size of displacer piston

Moderator: stan.hornbaker

Forum rules
Be nice!
Post Reply
schiz0preni
Posts: 13
Joined: Tue Nov 25, 2008 12:52 am
First Name: Qamarul
Last Name: Hazimin

size of displacer piston

Post by schiz0preni »

guys,im a new member here..
would like to know whether the displacer piston can works if it is
smaller than the cylinder?i mean much smaller,where the hot air can
leaks from the top to the bottom of the piston...

currently i'm doing my final year project on Gamma Stirling engine

thanx in advance!
bptdude___2569
Posts: 177
Joined: Sat Jan 13, 2007 3:31 am
First Name: Joe
Last Name: McLean

Response to size of displacer piston

Post by bptdude___2569 »

Well, welcome, and good luck with your project.
Hopefully, one of the more hands-on folks will give a more specific answer, but ....

You want your displacer to be smaller, such that it moves quite freely. It has the purpose of "displacing" so air is suppose to slip by it from one end to the other. But, if the displacer is too small, it will move up and down, but not move the air enough.

schiz0preni
Posts: 13
Joined: Tue Nov 25, 2008 12:52 am
First Name: Qamarul
Last Name: Hazimin

Response to size of displacer piston

Post by schiz0preni »

thanx Joe..so that means it can works if the diameter of the displacer smaller than it's cylinder but not too much..isn't it?

i'll post some pictures some other day..
actually,the engine was developed by my lecturer last year but couldn't work out (no power output produced)so,my task is to make it run in order to get A in the project..

hopefully the other members will share some of their knowledge with me..
bptdude___2569
Posts: 177
Joined: Sat Jan 13, 2007 3:31 am
First Name: Joe
Last Name: McLean

Response to size of displacer piston

Post by bptdude___2569 »


pictures would be great.
we are all interested in real engine attempts.

don't forget to include the funny ones,where the engine flies apart on early attempts! :)

also, do not count on getting real power out of the engine. it is too complicated here to explain all that, just trust me. to get your A in the class, maybe find some excuse to use the occilating engine to fly a small flag to signal back and forth, or something.

Post Reply