Search found 35 matches

by alpha stirling
Sat Jun 02, 2007 1:48 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Air Cooled Hot Air Engine Plans (tin can engine kind of)
Replies: 1
Views: 5853

Looks pretty primitive, but at the same time it is also very nice... I like the "stove" made for the hotcap (intendig to build one for my engine too to shield the flame from the wind)
by alpha stirling
Tue May 29, 2007 10:53 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: It works!
Replies: 6
Views: 9636

Hi! Polyacetal is indeed NOT ideal piston material. Let it be self lubricating plastic with very low friction ratio, but its thermal expansion is the thing here that makes it of limited use. That is also why I was enquiring different piston materials here a while back. The only actual reason for me ...
by alpha stirling
Sat May 26, 2007 1:45 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: It works!
Replies: 6
Views: 9636

Some updates: The engin now runs alright, but the alcohol burner came to and end of its way. There was some kind of leak issue about it's core, and lots of vaporised alcohol was allowed to escape the glass container. This eventually led to uncontrolled burning which had to be put down with water. Th...
by alpha stirling
Thu May 24, 2007 2:15 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: It works!
Replies: 6
Views: 9636

It works!

Some update from the prewious posting (see http://boydhouse.com/forums/viewtopic.php?t=281&sid=8796b0833d844190a28dbd8a0b7b1030 ). Today I machined a new power piston out of polyacetal bar. The new piston Moves freely in the cylinder, but is so airtight that it feels like there's a spring under ...
by alpha stirling
Wed May 23, 2007 1:00 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: displacer sleeve
Replies: 2
Views: 5889

Succesfull test run!

I got the engine assembled today with some of the gaskets in place. I was anxious to test the engine, so I lit up the spirit burner, and started to heat it up. At first nothing happened so I detaced the power piston con rod: When turning the flywheen the power piston really moved slightly. I then at...
by alpha stirling
Wed May 23, 2007 12:43 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: the new guy :P
Replies: 2
Views: 5183

An LTD huh? ok, haven't worked with those yet, but look at these threads for some answers: About the cylinder diameters and ratios: http://boydhouse.com/forums/viewtopic.php?t=48 About displacer seal or sleeve or whatever it is called: http://boydhouse.com/forums/viewtopic.php?t=281 Hope this helps!
by alpha stirling
Tue May 22, 2007 11:05 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: displacer sleeve
Replies: 2
Views: 5889

Got the problem solved... I quess

Ok, the problem was too short sleeve and too heavy displacer. The sleebe being too short allowed the rod to vibrate a litle. Too heavy displacer twisted it downwards, where it made rubbing contact with the sleeve pipe. This caused the overall vibration that robbed away power. I got the problem fixed...
by alpha stirling
Wed May 16, 2007 2:08 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: displacer sleeve
Replies: 2
Views: 5889

displacer sleeve

Hi there! As the story goes, I was building a small alpha stirling engine, but it turned out to be too hard to accomplish. It had so great compression ratio, that the temperature difference required to run was astounding. I'm currently rebuilding it to gamma engine. I'ts ok this far, but I have prob...
by alpha stirling
Wed May 09, 2007 11:36 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Compression cycle.. worthwhile?
Replies: 7
Views: 9652

The terms "Compression" and "compression" are amazingly similar. In the internal combustion engine compression really means compressing air and fuel mixture into high pressure to allow it to burn efficiently. In the stirling engine, however, compression occuer when the working fl...
by alpha stirling
Wed May 09, 2007 11:28 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: cylinder ratios
Replies: 14
Views: 70225

so... I'm converting my failed alpha engine (I needed to heat it red hot with acetylene flame to get it even turning) into gamma engine. My power cylinder bore is 25mm (1") and the stroke is about 30mm (1.2"). The stroke of the displacer would be the same 30mm. I calculated that If I gave ...
by alpha stirling
Wed May 09, 2007 12:36 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: cylinder ratios
Replies: 14
Views: 70225

it is generally said that 1,5 volume ratio between power and displacer cylinders is desirable. Where does this number come from? I know engines with ratio less than 1,5 will have difficulties to run properly, but what would happen if the ratio was greater than 1,5? If the displacer cylinder free vol...
by alpha stirling
Fri May 04, 2007 12:49 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Alpha stirling engine project
Replies: 5
Views: 8215

Today I got the flywheel attached. it's bout 1 lb steel piece. The engine turns very smoothly with it, and runs through several cycles when the cylinder heads aren't in place (ie. air can move freely in and out from the engine). But when the cylinder heads are screwed in place, and the system is sea...
by alpha stirling
Thu May 03, 2007 1:15 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Compression cycle.. worthwhile?
Replies: 7
Views: 9652

This (I quess) Have been tried by several groups. I quess one japanese group actually got a working engine. I have no information about the performance... I also have lost the document where I had all of the equations to describe the stirling cycle in mathematical ways. Would have been possible to t...
by alpha stirling
Thu May 03, 2007 6:06 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Compression cycle.. worthwhile?
Replies: 7
Views: 9652

There are also devices called ringbom stirling engine, which has no mechanical means of moving the displacer piston. The displacer is swayed back and forth by the pressure difference between the displacer cylinder and the athmosphere...
by alpha stirling
Thu May 03, 2007 6:02 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Compression cycle.. worthwhile?
Replies: 7
Views: 9652

Under ideal conditions there is little actual pressure rise inside a stirling engine under the compression stroke. The compression stroke happens when the piston is moving inwards, but in the meanwhile the air temperature in the engine is decreased (by most of the air being on the cold side). This a...