Milling A Motorcycle Engine

Real motorcycle enthusiasts design and mill their own engines. Well, perhaps that’s an overstatement. Certainly it takes to more obsession than enthusiasm to go to these lengths. But this gentleman’s modifications started out simple enough, and managed to make it to the most extreme of hardware fabrications.

The used bike came with a modified camshaft that seemed like a botched job. As he got further into tuning up engine performance the prospect of just replacing the entire thing with his own design started to grow. Using a manually operated milling machine he cut his own molds for the new cylinder head out of wood and sent them off to be forged out of aluminum. They come back in rough shape but he just “filed the cast without mercy” and machined the tolerances to his specifications. Apparently the first test ride had him a bit nervous — he also milled his own brakes for the bike. But after a few times around the block he gained confidence with his work.

[Thanks Carlos]

30 thoughts on “Milling A Motorcycle Engine

  1. This guy has some real talent, not only did he design and mill his own motor he developed an electronic ignition system and then uprated the gearbox to cope with the improvements made from the better engine and electonic ignition… niice

  2. I can understand doing it for the sake of doing it, and Kudos to him if that is what he wanted to do.

    But making your own engine, That is done for the love of engineering, NOT because you want something to run.

  3. The site, she is gone… I wish someone had cached it. Anyway, there was a rather excellent movie with Anthony Hopkins a few years ago called “The world’s fastest Indian”. AH portrayed a retired hacker from NZ who wanted to set a record.

    I had assumed it would be just another family-safe snooze-fest, so I took my various relatives to see it.

    I was surprised when the guy started casting his own pistons for his bike, and the moving kept surprising me – bizarre gardening tips, tramp freighters, peyote popping shamans, dates with tranny hookers, an amazing amount of ingenuity and most of all, an excellent illustration of what it feels like to tackle crazy challenges.

    I highly recommend it to the “here, hold my beer…” crowd as well as the ardent arduino enthusiast, who will no doubt find the movie to be enjoyable for other reasons.

    I’ve often thought to experiment with engineering upgrades to build a type IV style engine using Subaru internals. Leaking oil, lousy tolerances and crappy metallurgy are the bane of every british, german and italian enthusiast in the world.

    I knew a guy who have pulled apart Norton Commando Engines and rebuilt them from the ground up, completely changing the internal lubrication systems, bearing tolerances and materials and even altering minor engine internals. Amazing work!

    If the site comes back up, I hope someone will cache it.

  4. I’ve said it before on numerous forums, if you decide to shine a light on something you have a moral obligation to make take some of the sting of web traffic spikes off the source. Many people toil in the dark on projects and sometimes the documentation of that toiling catches the attention of the web at large. Thing is, the web is mercurial and hits the unprepared hard.

    Slashdot, reddit, HAD, Gizmodo, engadget et all have an obligation to either contact the source and get permission to mirror or do so independently via sites like the coral cdn.

  5. I read the article – he didn’t build the motor, but modified it very heavily using donor parts. He also built a fuel injection system, and a number of other interesting projects. It’s pretty close to building a motorcycle.

    The guy in france making replica early 50s Vincent/Egglis had a nice site for a while.

  6. This is GODLIKE.

    No other words. This guy is a god of machinists. I can’t see the site, but only maybe a handful of people on their own have even done this. It’s completely insane!

    As a watchmaker with a manual machining and protoyping background, I love to see stuff like this. It inspires me to go further. I always wanted to hand mill my own boxer engine, a replacement for my own old 75′ BMW R90/6.

    This man… I’m just in awe. The tolerances he had to hit, design work, prototyping- it’s like being a mechanical, tribological, and electrical engineer, master machinist, and bike builder all in one. It’s the real world equivalent of the ninja class from FF Tactics- everything.

    I would kill to meet this dude. BTW, thanks for reminding of that movie- “World’s Fastest Indian”, I totally forgot about it- heard it’s amazing from my old machining teacher.

    1. Depends on the guy. It’s kind of like DIY furnace repair and modification; it scares some people to death, and you could potentially get featured on the 11 o’clock news as a darwin award recipient, along with your family and perhaps a few small animals.

      Anyone with an ounce of sanity would not accept those risks, and would ALWAYS trust the professionals to do that work and sell them the $300 repair and the $5,000 furnace upgrade instead. It’s cheap at the price, especially if you value your life.

      Then there’s “that guy” – about 15-20% of HAD’s readership, it seems – the guy who knows that even the most sophisticated household furnace has to be basically one of two things:

      It’s either an expensive barbecue grill or a relatively gutless and complex IC engine designed to remove all the water it can from the surrounding atmosphere and use it to slowly self-destruct.

      There are no other designs in common use, so establishing first prinicples is well within the grasp of your average “hard books” reading sixth grader.

      These are the guys who understand that behind all that sheet-metal, price tag, poorly designed electronics and sub-standard components is a simple machine designed to last through the warranty period by about 3 months, and then stop functioning in a way that won’t trigger lawsuits.

      This guy may or may not bother to pick up a couple of HVAC textbooks and skim through it, and he’ll probably discover that apart from the crappy electronics and purposely un-lubricated blowers, there are only about three or four things that ever go wrong, and these are so simple that even that sixth grader could be taught to identify and fix them in a few hours.

      Naturally, this doesn’t make the guy qualified to repair a furnace by any stretch of the imagination, any more than understanding black IPT, teflon and gas leaks makes you qualified to install natural gas lines.

      But he knows a little, he thinks, and is pretty comfortable with the technology and as long as he stays within the shallow end of the pool, he can probably do a pretty fair job of diagnosing the problem, and that’s where it gets interesting.

      Some guys look at these things and understand the risks as well as the “engineers” who designed the box in the first place, even if they don’t have an adequate grasp on the metallurgy or doing the performance calculations.

      The funny thing is, it’s not uncommon for the guys doing the original engineering to be essentially copying the guy before him, who copied the guy before him, who copied the guy before him… who was in reality copying some idiot who built a prototype or two in his garage, hobbyist lab or machine shop, or some dusty aircraft hangar.

      As the invention or device moves up the chain from “hey, it worked!” to consumer or industrial product, it got prettier and more opaque, and various improvements get made in packaging and maneuverability.

      At the same time longevity, durability and ease of maintenance probably went down, since the commercial entity is ONLY there to make money and avoid lawsuits.

      This is why there will always be guys who will do (god save us all) amateur surgery and build death traps to drive or fly around, and who will play at every professional art from law to love, which includes engineering, psychology and war.

      Some of them will make examples of themselves – because they were lacking some element of common sense and information, or because lady luck decided to wander off for a pack of cigarettes and an espresso on that day.

      But – they are the only ones who can make that decision. If we remove the ability to do so, we hamper our ability to progress as a species, and that wouldn’t be any fun at all!

      So here’s to you, Mr. “Hey-look-what-I-built!” Carbon Dioxide Underwater Re-breather apparatus, and to you, Mr. Human Helicopter ne Organ Donor, and to all the men and women out there who think to themselves “this will be a piece of cake” as they fire up that oscilloscope, soldering iron or oxy-acetylene torch: Good on ya!

    2. Seems so.

      Remember, “a professional” is just the name we use for someone who gets paid to do a thing.

      An amateur is someone who does a thing for love of the thing. Not as some seem too easily convinced, someone who does sub standard work.

      Talk with someone who is not only enthusiastic, but knowledgeable, and you will understand.

      1. Hence my love for amateur doctors.

        Really, Boris Karloff’s film career (and eight generations of cigarette smoking guys dressed like butchers and providing “services” to frightened women) have given the hobby a bad rap.

        Now, if you’ll excuse me, I have to go check on my frankenhamster. It’s been three days, and although I got the heart beating again, I just can’t seem to get his CNS up and running far enough to open his eyes.

        I should have used more Kites.

  7. There is a long history of homemade engines. For older ones look up the Jones GP bikes in the 1950s and 60s, He was making 4cyl OHC engines while British manufacturers were thinking abortions like the Norton Commando was the way to go,
    Jack Brabham started off in a similar way.
    Then there’s Alan Milyard – his bikes are awesome.

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