This project has been sitting on the shelf, in a well over half finished state for around two years. Time to finish this model; maybe I can even get it to a few engine shows this fall.
This project is a build from castings and drawings supplied by Rocky’s Model Engines. It’s a 5/16 model of the Root and Vandervoort 4 HP vertical. It makes a very attractive model and is complemented by an external water pump, driven by a belt, and a cooling tower.
The vendor supplies two iron castings, nine brass castings, 21 aluminum castings, and the gears. You have the choice of cast iron or brass flywheels; I choose brass.
This is the third hit-and-miss engine I’ve built from castings, and the second that uses an igniter. I wouldn’t advise this project for your first hit-and-miss engine, nor your first igniter. The vendor assumes familiarization of hit-and-miss technology as well as an understanding of igniters so you might be left in the lurch if this were your first project.
I pulled this engine “out of mothballs” so to speak and started on it again a few days ago. I wasn’t planning on a build log, but the morel I looked at this project the more I thought some of you might like to see this build completed.
This log begins after a lot of the machining has been completed.
Below shows a photo of the project to date.
The intake manifold can be seen in the head. The engine has an enclosed crankcase, but the crankcase is just vented by a cap as seen in the photo. The gas tank is in the base.
Another view from the same flywheel side but now from the rear of the engine.
Here you see the water inlet and outlet on the cylinder and head, also a bit more detail of all the interesting motion on this side of the flywheel.
Now I give you a view from the other flywheel side where the exhaust leaves the head. An oiler will be installed in the lower opening on the cylinder that passes into the bottom of the combustion chamber.
This engine has lots of interesting details, carried over from the original. Here is a rocker that is supposed to hold the intake valve closed while the detent holds the exhaust valve open.
This engine uses the exhaust pushrod to actuate the ignitor and also operate the exhaust valve rocker arm.
The cam is a complex shape that needs cut out and ground to shape to that the pushrod motion will time the ignitor and exhaust valve events correctly. Here you see the ignitor trip and the exhaust open and close.
All this is accomplished by the motion you see in this video.
Here you see the exhaust pushrod moving up and down in response to the cam. The fuel pump is driven by a bell crank on the left and the detent is poised to lock out the exhaust motion.
The detent is actuated by a weight on the flywheel that centrifugal force drives outward against a spring.
As you can see this project is well on the way to complete. I store my models in my daughters’ room (it’s true: when the children move away you don’t lose them, the house just gains more rooms
). She went her way a while back, but did leave her stuffed animal collection behind. When I went in to retrieve the few castings that were left to complete this engine I found this:
So Sirus’s influence must reach across the pond and is now influencing things here in the colonies.
I’ve been working on this model off and on for quite a while, time to get it finished.
