Making a New Cylinder for the 3D Printed Gas Engine (so it runs, like, properly) 

Love how this project evolves from 80% 3d printed plastic parts to like 20% 😂

I think you’ve officially gone from “building a 3D printed engine” to “building an engine”!

You need to rejet the carb. if you take the bowl off you will find two jets. One right under the throttle, called the main jet, and one in front called an idle jet. Turning that screw does basically nothing, and is only really meant to fine tune it at idle. The main jet limits fuel at high throttle, the idle jet limits fuel throughout the range. You need to go up a size or two in idle jet, and a few sizes in main jet. The needle can also be moved up or down to give it more or less fuel, and sometimes you need to change the needle out for one with a different shape in order to fine tune it so it runs good at all throttle openings, loads and rpms. Properly tuning a carb is an art, but getting it good enough to run ok is easy

I love the switch from freedom units at buying to metric for precision machining

Crazy how the engine went from running on hopes, dreams, and starter fluid to actually being able to idle on just gas. The project truly has come a long way from the blocky plastic days

just fyi, you can make the case 200% the current strength in the axis it's shearing just by rotating the print on its side

Once it's complete, I think it would be cool to recreate the same thing but all metal.

Insta-liked faster than I ever have. Used to have a friend named Camden, he’s no longer with us. I miss him, he was a good man.

9:44 after comparing to "3 Hours of Volkswagen 1.9TDI idling ASMR, relaxing sound", I can confirm that genuinely sounds almost exactly like a 1.9 TDI idling.

Definitely look into adding a crank case ventilation valve or line, just so that you don't end up with the lower end being any more of a pressure bomb than it already is with the crank trying to force it apart

“But I figure if there’s both fuel in the engine and in the fuel then I’ll be okay.” I haven’t ever laughed so hard at an engineering video I love it

I studied machining in college, and it looks like you need some oil to lube up the cutter. The feed rate, which is turning speed and turning speed combined. Your turning speed depends on grade of medal.

8:08 My boy, you should go back in time. Engines were pretty much simple affairs back in the day. Sandwiching the bore between two plates with 4 bolts would've been sufficient. No need to weld as long as the fitment is good. 13:11 when you don't have the spreader tool, you just take a pair of scissors you don't like and cut hooks (facing outwards) into the ends. Those hooks hook into the ends of the ring and spread it. With one hand you spread the scissors and with the other you keep the ring aligned and guide it unto the cylinder.

its too emotional to see her running 🥲

You should consider getting an end mill. Then you can bore out a cylinder into a solid chunk of metal. You can also cut keyways. You could also make a connecting rod out of a solid chunk of metal using the mill

This is the RU-vid I love most. No fancy 6-axis CNC machine, no fancy machinist certifications, just a dude with a $300 lathe, a cool idea, and a LOT of patience.

That is OFFICIALLY an idle! Most people never get even remotely this far in their engine from scratch projects! Incredibly well done!

Genuinely underrated channel

This series should be called "3D Printed engine becomes more and more metal"

I’m a motorbike mechanic and specialise in classic and vintage 2 strokes and this is the first time I’ve seen someone put a 2 stroke piston in a 4 stroke set up ☺️ good on you tho for never giving up on the build 👍

I love the bringus studios style editing, gets me every time

That is so awesome, I've been wishing for years for someone on youtube to build their own engine, great job getting it to run.

Finally seeing the engine run on gasoline is so impressive! Can't wait to see you incorporate more machining into projects! It was really interesting to see how much actually goes into making a lathe usable in the last video and how its quirks still show up... The world isn't ready for what you could create with a proper non-shaky lathe setup! I love how much I learn about engines just watching you build better versions each time! I had no idea about cross-hatching but it makes so much sense when you put it in context!

Putting those bolts all the way through and down into the base was the ultimate final addition to your creation. It essentially clamped itself together. Rather Than explode itself apart from little plastic screw points. You knocked this out of the park. That lathe really came in handy

I’ve been following this series and this is actually so inspiring, good work!

I love this project, I've always thought about building an engine myself from scratch, and this series has taught me a lot for what I can do to make my life a bit easier

I love seeing this series, I hope to see more iteration on this, I'd love to see you try to replace the remaining plastic parts with metal parts within the tools you have.

Now it's time to get it to rev up higher! Excellent work!!!

I wish I could do a project with you.This is cool stuff.Please keep going because you seem to be ridged despite many adversities.Thanks for the educational material

Bro so cool! been watching this series from the story and I love how this eloves! I would really like to see atleast another video with this engine when you will upgrade it to its max so cool keep going! :D

Thank you for keeping this series going. I've been so looking forward to it

i would love to see this engine run without problems keep up the work this is amazing

To fix that bogging, take out the slide from the top or the carb, and there’s a needle that you need to move up. That needle blocks the main jet so at any other throttle position than wide open, it’ll have about the same AFR.

Awesome video! Thoroughly entertaining, enjoyable and informative. What more can you ask? Yes, you have figured out your personal, RU-vid "formula". I watched the whole thing! Good work! WANT MORE!

Hell yeah I’m so glad you’re going with stronger materials and it’s actually working and running on gas love these videos also your voice is nice

Hell yeah dude, nice work. love your engine vids!

Damn exiting stuff. I'm totally in for DIY forged parts.

Congratulations on completing this project. I’ve been watching since the beginning. Your videos helped me get through really tough nights alone when I was going through chemo the past couple years. Thank you

I appreciate the amount of work it took to make this. Keep doing what you’re doing!

i cant wait to see this engine actually doing work, running something, but i don't know what at this scale, maybe a motorized bike?

I appreciate all the hours of work put into just this video, let alone the whole series.

amazing video, you are easily on my top 10 favorite channels. i wonder what comes next.

Yes!!!!! Been following this project from the beginning and I gotta say I’m impressed asf!

I never EVER thought I would see this engine idle, 👏👏👏

Brilliant work can every upload you push into new territory for greater performance! This is epic 😎

I’ve never seen a black iron pipe look so nice. Even the new ones usually have a little bit of rust. Fun fact, Dawn dish soap will aggressively rust black iron to a nice bright orange in like 24 hours. (Leak tested a new outdoor gas line and forgot to wipe off the soap)

your projects are insane

I actually like how this transitioned from a 3D printed engine to an actual engine. I see it as a great way to prototype certain parts. You could take this even further and slowly fabricate each part in metal with plastic prototypes!

i've been waiting this video since months, thank you Bowen

please never stop improving this engine

you're in the great tropical southlands of canada, while i'm your neighbor to the north in alaska, and i've been able to keep my garage door open for weeks now. maybe the engine had trouble because it didn't have enough oxygen heh watching your progress has been great, thanks for keeping at it, keep 'em comin'

Using needlenose pliers to tighten nuts. Takes me back to my crazy 90s kid projects!

Saw your last video and was super surprised you didn’t have at least one of those vevor mini lathes. I’m sure you’ll make good use of it! I love mine

WOW im so glad to see this return!!!!

Awesome job man, Its fun to watch you engineer and build this this engine. The all success and failures included. build a heavier flywheel or add weights to the inside of the current one and retest. It will make everything more forgiving. then you'll be able to dial in the carb.

Certainly an interesting idea to just use a toob from the store as the cylinder "bank". Also, I noticed the bits of music in the video, nice touch! Keep up the good stuff man! : )

The screw closest to the front of carb is an air Mix screw. The one further back is fuel mixture. Try adjusting while running. Love these videos!

This is AWSOME!! Great work!!

I just ❤ your tenacity!

The engine looks really cool, good work but could you mabey make it a 2t

Impressive! This is definitely the kind of stuffni like watching!

Those mixture screws you were adjusting are the idle mixture screws, it seems like the engine needs more fuel all together. Take the screw cap off of the top of the carb and pull the slide out, there should be a little needle coming out of the bottom of the slide. Take out that needle and you should see multiple notches cut out of the needle and a c clip. If you take the clip out and throw it into one of the lower notches it lifts the needle which lets more fuel in. If the clip is too high on the needle, the needle will sit too low in the carb it will be letting barely enough fuel in, and it will cause your idle mixture screws to only be tuned to an extent. Hope this helps👍

I just had a similar problem at work boring out a 1" hole to within 0.005". I've found that cutting the RPM down can help dramatically.

nice weld at the cylinder! :D

To mesure precisely a piston you gotta take the mesurements on it's skirt since it"s a little bit wider due to the expansion of the alloy on it's crown, the top heats up lot more than the skirt

Awesome!! Thanks for doing this!!

Well done mate 🎉

I love your Projekt hope to see more soon

You need ignition advance via flyweights and ideally a vacuum diaphragm, in addition to tuning the jets on the carb.

19:40 based off the faced that that carb is probably for a much larger engine it might be flooding would also explain the smoke coming out of the intake when it shuts off

Finally something interesting on youtube thank you Is really hard to faind this good stuff

Hay man, I found your channel yesterday and watched the full series, and i was so excited when the engine was running by itself today. It will be a nice evolution if you try to make fuel i injection with ardoino for example.

was waiting these last few days for it to drop lolz

Finally, revisited and a new video!

I think he should make a gear box for it and see how well it goes good job for making it work

You should have the valve timing so the exhaust begins to open right before BDC, to reduce load on the engine. Also make an inline 6 with this architecture and run a go cart with it!

you got a really good surface finish on the lathe for what it is, cheap lathe with some mystery metal pipe. would've expected way worse

Youll probably get more smooth running on the engine when the exhaust tapers in and out with some bends it in. You might not have enough Decompression on the down stroke, still sounds like it's resetting the cycle HARD. That might also explain the explosive down stroke when timing starts to dither. The flywheel wants to keep going and add cycles/torque to compression, the exhaust helps by have gases for the piston to still be expelling, almost acting like an air cushion. If you revisit this, you should show levels of exhaust and differences between em ;)

You should add a speeduino to this fantastic mix.

it's more impressive to do everything with 3d printed parts like I know a ytber who used to work in all 3d printing and they recently expanded their toolset and it's significantly less fun the challenge of working with 3d printed parts is the way to go but your stuff is still, fairly interesting I get excited when I see a new "3d printed engine" video

Hey man a tip for putting on piston rings to make it much easier.. Were the ring split is push one side into the piston slot the lift the other edge of the ring and rotate completely around the piston and it will slot into place

Haven't watched the video, can already tell it's a banger.

16:10 what a god damn gigachad! Look at that beauty! Edit: very impressive BTW. Small engines like that require a lot of precision. Very well done! Keep going!

When you eventually get to turbojet engines, things are going to get nuts lol. This is mighty impressive!

Please keep building engines this is so cool

when you tune a carburetor, make sure you dont have any air leaks, mainly 3d printed parts have microscopic holes, which will make it have a bad air leak, air leaks can cause it to run away, stall, and not even start

The engine has a nice idle sound tbh

Maybe instead of mixing just straight up motor oil into the gas, you could try mixing in some Rotary Engine premix? That's designed to lubricate engine components while being burned, so maybe it'd work

Got to love how many stupid mistake sand mishaps you don't edit out, makes me feel better about how much i worse i am at machining

Holy hell, dropping that metal pipe was an instant subscribe button smash. I expect big things from you.

far from 3d printed now, but still a blast to follow and learn about! I'm surprised the bottom end is fine! You must have a serious passion for this now xD

Too much fuel on idle...and probably on the main jets...tighten screws all the way down...back out 2 turns...might need less since it's a big carb and a teeny bore (remember you stepped up size of carb so more fuel per stroke) So awesome to see it hammering along! Keep em coming!!!!

Absolutely awesome. I think that the facemask and respirator could be used while running the motor.

to fix the issue with heating, if you cant add a radiator, then maybe a water jacket around the cylinder. it could help with keeping temps under control

For a smooth bore, use seemless pipes. That will save lots of work.

The King of Random channel has a couple different videos on how to build pretty good foundries for a decent budget.

When you eventually buy milling maching, which is inevitable, try getting one with 3phase ac motor, they are good, ones with DC electromotors get fried after a year.

IDEA put the enjine on a home made go-cart, love to see more man!

You're doing great work brother man! I hope you get big on RU-vid! You definitely should 🤨

HE DID IT. FINALLY. This is dope.