Homemade 4-Stroke Single

Discussion in '4-Stroke Engines' started by boogerballs, Dec 10, 2009.

  1. boogerballs

    boogerballs Member

    A friend of mine who is a vintage/race car fabricator as well as having the prestigious title of the world's fastest 50cc streamlineris at it again. I just left his shop and am still amazed at what he's accomplished. He took a Honda crank, a VW piston, barrel and head and a Tillotson carb. He heavily modified the head, made his own rocker assembly, and is using an atmospheric intake system (no intake pushrod, just a spring) that uses the vacuum created in the combustion chamber to open the intake valve.
    He completely fabricated the crankcase from an aluminum tube and a couple of chunks of aluminum billet. Well he started it by hand and it started real easy. Since he hasn't balanced it yet, it shakes and vibrates quite a bit. Here are some images.

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  2. Al.Fisherman

    Al.Fisherman Active Member

    When I see posts like this, the way it's titled as "Made" I automatically throw up the BS flag. Let me pull it down real quick...One heck of a job.:eek:
  3. vazfx16

    vazfx16 New Member

    now that is art
  4. ibdennyak

    ibdennyak Guest

    Outstanding!! I have nothing but admiration for people who do projects like that. I have a few friends in Wisconsin the "restore" the hit and miss engines. By restore I mean they fab their own rings, pistons etc....whatever the engine needs. They are a fascinating group of people.
  5. Turtle Tedd

    Turtle Tedd Member

    This is the kinda stuff I like...focused ,obsessed ,genius at work....
  6. Mountainman

    Mountainman Active Member

    wow ---------- yes ------------ fine homemade

    would that THING look so fine on a motorized bicycle ??

    man oh man

  7. mlcorson

    mlcorson Member

    I admire a person who can, just for the fun of it, create a vision and then overcoming all obstacles, summon all his/her powers and skills to fulfill it. Amazing work.
  8. That is sweeeeet! The atmospheric intake valve is an old idea that worked fairly well in WWI fighter planes. The Gnome Monosoupape (one valve) rotary engine is what I am thinking of. The atmospheric valve does limit power output compared to a cam operated intake valve because the valve doesn't open as long or as wide as a cam operated valve and valve timing is severly limted.
  9. ibdennyak

    ibdennyak Guest

  10. boogerballs

    boogerballs Member

    I know John was trying to keep the power down on purpose and the atmospheric intake did its part. Since the VW barrel and piston was about 300-400cc at its stock stroke, he cut the connecting rod in half and joined it with the Honda 125 two-stroke roller bearing crank after cutting that connecting rod as well. He joined the two rods together with the resulting diplacement at around 250cc. The carb is tiny as it came off a 50cc two stroke engine. He figures it's going to produce about 2.5 horspower. I've included a somewhat blurry picture of the other, non-modified, half of a VW head. The other half is what he trimmed off lots of fins and such.
    I watched him experiment with using just one ring versus two rings on the piston, since one didn't produce enough compression for him. He also switched out the atmospheric intake valve spring with a lighter one so it might idle better. Just amazing!

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  11. flashstar

    flashstar Member

    If he could make us engines to replace the outgoing HT's, that would be truly amazing! You don't see many people like this though. Most of the guys who work on engines that I have encountered replace them rather than build them themselves.

    How much power does he think it could make without being limited?
  12. boogerballs

    boogerballs Member

    Well that would be truly amazing! John loves everything vintage and when push comes to shove, he chooses to do it the old fashioned way. It was always my idea that someone should remanufacture something like those old turn of the century 4-strokes. I had spoken with John about it a long time ago and when he started to build that engine that's the direction he took. I don't think that this would work in this modern, environmental impact time. I do wonder what we'd need to do to make one be able to pass the EPA tests yet still retain that look and function. The little modern 4-strokes look essentially like little briggs & strattons (ugly) to me. But ****, it's just that those modern motors were design for things like weed whacking and such that they ended up looking like that. Someone just need to rework their little crankcases a bit to make them round and then lengthen the stroke so they'd be better suited for a bicycle application. At least John's motor is a step in the right direction.

    I don't know that he would go to try and get the "most" power out of that setup since then it wouldn't be suitable for a bicycle. He only went with that setup for two reasons. One, it's about the size/configuration of most of those old motors and two, he could get the cylinder, piston and head from the VW and the crank from a Honda 125 motocross bike easily (as in free) or he already had them.
  13. boogerballs

    boogerballs Member

  14. Irish John

    Irish John Guest

    Threads like this one are just amazing - most up;ifting thing I've seen for a few weeks.
  15. motor_head

    motor_head Member

    i was thinking this was bs but once i looked at the pictures i thought thats freakin awsome
  16. Egor

    Egor Guest

    Well John beat me to it. I have been saving parts for a while now. I was looking for a barrel for the 36hp VW it is 3" and a perfect fit for some of the B&S engines I have parts saved for. I built a small Hit & Miss engine a few years ago and ended up making my own intake spring. If the valve is heavy it will have a hard time at speed. You can turn it down on the lathe. Good job and that is going to look beautiful hanging in a period frame. I am going to follow this one close. Have fun, Dave
  17. boogerballs

    boogerballs Member

    Dave, I don't think we can't have enough of projects like these so good luck with yours and keep us informed. John must have had the same koolaid as you. When he showed me the intake valve off his motor as he was changing to a lighter spring I couldn't help but take note of his modifications. He had taken the stock VW intake valve and hollowed it out to within about a half an inch from the head. Then he had carefully dished out the valve face to remove as much weight as possible. I'd love to see your progress on the motor you're collecting parts for and if you have pics of your hit an miss.
  18. Chris Crew

    Chris Crew Member

    I love this country!
  19. robin bird

    robin bird Member

    In my books that guy is a genius--i wish i had one tenth his skills !!
  20. Egor

    Egor Guest

    This has got the juices flowing. I am going to get the parts in order and start getting this thing up on the bench. I have a few cranks, cam's and others. I like the head, and I have a VW head. I just got a lathe and mill. I have the plans for an engine out of the Boy's book from the twenty's saved. I have boxes of B&S parts from a shop that shut down, been thing about this for a long time. Have fun, Dave

    The pic is of the Hit & Miss I built. Honda 125 crank and barrel

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