with aggressive tires if you want an offroad meme. Buy a diesel Volkswagen for the drivetrain. adapt to air-cooled VW transaxle and otherwise build a classic VW custom trike.
You can copy any of MANY VW trike designs (trikes register as motorcycles in the US) easily and most importantly, very inexpensively if you don't care about cosmetics. Paint the thing a military color or whatever, something you can touch up as you modify it.
You can choose from many motorcycle front fork arrangements. I'd buy a wreck for all the small parts you don't think you will need. You can snip the frame apart with a recip saw which is a common way to scrap motorcycles.
A two wheeled diesel will be shit, but a trike will weigh little compared to its parent vehicles and not suck to drive! The designs are proven by Stires etc since the 1960s. If your wrecked bike has a title (a wise idea since your donor car title is useless) you can keep the front frame section with the VIN and blend neatly into your project.
Look up "diesel vw trike" for lots more info than you suspected exists including modern turbodiesel builds.
Your problem is now solved in a way giving you good power to weight ratio (not possible with some little industrial or tractor diesel), good brakes, and decent handling if you do it right! You can place your engine forward instead of behind by flipping the ring gear in the aircooled VW transaxle. Common mod for sand rails. Post a build thread on a trike forum so you get feedback from people who can fab and spin a wrench.
Juan Carter
Noob tips: TAKE PICTURES BEFORE YOU CUT SHIT UP, AND LEAVE EXTRA METAL WHEN INITIALLY DISSECTING DONORS. Buy the fucking factory service manuals for your VW donor vehicles. You'll be building a library. WIRE IT PROPERLY AND NOT WITH A BUNCH OF SHIT FROM THE LOCAL AUTO STORE.
Visit chopper forums because the good examples of fabrication and ingenuity are worth a look. My nick is "farmall" on various forums including Chop Cult. When you get further along, drop a build thread there.
Learn to weld, and not using some shit flux core ChiCom junker. You can start a tool thread later on if needed so you buy wisely. Hang out on Weldingweb and the Miller forums and look at finished projects. All you have to do is supply PERSISTENCE and DETERMINATION to become a mechanic and fabricator. If you can do that, you will change yourself in ways worth far more than what you build. See welding forums for info on best equipment options for your situation.
Read "Zen and the Art of Motorcycle Maintenance" by Robert Pirsig. Free download with some looking. I read it in high school and was bored. Then decades later I read it as an experienced gearhead. It's still windy, but you will understand.
Remember someone, somewhere knows how to do every individual task you need to do. Go learn. You will spend a few hundred hours reading at least, but that's more interesting than weebshit.
Never hurry and you'll finish quicker.
John Reyes
diesels have shit throttle response without forced induction. Why give up the one quality inherent to small engines?
Elijah Gutierrez
Custom titles are an asspain. I collect frames with clear titles for future use on customs. Do that.
Fortunately for you, dead Jap bikes with clear titles are plentiful. Dead Jap touring bikes like Gold Wings and Ventures go for close to scrap money and you can part them out on Ebay.
David Nelson
You can do it if you really want to but you should keep in mind that there is literally zero point in doing so other than perhaps the satisfaction from some kind of personal challenge. Motorcycle engines have become so refined and efficient over the years (particularly the inline four configuration used in racing) that you literally have 150 pound engines producing 240hp at the crank and 90+ft/lb of torque on gasoline while still averaging 50 mpg. The engine is just so far developed that nothing will ever compete.
Jacob Russell
True dat, and turbos are plentiful with the auto engines they come on.
OP can also do a reverse trike with the entire FWD drivetrain and rear wheel of his choice.
>that you literally have 150 pound engines producing 240hp at the crank and 90+ft/lb of torque No you literally don't except for maybe one or two examples used exclusively in racing.
Isaac Brown
yeah well trikes are gay 2bh
Owen Hill
>yeah well trikes are gay 2bh
Not if you add horsepower. HP and torque are testosterrific.
Camden Hill
that's closer to a 3 wheeled car. Those fags on 3 wheeled Harleys and Can-Ams are blatantly too afraid of motorcycles yet want to partake in the act of riding and pretend to be badass etc. A very small percent of those people are disabled so they can't ride two wheels. But even then my old boss had a bum leg and rode a panhead.
Ian Rivera
Those Can-Ams are IMO a ripoff, but some people like them and many of those folks also own motorcycles. I wouldn't own a Harley trike because changing belts sucks on those. If I felt trikey I'd use a Gold Wing for the shaft drive and abundant conversion kits.
I wouldn't personally want a trike unless it was done BMW/Ural style (common rear axle makes them not really a "motorcycle" except for licensing) set up for offroad. Ural fanatics take their rigs into some shit....
However OP is painting himself into a mechanical corner so it's either an awful diesel two-wheeler (he hasn't figured out non-awful options exist and must learn that himself) or what could be a usable, torquey "cyclecar" (to use the old term for such rigs).
All I did was tell him how to get there.
Jordan Thomas
As much as I dislike trikes, this isn't actually that bad an idea. I could start with a trike project just to give myself more room to work with. Thanks for the input.
Isaac Turner
Nono, I thank you for the advice. You have given me the most out of everyone here. Ill look into a trike project over a diesel cycle one. I'd like to keep it diesel simply because it's what I'm most interested in. The idea that I can find VW parts for a project like it might help lessen the pain of searching for them.
