Author Topic: Building a Poppin  (Read 41091 times)

Offline b.lindsey

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Re: Building a Poppin
« Reply #15 on: December 10, 2012, 06:01:04 PM »
Bob thanks for the info.  I ordered bearings for mine this morning. Out of curiosity...what do you use for lubricating the piston?  The original article mentions marvel mystery oil, but I have always thought that oil and atmospheric engines didn't mix since the heat would eventually gum up even the thinnest oil. That is why I am planning on using graphite instead.

Bill

Offline 90LX_Notch

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Re: Building a Poppin
« Reply #16 on: December 10, 2012, 06:19:40 PM »
Bill-

All types of oil.  I have an old can of Sears Household oil that I've used in it.  (It's so old the Sears logo is in a black circle.  It was my grandfather's.)  I've also used Air tool lubricating oil that I picked up at Sears.  I've also run WD-40 in it.  All without any problems.

My understanding is that the fuel is the real key because the alcohol draws in moisture with it.  The alcohol I use is for use with marine stoves.  After it cools down I usually spray a little WD-40 in the port and turn it over a few times before I store it. 

-Bob
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My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline b.lindsey

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Re: Building a Poppin
« Reply #17 on: December 10, 2012, 09:51:16 PM »
Bob, I just looked at your video ...nice looker and runner both!! Maybe I'll make a piston out of both materials as see if the running characteristic differ any. Hard to argue with success though and yours sure runs well.

Bill

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Re: Building a Poppin
« Reply #18 on: December 10, 2012, 10:04:54 PM »
Hi Bill, As Bob says they are not to fussy about oil I just used cycle or sewing machine oil but can now run dry with the graphite piston.The only oil that didnt seem to burn was peanut oil??
I found that the oil seemed to burn and form a gum or it may have been the dye used in the UK meths ?
She is looking very lika a poppin :ThumbsUp:

Offline 90LX_Notch

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Re: Building a Poppin
« Reply #19 on: December 10, 2012, 11:15:54 PM »
Bill-

Thanks for the compliments.  The video was shot right after I completed it.  Since the video, I prettied it up some.

I'd bet Starrett tool and instrument oil would work well.  Also, Hoppe's No.9 gun oil should work well.  (Any type of oil that would be dewaxed of paraffins.)

What I found is that you don't need a lot of oil.  That's probably why the plans show the pin style regulator.

I bored and reamed the cylinder and polished the piston with wet/dry paper until it started to fit.  The final sizing was done by "lapping" the piston to the cylinder with Crest MultiCare Whitening Fresh Mint tooth paste.  I guess it worked well? 


-Bob
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My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline b.lindsey

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Re: Building a Poppin
« Reply #20 on: December 11, 2012, 12:48:32 AM »
Yeah i guess it did Bob :)  Bet the bore smelled nice and minty too :) I looked at my Duclos flame eater this morning and closed the port with my finger and the steel piston in an aluminum cylinder still fits perfectly after years, and creates a good vacuum. It does require an occasional squirt of graphite powder though for lube.

Bill

Offline b.lindsey

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Re: Building a Poppin
« Reply #21 on: December 12, 2012, 01:29:33 PM »
Not much progress yesterday as work got in the way but did manage to get a couple of small items done. First the valve return spring in photo 1 made from some .022" spring wire I had on hand. The plans call for .020" but hopefully this will suffice. Then the valve...I sketched out the outline in AutoCad and glued it to a piece of .003" shim steel stock and cut it out with scissors. The center for the hole was included in the template so a quick drilling of the 1/16" was done (photo 2). Then the template was removed...no crinkles in the valve itself but a few ragged edges from the drilling and the scissor cut (photo 3). Finally some careful sanding with some very fine grit paper and the valve is finished.  The roughness around the hole will be sandwiched between two nuts on the valve rod (may add washers to either side as well) so that shouldn't be a problem. Hopefully a little more progress today.

Bill


Offline rebush

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Re: Building a Poppin
« Reply #22 on: December 12, 2012, 06:29:22 PM »
Bill: I've had good luck with fishing reel oil. My reels work smooth in salt water, I figured my engines would too. Roger
Hopelessly lost but making darn good time.

Offline NickG

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Re: Building a Poppin
« Reply #23 on: December 12, 2012, 07:00:15 PM »
Bill, great to see another of these. I have also built two and both ran 1st flick of the flywheel  ... I made both with simplified graphite pistons also.

Because they both ran straight away I never bothered fiddling with the cam timing, maybe there are further improvements to be yielded. The good thing about the design of poppin is that the valve is forcibly closed by the cam, due to the thin, springy nature it will open when good and ready - or when the internal and external pressures are such that the forces are balanced on each side of the piston would be the technical explaination!

It's a great design though..

Another flame licker I built I used a cast iron piston, I use synthetic engine oil on that but because of that it takes a while to heat up. With a graphite piston you don't need to worry about lubrication, very easy to get a perfect fit too. For fuel I use industrial meths which is more pure.

Here are my vids:

<a href="https://www.youtube.com/watch?v=pMfmtRP4OPc" target="_blank">http://www.youtube.com/watch?v=pMfmtRP4OPc</a>

<a href="https://www.youtube.com/watch?v=1cz9uHkp8Q4" target="_blank">http://www.youtube.com/watch?v=1cz9uHkp8Q4</a>

Sorry can't embed them for some reason!  :wallbang:
« Last Edit: December 12, 2012, 07:04:02 PM by NickG »

Offline b.lindsey

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Re: Building a Poppin
« Reply #24 on: December 12, 2012, 07:46:17 PM »
Nice videos Nick...two good runners too. Thanks for sharing them and the info also!!

Bill

Offline b.lindsey

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Re: Building a Poppin
« Reply #25 on: December 13, 2012, 02:15:02 AM »
Roger, Thanks for the tip on the reel oil. If I go with the graphite piston as expected, it wont be needed on this engine, but something to keep in mind for lots of my other ones. 

I got a little more done tonight. Got the crankshaft machined and fabricated and look for the bearings to be here tomorrow hopefully. Also got the locking nuts that hold the flywheel bushings in the flywheel drilled, tapped, and finished. Just a couple of update pictures below. More to follow tomorrow evening.


Offline Don1966

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Re: Building a Poppin
« Reply #26 on: December 13, 2012, 02:57:08 AM »
Bill you are making great time with this one, it sure is looking good. Still following along to see it finished.

Don

Offline swilliams

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Re: Building a Poppin
« Reply #27 on: December 13, 2012, 08:48:28 AM »
Very nice Bill, it's looking great

Steve

Offline ths

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Re: Building a Poppin
« Reply #28 on: December 13, 2012, 09:01:14 AM »
What a great engine to make, Bill. I looked at Nicks vid links, well done x 2!

Can anyone tell me where you get graphite from to make pistons? And what form is it in? I tried graphite rod on eBay, and I suppose you can guess what I found, nothing to do with this.

Cheers, Hugh.

Offline Jo

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Re: Building a Poppin
« Reply #29 on: December 13, 2012, 09:17:14 AM »
I am beginning to feel inadequate. This thread was first posted a couple of days ago and I have been astounded by the progress. Bill please tell me you are not posting this realtime during the machining :paranoia: Otherwise I may need to take up embroidery.

Jo
Enjoyment is more important than achievement.

 

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