Stirling Engine Generator Homemade DIY 0.47 KW ! Part 3

A lot of people have been asking about the power output of this engine so here it is!

To see other videos of the Mk2 stirling engine:

If you need to contact me:

If you want to see the power results, skip to 9:29

We've done a bit of work on the engine over the last few months,

-Stripped engine down and cleaned out oil/was residue that had built up. We are now trialling silicon oil as the lubricant which seems to allow the leather seals to slide extremely freely. This has the added benefit of being fairly inert and able to put up with high temperatures.

-Dynamometer brake built to allow us to measure the torque output. Its a little basic / crude but should allow us to get an idea of power output

-New leather lip seals have been manufactured and fitted. The originals were tight on the pistons and jammed up (the engine oil lubricant may have caused this!) These are now 3mm thick instead of 6mm. They have been soaked in neat's-foot oil for a week and lubricated with silicon oil after installing. So far really happy with these.

-Alternator was removed because it was dragging engine down to much. We might refit this again with revised gearing that better suit it.

Overview of test

For the test we have a built a fairly hot fire using welsh anthracite coal. The crank phase angle is set to roughly 100 degrees. We took a range of torque readings between 300 to 1000 RPM.

Conclusion

Maximum recorded output was 0.63 horsepower (472 watt) at 600 RPM. This way have been slightly more if we were able to disconnect the chain drive to the second shaft (needed so we could start it!). The sweet spot for power output is between 600 to 700 RPM. This is probably not to bad when you consider how inefficient this engine is with big mechanical / heat losses.

The crank phase angle was set at 100 degrees for this test. Adjusting this may have gave us slightly more power

Next steps

Now that we know the power output we can work out what to power with it. We could refit the alternator or perhaps drive something mechanical? Not sure yet? Any good ideas?

We will be running this engine at local rallies this year so will get a better idea of the reliability of this setup. We don't plan to develop this one any further because of the restrictions of the design.

We do plan to built a 3rd engine of better / simple design that is smaller but still easily built with basic tools / materials. This will probably be a project for next winter!

Specification

Piston to tube clearance cold side 3.5mm
Piston to tube clearance hot side 3.5mm
Hot bulb clearance from inner tube 3.5mm
Cold cylinder outside tube clearance from piston 3.5mm
Hot Cylinder length from bottom of regenerator to bottom of inner tube 274mm
Cold Cylinder length from bottom of regenerator to bottom of inner tube 565mm
Pistons OD 139.7mm OD
Hot bulb heat area inside (measured from bottom of regen housing) 1640 cm2
Cold jacket cold area internal (measured from bottom of regen housing) 2830 cm2
Stroke cold piston 186mm
Stroke hot piston 204.5mm
Fire grate to bottom of hot bulb 198mm
Leather seal (bottom) from bottom of regenerator 275mm
Regenerator height (flow area) 55mm
Regenerator length 216mm
Regenerator width 100mm
Displacement 11.4 litres

[Nargleberry]

Beautiful. Never seen a Stirling engine that size running before. Thanks for putting this online!

[DamonsMetalCasting]

That’s awesome you quantified the power of the engine most people on youtube report RPMs only which doesn’t mean anything by itself.

[johanengelen]

What i always found strange about Stirling engines is that there are a lots of small ones and really huge ones for submarines and so on but a useful engine for home use isn't available

[TheMikesylv]

I spotted small train tracks going around the house, this guy intelligently didn’t forget his childhood and revisits it on occasion

[numbnnuts]

That sound is intoxicating. Record that for 2 hours and put it on Youtube as an ASMR video. That would make any gearhead fall fast asleep and the rhythm will soothe a rowdy Beautiful machine Bro

[scottn]

This looks like a great start. Balancing/weighting your flywheel should give you a decent boost in speed and power. Not to mention it will reduce/eliminate the shake and noise.

[jorgehernandez]

I always search for big Stirling engines and can't find anything, so really take my hat off for this one. Congrats for such a nice project!

[gregorywitt]

Thank you for taking measurements and sharing the video and specs in the description. Very appreciated and very impressive.

[AKrn]

What an awesome contraption. I love the actual cup used for water. Coming back later to find out more about those tiny train tracks I see.

[forextraderradioman]

Thank you for this video! Your neighbors deserve compassion! ;)

[jmyers]

bravo! that has to be the most vigorous large homebuilt engine ever

[dieguerrero]

Awesome work guys!!!! Great power output!! Looking forward to future tests and engine 3!!

[RedGearHeads]

You’ve done a great job! Impressive build sir. I hope your quite proud of it.

[jimparsons]

Interesting and thanks. I've seen photos of similar devices from the early parts of the last century for pumping water. Smaller gasoline engines became popular during the 1920s, also for pumping water. Note, what might be a fairly new car coolant radiator on the side of this widget.

[moschettiflavio]

The most incredible stirling engine i ever seen. You guys did a great job with this machine.

[BigMilan]

Perfect! Throughout the whole video i was wondering how much power the producers and then you show us just that, and in more detail than reasonably expected <3

[chriswilliams]

Fair play to you guys for that! I came across this vid looking for ways to generate power for a homestead. Too noisy for me, and would require constant attention regarding fuel, but amazing how you did it. Things that I make that run at that speed tend to be dangerous and nearly kill the dogs. Yours held together admirably. Respect. :)

[abbasamro]

Great job bro,
I noticed that such an enhancements could be done on it to increase its efficiency, like using light robust pistons, isolating chamber from outside, create furnace chamber in circled shape so that heat concentrated in a more efficient way, water based cooling system.

[solanaceae]

Certainly the largest Stirling engine I've seen. Well done, lads.

[MoizRehmanK]

Great. Keep up the good work. I think you've done a great job. Striling engines have been neglected in the past but they can be a solution to our future energy needs.