Swifty's build of Rupnow engine.

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Latest update, we have spark!!! but only after I turned the Hall Sensor around 180 degrees, no spark initially, but then I remembered that the sensor only works on one side. I cobbled together a fuel tank and cranked the engine over with my battery drill, it fires and blows out smoke but won't run by itself yet.
But I have a problem with the square bar that works the exhaust valve, Brian stated steel on the drawing but as I had some 1/4" square brass, I used that. However the bar has bent where the holes are for the governor latch extension.I will straighten it out, make the latch extension, and bolt it on. This should provide enough strength to stop it bending again. While I'm working on it, I will put a pin through the shaft to make it easier to turn over with the drill.




Paul.
 
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Swifty--I was concerned that might happen when I seen you using brass instead of steel for the pushrod. Probably if I had stayed with my first design where there was only a notch in the underside of the square bar and no holes, brass would have been okay. I think Luc is going to try and use the original design, so that will answer my question as to whether the first design would have worked or not. Thanks for posting, and good luck with the sparks.---Brian
 
Well, bending the bar back wasn't a bright idea, it broke. So will have to make one out of steel now. In the mean time, instead of a pin in the axle to start the engine with, I've made a "spiral clutch", don't know if that's the right name, but will take a picture when I'm in the garage next.

Paul.
 
Swifty said:
Well, bending the bar back wasn't a bright idea, it broke. So will have to make one out of steel now. In the mean time, instead of a pin in the axle to start the engine with, I've made a "spiral clutch", don't know if that's the right name, but will take a picture when I'm in the garage next.

Paul.
Click to expand...

Paul I'll be using the original design but using a over center spring set
up it should work pretty well
Love your engine ;)
 
G'day Paul, great news on the spark and puffs, not so good about the bent rod. At least it is a reasonably easy fix and will be interesting to see how Luc's turns out.
Back to the drawing board and work bench Swifty.
Eddie
 
I mentioned in my earlier post that I used 1/4" square brass, that should have read 3/16" , but I'm getting on top of it now, I'm making the new one out of gauge plate and beefing it up a bit. If it looks a bit out of place on the engine, I will replace it later.

Paul.
 
Paul---I'm on pins and needles over here on the other side of the world!!! It looks like your engine may be the second ever Rupnow Engine to come to life!!!---And the very first air cooled version!!!---Brian
 
Hi Brian, well it's come to life in short spurts, my wife can verify this, as I was so excited I called her in to have a look. There are still a few problems with it, the timing seems to get out of sync easily. I think that this problem is caused be the axle moving in the flywheel, the press fit may not be tight enough so I will pull it apart and pin it, it seems that the inertia of the flywheel and my starting it with my battery drill may be the cause.

The new exhaust valve pushrod is working well, when I have everything pinned, I will only have to concentrate on the fuel intake then.

Paul.
 
Swifty--That's wonderful news!!! I had never press fitted a flywheel to a shaft before, and I ended up buying a .3735 reamer for the flywheel and using 3/8" drill rod that measured .3755 to give me a .002" interference fit. I had tried earlier to use 3/8" cold rolled that measured .3745 but it seemed like a very light press with only .0015 interference, and I was afraid it would slip. I used some Loctite as well, but with a .002" interference fit I think all of the Loctite gets scraped off anyways. Good luck with your engine. I will have my fingers crossed for you.---Brian.
 
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Unfortunately today is grandson minding day, been out to the local mall to keep him occupied. He is now having his lunch and then nap time for him, so it's into the shop for me as soon as he's in bed. I have decided to try putting a grub screw between the shaft and flywheel, that should stop it from moving. Will post some pictures later today.

Paul.
 
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Looking forward to your photos :).
I will probably use 303 SS as I have lots of it from a previous build.

Pat H.
 
Well it's amazing what you can get done in an hour, I've pinned the shaft with a grub screw,


And here is my makeshift fuel tank with adjustable height.



And here is my spiral starter mechanism.



Now to put it all back together, stay tuned.

Paul
 
OK Brian, we can start handing out the cigars, we have a new offspring running.

I only used my pocket camera video, which is not very good, but I think that it's better than nothing. The clamp wasn't holding very well, so everything was shaking.

Pull up your chairs and turn the speakers on.



Paul.
 
Congratulations Paul, it looks and sounds like an engine. And one you can be proud of.

Jim
 
Nice one Swifty :cool:
Pete
 
The sweetest music from a Hit & Miss Engine.Congrats!!!!! Paul.

Plan to put a key-pin to to ensure shaft and flywheel stay locked. We use this method to lock up overhung shafts for Ingersoll-Rand Small Air Compressors.

By this week end will see good progress on my engine but I am not rushing though I am now a wee bitty excited after viewing your beautiful engine running. After this I am wondering which engine would Brian come up with.
 
Hi Gus, it certainly was a thrill for me to get the engine running, but still a bit of work to do yet.

I think that Brian deserves a short break after the amount of work that he put in designing and building this engine, but from what I've gathered over the time I have been on this forum, Brian is probably already thinking about his next project.

Paul.
 
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