Diesel Bike Build: Round 2


[Alex] has been hard at work on his second vegetable-oil-powered diesel bike build. The last time we checked in, he was finishing off work on his Honda CB400. Unfortunately, he felt it wasn’t quite big enough to ride comfortably, and as most first builds go, it was burdened with its share of problems. Now he’s snagged a Yamaha XJ600 off eBay, cleaned it up and started the modifications. [Alex] extended the frame to accommodate a new engine, rebuilt the gearbox, and perhaps most daunting: turned down the pulleys with a vintage 1950’s lathe.

Now that [Alex’s] bike has passed the MOT inspections, he can enjoy cruising around while doing his part to save the environment. His build log details the process, and is packed with enough pictures to keep you busy for a few hours while it walks you through each step. You can watch the bike’s test-run video below. For you off-road types, check out the all-wheel drive motorcycle from last month.

32 thoughts on “Diesel Bike Build: Round 2

    1. The thing with diesel engines is not the CO emissions, but the small carbon particles, on factory setup, they usually use filters that gather carbon and then burn it in this filter, from the heat coming from engine. But still the smallest particles of carbon still find their way throw that system and they are the most dangerous causing lung issues.
      But anyways nice build, except maybe the welds on the frame:)

      1. The MOT is yearly in the UK, and they don’t have emissions tests on motorbikes, yet.. This should’ve passed an MOT easily enough, all that’s checked is suspension components, lights, wheels, bearings, cables, fuel/brake fluid leaks, and things loose.. That’s pretty much as far as it goes.

      2. How ’bout them NO emissions and resulting O3 build up. Our poor air quality days around here are usually Ozone alert days. That’s the main problem and why diesel is being regulated to death in the US with ULS diesel, Urea injection systems and more.

    2. It’s a very cool build, though I guess the motive will be lower running costs. In the UK, vegetable oil attracts no sales tax whereas diesel or gasoline for highway use attracts a large levy. Burning a limited amount of veg oil in a road vehicle is allowed but burning cheaper fossil fuels like heating oil or paraffin is strictly prohibited.

      It would notionally be low carbon if he were to fuel it with waste oil that has already been used for cooking. Using fresh vegetable oil merely shifts the carbon emissions to the place where the crop was grown or the fertilizer used was produced. The soot the engine generates only pollutes the immediate local environment.

    3. I don’t know the carbon stats for diesel vs gasoline. I know all the worlds freight industries use diesel because they can produce high compression/torque without burning the material of the valve system and cylinder sleeves, and it doesn’t take a parted ignition system.

      You couldn’t run the freight industry off the current electric or alternative-fuel motor&engine tech because of the torque needed for logistics.

      It’d be interesting to see some emissions test done on this vs it’s original gas engine.

      1. Hi All
        This is my build. I completely agree on all counts. Mainly though that its a carbon neutral bike (apart from the carbon used to make it) if used vegoil is burned. I currently obtain my vegetable oil from a old restaraunt that would otherwise chuck it to a waste managment company.

          1. Its mixed wtih 10% petrol. This reduces the viscocity enough for the summer. In the winter I will be using a slightly higher percentage of petrol to reduce the viscocity further. I am also going to modify the injector pop pressure higher, so that the fuel atomises better.

            A 3rd thing I am looking at is heating the injector line, but that uses a lot of power, which isnt really available.

          2. I believe you will find that the petrol won’t keep the waxes in the waste oil from clouding up in the cold. The problem with regular diesel fuel too is that unless you use a mixture designed for cold weather, it gums up the fuel filter. If you have no filter, it destroys the injection pump. If there’s any animal fats in the waste oil, tallow etc. it starts to cloud up as high as +16 C.

            Waste oil can be treated e.g. with a bit of methanol and lye to remove the glycerins and waxes and significantly improve the cold pour and cloud point properties. It’s relatively easy to turn it into proper biodiesel that way.

      2. IMO vegetable oil only creates another industry who’s demand will be targeted by inflation and plutocracy..

        There needs to be a tech for compression driven engines that uses elements of the breathing air composition or some type inevitable waste. This way there is a perpetual carbon footprint that self-consumes and it’s not tied to any corrupt market..

      3. Here in Europe a large part of the railways are electrified, the one thing that is diesel only are in fact light passenger trains :P
        Most freight stuff is actually electric, since you can cram a lot more power into a given size locomotive, plus it’s cheaper to run.

        As far as torque goes, an electric motor will always beat the crap out of a similarly sized diesel…as a (fairy substantial) bonus, you do not need any kind of variable transmission or clutch, they use a fixed ratio (or direct drive)…

        Even in US the huuuuge freight train locos are diesel-electric (can you guess why? :P), the only reason the US doesn’t use electric trains is lack of (expensive) infrastructure.

        1. It seems like it’d be better to have a transmission on an electric motor, or have a torque converter that doubles or triples torque. An automatics with a low gear stage half way then some high gears for cruise. Make it less expensive to maintenance than the motor.

          You’ll likely not see electric 18 wheelers implemented anytime soon..

          1. Electric motors designed for multi-range operation usually have ways to switch the number of poles as a sort of electric reduction gear. Otherwise the problem becomes that under low operating frequencies the impendance of the coils drop too much and they essentially become short circuits, drawing loads of current and not doing much work.

            The effective adjustable range of a regular AC induction motor is approximately 25-125% of its nominal rated speed. Outside of that, either the efficiency or the torque falls off quickly. That’s also the reason why electric cars have to limit their top speed; if your top speed is 125 MPH then your minimum efficient speed is 25 mph and below that you’re wasting energy.

    1. I agree ICE aren’t very environmentally friendly.
      But if people are going to keep using ICE (and they are) then modifying one to run on a renewable waste material that is net carbon neutral is a step in the right direction.

  1. I really hope that’s a private road, as the British Police don’t take kindly to people riding motorbikes without helmets. Although they do love it when said people take videos of them doing just that and post them to a public site :)

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