RARE! Antique Homebuilt Two Cylinder Opposed Piston Engine. WILL IT RUN?

[@gilbertnowak5770]

That engine is what is called aProof of Concept built in a Lab of a engine company around the early 1900s. Companies like Fairbanks-Morse had Labratoryies which they had to build Proof of Concept to make sure they would work and test prior to going into building a Proto-type engine. My Dad used to work in a Crane company which was started in the late 1800s and they had a lot of stuff like that!

[@MmmHuggles]

A lot went into that engine.

[@kennedy67951]

This Engine was a young boys' high school Shop project to demonstrate the youths knowledge before graduating high school Mechanical and Mechchine Shop course. For this Engine to still be around today, this young person had to take first place ribbon. Those that did not win would just scrap thier projects.😊 Thanks for sharing this piece of history with me.😊

[@raygale4198]

So what you have is a four piston, four valve, single combustion chamber high expansion ratio model engine. Someone was exploring thermo dynamics trying to extract more energy from the fuel by increased expansion ratio. As others have said a proof of concept model, it deserves to be in a museum. The construction hours in that model shows the dedication the builder had, the construction techniques are brilliantly simple. You don't need big frame bolts holding the cylinders and heads down when all the forces are balanced by the other pistons, it's the crankshaft that holds it all together, brilliant.

[@cruddycornstalks]

the crankshaft in my machinist/engineering opinion is not beeffy enough to withstand a lot of stress. after editing the video that was what I narrowed down to the weak link in the structure of the engine. despite looking big in the video because how close I filmed the journals are only about 5/16 thick . with no bearing braces from the upper throw and the lower throws it almost has to be flexing as it runs. that and the home made chain. I had to readjust the tensioners twice top film what little running I did .

[@peterupsall8542]

It would be nice to make a close tolarance and stronger engine with the same bore and stroke and cooling. Just to see how much power & tourque it can make on a given amount of fuel. IT'S JUST BRILLIANT. It does need to in a musieam and taken care of thanks for the video👍

[@BiffTannen1983]

​@@peterupsall8542 it could definitely use a water jacket.

[@GORT70]

Close. It doesn’t have valves. It has vanes like a 2 stroke Detroit.

[@GORT70]

Oil drip pan is the base….

[@jasondk5127]

Some dude never thought that his home built engine from his HS Science Fair project would ever be in a tear down and run video! 😊

[@cruddycornstalks]

I have made things in my life i bet someone will find cool in 80 years to!

[@theodorgiosan2570]

It's likely so old that movies with sound would have been relatively new. So it would have been much more profound than that. An entire short film made about the engine he built.

[@L98fiero]

@@theodorgiosan2570 Not likely that old, looks more like 1940s to 50s tech but pretty impressive in that almost everything is hand made right down to the chain.

[@hotasianstepsister3039]

​@@cruddycornstalksprobably your future grand children

[@TheZombieSaints]

That's one hell of a science project!

[@nlo114]

What a lovely engine! I'd be tempted to clean it thoroughly, then do a planned video of it running. Afterwards I'd stick it in a plexiglass box on display. It would not last very long as a runner, but is truly worth preserving in it's as-built form for all to see.😍

[@cruddycornstalks]

My friends and I are way to hands on to lock it in a box. The weathering on it shows it's age well and I bet it wasn't spotless when the guy made it. So this is how it will stay

[@mikehart6708]

A really impressive build. Makes me wish I knew who built it and that I could meet and talk with him. The time he must have spent doing this is incredible. The chain simply whigs me out. I've built engines before and I never even THOUGHT of making my own chain!

[@cruddycornstalks]

I'd love for someone to show up and say they know where it is from. Be cool to hear the story

[@ogreunderbridge5204]

This must be the best "Abandoned for 80 years. Will it run?" project video on youtube so far :))

[@garyhooper1820]

Fascinating ! Possibly a proof of concept prototype. All the appearance of being a century old . Maybe the brain child of an early auto or air craft designer . What a Gem !

[@cruddycornstalks]

it is truly a unique piece

[@Wingnut353]

hobby engine.... a prototype would not have hand made chains and gears it would be all off the shelf stuff, faster better cheaper... and really the only explanation for it not to be that way is it being a hobby engine.

[@NathansFerroceriumrods1]

That's a work of art.

[@cruddycornstalks]

yes it is!

[@frosthoe]

Thanks for showing this to us! Im a machinist / builder and am in the middle of fabricating a 2 cylinder TF engine. Perhaps a bit more agressuve then this example but still this is soooo neato! Thank you so much, for letting me see another machinists ideas and approach..

[@cruddycornstalks]

It be a fun project to make an improved version of this with more understanding of how engines need to be designed.

[@gaildimick1831]

Some find, glad you took the time to show us. Very nifty. Thanks a lot.

[@cruddycornstalks]

no problem. neat piece that deserve to be seen by others.

[@deborahchesser7375]

@@cruddycornstalkshopefully you can dig some more vintage motors up for us

[@cruddycornstalks]

@@deborahchesser7375 I try to make a video every other week. Just doesn't always happen

[@deborahchesser7375]

@@cruddycornstalks oh I get it, it’s plenty of work and it’s appreciated. Hint hint, old bikes are a blast because you can ride them after doing the work lol. Thanks brother✌️

[@jean-charlesweyland129]

This type of vertical opposed pistons engine was the trademark from a French car manufacturer named Gobron-Brillié. They produced big luxury cars with 2, 4 and 6 cylinders with opposed pistons from 1885 to 1922. Their biggest 6 cylinder had a displacement of 976ci ! Most of these engines had side-vales but in 1921 a sleeve valve version was offered. They were the first in 1904 to hit 100mph (103,55mph) setting thereby a new land speed record.

[@douro20]

Could you believe there is one in Argentina? It's a 1911 50hp model which belonged to the founders of the town of Intendente Alvear. It was restored in 2011 by the town government and a group of enthusiasts. Unfortunately most of the body was gone so they had to fabricate a new one.

[@jean-charlesweyland129]

@@douro20 I know of that car, it's a dark blue 40/60HP open tourer. There's a good reason he chose that car, it was designed to run on anything flammable (it could run on Alcool) making it a good pick if petrol was harder to come by than booze. The Tsar had a number of Dellaunay-Belleville that were know for their reliability, you can see that as buying an exotic sports car to differentiate yourself from your neighbor.

[@quantumleap359]

Beautiful little model engine. A very dedicated person put many hours into building this jewel. Great find!

[@un65tube]

Great work has been done by the builder of that machine! My deep respect to who ever made it! Fantastic to see it running. Many greetings from Germany!

[@deborahchesser7375]

Man that is neat, some people have magic hands.

[@leonardburlile9623]

Very Impressive! Nice going on getting the homemade engine running.

[@aaron71]

...wow! I LOVE home made stuff like this. So awesome!!

[@ronalddaub9740]

I've worked on engines all my life and that thing is amazingly built and I understand it You have something

[@JosephCowen-ru7up]

Impressive understanding of the Otto cycle , at first glance I thought it was a two stroke opposed piston engine like the Commer TS3 Truck engine , but this is a four-stroke ! Commer TS3 Truck Design was around for decades , I worked on a farm when I was an apprentice and one day the farmer said " bet that you have never seen a 3 cylinder engine with 6 pistons , one crank shaft that drives rockers with 6 pistons , and the pistons meet at top dead centre , and it's a two stroke , and it's got ports with no valves ! I thought they were having a go at me ! But please look up the Commer TS3 engine ! Legend the opposed piston engine !

[@BiffTannen1983]

BRILLIANT DESIGN!!! I LOVE how the top 2 pistons are connected to the crank shaft!!! 🤯❤️🎉

[@hilmanrootes]

the guy who built this was very skilled and clever. hats down.

[@Yukanhayt-Mhenow]

Absolutely amazing project! Im glad it ended up in good hands to show it's glory!

[@cruddycornstalks]

Thank you. Try my best to take care of things!

[@jaredkennedy6576]

That is an amazing and fairly unique way of building an opposed piston engine. Ive seen plenty of double and triple crankshaft as well as single crank rocker style, but this is almost like a steam engine or early coalgas/natural gas engine with that extra crosshead throw. I'm definitely filing this one away for if I can ever have tinkering time. Edit: Very similar to a Junkers-Doxford style engine. Incredible tech.

[@cruddycornstalks]

Yes. Very unusual for sure!

[@fzr400rr100]

Absolutely beautiful piece of work.

[@cruddycornstalks]

Thank you.

[@davida1hiwaaynet]

What an amazing find! You get all the good stuff LOL! I can only imagine the amount of time which went in to the construction of that engine. Blown away at the hand-made chain links and sprockets. Your piston ring o-ring modification worked well. I am sure you feel it's an honor to have this one-off piece in your collection. It makes me wonder what concept the builder was exploring. It looks like it might be possible to achieve perfect primary and secondary balance with that design, for one thing.

[@RustyInventions-wz6ir]

Wow. Very nice beautiful engine

[@cruddycornstalks]

thank you!

[@jhndijkman]

I didn't realise the video was from you Mister Cruddy. I was truely facinated with this a home made little engine. You are right why would even bother to make chain and gears. Must of been fellow who made this. Very cool.

[@clockbuilderhg]

That's a cool design! I've seen Opposed piston engines before but the elimination of a second crankshaft is very neat.

[@driverjamescopeland]

I'm a sucker for cobbler engines. Thanks for the content!

[@KenHarrison-m2y]

Absolutely fantastic engine, absolutely fantastic video. Please keep up this great work. Thank you so much for sharing, the engineering world is blessed with what your doing here.

[@colin_5839]

That's a really cool piece right there!

[@davidduncan6280]

good video!!! Thank you for showing us this and yes the craftsmanship is amazing.

[@cruddycornstalks]

Thanks you

[@thebrain9384]

Intriguing. I've always thought the hit or miss engines could be an answer for many applications.

[@1961kickboxer]

The guy who made this was a genius

[@cruddycornstalks]

He truly was

[@IowaBudgetRCBashers]

This is absolutely amazing craftsmanship

[@tannertolson]

This is impressive. Glad it worked out. That’s life without cellphones and computers.

[@pepperonipounder]

Beautiful little machine

[@jorothquicstar7050]

That's pretty amazing to be hand built. That should be in museum

[@ramongonzalez2909]

Man that’s amazing and it runs smooth too

Did you say nothing special ? No youtube, no cnc, just books and friends, hand tools... Its amazing! Handmade carburettor? Its absolutely fantastic!

[@dmckenzie9281]

That is very cool! I have been interested in the opposed piston design of Achates Power.

[@markysspotlight2472]

Absolutely amazing craftsmanship 👍

[@GoingtoHecq]

This is incredible. I am just amazed by it.

[@ihus9950]

Are there any Markings on it? Thing belongs in a Museum, really a Awesome little engine for sure 👍🏻

[@cruddycornstalks]

Not a single mark anywhere no numbers nothing. a true mystery

[@pisstinpete4700]

The person who made this was a genius.

[@waynegarfield6607]

I didnt see opposed piston engine. It looked like a inline twin with normal layout except pushrod / valve train looked different. Small bore long stroke. O rings wont last long. Drill tiny holes on top of piston that channel to ring center with pin as to stay in one spot ( 90 degrees to rod. The combustion pressure should then bleed to center of ring helping expand it against cylinder. Run good synthetic oil or 100 :1 premix ....it will lube piston/ cylinder and help seal it.

[@cruddycornstalks]

It's very much is an opposed piston engine. 2 cylinders four pistons, there's two piston on top coming down into two pistons on the bottom with a common combustion chamber . The o rings would outlive the engine if ran much as it's not built to be ran very much. And neoprene o rings can handle the heat and pressure. Aswell as they seal.on the poorly machine bores of the engine.

[@andrez3640]

Can I close my mouth now..... unbelievable...simply awesome.....

[@JoeRocket-sf6qs]

That thing is dukin awesome man,i love the chains.

[@cruddycornstalks]

It definitely is something special

[@Gwen-x6d]

Excellent Video and Audio. Nice.

[@Freesavh1776]

Dont you just love those 40 mile long nits & bolts. You just turn & turn & turn. AND IT NEVER SEEMS TO END!🤣🤣🤣🤣🤣

[@nunyabizznizz7326]

it has the cool factor for sure!

[@gwheyduke]

Very cool engine! And it really runs. good video.

[@garywhite3264]

This is the first opposed piston spark ignition engine I've seen! All others have been 2 stroke diesels, which lend themselves to the opposed piston layout, the Napier Deltic the most complex, a 3 crank, 18 cylinder, 36 piston design.

[@cruddycornstalks]

Very few brands used it as it didn't really give enough benefit for being gas powered

[@rogerbrennan4170]

Nice find. It's awesome

[@cruddycornstalks]

Thank you

[@dominicrichardson5546]

Awesome how it runs so smoothly since a lot of the vibration is cancelled out

[@shawnrobinson5156]

Just cool as hell thanks for sharing

[@rebekahfrench5747]

Looks like a student project from the 50s or 60s.. trade school project.. interesting though barrel fins weren't incorporated to disipate heat.. proof of concept it runs under its own power..👍

[@crazycoffee]

Thats so cool someone definitely was in school when they made that. Or it was a concept for a bike mower or something. 2:55 it looks like an old battery tray.

[@joshuawise6518]

I think it's beautiful

[@JackWilson327]

That’s an amazing find! Should be a lesson that you don’t need all the tech of a modern engine to get something to work. Work efficiently and be clean… another story of course. Totally cool man!

[@oldamericaniron5767]

Would love to see how combustion chamber is configured with one spark plug for 2 cylinders. Do both cylinders compress into 1 combustion chamber. At any rate a great collectors item to study and enjoy.

[@cruddycornstalks]

You are correct. The guy just drilled a common hole between the two cylinders and that's where the sparkplug is.

[@oldamericaniron5767]

@@cruddycornstalks So there are 2 intake valves, 2 exhaust valves , 2 cylinders , 4 pistons all into one combustion camber? I say it ranks up there with one of the most unusual internal combustion engines ever built.

[@cruddycornstalks]

@@oldamericaniron5767 yes correct. It very much is.

[@helixworld]

There is enough hardware to run an even-firing 2 cylinder engine. It only needs another spark plug and a distributor. The nice thing about this engine is good primary balance due to the opposing pistons.

[@JDawghasaTruck]

Very cool! Somebody had a LOT of time to kill!

[@sapieattersisingere3288]

That was amazing little engine.

[@justs-28445]

The FACT THAT IT EVEN RUNS AT ALL IS AMAZING IN IT'S SELF! and to run well at that!! Highschool project or factory experiment? Who REALLY KNOWS,, BUT IMAGINE IF IT HAD SOME KIND OF COOLING SYSTEM IT MIGHT RUN A LONG TIME.....

[@peterparsons7141]

How coool is that machine! Wow.

[@rosewhite---]

It's not an opposed pistoon engines but seems to be based on Doxford and similar ship engines which have a vertical link to upper pistons. Look up Doxfords.

[@cruddycornstalks]

Well considering a doxford is called an opposed piston engine it would seem it is an opposed piston engine.

[@MidEngineering]

I guess the opposed piston layout makes it perfectly balanced & reduces the load on the crankcase so it only needs sheet metal construction. Just a single spark plug though - huh?

[@cruddycornstalks]

In all the smart decisions the guy made making this engine. He made both cylinders use the same combustion Chambers with separate valves. And then naturally the cylinders fire together aswell instead of alternating making it the lease efficient way to make the engine timing.

[@vumba1331]

That's what I thought, all of the driving forces taken by the 3 opposing rods within the cylinders so minimal crank case load. Interesting to note at this time that there were a number of 2 stroke air cooled motorbike engines that had 2 cylinders with only 1 spark plug working through a shared combustion chamber and they workd just fine, there are still people restoring and riding them. Perhaps that configuration was all the rage around this time, maybe ignition setups and plugs were expensive, hence this design attempt?

[@peterfreekinpan1300]

Bro you were holding an absolute piece of history that thing belongs in a museum somebody put thousands of hours into that I bet I really want to know where it came from and who made it now have you gotten any more information on where it came from?

[@cruddycornstalks]

I have not. no one has come up with anything nor have we found anyone.

[@joshjones3408]

Great video 👍👍👍

[@marque7583]

Well done 👍

[@enginecrzy]

Nice! I think some ww2 planes had opposed acting engines & also large Diesel power plants with 3 v engine piston/cylinder assemblies faceing each other in a opposed triangular manner. I wonder if the inventor was closeley involved with one of these engines at some point. Circa Post war suburbia was influenced with a lot of very clever d.i.y shop projects from Popular Mechanics magazines "build your own bench belt sander or mabie a homemade experamental helicopter/autogyro"... & hobbies like controll line airplanes, Go Karts/ Minibikes, & train layouts or slot cars to name a few... Very clever people around then. Now we get those lame life hack videos & kids eating tide pods for thier ticktock chalanges🙄...✌👍

[@cruddycornstalks]

Hard to say. The most common opposed piston engine is the Fairbanks OP engines. They are still used in peak power draw power plants to this day

[@ludditeneaderthal]

Junkers jumo diesel (think stuka dive bomber) had an inline opposed piston, forced induction 2 stroke configuration. Pretty sure the delta configuration engines were British, not german. Small ones ended up in trucks, big ones in trains if I remember right.

[@mountainman0]

what you have is a modified copy of the French company Gobron-Brillie and their gas engine design from 1900. Although the maker of your engine has only used a 3 throw crankshaft, the original design has a 4 throw crank with the 2 inside throws operating the lower pistons and the outer 2 throws worked the upper pistons. Junkers made aircraft diesels 6 cylinder 12 piston engines that used 2 crankshafts that were geared together and were 2 stroke diesels with forced induction to supply scavenge air ( as used in the Faibanks-Morse engines) they were used in larger multi engine aircraft, Mainly the Ju86(only some versions) and some models of the Blohm+Voss flying boats. they were never fitted to the stukas. The Junkers engines were license built by Napier in the UK as the Culverin. Napier during WW2 then started to consider the deltic (inverted triangle) design to fulfil an admiralty requirement for high powered light weight engines for use in fast patrol craft (think PT boats and small cutters) and small mine sweepers. the deltic engines would then be used later in the Class55 (became known as the deltics after the engines) and the class 23 locomotives. Junkers also built 2 stroke opposed piston engines that used a 3 throw crank per cylinder with the centre throw working the lower piston and the 2 outer throws working the upper piston. (similar to your engine but reversed) the small models of this style were used to power pumps, generators etc. and also in some early model diesel trucks and other construction style machinery. the larger versions of this style of engine were used in marine and large power generation and pumping applications. Doxford engine works ( part of the shipbuilding firm) built these engines until closing in 1980. @@cruddycornstalks

[@arthurn9237]

HAY NOT TO MENTION POPULAR MECHANICIS HAD ALL THE INFO TO BUILD YOUR OWN MINI BULLDOZER ☝️ KID SIZE WITH A BRIGGS MOTOR ☝️ FROM SCRATCH I SAW ONE DEN IN FORT MEAD FL. AT FL.FLYWHEELERS LAST MONTH

[@johnsherwin1104]

Off setting the crankshaft to the compression side of the cyl8nder is a common way to almost completely remove oval wear pattern on the piston and cylinder. Additionally important to high compression motors.

[@benjamincresswell3713]

I am at a loss to understand why you call it an "opposed" piston engine. When I was a kid my neighbor gave me a "Standard Twin" powered 2 wheel walk behind cultivator tractor. In a "Standard Twin" engine both pistons go up and down at the same time like the one you have there. That engine was commercially built by The Standard Engine Company Minneapolis Minnesota. It was a very unique design and it ran great. Whenever I tell anyone about it they say it couldn't have had both pistons going up and down at the same time or it would have vibrated. All I can say is the pistons went up and down together fired alternately and it did not vibrate at all. It ran smoothly and sounded great. There are a few videos on KZbin where people run them if anyone would care to see one in action. After tearing that tractor all apart at least a dozen times I learned all about it, and I often wondered why John Deere designed his 2 cylinder tractor engine pistons to go in opposite directions causing an "odd fire" engine. Harley Davidson did it to save width, but width wasn't rally an issue on a tractor. OK, I said my piece, thank you for putting your hand-built twin on the internet. ben/ michigan

[@Michael-ly7vt]

Just amazing!!!thnx for this dude...just love it😊

[@DCT_Aaron_Engineering]

Very cool thanks for sharing 👍

[@Emilthehun]

Picture this. When this was built there was no youtube, no internet, no social media. Whoever built this never would've imagined that one day some strangers all over the planet could admire his creation through a small window we call smart phones. Amazing world we live in today for sure

[@cruddycornstalks]

We lived without Internet for two years back in 2013/14 and in that time I made two motorized bicycles and the one drove me around a few hundred miles.

[@Emilthehun]

@@cruddycornstalks that's actually pretty cool! I build cars as a hobby, but still use the internet while doing it

[@Goultek]

epic engine!! endless hours of craftinbg this marvel

[@bertjesklotepino]

what i would love to have seen is an explosion view of all the components neatly ordered. And perhaps a few detail shots of the more complex parts. Just to learn what makes this "clock" tick.

[@charleswilliams8197]

I'd like to see the home made rings just to see what they look like okay thanks Charles

[@cruddycornstalks]

Perfectly scaled down version of a normal piston ring.

[@Gearz-365]

Impressive engineering behind this. The fact it was homemade is even more impressive. Though ehat I'm wondering is what the original builder used it for, it has a lot of different possible uses

[@cruddycornstalks]

with the lack of cooling it was merely a concept engine or perhaps just something to pass the time and make.

[@Gearz-365]

​@@cruddycornstalks I'm sure it was worth it in the end. If it had a cooling system I can see it powering a go-kart :)

[@dawsonblanchard5832]

Thing is made more reliable and easy to work on than stuff made in 2024

[@TotoGuy-Original]

this is a super cool engine!

[@impuls60]

It deserves to have the rings retempered so it remains original.

[@cruddycornstalks]

You can only retemper rings so many times and these would not be able to.

[@RustyInventions-wz6ir]

Incredible. I love it

[@cruddycornstalks]

Thanks I do to.

[@davekauffman8727]

Very impressive craftsmanship, too bad there isn't a cooling system, it might have a use somewhere. Usually opposed piston engines are 2-stroke Diesels, so this is even more special, maybe you can finish what the builder started 🙂

[@robertmichael8036]

Awesome 👍😎 that is a good engine

[@BloatedBearucraticNightmare]

Appears to me it was constructed from a collection of brass plumbing fittings. Perhaps it was built by a Plumber? The pistons appear to be old shower and sink valve stems? or of a similar design?

[@markbernier8434]

Did you realize that it was set up as a pull rope starter? The style of the flywheel and the starter rand the horizontal carburetor reminds me of prewar outboard motors. I wonder if this was intended originally for marine use?

[@cruddycornstalks]

I did but they also had the ratchet for either a crank or drill start. The rope pilly was so shart it would cut through a rope really easy. Aswell as I forgot to mention in the video. The flywheel is made of lead so I didn't want to rust damaging it.

[@terrywarner8657]

The maker must have had arms and shoulders like a body builder after hours and hours of pull starts on a rope. You cheated with a power drill, and it still took a half-hour of spinning and setting.

[@markbernier8434]

That may be true, however, fwiw, I can say from experience that if you set the position of the flywheel correctly and your points are set correctly, a quick snap through 3/4 of a revolution will start a motor. Skill, not strength.@@terrywarner8657

[@daviddaniels6473]

Pretty impressive!

[@jamesraymond1158]

So cool! Wonderful comments below.

[@masterbryan7106]

Looks to me like this is a single crankshaft, four piston opposing engine.

[@TiborRoussou]

Imagine the hours put into making this. Interesting find.

[@paulasmathers2639]

He should try putting the old rings back in and warming up the cylinders with a torch or something to see if it would help it run

[@jimmystovepipe5072]

Beautiful!

[@mikalliz2167]

It's a mini Fairbanks Morse 👏🏼

[@craigtate5930]

Spectacular lil engine....even the chain is amazing...great find

[@cruddycornstalks]

thank you!

[@bikemike2777]

That is a cool find

[@Iowa599]

The O-rings won't like combustion. Stretch the worn-out rings (expand the gap). I wouldn't worry about heat treating them, because it won't run enough to cause much wear. Maybe just to soften them (before stretching them), so they wear to fit more quickly. I wonder if expanding snap rings come in the right size to be piston rings, they're close to the proper material & hardness.

[@cruddycornstalks]

Neoprene o rings are rated for high temp and high pressure aswell as beig low friction. Model builders use them all the time as they seal a lot better and easier then normal rings . You would need to heat treat the rings otherwise they won't ever seal better as they deform from us and won't work properly. They need to be able to spring open against the cylinder wall. The rings in there current state would deform my hand without any efforts and felt like bailing wire.

[@Iowa599]

@@cruddycornstalks no (factory produced) engines use o-rings for piston rings for a reason, but I guess that engine can't run long enough to cause severe wear issues. It does sound like the OE rings are very soft already, and probly can't be hardened. The expanding snap ring idea is sounding better!

[@cruddycornstalks]

@@Iowa599 the o rings are a better choice on an engine like this. We aren't dealing with a high use "factory produced" engine. It's a model. The cylinders are not machined very well and the o ring will help seal against that. And it's a lot less friction so the engine will run smoother. Aswell as o rings are dirt cheap and the day they wear out it cost a couple bucks or less to replace 4 of them. But as I have seen in other projects I've worked on. Neoprene o rings will last decades In some models or even fullsize hit and miss engines do to how little they run and how cool they run. Have some engines in my family that have one in them longer then I've been alive.

[@markcollard9326]

That is AWESOME.

[@BloatedBearucraticNightmare]

Way cool Mo D!

[@Dave5843-d9m]

Just two main bearings supporting three big ends is not a strong design. Two cranks would not have been any heavier as that would lose the central link rod and crossbar. It also loses the valves and doubles the power strokes.