Search found 91 matches

by Alfista
Sat Apr 28, 2018 6:28 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: A Stirling theory question on average pressures
Replies: 5
Views: 775

maintaining a balance of vacuum and pressure during warmup

I recently read an article having to do with the snifter valve. They have been used on a variety of engines. The article in question was looking at a Heinrici engine, many of which used the snifter valve. Over time, an engine, whether working or at rest will equalize with atmospheric pressure or co...
by Alfista
Tue Mar 20, 2018 6:59 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Large LTD Diaphragm Gamma Stirling Questions
Replies: 19
Views: 2588

Re: Large LTD Diaphragm Gamma Stirling Questions

Beautiful engine Ian !! By my calculation, your engine has a 96.17:1 ratio. Does that sound right to you ? I also chose a cast iron piston in a cast iron cylinder for my lastest engine after first trying a bellows. The piston / cylinder arrangement was quite an improvement. After making such an eng...
by Alfista
Tue Mar 20, 2018 6:10 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Large LTD Diaphragm Gamma Stirling Questions
Replies: 19
Views: 2588

LTD displacer to power piston ratios

There is a wide range of ratios that will work. Ususally, an LTD engine is in the range of 50:1 to 100:1. You are trying to build an ultra low temperature differential engine. I would suggest a ratio of 60:1 to 61:1. If you do not read the Senft book on this topic before trying to design your own e...
by Alfista
Thu Mar 08, 2018 7:42 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Large LTD Diaphragm Gamma Stirling Questions
Replies: 19
Views: 2588

Large LTD engines as art

playludesc, the Werdich and Kübler book covers some large LTD engines used as public art. They are interesting. Yours sounds like a formidable project. Good luck to you ! If you build something, please post information about it, whether "successful" or "unsuccessful". We will learn something either...
by Alfista
Tue Mar 06, 2018 5:26 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Unknown
Replies: 5
Views: 1023

Re: Unknown

Try searching Plank at
http://www.tapatalk.com/groups/modelsteam/

They are very interested in such models.
by Alfista
Mon Mar 05, 2018 11:31 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Unknown
Replies: 5
Views: 1023

Re: Unknown

Ernst Plank
by Alfista
Mon Mar 05, 2018 7:57 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Noob question - would these parts work?
Replies: 23
Views: 2587

I agree with Ian

To quote the Sherline Tools motto "Think big and build small". If you plan on building such an ambitious project, you should be willing to build up to it and one way or another build or borrow the tools necessary to accommplish it. If you can build even a small alpha engine, then you can build a la...
by Alfista
Mon Mar 05, 2018 7:43 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Large LTD Diaphragm Gamma Stirling Questions
Replies: 19
Views: 2588

Re: Large LTD Diaphragm Gamma Stirling Questions

playludesc, I too am fascinated at the prospect of building a large LTD engine and so far have written many pages in planning such a project. I am in the process of scaling up an engine in four stages. Currently, I am on the second of four. If after building three successful models of increasing si...
by Alfista
Sat Mar 03, 2018 8:01 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Noob question - would these parts work?
Replies: 23
Views: 2587

some alpha engines have displacers

Blaf, some alphas have displacers and since you have not started building yet, I would encourage you to consider the possibility in your design. Usually, this has the result of moving the rings of the the hot piston a good distance from the heat. Directly heating the cylinder and piston is rather p...
by Alfista
Fri Mar 02, 2018 7:55 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Noob question - would these parts work?
Replies: 23
Views: 2587

Re: Noob question - would these parts work?

Blaf, you may be able to make them work with some handwork. Personally, I would avoid making a power cylinder from stainless steel, but perhaps I have misunderstood you. If you are considering this as the displacer and displacer chamber, then the tolerence is much too close ! Perhaps you could make...
by Alfista
Thu Mar 01, 2018 9:38 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Converting Compressor to an Alpha Stirling Engine
Replies: 7
Views: 1795

possible but not practical


It is possible, there are examples, but it would be an easier conversion to a bash valve steam engine or even to an internal combustion engine.

by Alfista
Fri Feb 23, 2018 5:41 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Propane burner design
Replies: 7
Views: 1413

Propane burner construction plans

If you would like construction plans, you could try Steam & Stirling Engines You Can Build, Book 3. There is an article : "A Simple Hot Air Engine Burner" by Kenneth Duncan.

by Alfista
Sun Feb 18, 2018 8:45 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Making a stirling engine 5 kw generator
Replies: 8
Views: 2176

BTU of common fuels per pound

In researching this question, not all researchers come up with exactly the same figures. Please forgive any "errors" in the collected information. It is only meant as a general guide. BTU per pound of some common fuels Hydrogen 52,290 BTU per pound Acetylene 21,850 Propane 21,660 Gasoline 19,500 Ke...
by Alfista
Wed Feb 14, 2018 10:17 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: New flame eater with homemade gear
Replies: 8
Views: 1576

Re: New flame eater with homemade gear

Wonderful job Thanh-Cuibap ! on the successful gear and the great running engine !

Wayne
by Alfista
Tue Feb 13, 2018 1:16 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Expansion on the hot end
Replies: 4
Views: 1089

Re: Expansion on the hot end

Brass would be better than aluminum.