Building a Bonzer Bonzer

[Philjoe5]

Hi Brian,
Yes it arrived in today's mail. I talked to the postman and he said all deliveries yesterday in our neighborhood were canceled due to the storm.

Since we're getting another dose of winter tonight, I'm glad I received it today.

I assume I can use any kind of fuel tank with it as long as I bleed the air out of the line?

Thanks again for letting me try it out. Meanwhile, it seems as soon as I solve one problem, another one pops up.

Cheers,
Phil

 

[Brian Rupnow]

You don't have to bleed air out of the line. Just make sure that when the gas tank is full, the fuel level is about 3/4" below the center of the main air inlet on the carburetor. If the fuel is ever above the center of the main air passage, gravity will cause it to bleed out the tiny fuel port and constantly flood out your engine, or even drip out of the carb and puddle around your engine causing a fire hazard. Your gas tank will either need a vent hole in the cap, or just loosen the cap a half a turn to prevent an air lock, preventing the fuel from being sucked up into the carb by venturi effect. I tend to use a transparent fuel line so I can visually monitor where the fuel is. As you crank the engine over with the drill, the air rushing thru the carb to the cylinder will create enough venturi vacuum to lift the fuel that 3/4 of an inch to start your engine. If your engine starts and then goes into the "miss" cycle, and coasts in this cycle long enough, then the lack of air being drawn into the carb will let the fuel run back into the tank.--Then, when your engine finally is finished coasting and wants to "hit" again, there may not be enough momentum left to lift the fuel back up from the tank so your engine can fire again. That is why I recommend an "anti flow back" valve be installed on the carb of these hit and miss engines. But---To start your engine the first time, you should have the lever that props open the exhaust valve removed or taped back so as to disable the hit and miss function. It gets a little scary the first time the engine starts, because without the hit and miss function hooked up, you will have no idea how fast the engine is going to run. It may start and settle in at a nice even pace, or it may run away with itself, over-revving until it self destructs. You have to be ready to pull off the sparkplug wire or put your finger over the air inlet to "choke" it to death in order to get it to stop!!!---It gets very exciting very quickly. A good "starting point" for that carb I sent you is with the needle open one complete turn from fully closed.

 

[Philjoe5]

Thanks Brian for the information. I'm using a battery - coil ignition and I have an on - off switch that will shut the engine down. Right now, I'm puzzling over a sudden lack of compression. I've made a new rocker arm and have been playing with the valve rod length adjustment.

I think I'm much further away than I thought. But I am persistent.

Cheers,
Phil

 

[Brian Rupnow]

So---What happened to your compression? On my opposed piston engine, it was so stiff that I couldn't feel whether it had compression or not when I was finished assembling it. I spent most of Saturday spinning it and getting "pops" and short 15 to 20 second runs. It still hadn't took off and ran by the end of the day, but it had loosened up amazingly and I could definitely feel the compression when turning it by hand. I had to Loctite a 2" diameter knurled collar onto the starting adapter so I could grip it and turn it by hand. The compression really wasn't that great when I started, (as near as I could tell with the engine so stiff) but after getting a number of short term runs the compression improved dramatically. Now if I spin it quickly by hand and let go, it will bounce back when it comes up on compression.

 

[Generatorgus]

Thanks again for letting me try it out. Meanwhile, it seems as soon as I solve one problem, another one pops up.

Cheers,
Phil

Such is the life of an amateur machinist. I'm positive you'll get it all ironed out.

On a lighter note, the weather looks good for the get together at Kinzer, see ya there.

GUS

 

[Philjoe5]

Brian,
The compression mystery remains just that. When I got uo Wednesday morning this was my view:


and this


Thankfully, I have this setup


You know when it's a nice summer day in July and you tell your friends how you bought a generator, and a transfer switch they can make you feel like Noah (of the ark). Well it ran my furnace, fridge and coffeemaker through our power outage of 54 hours with temps going down to 10F at night.

While not directly related to the Bonzer build it'll add some time before I get back to the engine.

Bear with me. I'm probably going to disassemble the engine and do a closer inspection of the subassemblies.

Gus, I hope to get a few hours to get to the winter get together

Cheers,
Phil

 

[Philjoe5]

Had a nice time at the winter get together where I met Tin Falcon, Cheepo45 and Generatorgus forum members. Cheepo45 showed me the spark on his Upshur Farm engine. It made a nice snapping sound when it jumped from the end of the coil wire to the end of the spark plug, a gap of about an inch.

My spark is nowhere near as intense. So I'm planning to check my coil out.

I discovered the source of my inconsistent compression. I was 1/2 a turn on the valve rod off, allowing the rocker arm to hold the exhaust valve open during the compression cycle. My compression has returned and seems pretty good.

In another recent thread on this forum, Exhaust Valve Timing, Dieselpilot mentioned lash between the cam and follower being as being critical. I am slowly absorbing the importance of paying attention to this variable.

Cheers,
Phil

 

[cheepo45]

It was good to see my engine building friends, and get out of the house! I.C. engines can be frustrating to get running right. I'm sure it will be running soon.
cheepo45

 

[Philjoe5]

I'm sure it will be running soon

Thanks cheepo45. It was good to see you and talk about the trials and tribulations of these confounding (but fun) machines.

Your spark demonstration was a great help. When I got home I tested my system and found I had NO spark. Battery voltage has dropped to 5 V, so I think I need a new battery at least.

I like your use of the work "soon" since I can interpret that in terms of the age of the universe to mean anywhere from 1 week to several thousands of years

Cheers,
Phil

 

[cheepo45]

Glad I could help, Phil. My many works in progress will be done "soon".
cheepo45

 

[Philjoe5]

Before I get going on a proper ignition system it occurs to me that the carby Brian sent me will require a new fuel tank. I could modify the Ridder's vapor carb but at some point when I have a proven engine design, I'll want to try it out.

So I'll make one exactly like it but with a pipe going from a cap to the bottom of the tank, and a second fill cap with a vent hole. Same overall dimensions, with the window on one end, courtesy of GailinNM

Cheers,
Phil

 

[Brian Rupnow]

Phil--I converted one of the Jan Ridder vapour fuel tanks to a normal fuel tank on my build of the Atkinson engine. I simply welded in a tube at the bottom of the tank. It worked great, and you can see whether or not you have any fuel.---Brian

 

[Philjoe5]

I decided to keep the Ridder's vapor carby intact to try at some future time.

Without using plans I just sort of made the same "tank" with modifications to suit the carburetor that Brian sent. In this photo, the carby is screwed into what I call a "Transponder". It has 5/16 - 24 NF internal threads which the carby elbow screws into and 10 x 1 mm external threads that screw into the cylinder head.




In this photo I've shown everything loosely assembled for a trial fit.



The final position of the tank will be closer to the engine and slightly elevated so the highest level of fuel in the tank will be slightly below the intake of the carb.

Now that I think I have this subassembly finished it's time to finish dealing with the ignition system.

A foot of snow is predicted for tomorrow into Thursday so I expect a few more delays on the engine work.

Thanks for looking

Cheers,
Phil

 

[Brian Rupnow]

I'm not sure if I understand you or not, but its the highest level the fuel will ever reach in your gas tank that must be 3/4" below the center of your carb. Otherwise, if the fuel is ever higher than the center of the carb, once you start it running syphon effect will keep it running and flood your carb like crazy.

 

[Philjoe5]

Brian,
I edited my post to clarify what I was saying. I think we're on the same page here - keep the fuel level below the center of the carb, always.

Cheers,
Phil

 

[AussieJimG]

Closer and closer ...

Jim

 

[Brian Rupnow]

Phil--We need a progress report. You should be running by now----Are you having further issues?

 

[Philjoe5]

Brian,

I finished the fuel tank and assembled it but haven't checked it for leaks yet



I've been playing with the length of the exhaust valve push rod and I think I've got it about right. I get a bounce on the compression stroke.

The inlet tube on your carby is 0.176" which is loose fit on the 3/16" ID of my fuel line. I suppose I could have wired it on, but I ordered some decent tubing clamps and will probably get those on Monday.

Monday will be the day I spend some time at a local motorcycle custom shop and have a discussion about ignition coils. I prefer to deal with folks like this because they have a keen knowledge of mechanics and in all ways we are like minded.

Meanwhile, this was the view outside yestderday



But the neighbors kids are loving the year of the big snowman



Thanks for looking in

Cheers,
Phil

 

[Lawijt]

You make a nice work. I believe also in Jan 's fuell tank.
Nice pictures of the snow. Very beautifull. Here in Belgium Always rain & storm.

Barry

 

[AussieJimG]

That's a beautiful fuel tank but I don't like the look of the backyard.

Jim