Author Topic: Design and build side shaft hit and miss engine from bar stock  (Read 51826 times)

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #300 on: January 19, 2019, 10:30:53 PM »
 Update--Engine now runs like a fiend on gas from the lower tank. What did I change?--I took the 3/16" check ball out and put in a 1/8" steel ball. If I shut off the engine, the fuel drains past my home made check valve and runs back down into the tank. This says a lot for my diagnostic skills but gives me very poor marks as a check valve maker. Conclusion--there wasn't enough vacuum to lift a 3/16" ball but there is enough to lift a 1/8" ball. Now all I have to do is figure out how to make a check valve that works. In fairness to myself, I modified the existing 3/16 ball check valve to accept the 1/8" ball. The ball seat may have been a bit screwball because of this. I will try one more time to make a check valve that actually works with a 1/8" steel ball.
« Last Edit: January 19, 2019, 10:41:35 PM by Brian Rupnow »

Offline crueby

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #301 on: January 19, 2019, 10:45:59 PM »
Even with valve work to do, you have the cause identified, excellent!




You need to figure out how to make 3/16" ping pong balls... Hmmm, are there small plastic bearing balls in a plastic that is fuel safe? I remember plastic balls used in sailboat track, but don't know what its made of.

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #302 on: January 19, 2019, 11:07:53 PM »
It's been a long day. I'm going to do this one more time and Loctite it so it can set up overnight.

Offline Jasonb

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #303 on: January 20, 2019, 07:11:44 AM »
Brian, Can't see it on your drawing but the hole that the ball is seated into should be reamed, bored or cut with a D bit. The reason is that a drill won't produce a perfectly round hole so you can get tiny gaps even if seating it with a hammer.

Also usual to have the hole more than half the dia of the ball, 3/32"  would allow the ball to settle down into the hole easier
« Last Edit: January 20, 2019, 07:53:38 AM by Jasonb »

Offline sbwhart

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #304 on: January 20, 2019, 09:06:05 AM »
I take it that the low tank has plenty of ventilation to avoid forming a vacuum in it that would suck the fuel back

Stew
A little bit of clearance never got in the way

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #305 on: January 20, 2019, 03:21:03 PM »
All of my gas tanks have a 1 mm hole thru the screw on brass filler top.

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #306 on: January 20, 2019, 03:57:40 PM »
There is great joy in Mudville (Casey at the bat)--The newest and latest anti-flowback valve that I built yesterday evening at the end of the day works. The engine starts and runs well on the tank mounted in the base, and when I shut the engine off the fuel in the fuel line does not run back into the tank. This is what I have been trying to achieve.---Brian

Offline Ye-Ole Steam Dude

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #307 on: January 20, 2019, 04:31:35 PM »
Hello Brian,

 :ThumbsUp: :praise2: :cheers:

Have a great day,
Thomas
Thomas

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #308 on: January 20, 2019, 07:26:23 PM »
My engine is right on the ragged edge of hitting and missing. I don't want to gas myself, so I'm setting in my office with the door open to outside. I'm about to quit because there isn't much to choose between gassing yourself to death and freezing to death. I have things adjusted so that at a specific rpm the governor arm tips and prevents the exhaust valve from closing. The engine slows down, and the governor doesn't tip the other way soon enough and the engine just dies. OR--I have the adjustments set so that the governor arm disengages freely, but then it doesn't want to tip down and hold the exhaust valve open. I have had it hitting and missing beautifully if I operate the governor lever by hand. I think it is simply a matter of refinement now.

Offline crueby

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #309 on: January 20, 2019, 09:02:48 PM »
Brian, glad to hear it is coming together well!

For running it inside, if there is a window nearby couldn't you make up a exhaust tube like they use in garages, length of flex tube (large diameter) with a fitting to go over the exhaust pipe end, and at the other end go through a hole in a rectangular piece of wood that you can close the window sash down on? Could even put a muffin fan in the end of the tube at the window. Maybe use flexible clothes drier pipe.


Offline Art K

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #310 on: January 20, 2019, 09:08:12 PM »
Brian,
That sounds like a multiple choice question A:fumigation B: freeze or C:wait Sounds like it wont be long till you have it running properly.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #311 on: January 20, 2019, 09:59:48 PM »
Chris--I'm not close enough to a window to make it feasible. I could probably get away with a 16 foot length of garden hose.  It is super cold today, should get a bit milder towards the middle of the week.

Offline Brian Rupnow

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #312 on: January 21, 2019, 12:23:29 AM »
Time for a summary. The engine does start and run very well. This always gives me a complete thrill every times it happens. Yes, it does suck up gas from the tank in the base without any trouble. My initial problems with this was using a carburetor with too large a bore. The air doesn't flow fast enough thru a large bore carburetor to create sufficient venturi effect, and you don't have enough vacuum to lift the fuel.  When I went to a smaller bore carburetor, that improved the vacuum, and it sucks up fuel with no trouble.  The anti backflow valve gave me some problems, mainly because the 3/16" ball I was using was too heavy. When built with the smaller 1/8" ball as in the second drawing I posted, it performs well to keep all of the fuel from draining back into the tank when the engine stops. The carburetor is intended to be used with a hit and miss governor system, and consequently has no throttle plate. When ran without the governor hooked up, the engine runs fast enough to be rather frightening, and the only way to slow it down is to open the needle valve in the carburetor to the point where it is running too rich, however it does slow things down a bit. The flywheels are very heavy at 6" diameter and 1" wide, however that doesn't really affect an engine which has no acceleration curve and runs at a constant speed. The engine has "loosened up" a lot with all of the running it has been doing. As in all of my other i.c. engines with steel valves and brass seats, the compression has improved remarkably after being ran for a while. I am using one 1/16" Viton ring on the piston, in a groove .093" wide x 0.060" deep. The face cam seems to be a success. I had never built a face cam before, and my thanks go out to George Britnell and to Jason for help with the design. My next step will be to tame the hit and miss function so that it operates smoothly.

Offline Craig DeShong

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #313 on: January 21, 2019, 12:42:28 AM »
Great progress Brian.  I'm  :popcorn: :popcorn: :popcorn:
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline rudydubya

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Re: Design and build side shaft hit and miss engine from bar stock
« Reply #314 on: January 21, 2019, 06:38:28 AM »
I've been following along quietly since you started, Brian.  Nice work.  Looking forward to seeing it hit and miss.

Regards,
Rudy

 

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