I started a new project. I am trying to convert a V cylinder air compressor into a Alpha Stirling engine.
After taking the heads off and spinning it by hand and relating to videos I have seen of working engines there seems to be to much friction caused by the piston rings. The construction of all the compressor parts appear to be Iron, with Aluminum pistons. I have to open the crank case to see if the bearings can be replaced with sealed bearings, maybe that will help reduce the friction. Over coming the friction caused by the piston rings seem to be the biggest problem. Any ways getting the compressor out of the box is always a good start.
Before removing the heads and removing the crank shaft I noticed a lot of air entering and existing the crank case when I was spinning it by hand. There is a lot of back pressure caused by the pistons. I am going to try to replace all the bearings with sealed bearings and leave the crank case open. This should remove some of drag and maybe it will run using dry lubricate and the original Piston rings.
The cylinder heads have two ports. Both can be used to pass the gas between the cylinders. Using a dual regenerator configuration should reduce drag and may help the Stirling cycle.
Completed concept drawing of Reed Plate and Cylinder Head modifications. Removing un wanted material from the Reed Plate and Cylinder Head will allow installation of heating and cooling tubes. Displacers can also be added to the tops of the pistons. As always making the concept drawings is the easiest part. Now the real fun begins, fabrication. At the very least it is a opportunity to improve my machining skills.
I noticed a Beta on you tube that used a Snifter Valve on the crank case and feeds the output back into the cylinder above the piston. If the pressure above the piston in the cylinder is greater than the pressure in the crank case does this prevent oil from entering the cylinder? I read that hot O2 can mix with the oil and cause a explosion, this is my biggest concern. Comments welcome. Best Regards