Building from scrap w/ 8 hp Briggs

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UglyJeep

New Member
Sep 14, 2012
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Tucson
I've been collecting parts for a little while now, and just started building. So, I figured that I should start a build thread.

It'll be powered by an old 8 hp briggs, that I got for free (starts every time on the first pull) coupled to a centrifugal clutch. The fuel tank is being built out of a section of diesel exhaust pipe (not the piece in the photo). The donor for the frame was an older women's bike. I think the wheelbase is at 49". I think the tubing we are using is some old scaffold frame pieces.

I will not be using the bicycle chain or sprocket on the pedals. I will use the extended crankshaft as the jackshaft for the engine, but instead of just having standard bearings it will have a one way bearing. The engine will be able to overrun the pedals, but with the engine off (or at low rpms) I'll be able to pedal the bike using the chain normally only for engine drive.

Here's a pic of the frame as of last night. You'll notice the funky square tube and odd down tube - that is my grandfather's contribution. I was planning on having the ubiquitous drop loop style fame. He's old and stubborn and helps me on my projects. Often I'll come home from work and my project has taken a different direction.



Oh and the name for the project - "утильсырье" which I'm pretty sure translates from Russian to scrap or junk. It is also getting painted on the side of the tank.
 
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UglyJeep

New Member
Sep 14, 2012
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Tucson
It is great working with him. He can be a pain in the rear though.

I doubt that he'll have one for himself, but there is no telling what will happen once it's going and he see's how much fun it is. He is fond of his toys.
 
Goat Herder

Goat Herder

Gutter Rider
Apr 28, 2008
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N.M.
Signing on for this thread. Scrap builds have always been my favorite thing to check out. It is always refreshing to see what folks come up with and fun. This is as exciting as when I get to rummage through and build my own stuff !!
 
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msrfan

Well-Known Member
Sep 17, 2010
1,808
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Southern California
Cool bike, I have an 8hp in a Schwinn and it's a blast to ride. Your jackshaft and sprag bearing sounds like an interesting feature. How will you start the engine? A kicker would be awesome.
 
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UglyJeep

New Member
Sep 14, 2012
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Tucson
Building from junk/leftovers is always fun. I love creating something out of nothing (it makes me feel like a magician).

I have been thinking of doing a kick starter, but it'll prolly just be pull start at first. I've also been thinking of modifying a centrifugal clutch with another one-way bearing for pedal start (dunno where I saw that one ;) ).

The bike is going to have to sit neglected this week, because my father-in-law is visiting and the Jeep (which is quite ugly) sustained a little damage from a recent trail run (I cracked the chassis in two places and lost a front u-joint). I was able to get the motor mount welded in.
 
dracothered

dracothered

New Member
Jul 25, 2012
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Howell, MI.
UglyJeep said:
Building from junk/leftovers is always fun. I love creating something out of nothing (it makes me feel like a magician).

I have been thinking of doing a kick starter, but it'll prolly just be pull start at first. I've also been thinking of modifying a centrifugal clutch with another one-way bearing for pedal start (dunno where I saw that one ;) ).

The bike is going to have to sit neglected this week, because my father-in-law is visiting and the Jeep (which is quite ugly) sustained a little damage from a recent trail run (I cracked the chassis in two places and lost a front u-joint). I was able to get the motor mount welded in.
Click to expand...
Is it an AMC CJ5 that you have?
 
C

curtisfox

Well-Known Member
Dec 29, 2008
6,048
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minesota
UglyJeep said:
Building from junk/leftovers is always fun. I love creating something out of nothing (it makes me feel like a magician).

I have been thinking of doing a kick starter, but it'll prolly just be pull start at first. I've also been thinking of modifying a centrifugal clutch with another one-way bearing for pedal start (dunno where I saw that one ;) ).

The bike is going to have to sit neglected this week, because my father-in-law is visiting and the Jeep (which is quite ugly) sustained a little damage from a recent trail run (I cracked the chassis in two places and lost a front u-joint). I was able to get the motor mount welded in.
Click to expand...
Check out Goldy's build shows how to do the clutch so it can be pedal started.Awesome simple.http://motorbicycling.com/showthread.php?t=28747 ..............Curt
 
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UglyJeep

New Member
Sep 14, 2012
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Tucson
Curtisfox - Thanks for the link! I hadn't seen Goldy's build (though with the way he has his pedals/jackshaft it would seem I had). That should simplify things considerably.

dracothered said:
Is it an AMC CJ5 that you have?
Click to expand...
No, I have a Kaiser CJ-6a with a buick v-6. If it were a later jeep it might run half of the time. Right now the jeep only runs .0000001% of the time (maybe less).

My grandfather has been getting work done on the bike - he is rarely phased by the lack of my presence when working on my projects ;).

Here's the motor mount - that he's welded nuts to the underside.


This engine is massive!


Here's the filler neck and cap. It is difficult/impossible to tell from the photo, but the sides are knurled and the top is domed. He made it out of a chunk of 2"x2" aluminum bar (I wanted to go with brass, but the aluminum was free). The inside is threaded for a check valve, but I have doubts about the effectiveness of a one way valve for venting a fuel tank. And, no the filler neck will not stay that long, it will be cut to length when the rest of the tank is finished.
 
Dan

Dan

Staff
May 25, 2008
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Moosylvania
Awesome Jeep. Very cool build.


Wife; "Dan, ya ever gonna get rid of that junk?" Me; That ain't junk. It's a pile of future components"
 
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UglyJeep

New Member
Sep 14, 2012
7
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Tucson
My father-in-law had to leave early, and I can't buy the parts to fix the jeep right now, so....



The tank is about 1/2 done - the rear taper still needs adjustment, and we have to install the outlets.



One outlet, at the front, will have a "stand pipe" to prevent picking up the last 1/2-1/4 gallon or so. The rear outlet will be flush (or close) to the bottom of the tank - to act as my reserve (I often forget to check the fuel in my jeep - I always keep the 5 gal can full). The "petcocks" are two brass valves i scrounged from some junk at work, another piece of equipment donated two brass balls (~3/8 dia.) to serve as knobs on the valves. Hopefully it'll be done tomorrow
 
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curtisfox

Well-Known Member
Dec 29, 2008
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minesota
UglyJeep said:
Curtisfox - Thanks for the link! I hadn't seen Goldy's build (though with the way he has his pedals/jackshaft it would seem I had). That should simplify things considerably.



No, I have a Kaiser CJ-6a with a buick v-6. If it were a later jeep it might run half of the time. Right now the jeep only runs .0000001% of the time (maybe less).

My grandfather has been getting work done on the bike - he is rarely phased by the lack of my presence when working on my projects ;).

Here's the motor mount - that he's welded nuts to the underside.


This engine is massive!


Here's the filler neck and cap. It is difficult/impossible to tell from the photo, but the sides are knurled and the top is domed. He made it out of a chunk of 2"x2" aluminum bar (I wanted to go with brass, but the aluminum was free). The inside is threaded for a check valve, but I have doubts about the effectiveness of a one way valve for venting a fuel tank. And, no the filler neck will not stay that long, it will be cut to length when the rest of the tank is finished.
Click to expand...
How about the way he did his clutch to start the engine? At the end he even gives the patern.............Curt
 
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UglyJeep

New Member
Sep 14, 2012
7
0
0
Tucson
curtisfox said:
How about the way he did his clutch to start the engine? At the end he even gives the patern.............Curt
Click to expand...
Sorry, I wasn't clear there. His clutch modification will be far easier than making the modification I had purposed (which was based on a post by msrfan). I greatly appreciate you posting the link, which will likely save me days of machine work. I do still intend to have the gear cluster/jackshaft assembly supported by the crankshaft, rather than having the gear cluster support the pedal crankshaft (as with Goldy's build).

Here is my paint rendering of what I'm thinking (this computer doesn't have any CAD software, that'll be fixed in a few minutes).



Dark grey - the gear cluster
Pink - pedal crankshaft
Blue - crankshaft support bearings (sealed bearings scrounged from a Haro BMX)
Green - retaining nuts
yellow - bronze bushings (I have an oilite bushing with a .5 ID, 1.25 OD, and 4" long)
Light grey - One way bearing (I'll use an equivalent of McMaster PN 2489K13)
 
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