Building a Stirling Engine that is Wood Fired - Part 7 - (It works, Just about!)

Second test run of this novel stirling engine design
I've been building this all winter and am very excited to see it run! If it doesn't work I'm not sure what to do!
To see other videos of the Mk3 stirling engine:
• Building a Stirling En...
Contents
3:56 Start the fire
5:42 Success!
8:37 Experiment with crank angles
After the last disappointing attempt of trying to run this engine I made a few changes. First off, I added another flywheel to add more inertia to the system. Second, I remade the fire box to create more direct heat upon the hot heat exchanger.
The simple objective is to at least get it running. Once its running, I can play around with parameters to see what improves the situation.
I'm happy to report the engine does in fact run ( just about). I am really quite happy about that (and relieved after the work I've put in!). I now need to think about what can be improved to make it better.
I'm very interested to hear peoples thoughts and ideas to help progress this project
Cheers
If you need to contact me:
[e-mail]

[@olalekansalami5773]

it's a neat piece of art (engineering) I love it... my suggestion, try cooling cold side the more, perhaps adding fins to the cold side cylinder... since the temperature difference plays a major role in the running and efficiency of Stirling Engine. Nice job, Mr. Shane. thank you for sharing.

[@stephenbracken]

Great to see all your hard work coming together Shane. Thanks for taking the time to share your journey.

[@perrymattes4285]

Congratulations you have a runner

[@imagineering3dstl394]

And you worked through the difficulties pressing on to end up with a great result. Congratulations. Very enjoyable to watch thank you for all your hard work.

[@evanburroughs9329]

A taller chimney will help with the draft and heat up the fire, and cleaning the soot off of the heat exchanger will help with the heat transfer. Very thin layers of soot are great insulators on the tubes off steam boilers.

[@David_Mash]

At the halfway mark made me smile. Good water heater for the house

[@Lechoslowianin]

A good start. My congratulations. You, as the constructor, know best what modifications should be tested. Regards

[@rommelfcc]

Try running a coldwater jacket on the cold cylinder 🤔 Could also have a reservoir above, so can fill it with ice to run water through it, and into the jacket, that would make a nice temperature differential And a water valve at the bottom, so it can control the flow. 0r. Connect a on the flywheel to pump & lift the water back to the reservoir, so it would be like a primitive radiator.❤

[@ShanePomeroy]

I think adding a cooler to the cylinder on the cold cylinder is a top idea, many thanks. I'll. Add it to the list for the next phase.....

[@MadeleineTakam]

Fantastic job getting it running.

[@MrDerbee]

Brilliant piece of home engineering! so smooth and quiet. Would make a practical urban generator.

[@Sam-black]

Congratulations well done looks fantastic can't wait to see what more you can get out of it

[@glennosmond4306]

Dude ...I am so impressed with your work! I am inspired and I absolutely will be building myself one of these starting tomorrow. Thank you so much for posting your progress!

[@redshiftcnc]

Beautiful. Excellent work❤

[@gitpharmmakes7985]

This modified version looks even better, great job!👍

[@AdlerMow]

Beautiful, and silent! You are on the right track. Can I suggest something? Built a heat exchanger to preheat the intake air by putting the chimney pipe inside a larger diameter pipe that connects to the combustion chamber, it will improve efficiency. Also, if you use a separate heating coil and radiator instead of the displacer, won't it be more efficient, since you are heating and cooling separate hardware, so minimizing losses to conduction?

[@janposthumus8735]

Congrats! Good job... thanks for sharing mate

[@JustinTopp]

Great to see it running!

[@ronnwalk9597]

Great job

[@themechbuilder6171]

runs quite smoothly!

[@trygvetveit4747]

Please try to put load on your fantastic design (really) It sounds exacly like and old norwegian diesel (SABB) going from idle to load with a variable pich propellar when you "choked" it with your hand! Many "large flywheel motors" of different designs will stall if no load applied to the motor system Really think you are on the rigt path! Please try to make som kind of electrical load and record it at different rpm/temperatures and so on! (SABB diesel🤩, and even a larger flywheel and a one direction bearing ?)

[@StanislavZachazevski]

The nicest thing is to see it running at last. I was quite happy to run simulation for this one engine, and as it looks - that max rpm (where all work done is "eaten" by pressure loss at regenerator) at current setup of displacement / heat ex changers and re-generator is on its place. Comments on compression ratio - compression ratio in alpha configuration is changed using different phase angle, changing displacement of any piston just adds some dead space. Next - running on 90 degree gives much higher compression ratio, which expands/cool gas more than our available temperatures at hx exchanger - which overloads our tiny heat ex-changers even more. And - you still owe me one way valve before pressure gauge to see max and min pressures in cycle. This one will tell a lot of iternal process. Sniffer valve close and bigger rpm - less average pressure / more loss at heat exchangers / regenerator. But after measurement of power - it may show less power too. Cheers !

[@ShanePomeroy]

Many thanks for your help, much appreciated. I'll improve the engine as much as I can within the heat exchangers limitations. I'm changing regenerator with annular plates instead. When I next run it I'll get that pressure gauge reading : ). This has been a fun experiment so far......

[@StanislavZachazevski]

@@ShanePomeroy Just drop a visit to a scrapyard, 110kw vauxhall 1.9 diesel engines have first catalytic converter in perfect shape for your regenerator - 90mm long, 90mm diameter. And nice ducts on one side too. Got one from friem, will sent you photo today.

[@TazerGames]

Congrats !

[@vittoriosandoni7064]

Great job!

[@anthonyd5079]

I've been waiting to build my own setup and have learned a great deal though seeing a larger setup. As it so happens, when you close off the one way valve you pressurize the air and it becomes a working gas. I've seen some of these other Sterling generators use higher PSI, so I would proceed with caution with such a large setup.

[@IronGoober]

You just made my Saturday!

[@aidenjohns8248]

great work! runs great! smooth!.. ya need a number of strong magnets glued to that new flywheel, and a stationary coil on the frame!, keep at it, i had it designing my stove! simetimes it all would go wrong!, thats when its good to walk away for a while.. good stuff matey..

[@whitewinterresorts7679]

You are a legend. Absolutely love your work!!

[@ShanePomeroy]

No, just a fool, cheers

[@ronmoore6598]

Nice! Well done Dude!!! Amazingly Quiet! Thanks so much for documenting this! Subbed.

[@rsdionisio]

Nice engine,congratulations

[@jimmyboy163]

Great work, I want one

[@Sammy-eb2cy]

Glad to see you got it running! You've put a lot of hard work into this. It's very rewarding to see your success! I like that you polished the pistons. It should help reduce the friction loss once it is broke in. I think if you wrap the hot side cylinder with insulation, it will help with the heat loss and speed up the warm up time. I thought I read somewhere that a sterling engine works on both pressure (heat cycle) and vacuum (cold) cycle. That may explain why plugging the value with your hand increases performance. A cold water jacket sounds like a great idea! Should help with the cooling! One last thought, on your next build. If you were able to design separate components (heat,regeneration,and cold)and put a insulating gasket between them. You may have better performance. Looking forward to see what you do next!

[@ShanePomeroy]

Hi Sammy, thanks for all your ideas, where's my pen! I'm probably going to change a few things at some point, cheers

[@albertorossetti5375]

It is working 👍👍👍 now you have to refine some detail and chk the power output 🥰 then sell the "kit"

[@kallakrastev769]

It needs some lubrication, great job ! Bravo!

[@martinnutter6691]

Congratulations Shane, you've done another brilliant job! From where I'm sitting it's a nice looking, smooth running and possibly fairly powerful (for a Stirling engine) piece of kit. Hope to see it round a show some time. Not doing Stithians this year but doing Boconnoc House instead. See you sometime. Martin.

[@ShanePomeroy]

Hi Martin, hope all is well : ). I may see you at Boconnoc then. Cheers

[@PALM311]

Yes success! Nice work Shane! When your engine is running, try putting your hand over that valve and look at your gauge to see if the compression goes up or down. I should think that will tell you what’s happening when you do put your hand over that valve. perhaps you can build some kind of a preheater to get the regenerator warm prior to the fire getting up to where it needs to be? Congratulations!~Paul

[@ShanePomeroy]

That's a good point with regards to checking the gauge for compression change, cheers

[@theinstrumentinventor1345]

You should make a blower pup that runs off the engine to pump more air into the burner into hot side of the engine, to increase the temperature of the fire witch well help to keep the engine running better

[@ShanePomeroy]

Yes, the fire is limiting things at the moment. A blower could be the way to go with this, many thanks

[@Perky_the_Great]

An electric blower would work sure. Another option would be to use a small turbocharger setup in the burn chamber, it would have fewer parasitic losses and increase oxygen concentration. Make sure to limit pressure

[@rogueart7706]

Yes!

[@matte.9047]

Great, the residual energy at the end of the cycle is the slowest part of the rotation, so not much energy left for this size engine, getting the temperature up would help, but at the same time you need to provide enough energy to the heated piston and exchanger to flow through and get a kinetic output from its cycle after the innefficiencies have blown away, getting the temperature of the cold side down will also help, same goes here for overall energy out per cycle but you cant get more out than the energy provided to the cold sink from the cycle exchange given to it from the cycle, although some energy will go directly from the fire to the coolant because nothing is perfect. If you can get more heat into the heat exchanger and make the heat flow more immeadiate from both cold to hot and hot to cold exchanges then the overall poer out per cycle will increase, one way might be to have a spinning heat exchanger but you might run into maxwells demon.

[@averyanderson8402]

Put a damper in the stove pipe will allow you to cpntrol how much heat that escapes.

[@sailaway8244]

Rocket stoves need draw to burn clean,he doesn't seem to have any secondary air intake (that i can see) which would be where you would dampen (or the primary air)

[@johndoe-rj1ls]

Hi Shane. Nice work. I was wondering if you might use the packing materiel i used to do the sailboat prop shaft seal for the piston seals ? It is a fiberglass/asbestos ?, impregnated in graphite sort of material. Another thought would be to have the cold side below the hot rather than beside it. I would love to have one of these to run the axial flux generator i built.

[@johnnyporker8837]

Due to it all being from metal the heat I think eventually spreads to the cool side which is the main thing that can make stirling engines inefficient as they run off the temperature gradient. I've never made one this big so you probably know more than me, but I think getting some liquid cooling for the other side would make it run better. Saw someone else mention it and just wanted to say I agree

[@ShanePomeroy]

Hi Johnny, yes I think you've got a valid point. This engine was originally going to have flanged joints between the hot cold sides with insulation between but I ended up welding for simplicity. All the best

[@paulwilson2204]

Really impressive stuff. I wonder if a rocket stove format might get you more heat? That way, the air is flowing through the coals rather than over the top of the wood.

[@markgeurts258]

Hey Shane, Glad too see it running! Still got a little bit of tuning to do I think, but it runs very quietly and with far less vibrations then the previous model, I also like the more compact size. Is it maybe possible to measure the heat going out of the chimney and reduce this somehow if it's too high but without losing heat inside the burn chamber, for example with a thinner chimney pipe? Or maybe the water heat exchanger is just working too well and therefore you must limit the water flow 🤔. I'm just spouting some ideas, I have zero experience with heat engines.. Good luck, Cheers mate!👋

[@sunoncream1118]

if the crank case is not pressurised its useless to try presurise the working chamber of the stirling... and, higer pressure u go more power u can get but more aera to heat u need... try get rid of those lubricated piston... it slow the engine ... try run it atmospheric .. or build a crank case to hold the presure but u gonna need more heat exchanger and larger flywheel

[@ShanePomeroy]

Your right : ). The flywheel size does start to become a bit of a problem on big low rpm machines , many thanks

[@sunoncream1118]

@@ShanePomeroy if u can enclose all the engine and start it with ur electric generator u can near double the atmospheric power just filling it with helium .. ok helium expansive but not gonna leak for mounth if all moving part enclosed :) (helium is more fluid and absorb heat much more hydrogen is better but will destroy metal... ) im still verry impress on the power u managed :) near 500 watt make wath? a 8/100 ? 10/100? (double adavantage of fully enclosed is sound management ^^ u put that thing in ur saloon to heat the room ^^

[@davidunderwood9037]

Surprisingly quiet!

[@karlstruhs3530]

Increase cooling jacket down at least Half way down the cold cylinder(pack it with some ice water just for fun) the vacuum created will assist in the power stroke, pressure differential is key also regenerator needs to have air flow you may have packed it too tight. Make sure you only change one item at a time. reburning smoke and preheating air should get you to 3/4 horse power so you can create 500 watts when you hook up the generator. good luck.

[@ShanePomeroy]

Hi Karl, I think your on the money! I'm making a few changes as we speak, cheers

[@karlstruhs3530]

@@ShanePomeroy cool beans

[@FrankensteinDIYkayak]

what about a compressed air motor to start it?

[@LeoLeoJR]

Nice to see it running :) Maybe the one way valve is not airtight enough and when you close it with your hand, you close leaking and it causes the engine run faster?

[@ReviewThisTestThat]

between the hot and cold piston do you have a heat regenerator iv seen in smaller setups they use steel wool to reheat the air as it comes back to the hot side. on the wood burning side do you have an air passage around the wood so their is enough air to combust the smoke for my BBQ rocket stove i wrapped the wood in wire and elevated it about 2 inches so air could flow around the wood it made everything glow bright red. iv seen in newer designs they have a empty chamber that meets at the back end just to feed air to the burn chamber. I'm am so glad you got this working i cant wait to see what happens next. don't get caught up in your pully rope :)

[@ShanePomeroy]

Yes there is a regenerator there. It is made of stainless scouring pads. Combustion is a slight problem I'm planning to change things to solve this. Thankyou for your ideas, cheers

[@kcinelgoog]

Well done on getting her running but there does seem to be an awful lot of friction. I wonder if perhaps your previous engine was better in that respect due to the rocking levers reducing con rod angularity and hence side thrust on pistons? Oh, and what are those things called that you've used to fix the cranks to the shaft? Not come across them before and they look useful!

[@whitewinterresorts7679]

I had to comment again. When it started up I was giddy with excitement. The faster it went, the more I lost it. How are you so calm?

[@ShanePomeroy]

I think Im always to busy looking for the next problem and never satisfied! The curse of building things!

[@bussi7859]

Fiasco

[@williamjames9515]

Have you considered using a heat powered fan to blow on the fire?

[@dansw0rkshop]

The hot piston needs to be smaller than the large, I think.

[@fightline4741]

I don't know if this will make a whole lot of sense but maybe you should look at a steam locomotive and see how they create a stronger draft they use the steam in the cylinders then shoot it through the stack to create a stronger draft you might be able to do something similar with a fan that's ran off of the engine it should help you get your temperature up a lot further as well maybe a small squirrel cage fan

[@trygvetveit4747]

And look at the vacum side of steam motors(actually a sterling type at the LP side of a steam engine) Old large fhising boat Diesel engines with enormus flywheel will for the most of the working cykle be a "inverted/wringed inside out/in" Sterlig motor system Only reason for the extreeme compression for Diesels are to acctually ignite the fuel...

[@bobkelly2447]

I realise the cycle of the engine is old hat to you but many of us are not up to speed on your engine....how it works and all that an explanation or drawing would be real helpful you have accomplished a great deal making a big stirling engine ! Congratulations ! i think your method of using a big stirling engine to generate electricity will be far more efficient than any other methods used.... especially for off grid people the problem as I see it is the fire type and how much it uses per 4 hour run.... I say 4 hour run because currently it takes about 4 hrs to charge up a bank of Li-Po batteries to keep the homestead charged up on cloudy days..... but if the fire uses a cord of wood to do that it would be unusable or 3 gallons of diesel etc.etc. However I do not think that will be the case with your setup. in fact it will be far less fuel usage than any other method in current use ! this is great ! the unit needs to be a stand alone unit...able to withstand below freezing temps with no ill effects . If this unit can be made to power a generator for 4 hrs with an arm load of wood You'll have a big winner.... then the problem comes down to how much can it generate in electricity 24VDC or 48 VDC would be great and plug right in to solar charger units where on the homestead a weeks worth of heavy clouds the batteries get low... so you walk out to the generator with a arm load of wood and start a fire and turn it on..... this would solve a major problem with the current solar setup ! many would pay handsomely for this convenience ! a larger fire box would be needed for wood or a smaller one for diesel fuel. the problem is how much would it generate in electricity.... that's the big question ! you will probably need to make your own flywheel magnets and coils to get enough power to make it viable......but it can be done I am sure ! Keep up the good work the world needs this badly right now !!!!!

[@ShanePomeroy]

Hi Bob, hello from Cornwall, UK. We are very familiar with cloudy days here! I am slowly edging towards a practical / simple design. Checkout my most recent engine on my channel, it uses diaphragms instead of pistons. I'll keep on developing it till I run out of ideas : ) Thankyou for all your comments, they were great for refocusing me on an end goal! Watch this space...

[@dirgethesergal319]

if in doubt, bigger firebox

[@stumblestorms7881]

Congratulations! A wonderful achievement! Do you have plans on attaching a DC motor, with boost converter, inverter, voltage regulator, ect..? I am interested in power output.

[@ShanePomeroy]

Eventually. I've got a few changes in mind over the next few weeks, cheers

[@David_Mash]

You have an air intake with the one way valve? I thought the working fluid should be a closed system, maybe thats why it worked better when your hand blocked the inlet? Bravo! I like the water jacket idea for the cold side. Could do the same for the hot side actually.

[@ShanePomeroy]

The valve is meant to replace air that has leaked out. Maybe it finds its own balance point without one? Cheers

[@David_Mash]

@Shane Pomeroy might be better to solve the air leak? You're build is inspiring. I'm thinking a a cold water jacket and a hot water jacket. Might even help with air leaking. You do seem to have friction somewhere that shouldn't be.

[@TheBaconWizard]

One advantage of that geared flywheel is the increased speed at the rim: glue magnets to it and set it within a serpentine coil and you'll get some good numbers off it. I imagine in an ideal world though, you'd get rid of the gearing and set a larger-diameter flywheel directly on the crank. Would require a bit more height. I am a bit surprised by the snifter valve assuming it's working ok. I'll have to think about that. I wonder if the regenerator needs some work?

[@ShanePomeroy]

Yes , ideally I would have a direct flywheel. Ive already got ideas of turning the whole engine horizontal to allow this. It would also allow the flames to more uniformly flow through the heater upwards. I think the compression is technically to great and closing the snifter valve lowers the compression ratio to a more suitable point. As for the regenerator, any good ideas? I was thinking of installing lots of annular plates?

[@TheBaconWizard]

@@ShanePomeroy I am no expert. But personally I would start by having the largest chamber possible between the 2 cylinders and then pack it quite tightly with stainless steel wool in a spiral, leaving a small hole through the centre. And then it would be a case of playing with how much friction it creates vs how much thermal efficiency... but by packing it in a spiral, you can cut (or maybe ram, with a piece of rebar) other holes or widen the exisiting one, until it works right. Just my thoughts.

[@charliepearce8767]

Love your channel and mad on Sterling engines. If I may ask what is the diameter of your pistons and cylinders. Do you have any plans available ? Note, the Rider hot air engines built in the 1800s had its hot side cylinder end directly over and in the top of the fire box to obtain as much heat as possible.. I absolutely love your work..your my hero !

[@ShanePomeroy]

High, pistons are 139.4mm stainless tube and cylinders are 152.4mm od ( insides roughly 6mm less). I don't have plans, just a few doodles! Your welcome to anything just email. Your very right about the rider engine cylinder position! That is a slight flaw in my design really. Riders engine is an incredibly well thought out design (probably why it was one of a few commercially successful ones ever!) I ain't no hero! Just to much time and enthusiasm! All the best

[@charliepearce8767]

@@ShanePomeroy Ha ha , thanks mate for your speedy reply. The distance between the cylinder wall and piston is much appreciated information. Yes, the Rider Hot Air Engine is a magical machine.

[@SetitesTechAdventures]

Is there a way to make this design work with hot water instead of wood fire? I'd like to find a way to use a Stirling Engine to extract energy from a tank of heated water. I think it'd be a neat way to store solar energy cheaply. Can the heat exchanger use a hot copper pipe or radiator that provides hot water or provides hot air from a coil submerged in heated sand.

[@ShanePomeroy]

Hi, I think with this particular design it wouldn't work because there would be to much mechanical resistance compared to the temperature difference. There are specific low temp stirling engines that might get worth a look : )

[@wishbonesi]

What if you replace the heat source with concentrated sunlight with fresnel lens or something

[@ShanePomeroy]

I could do. I don't live in a particularly hot part of the world through. If I could run it on rain I'd be alright!

[@grapsorz]

dont moste of the heat you take out from the heatexchanger get stored in the regenerator? or r you running without one?

[@ShanePomeroy]

From what I've read,they reckon that 4/5 of the heat in the engine is recycled and the heater tops up the 1/5 that is used

[@grapsorz]

@@ShanePomeroy hmm i have seen other engines run a long time on the energy from the regenerator alone. this one struggle to stay running with heat added.

[@grapsorz]

@@ShanePomeroy what is the regenerator made up of in this engine? copper plates? mesh?

[@ShanePomeroy]

@@grapsorz the regenerator is stainless scouring pads you get. I've never seen a stirling run without heat going in. Technically the regenerator has to recover unused heat from one cycle and then add it back to the working gas before reheating. Could you point me in the direction of some of these stirling engines, many thanks

[@grapsorz]

@@ShanePomeroy to replace the stainless part. that metal is just horrendous for heat movement and storage. i have seen some run for a bit on the built in heat. slowly tapering off until it stopes unloaded.

[@abdullahdeeb2242]

I think you need a bigger heat exchanger.

[@itanc1]

awsome dood! silent running with plenty of momentum. can i ask why the stirling diaphragm version didnt work?

[@ShanePomeroy]

Hi Buddy! I'm giving the diaphragm another go on my current engine build, cheers

[@itanc1]

@@ShanePomeroy hey dood, i have tried a few stirlings and had limited success but one idea i did realise was a magnetic link between displacer rod and displacer piston. this allows the rod to move the displacer through a sealed brass tube thus no moving seal thus no loss of pressure. coupled with a diaphragm power piston which also has no moving seal you can theoretically have a completely sealed crankcase which means you can pressurise it and vastly increase the power output for the same input. there are equations that describe this relationship that i have seen but not studied but im sure you are aware of the fact. anyway love your work, you have achieved many times what many of us spend way too much time dreaming of and not doing!! keep it up sir

[@ShanePomeroy]

The magnetic displacer coupler sounds pretty cool. There's always someone that thinks outside the box and comes up with something different : ), nice one

[@dougpine4746]

Looks good. Have you tried shortening the stroke of the power piston?

[@ShanePomeroy]

I haven't tried that. I think (if I remember right!) The original rider engines had a shorter power stroke. I can't really get my head around what this changes? I don't suppose you know? Cheers

[@IronGoober]

@@ShanePomeroy Reducing the stroke length (by changing the attachment on the flywheel) reduces the compression ratio but also introduce some dead space (areas where the air isn't moved from one cylinder to the other) so some extra material at the end of the pistons would need to be added to minimize it. But reducing the compression ratio should reduce the needed temperature ratio, so it should run at lower temperatures.

[@ShanePomeroy]

@@IronGoober some extra insulating material on the end of the hot piston might be beneficial to reduce heat transfer to the seal, many thanks

[@IronGoober]

@@ShanePomeroy indeed that could help. I would suspect that a lower compression ratio might be beneficial for your engine not only for the lowered temperature needed to run, but also to reduce the amount of leakage. I imagine that the reason the snifter valve being covered made it run smoother is that when the extra air enters the system, it has to be compressed, but leaks out before it can complete a full cycle, just causing more compression than expansion. When you cover it the leakage is essentially equal in both directions and you have slightly less parasitic loss from extra compression. Lowering the compression ratio might further help with this

[@ShanePomeroy]

@@IronGoober Many thanks, that seems logical. I'll put this at the the top of the list to try and improve things. I don't suppose you've got any advice for compression ratio to aim for. I'm thinking of about 1 : 1.7. Currently it's over 1:2. If I had another shot at building this I would increase the heater exchanger sizes to lower compression. Best laid plans..... : )

[@hardwareful]

lots and lots of friction, it seems. Also see if you can find a notched v-belt or a way to switch to a synchronous belt.

[@ShanePomeroy]

Certainly more than I wanted! Notched belt is a better idea. Currently it slips when I'm trying to start it. Many thanks

[@mveljko78]

how much watts? :)

[@TheBaconWizard]

There's no generator.

[@malikfarooqdeena]

Will it work woth Concentrated Soler Power?

[@ShanePomeroy]

I'd imagine probably not very easily.

[@malikfarooqdeena]

@@ShanePomeroy thanks Dear. Can you recommend any DIY design which can work on CSP.

[@ShanePomeroy]

@@malikfarooqdeena I think the most promising design type I've seen is the sun pulse 500. Unfortunately they seem to have stopped developing it. The design looks good through and lends itself to rays of sunshine, just my thoughts : )

[@flatbrokefrank6482]

Is that a racing outfit behind you? do tell !

[@joelsoncdma]

Hi, I like your project. I think this compression measuring device is dampening the power...Run without this please. thank´s!

[@Jkauppa]

try also a wood fired no-moving parts kinda-steam-engine jet thruster engine (heat transport air expansion engine), where the burn chamber is separate from the thrust heat ramjet

[@Jkauppa]

large fire, so that you dont need to mind about compression nonsense

[@Jkauppa]

well longer pipe or better heat transfer heat sink plates if the passing air is not directionally heated enough fast

[@Jkauppa]

the heat transport pipe is meant to be hot/heated by the fire in the burn chamber, just like sauna stone heater, bottom is super hot fire, but air passes through the hot stones constantly, yes two air inlets, other for the burn, other for the thrust, not directly linked, only heat transfer

[@Jkauppa]

more like old steam locomotive steam burner, but to a jet thrust engine

[@Jkauppa]

air is already a gas, so no steam explosions

[@trapper1211]

why no power measurement???

[@ShanePomeroy]

Lol, getting it running was hard enough 😂. Quite a few improvements to be made first, cheers

[@trapper1211]

@@ShanePomeroy how will you know if youre doing well if you dont measure anythning

[@ShanePomeroy]

@@trapper1211 you are quite correct lol

[@lawrencecole6527]

Fans run faster in a vacuum because they're not doing as much work, I wonder if that's what's going on here with your engine and plugging that hole.

[@gitpharmmakes7985]

There's one interesting system you should take a look: kzbin.info/www/bejne/jJbdc6WiiLh9pLc This rocket stove powered engine is manufactured by MomoseMD (百瀬機械設計株式会社). That 300Watt engine is quite compact but each unit costs 880K JPY / 5,293 GBP!

[@ShanePomeroy]

Thanks for showing me that. It's an interesting design. I don't think it would cost that much to make. I can feel another experimental engine on the horizon. I've got a spare rocket stove to experiment with. Many thanks

[@reneperennec5516]

Je ne voudrais pas être désagréable, mais beaucoup de baratin pour pas grand chose.