V twin air compressor to Alpha Stirling engine conversion

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



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Cool idea! I think you may consider pressurizing your engine with helium. That would mitigate the explosion problem you're worried about. The other concern that I would have is how well that engine can handle the heat needed to power an engine of that size. The seals are probably not meant to be hotter that what is typically generated by compressing the atmosphere. I like the project though. Have you made any progress lately?

I haven't made any large Stirling engines yet. However, I have made a little tin can Stirling that worked pretty well

Justin

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DIYStirlingGuy my site: http://diystirlingengine.com/

Hi, I shelved the project until I complete a VAWT project I am working on. I am meanly searching for methods to produce electricity at 12 volts a using a permanent magnet alternator. I recently learned that add a MPPT circuit to the PMA will greatly increase the output by reducing heat at the stator of the PMA.

The idea of using fire or solar energy to drive the Stirling engine would be very beneficial if it could be achieved in a safe manner. I have no experience with Stirling engines and after reading that using oil to lubricate the pistons rings could create a explosion I am searching for a substitute to avoid the problem. If anyone has any ideas please let me know. Thank you for your suggestion.