Hornet A (oz13770)
About this Plan
Hornet A. Model aero spark ignition engine.
Quote: "Build the Hornet engine, by Paul W Lindberg. This month we present a little different project for the model fan: building a gas engine at home. The engine selected is widely used and reliable.
Due to the great number of requests from our readers, we are proud to present detailed instructions on building the Hornet model airplane engine. This engine is one of the latest designs and will give you many interesting hours of work in its construction. As to its practicability and performance, it is second to none for its bore and stroke. Cost of materials for its construction is about $2.50. At least 50 duplicates of the one shown here have been built and tested. They all are in perfect running order up to date.
Although many model enthusiasts have the idea that elaborate machinery is necessary to make a model gas engine, that is not true. To build one or two engines any home workshop with a machine lathe is all that is necessary.
To begin with, it is necessary to make a pattern of the crankcase. This is clearly explained on the plan. A split pattern is not necessary, as the foundry can make the parting in the sand. Any local foundry will gladly cast this in aluminum, at a nominal fee.
The crankshaft housing may be extended slightly, so that it can be gripped more securely in the chuck of the lathe. Make sure the pattern is finished to a high, smooth luster, as this will assure smooth cating. It will be necessary to clean up the casting after its return from the foundry. Do not drill holes in wood pat-tern for fastening down bolts.
Chuck the casting in a lathe, as shown in photo. Cut back required depth as shown on detailed print. Diameter of hole is 31/32 of an inch. After this part has been finished, a hole is drilled through remaining part of casting to receive main bearing. Note: The size of this hole is .002 inch under 5/16 inch, so that main bearing may be pressed into place. Do not press the main bearing into the crankcase casting until it is completely machined. With the casting still in the chuck, thread that portion of the crankcase which receives the crankcase cover. It will be necessary to have a thread-cutting lathe for this operation..."
Direct submission to Outerzone.
See also build thread on RCGroups https://www.rcgroups.com/forums/showthread.php?2857462-1939-Lindberg-Hornet-A-Motor by Ed Crowell.
Supplementary file notes
Did we get something wrong with these details about this plan (especially the datafile)?
That happens sometimes. You can help us fix it.
Add a correction
Do you have a photo you'd like to submit for this page? Then email firstname.lastname@example.org
User commentsNo comments yet for this plan. Got something to say about this one?
Add a comment
* Credit field
The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.
This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.
© Outerzone, 2011-2022.
All content is free to download for personal use.
For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.
Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.