Search found 99 matches

by Cartech
Fri May 21, 2010 12:23 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Timing/RPM question
Replies: 2
Views: 4680

Re: Timing/RPM question

Nice machining work Microwave, I am currently running a LTD engine with the displacer about 20 degree's ahead of the power piston and it runs best like this. It will run at 90 too but at a higher temp. Another semi-LTD I've built that has a simular design will only run at 90. It seems to vary engine...
by Cartech
Mon Jan 25, 2010 8:15 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stoddard engine
Replies: 3
Views: 7872

Re: Stoddard engine

I took some time to look at the original design again, your right, not an alpha with valves. I too would like to see a working model. If you attempt to build one, please let us know how it works out. I'm currently working on a rotary gamma that will feature port valves just for kicks. Not sure if th...
by Cartech
Mon Jan 25, 2010 8:07 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: IT RUNS!!
Replies: 4
Views: 7660

Re: IT RUNS!!

Well done. Nothing quite like that moment when it runs on it's own power the first time.
by Cartech
Mon Jan 25, 2010 8:04 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: My first stirling project. Is everything ok?
Replies: 4
Views: 7231

Re: My first stirling project. Is everything ok?

That is a well proven design, should run very well as long as the friction is low and the compression isn't too high. When completed, it should rotate many revolutions with a good flick of the flywheel (before you heat it)
by Cartech
Mon Jan 25, 2010 7:59 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: TODO
Replies: 2
Views: 5229

Re: Which is better - Big cylinder or lots of cylinders

You could gain some power (torque) with additonal cylinders over a single large engine if the cylinders power stroke is staggered. (like in any multi-cyinder internal combustion engine) You will get multiple power stokes in a single crank rotation. The friction problem has more do due with your abil...
by Cartech
Mon Jan 25, 2010 7:42 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Lemon
Replies: 1
Views: 4167

Re: Gamma Power Cylinder Question

It's best to keep the stoke and bore close to the same. A large bore will also have more friction than a smaller bore with a longer stroke. A larger diameter cyinder with a short stroke will aslo respond better to smaller changes in pressure. It really depends on the type gamma your trying to build....
by Cartech
Mon Jan 25, 2010 7:29 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: I need help about double acting stirling engine
Replies: 1
Views: 4483

Re: I need help about double acting stirling engine

I have drawn one up but have yet to build it. My version will have two seperate displacers with each hooked to each end of the double action piston/cylinder assembly. There is a thread here http://stirlingengineforum.com/viewtopic.php?f=1&t=360 that shows some examples of working double action S...
by Cartech
Mon Nov 30, 2009 1:38 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Dual Acting Cylinders
Replies: 27
Views: 27078

Re: Dual Acting Cylinders

idkleine, Thanks for the link! I think I came accross that one a while back too. I have drawn up a model with two displacers and a double action power cylinder (which I have now) but have not had time to build it. My model will be small and not much in the way of power producing. I was mainly intere...
by Cartech
Fri Nov 13, 2009 8:01 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: High Compression
Replies: 1
Views: 4147

Re: High Compression

It is possible to have too much compression on an LTD Gama engine. I have found a short power piston stroke results in your engine running at lower temp differentials. As always, your engine should spin half a dozen (6) or more revolutions with the flick of the flywheel. You should be able to feel s...
by Cartech
Fri Oct 30, 2009 11:08 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: New Memeber tries and fails
Replies: 4
Views: 6222

Re: New Memeber tries and fails

Sounds like compression is a bit high. You should be able to have it spin over half a dozen or so cycles with the flick of the flywheel. I would shorten the power piston stroke or possibly try a heavier flywheel if changing the stroke isn't an option. Yes, it's a "closed loop"...but, I hav...
by Cartech
Fri Oct 30, 2009 10:58 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: awk
Replies: 1
Views: 9620

Re: Gamma engine - tech question

yes, 90 degrees offset. Same as Alpha. This can be varied slightly for better results on some engines.
by Cartech
Fri Oct 30, 2009 10:55 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: What are rules to design a Gamma from scratch?
Replies: 9
Views: 17643

Re: What are rules to design a Gamma from scratch?

I have read the ratio should be 1.5 to 1 (displacer volume to power piston volume) This is the ratio for a typical power producing (some power anyway) engine. An LTD Stirling has a ratio of 10 to 1 or more. The higher the ratio, the lower the temp ratio becomes.. to a point. Friction and weight of m...
by Cartech
Mon Jun 15, 2009 9:20 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: I've started building my walking beam 55 gallon drum
Replies: 25
Views: 24486

Re:

The problem is the drums are comparativley very thin and to get any real work out of the engine you need to apply significant pressure to the working piston. This is not a problem with toy engines that can barely overcome their own friction. They no not operate at pressures even approching 1 PSI. T...
by Cartech
Mon Jun 15, 2009 9:08 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Is there anybody help me?
Replies: 2
Views: 20156

Re: Is there anybody help me?

Maybe this site will help.
http://heetgasmodelbouw.ridders.nu/Webp ... ameset.htm

Has some good drawings too.
by Cartech
Mon Jun 15, 2009 9:07 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Large LTD Engine
Replies: 4
Views: 7765

Re: Large LTD Engine

I'm still waiting to see how the 55 gal drum "can" engine works out. There have been quite a few fairly large engines made and are pushing small tractors and small boats around but I've never seen a large "LTD" yet. It seems possible but I'm betting the increase in size would of ...