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

The work in progress has gotten rather long, so it is now in 2 parts, Go to making it run

Building the Engine.

First posted 5/11/2006

The cylinder is made from cast iron, and lapped.

I made my rings using the method in SIC. When I parted the rings off they were .003 too thick. I made a mandrel that they push on and faced them to the perfect thickness. I snapped them put them on the expansion fixture, heated them to dull red for 5 minutes. I think this is the best set I have ever made.

The crank is turned from a rectangular bar. I drill off excess material to speed things up a little. The brass plug keeps it from bending when the main shaft is turned.

A tapered end on the shaft will lock the flywheel and crankshaft together.

A regular connecting rod design and an aluminum piston finish up.

5/31/2006

The cylinder is sandwiched between 2 plates.
The lower plate is the top of the crankcase and supports the valve follower bearings.
The middle plate will hold cartridge valve assemblies.
The top plate is the flat head.
These parts were machined flat and square on the lathe, larger holes were made on the lathe as well.

6/11/2006

The Crank shaft ended up a few mills under size so custom bearings are needed.

A simple carburetor that uses a sewing needle .

7/30/2006 It's been a while since I worked on this. I squared up the sides and bottom on the lathe. When I pressed the bearings in they changed just enough so the crank shaft will no longer pass through. I found the small timing gear but can not find the big one for the crank shaft.

I thought I might get the piston moving but that is not even close. I thought the connecting rod was done but it has no bearing.

8/18/2006

After 3 weeks the crank case is together. It started when the crank shaft would not fit in the bearings after they were pressed in. I had gotten this far with no tool purchases for the project and now I needed a reamer. Then I found the gears did not mesh. A CAD error, I think I moved one gear but not the other, so I moved and enlarged the bearings and mounting holes and it all fits and works.

Cams were turned. They will be secured with LocTite until the engine runs then they will be pinned.

Valves are started as 2 part assemblies silver soldered together. They will be machined when the engine is a little further along.

8/20/2006

Valve assemblies are just waiting for springs and final lapping be for being pressed in the crankcase.

The connecting rod has a split bearing. The brass for the bearings was soldered together with low temperature solder, turned, and heated to separate.

8/27/2006 A few more small parts have been made and others fitted. Piston moves good and valves move and have been lapped. Still lots of little stuff before that first pop.

9/4/2006 Almost ready to run. I just need a head gasket and a Hall Sensor for the ignition. Parts move smoothly, valve timing looks good, but there is not much compression, I hope it is just no head gasket.

9/10/2006 I got the 0.010 thick Teflon film for the head gasket. I got some compression but the exhaust valve was leaking. I lapped the valves again and got a good even dull line at the intersection of valve and seat. I put it together and it was not much better. After some poking, I found that the lapping eliminated the clearance on the cam follower. A quick adjustment and I had compression, it pumped air out the exhaust and sucked on the intake.

The work in progress has gotten rather long, so it is now in 2 parts, Go to making it run