Hogan Half-Twin

I received this e-mail from Hogan Liechty back in Aug '17:
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I am in the process of designing and building a single cylinder overhead cam 4 stroke model engine loosely based on the design concepts of Jerry's V-Twin.

I have not directly copied any of Jerrys designs but I have used them for inspiration.  Jerry's V Twin was the most difficult yet satisfying build I have completed.  Mine runs great.

Because it was so difficult to build the gear train and I wanted to try designing an overhead cam engine, I designed a single cylinder using Jerry's basic crankcase, cylinder, head, and flywheel concepts.  My final goal is to design a V-Twin OHC engine using the same concepts.

The obect of this e-mail is to give credit where credit is due. I have no desire to profit from my design work but would like to share it with the model making world.

I would be happy to give you a copy of my designs in PDF format and you can do with them what you want.  They are by no means ready to market on your web site since they are for my own shop use and are not fully detailed. If you want to complete them and make them market ready feel free to do so.  All I ask is aknowedgement  for the concept.

I am almost done with the build and will be trying to start my engine soon.  I have also shared part of my build on HMEM forum and have tried to give Jerry credit for the design concepts I have used.

I will attach a couple picture to show what I have done.

Please let me know if you want the drawings and will send them to you as soon as I have my engine running.

Thanks,
Hogan Liechty
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Click on the photos below to enlarge.
Hogan sent me his drawings.  Click the link below to download for free or up to $5.00 donation.



Great project.  Thanks for sharing, Hogan.

Matt Parker's "Bill"

Got this email from Matt Parker on July 4, 2017.  Click the youtube link at the bottom to see it run!
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Allen,

Thanks again for helping me to solve my hall sensor problem. Even though it wasn't anything more than a bonehead move on my part, it was you who insisted it was the hall sensor leading to me finding the issue.
The below video is my engine finally taking its first breaths of life. Thanks to your father for a great set of plans which allows folks like me to accomplish these builds. I look forward to the next engine build.

https://youtu.be/HcVUV9TMys4

Thanks again,
Matt Parker

Matt Parker's Powerhouse

Got this email from Matt Parker on July 4, 2017.  Click the youtube link at the bottom to see it run!
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Allen,

Thanks again for helping me to solve my hall sensor problem. Even though it wasn't anything more than a bonehead move on my part, it was you who insisted it was the hall sensor leading to me finding the issue.
The below video is my engine finally taking its first breaths of life. Thanks to your father for a great set of plans which allows folks like me to accomplish these builds. I look forward to the next engine build.

Thanks again,
Matt Parker


https://youtu.be/HcVUV9TMys4

Missing crankshaft/bearing hole on Farmboy?

Here's a valid question I received from Richard Piaseki on May 1, 2017:

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I just bought the plans for the Farm Boy engine and after reviewing the drwgs., I have a question. Sheet #3 does not show a .500 hole for the crankshaft/bearing. Is there a reason for this or just an omission error?
Regards,
Richard Piasecki
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I wasn't sure, and I also noticed a similar issue with the connecting rod end, so I asked "EngineMaker" Jim (builder of Farmboy #3).  Here's his reply:

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On page #3 your Dad gave the dimensions for the placement of the holes as 1.820" from the back edge of the frame and 1.280" from the back of the lap joint. Now the size of the hole is the .500" dimension shown on the crankshaft bushings shown on page #9. Half of the hole is in the bearing cap and the other half is in the frame. I drill and ream my 1/2" holes as the bearing should be captured by the bearing cap ( so it doesn't spin) bur not crush the .376" inside bushing dimension.

On page #8 if you look at the connecting rod drawing, the bottom of the connecting rod dimension is .400" wide and the cap is also .400" wide. The hole goes at the seam of the 2 parts and in the center ( the .900" divided by 2 = .450") from  the edge. The hole size is the .561" dimension shown on page #8 as the rod end bushing. You could actually make the hole drilled an reamed .562" and the bushing .561" dimension .562". In this case the rod cap bolts going through the bearing keep the bearing from turning. My guess is that your Dad meant to say "Drill and Ream a .562 hole through rod big end" instead of .282" as shown on the rod big end assembly picture shown on page #8.