Simple 4 cycle vertical model engine

David Kerzel, Pompano Beach, Florida david@FloridaAME.org

Simple 4 cycle vertical, 1.00 bore X 1.00 Stroke, Build 3

Last year I built the first in this series of engines. The first one (click here to see it) was designed for construction on a lathe and drill press only. Next (click here to see it) was a refined design that needs a lathe and mil for construction. It is a overhead valve version and just needs some polish today. This engine design is intended to morph into other engines. I started a simultaneous build of a 2 cylinder V version but have temporarily lost interest. 11/18/2007

11/18/2007
I needed to do more than polish the last vertical so I took my sketches and notes and started cutting metal with no plans. Its has been a while since I worked in the shop and it was great. Even if these parts are scrap it was fun.

The engine is going to be a flat head vertical. I will move the cams in line and above the crank shaft which will greatly reduce the size of the crankcase.

12/18/2007

I cut a set of gears

On my last few engines I turned my cams. This time I milled them and got the best finishes and got the flat faces exactly 90 degrees apart.

1/1/2008

I spent time in the shop over the holidays. The crankcase is nearly done and the valve modules are ready to be inserted and lapped.

1/14/2008

More work on the gear and cam housing. It looked great as a sketch, better as a drawing, but in metal it was a lot of work and it could be done simpler. So next week I will turn most of that fancy stuff out.

There had been some talk about assembled crankshafts and I realized I had made them for smaller air powered engines but never for a larger one. It is made of drill rod and steel with steel pins. Silver soldering is next. Ooops, the tapered drive shaft should have been in the middle, luckily I noticed before it was soldered and I did a careful layout for the pins.

I started the connecting rod. I used the adjustable compound on the Sherline to turn the taper.

As I was rough cutting the part the lathe started to change speeds and loose power. I opened up the speed control and took some measurements, everything looked good. Then I noticed the plug-in power resistor was loose, I pushed it back in place and finished the part.

1/21/2008

I added counter weights and turned the silver soldered assembly. It was much simpler than making it from a single solid bar.

1/26/2008

I finished the connecting rod, main bearings and cut the fins in cylinder body. It is starting to look like an engine. Valves are ready as is the cylinder and piston. Cam fit and finish with all those shafts, bearings, and gears is next.

2/4/2008

I pressed the cast iron cylinder liner and the valve assemblies in to the cylinder body. I still need to add the intake and exhaust ports I also turned a flywheel from 3 1/2 cast iron bar.

2/17/2008

I started a new carburetor. My last one worked good but the idle was touchy. This one will use a idle adjustment like a OS airplane carburetor. It was going a long great, then suddenly I could not find the rotating barrel. I spent a hour cleaning and looking for it. Its still missing in action out in the shop.

3/9/2008

I found the missing part in a drawer with the taps. The carb is ready.

This engine has a bunch of gears and bearings. The large gear in the back is driven by the crank shaft. That shaft will drive the magnet wheel for ignition timing. Then there are 3 identical gears to drive the cams. I was fun cutting the gears and it looked real simple in CAD. Getting all those bearing holes perfect has taken 2 tries.

This is the first try at assembly. The connecting rod just touches the inside of the cylinder at 2 o'clock. I pressurized the cylinder and the valves need another cycle of lapping. The rings seem to be sealing.

The cam angles still need setting and pinning, Cam followers need to be made and the whole ignition is open.

3/23/2008
Nothing new to show but progress has been made. Little details as getting added to parts. The ignition parts are together, not pretty but ready to run. This engine and one other in progress needs polish in the next 2 weekends. The starter in my car has failed and I am concerned it may require too much time during these critical days.

4/15/2008
It is together, spins good, has compression, timing looks good but as I was running out of time for NAMES my battery needed charging and there was just no more time to try and start it. So when we get home I will try to get it running.

I forgot to take a picture of the assembled engine.