Page 1 of 1

Two Questions.

Posted: Tue Apr 12, 2022 8:39 pm
by Bob Hornby
I am designing and building a simple "Cup of Tea" engine. The displacer diameter is 95 mm internal. The height is 20 mm and the displacer is 9.5 mm thick with a 10 mm stroke.The power cylinder will be 6.5 mm diameter with a 12 mm stroke. The power cylinder and piston are not yet made so I can change these. I can also change the stroke of the displacer piston. My progress so far is to make the displacer cylinder and top & bottom plates.
So, my questions are -
1. What clearance should I make between the displacer and cylinder (on radius)(I am thinking about 2 mm) ?
2. Is the ratio between the displacement of the displacer and the power cylinder OK ?
Regards Bob

Re: Two Questions.

Posted: Wed Apr 13, 2022 8:22 pm
by Tom Booth
That is all about the same as this engine, except the piston diameter, which, on this engine, is a bit bigger at about 9.5mm, and the clearance around the displacer is slightly less, about 1.5mm if that's any help.

IMG_20220413_230332781_resize_91.jpg
IMG_20220413_230332781_resize_91.jpg (55.49 KiB) Viewed 2831 times

Re: Two Questions.

Posted: Thu Apr 14, 2022 12:39 am
by Bob Hornby
Thanks Tom. that helps a lot giving me confidence that I am on the right track.
Bob