Twin Supercharged 4 Cylinder Nitro RC Engine 

Alot of people asking about the WaterJet I use, heres a link: bit.ly/ProtomaxWaterjet

Insane! 3 psi on that scale is monumental! I agree, going bigger should bring even better results. Also, double check all connections for boost leaks. I thought I sorted that problem out, but it was still there. Can't wait for the next part!

You know my guy likes to party when he got missing fingers

I am seriously impressed, the welds, the programs it takes to do this, the expertise, the measuring. Definitely earned my subscription!!

When you run two stages of boost like that, you need to size your compressors accordingly. They can't be identical. When they are, either the first stage is overflowing or the second is starving. The first will necessarily need to be bigger than the second. I've run some numbers for you: - The engine displacement is 14cc - Maximum rated speed is 13 500 rpm - Total volumetric flowrate (ideal) at that speed is 1575 cc/s (call it 1600 or 100 ci/s or 3.34 CFM). You can't fill the cylinders that quick, but that's the goal anyway. - Your compressors have a pressure ratio of about 1.68 (10psi overpressure) - Assuming adiabatic compression (no heat loss), that means a volume ratio (inlet to outlet) of 0.69, or sucking in 1.45 times more air volume than what comes out. You'll obviously lose some heat, but this should be close enough - This means that the second stage must suck in roughly 2300 cc/s, which means the first stage must be able to supply that at its outlet - Assuming the same pressure ratio, that means the first stage must be sized to flow about 3400 cc/s at its inlet You also need to mind the heat here. Keeping to the assumption of adiabatic compression (because the air moves fast enough to lose very little heat), and assuming your workshop is at about 20°C (68°F), your first stage outlet temperature will be about 67°C (152°F) and your second stage - 121°C (250°F). Obviously some heat will be lost to piping/environment/etc, but at those pressure ratios your cylinder inlet temperature will still be upwards of 100°C which may or may not be too much for the engine. I'd check with Toyan. You might need intercoolers to protect it (either at every stage, or just before the manifold). If you do, it's worth recalculating the sizing for the compressors, because the total volume ratios will change.

Amazing job with the superchargers! Looking forward to seeing more!!

The "compound" idea is flawed; the pressure isn't additive the way you're calculating it. That's why you're getting so little pressure overall. It wasn't the boost pressure pushing out the intake pipe - it was the vibration. You have a bad bearing in your idler pulley. And you're running your fuel mixture way too lean, which is why your engine temps are rising so fast; your "increasing the air charge" isn't all that you need to do!

AFR's are massively important to keeping the engine cool while running aswell. Fuel "cools" the combustion cycle. so a richer mixture may not produce quite as much power, but it will massively improve the temps you're seeing and how fast it gets up to temp. Super cool video though, these little motors are super cool.

It's fantastic how you are able to go out and get one of these little engines and be able to show your children how an engine works in real life without having to take your car to bits . I'd also love to do a build with one to make a R.C controlled car or boat . What a great build this would be and I would love to see what the potential you could get from this

I’d love to see this in an absolutely insane RC dragster

One thing. For compounding to work the first supercharger needs to be bigger at the same RPM or be the same size while spinning faster. Because right now the second supercharger is creating suction at its intake which completely destroys the boost from the first supercharger while creating more heat than a single charger setup.

This is so freaking wicked!!!! Thanks for making something so cool, and showing all the programming it took to build all of the brackets and other parts!!!

You sir are super talented & honestly a genius of course it has to be nice to have a waterjet & lathe at your fingertips. All you need is a vmc. Nonetheless to have all your skills, programming, welding, knowledge of electronics, machining, engines, etc. I'm in awe. Being a machinist all my life your skills are 2nd to none. I stumbled onto your channel by accident with the jet go cart. I'm so glad I did. You have a new subscriber. I'm intrigued by your genius. Keep up the great work. I'm enjoying your vids. Thank you.

The engineering alone... Wow

Incredible and insane at the same time. Something about the scale makes this even more impressive.

I'm glad someone finally made an app like that. I thought of that idea years ago but wasn't sure how the heck to get it done so props to you and your sister for knocking that out.

What a beautiful engine. What he does here is just brilliant! Compound blowers on an L 400 ! WoW!! When I hear " compound engines" I always think of WW 2 aircraft powerplants and the big Pratt n Whitney and Wright compound Turbosupercharged radials .9, 18, & eventually 28 cylinder.

That startup at 9:48 sounds cute and mean at the same time

I have been an ASE certified master mechanic and emissions specialist for 35 years and I just stumbled across your channel. I love watching you do your thing. Thank you so much for what you do.

watching people make custom performance parts for these little Toyans could be the most entertaining and fascinating videos iv ever come across down the rabbithole

That opening build sequence was hypnotizing

Man I follow you for years, it blows my mind the level of improvement in your "metal work" skill. Really impressive stuff!

the amount of work and detail you put into this is unreal, LOVE IT!

Dude as a speaking as a coded tig/mig welder you got some insane fabrication and machining skills. Life goals in a nutshell!

@8:50 the way that pulley flies off and how it spins off axis but then has moments of balance, then back to off axis - really fascinating to watch.

(Overheats Engine and blows up cooling system) “Alright, I think that went pretty well”

*Nice work!* 😎 I think a small turbo engine war has begun 😂

Just listening to the dark theme music in the background makes you feel like you're watching a dark sci-fi movie 🤣🤣 I love it!

I just can’t get over how interesting and informative this channel is. He’s a beast of an engineer and machinist extraordinaire, welding guru mad scientist lunatic! Love this man!!!!

Looks like you're having fuel delivery issues as well. Using boost pressure to control the fuel pressure will never allow you to have full throttle. At part throttle you're building boost against the throttle blades, but on the engine side of the throttle blades you have less than the 3psi the superchargers are producing which is allowing the 3psi of fuel to be injected. At full throttle the boost and fuel pressure will be equal and you'll never get fuel to the engine. In simple terms the fuel pressure has to be higher than the boost pressure if it's ever going to work at full throttle. You have to remember those aren't carburetors, they are a very simple form of mechanical fuel injection and the fuel pressure has to be higher than the boost pressure.

2:16 that’s so satisfying

That fuel system is super smart! Using the boost pressure directly to increase fuel! I'm sure it doesn't work perfectly, but the simplicity of it is what I love.

Bro that's some mind-blowing craftsmanship on that intake manifold!

Love the channel. One thing though. In a compound setup, your low pressure compressor should be roughly twice the size of your high pressure compressor. Have both compressors the same size doesn't yield any pressure gain and generally increases your charge temp witch costs you power.

I think you need to 1) shorten your coolant hoses and 2) increase the hose diameter. You have a lot of resistance to flow through those long little hoses. You can see when the bubbles go through them how fast the water is trying to flow. Fast water = lots of friction loss

Excellent craftsmanship right there.

This is absolutely incredible. Love the workmanship.

The engineering here is so awesome. Love this stuff man, been a big fan of this channel for a long time.

That's the SICKEST THING I'VE EVER SEEN!!! I'm a heavy equipment mechanic and that engine is so little!!! Your work is awesome and I can't wait to see the end result.

3 psi in a small scale like that is nuts. my old skyline only pushed around twice that in stock trim lol that's crazy. very very cool man your very talented.

The things you do are insane brother!! So glad I stumbled on to your channel

I honestly think this guy is the coolest, most badass and straight forward person on youtube, none of his content is clickbait, and everything he does is cool

Wow, extremely glad I ran into this gem of a video. Excited to tune to future videos! Great engineering!!

That was the coolest video I have seen! Awesome the creativity and build you do...

I just discovered your channel and I have to tell you that watching you fabricate and build is the coolest thing on RU-vid

Very impressed with your micro metal workshop & workmanship! Awesome stuff!!!

The editing here is insane, the engineering even more so! Great video!

Just came across your channel. Wish I would of found it sooner. Third video so far. Man totally awesome!!!

Brilliant mate. Absolutely cracking!!!

You would be the coolest high school tech teacher a kid could have .

Can I just say that those welds were very impressive I'll give you props on that

Amazing machining and design! Well done!

Having the tools and knowledge to make the turbo system is pretty cool

Man, waht you make is incredible. This is simply a magical work.

This guy is sooo cool, great ideas, well executed! A must for mechanics and engineering fans!

Just found this channel and subject matter by accident. How COOL is this ? Love it.

DUDE YOU HAVE SOME MAD FABRICATION SKILLS, wish I had a shop equipped like yours

Ok, so this guy is kind of a genius. This vid was really cool.

You and a few other youtubers should do a little mini engine forced induction build off. See who can make the most power on that small engine.

That's hands down the coolest enginuty really cool 😎 stuff man. Good job

Very Cool, You and Project Farm are some of the best on RU-vid, Thanks, I'll be looking for the future posts. 👍

whats sick is when the slowmo hits you can see the exhaust strokes from the exhaust. so sick.

Amazing!

This was the first I've seen from you and it was amazing!

It looks great, fantastic job on this build it makes for a great video. Thanks for sharing.

My word I thought I built some cool stuff, this is just next level skill. I would do anything to be involved in these projects. Great work!

I want to see a twin charged mini rotary, that'd be cool

Your welding skills are out of control!! Wow, very impressive

Look the engine looks beautiful! I've never seen a twin supercharged v4 that small before!

I envy you talents in fabrication, especially on such a small scale.

After seeing a couple RU-vidrs fail with their forced induction and me recommending they try out a compound setup, I'm happy you decided to do it! :D Also, I don't know if you would consider this or not, but I remember watching EngineeringExplained's video on a turbocharger which had a mix of axial and radial compressors on the inlet. So at the very entrance there was like a superchargers screw that helped keep the turbo from surging (giving it a compound effect and therefore raising the possible boost) and after that screw was the normal radial turbo wheel. They reported improvements of about ~20% increase in pressure, if you would be up for the task of trying to build something similar, that would be awesome! :D

your designing technique is incredible

That was freaking awesome!!! Subscribed!

This is pretty awesome. My father was a machinist. A very well known, and in demand machinist in the greater Boston area, from 1960- 1996. He didn't have all the high tech stuff you guys have nowadays, but I guarantee he would love this video. He was the kind of guy that truly appreciated anyone that could visualize something, then build it from scratch. Very cool stuff man, and just know, that a very accomplished machinist would definetly approve

When I saw that engine, I genuinely thought, wow that looks cool

thats one beautiful tiny piece of engineering art!!

Just wow!! Great effort and well done

WOW- You got the tools, software and know how that really helps. The second I saw the initial start-up, I didn't like the way that belt was jumping. Too bad you couldn't add another belt tensioner. I was very impressed with the look and sound of that engine. The last engine build I did, I used a small block 400 to go into a 72 Camaro. If you aren't aware, a chevy small block 400 is known for running hot due to the fact that the cooling holes that normally are in small blocks become steam holes in a 400. I had to come up with a good cooling setup for this engine and did. Very interesting project!👍👍

When you installed turbo , you need to install Samco sport hoses and you also need K&N racing filter plus bigger coolant radiator and oil cooler 😅

Great show. Thank's for all your hard work

This has to be the coolest thing I've ever seen!

Adding bolt on flanges to your intake pipes will stop them vibrating out. Nice work mate. 🦘🦘

*I don't always comment, but when I do, it's a good comment.*

Compound turbochargers are used on petrol too, common usage is a small turbo feeding into a large turbo. Small turbo spins up way faster but only provides a little boost, big turbo spins up slower but gives massive boost. Helps to even out the power curve compared to having just the large turbo on its own in a performance application.

Dude this was so freaking sick!

That's a dope lil engine. Would love to see how it'd do as a full size engine dropped in a miata or foxbody.

You may want to lap the valves, I think JohnnyQ90 had a decent improvement from doing that.

Dam this is just insane! I'm loving what you just did brother. OMG I would've luved to of seen this engine in a car or truck. Def nicely done👍👍

Damn bro….I can’t believe you made everything from scratch, well done!

I have never clicked so fast LOL! Great video!

Absolutely a piece of clever engineering, , running way too lean causing cylinder heat, good little R&D though lol, cheers from OZ

These are the coolest little engines that could

Sounds absolutely incredible

You're having a fueling issue. Even the most efficient naturally aspirated engines run at several pounds under atmospheric pressure because of vacuum dilation from drawing in the air using a vacuum pulse. Since the engine is now running at 3 pounds over. It's actually seeing double the air. NA at high RPM is 14.5 - 8 = 6.5psi or less. This is why all but the most vacuum efficient motors see power loss at high RPM and why mid-history F1 engines could save fuel and still turn faster using high RPM NA grip. Then they survived the early turbo competition by running higher compression and using velocity stacks (like yours does). Giving them 7-8 psi (1.5 psi advantage). Remember this was before variable velocity stacks were invented and computer maping of intake plumes to time the refraction of intake pulse echo. Now your setup is 3 psi over atmosphere 14.5 + 3 = 17.5. That's more than double the air even with your velocity stacks power scavenging the vacuum pressure pulse in NA format. Now this is where the it gets complicated. Not only is there twice the air. Requiring double fuel to reach stoichiometry. People learned in the mid-history and before of racing to run richer mixtures well above stoichiometry for three reasons. 1.) Fuel cooling effect. The vaporization of the fuel draws heat away and puts it from the engine to the exhaust. Making better exhause flow, evacuation of spent gasses and cooling the head or intake gas. This also made more power by making the air charge denser alowing for even more fuel and therefore cooling. 2.) Rich mixtures turn more oxegen to CO2 and CO2 carries heat away with it. That why completely NO2 dependant drag motors use CO2 boosters to keep from melting pistons and valves. Enjoying a 2% power boost per charge and the ability to run even more NO2 and feul before structual failure of metal or meltdown/gauling occurs. 3.) A rich mix burns at a higher rate and continues to burn past the point of the exhaust phase. This creates more power and scavenging oportunities in maping the exhaust pulse reflection which then more completely emptyies the hot spent gasses. Which adds power by allowing more air and fuel to be added, but that also cools the engine better and the hot gas doesn't stay in place multiplying the cooling effect. Normally the forced air (boost) corrects this, but since you're running a naturally aspirated camshaft that effect is nullified. Using a stand alone fuel delivery method (a variable electric fuel pump) and increasing fuel delivery (injector pulse duration in larger engines) should correct this (firstly) and gain you the most benefit. Then change the cam. Then run an inline connected exhaust header. This will net 75% more power and keep you from overheating for 3x longer. Also allow close to an NA RPM ceiling. I really appreciate your CAD skills, but this is what you missed. Engineering doesn't teach this stuff. It's all learned through asking race heads who've been learning these tricks for decades. Can't wait to see you correct this and throw a rod for science. Get it on high speed please.

You should get together with JonnyQ90, he made a custom cooling setup for this engine, and he needs help with his turbo setup. Bad ass manifold man! That thing sounds awesome with the compound setup.

That is the coolest thing I’ve seen! Amazing

This is my new favorite channel. Love this stuff

These things are blowing up on RU-vid right now.

Tim, love your work! Really impressive. Have you tested the center main kit for the L400? Let me know if you are selling the kits. I have another new crank coming and would much prefer going back with a center main.

Dude ! Are you for real!? Pretty happy?! You're an amazing talent! To think that, fabricate and build from scratch absolutely blows my mind! Much respect! Very cool project! 👍