$70 Leaf Blowers Saved the 12 Rotor From Dyno Disaster

[@gragaloth6237]

as a machinist, seeing you use a boring bar as a fly cutter and just accepting the chatter gave me 13 types of cancer. This is why I watch this channel

[@airgunningyup]

yea, that was rough.. He didnt understand why he had no clearance , or why there was chatter.

[@matthewantos4776]

I now understand after watching it. I was legitimately going crazy hearing it.

[@mikehunt3987]

That was crazy.. I'm surprised he didn't break the tool.

[@graemescott1436]

Rob “adderall” dahm at it again

[@TeoGoYo]

[yet another comment from a "professional machinist" blowing something out of proportion] I love these comments. They're all the same.

[@BigDanSubaru03]

The Keeps marketing people are foaming at the mouth over these shots of Rob's air blowing in the wind

[@unlisted9494]

All keeps did for me was given me post finasteride syndrome where I have partial eggplant dysfunction as far as getting to full muster and pretty consistent depression, takes years to shake, just warning Incase anyone clicks this and is considering finasteride

[@BigDanSubaru03]

@unlisted9494 yikes man, sorry to hear that. I'm not intending to promote their product. I've never used it. Just thought the video would make a perfect ad for them.

[@epaminontas6972]

​@unlisted9494 yea that's a common side effect of finasteride. That's why minoxidil and liquid caffeine are the go-to's for regrowing hair

[@thedude7726]

I literally lost all my hair on my head. The side effects where fucking terrible for me

[@emilenel4548]

11:30 13:22

[@NorwayVFX]

1:36 Rob's machining is the epitome of ''If it looks stupid but works, it ain't stupid''.

[@aleksjenner677]

That chatter is the sound of a terrible surface finish

[@Bob-o-h4k]

No it can still be stupid you can gut your grass with scissors and it works but it’s stupid

[@8bithack]

It's definitely stupid... It feels like he doesn't know what he's doing. There's no reason to have that much of the tool sticking out.

[@TheChrisey]

@@8bithack Yep I was thinking the same thing. At least he should have fabricated a large disc with a lot of mass and attached a cutter to it instead of that chopstick of a boring bar

[@RyTrapp0]

@@8bithack "It feels like he doesn't know what he's doing" I mean, most people in the auto industry that aren't running a machine shop don't actually know what they're doing when it comes to machining, and they have this equipment and the roughest knowledgeable about how to use it as a means to an end lol. Kinda like MIG/TIG welding in the knife making world, most of those dudes have absolutely NO idea how to use a welder, but they have one because they need to glue metal together during the knife making process and the weld quality just doesn't matter.

[@ZoeyR86]

Rob can i stop by ? I'm an engineer and a machinist, i want to take a 3d scan of the 12 rotor and design and build a ITB setup for it just say Y or N in a reply and i will swing by with a laptop and a 3d scanner i might stop by with a few 3d prints for test fits before i handover all the cad files and i can do all the cam work with tool list so you can make the parts on the haas machine.

[@yeboi8045]

No

[@Ownsterx]

Not happening lol

[@paxlo_0546]

I'd love if he said yes. It would be so cool for you.

[@ZoeyR86]

@Ownsterx I have been to the shop before lol. "Grove" lol, I don't want to say more than that I'm not in the mood for useless comments from people that don't understand anything. 🙃 I have worked with rob in the past he just doesn't know this is my youtube account. I'm a mechanical and electrical engineer and in the past did custom ecu systems for specialized applications in the military.

[@hondahacks1014]

@@ZoeyR86 Hes named dropped mcfadden enough to figure out where he is

[@yutub561]

Gotta remember you're going to have positive pressure inside the manifold which will help to even out the flow through each port. Flow simulations assume zero pressure. The blowers flow but don't pressurize. You're also going to be sucking air in rather than just relying on flow so the issue may not be as present as it seems in flow testing

[@WildEngineering]

exactly, the simulations and the leaf blowers will not perform like it will on the motor with both boost and CFM edit this is what i wrote but posting it here for visibility "when its boosted, the valves(ports) will be blocking the flow and the whole manifold will be at pressure, the analysis with the leaf blower really isnt doing a lot here unfortunately. on the bright side flow is proportional to the sqrt of the pressure drop, you know the cylinder will be vaccum and the manifold at pressure, as long as all tubes are even cross sectional area and volume then youre fine. for N/A stuff its a different story."

[@N-Kryptic]

you are not always under boost though.....

[@yutub561]

@@N-Kryptic fair, but under load is when it's really going to be noticeable. Likely under boost. When you are not boosting you will be in a vacuum since the motor is sucking in air, negative pressure..

[@HerbaceousM8]

@@N-Kryptic not even a lil boost? i mean come on you are "mostly" on some boost

[@T3ddyRuxp1n]

solidworks cant model with pressure?

[@mayshack]

1:15 The massive chatter he got was because he is making his fly cutter extend out way too far. It only needs to be wide enough to clean up the flange.

[@alexcorreia5959]

Just needs a face mill for something that small or yes make the radius of that cutter much smaller 1:17

[@FastIsLife]

He is using a boring head as a fly cutter. Not good. I guess he hasn't run a mill to long. The table tilts when you use at extremes. Dove tail ways aren't that good. Want it flat find someone with a head and block mill.

[@chrisdunaway2562]

First off, that is not a fly cutter it is a Boring head with a boring bar. wrong tool for the job!!

[@mayshack]

@@chrisdunaway2562 I was so taken aback by how much stickout there was, I didn't even notice. Boring heads and some tools (depends on geometry) can be used for fly cutting, I've done it before with good results. Rob is rich-- he should get a shell mill cutter like others mentioned, for anyone else who doesn't want to buy tooling for a couple of cuts-- use as little stickout as possible.

[@thomaslindroos1667]

Might not have enough y axis

[@robboss1839]

I’ve been checking multiple times over the past two weeks to make sure my notifications weren’t messed up. These videos are some of my favorite things to watch.

[@johnthegiant320]

All I know is thatI don't know enough for this conversation. It is fun watching the video and going thru the comments and " Learning?" .

[@KalLanPIDT]

Put the throttle on top in the middle of the intake lol! This shows what happends when boost is applied at wide open. With throttle blades at idle or low speed the front rotors would get most air more then likely.

[@atw9913]

To figure out if there is a lack of flow or equal flow shouldn't you block off runners that will normally have the intake closed when the other is open? The air coming into the manifold will be at a constant velocity because there will always be lower pressure inside the manifold but each runner will have a pulsing airflow as the the rotor pulls in air and is then blocked. That brief period of time will change how much air is available to the other runners.

[@gp8666]

yea i kinda figured that wasnt quite right

[@tibo786]

I think that would also not be a perfect representation because the cycles are so fast the air doesn't really have time to start and stop in each runner. That's why long runners can increase airflow at high RPM, the air just keeps moving in the runner and builds pressure (pulses) when the intake port is closed. What Rob is doing probably isn't perfect but probably close enough.

[@JeremiahWaunch]

It won’t make enough difference to overcome just how bad the airflow is towards the front of the manifold. The pulses are just too short, especially with how fast rotaries run.

[@jdoe9518]

If the throttle blades move the velocity will change. If the RPM goes up or down the velocity will change. If boost is applied the velocity will change. Air will not change direction unless you make it change direction. The throttle bodies were too close to the front runners. Boost is a band aid for the issue since positive pressure can only be achieved once the manifold volume is exceeded. Given that the rotor is 1/3 the speed of the crankshaft it should be become obvious that 3 crankshaft revolutions are required to complete 1 full cycle of a rotor. Which yields a volume of approx 1.95 litres or 0.65 litres per rotor face. 12 rotors @ crankshaft revolution will result in 7.8 litres volume. So for 1 complete cycle 3 crankshaft are required, 10A, 12A, 13B, 20B, 26B or 12 rotor the crankshaft must complete 3 full revolutions to complete 1 rotor cycle. 23.4 litres by volume. They have some work to do.

[@TurboAcki]

@@tibo786 as they try measure the pressure drop the transient behavior is excluded. each channel on its own is the way to measure it correct.

[@zanerasmussen8889]

I’m dead when the music kicks back on and Rob gets into position for blowing his hair around lol. First time didn’t register, the 5th or 6th time I started to laugh.

[@Torontoflatlander]

1:15 Watching this made me have a seizure and when I came back my name was Watson, the year was 1880, and Sherlock was yelling at me "NO SHIT WATSON". Buy yourself some proper tools, a flycutter for one. I beg you Rob.

[@BIGGYBENJI69]

15 min of watching Rob’s hair get blown back like he’s in a photoshoot lol

[@jmazoso]

Rob = Fabio electric boogaloo

[@jsal92]

Best keeps ad

[@DavelyDriven]

He likes it too, secretly of course

[@squidikka]

@@jmazoso Robio, you mean 🤣

[@jmazoso]

@@squidikka done deal!!!

[@proudpennsylvaniaman7996]

I wish I was real life friends with Rob. He really is a cool guy.

[@Alexandrepgagnon]

I can hear the communal groan from the machinist world. Jesus I could barely watch it happen.

[@Fuscao_Preto]

Not surprised the blowers have a calculated CFM lower than advertised, their own methodology to measure it when advertising is completely wrong, I believe ProjectFarmar and The Torque Test Channel did videos on blowers like these.

[@psibug565]

Rob had turned the power down because the test equipment couldn’t take full power and I don’t think the speed controls are that finely calibrated. I don’t doubt that there would have been less power if Rob could have checked that. The blowers are house hold tech and would lack efficiency, especially being used to blow through the header.

[@TheresTyrannyAfoot]

It doesn't matter after it's turbocharged....you created a massive pressure chamber....once at pressure each rotor will be drawing from the chamber....at 5psi none of that will matter anymore because there's high pressure zone seeking lows....flow becomes irrelevant as long as volume potentials are the same...

[@RT10Viperman]

A variable that needs to calculated in is the suctions on the intake cycle which should be identical on all ports. That in its self should even out the intake charge

[@adanmccloskey3149]

Was just going to type this!

[@JacobTyo]

To complicate things further, there's a pressure wave that travels back up the runners. When those pressure waves collide, it'll either make flow better or worse, and should be accounted for. I don't expect his team to have that expertise, but just pointing out how complicated intake design really is. Edit: I forgot this will be boosted, so it's a little less important

[@jongrier5093]

Boosted

[@sethwalraven7786]

Can you explain further?

[@roberts4208]

when i was watching all of the 12 rotor videos you made,the original owners video popped up on yt for me from 2016 or smth and was fun watching them start it up.

[@12345benners]

Not an indicator in sight, it’s flat based on vibes 😂😂

[@NorwayVFX]

Can't wait to see this thing on the dyno, and then the process of installing it into the chosen vehicle. For sure going to be some more kinks along the way but the end product will be insane!

[@KSwapTheWorld69]

I'm pretty sure this is going on a boat... I get that information from one of the first 12 Rotor videos if not the first.

[@joeykeegan6909]

@@KSwapTheWorld69this 12 rotor came from someone who had it in a boat but was naturally aspirated

[@KSwapTheWorld69]

@joeykeegan6909 oh wait this is his now? Or I'm sorry I don't really know...😅

[@NorwayVFX]

@@KSwapTheWorld69 This is the same 12 rotor that there were videos of many many years ago. It was meant for a boat but Rob is doing something else.

[@KSwapTheWorld69]

@NorwayVFX ahhh

[@jonathanturner2433]

The throttle bodies are also going to change the direction of flow

[@mufnkiller808]

As an hvac tech i found it cool seeing rob unboxing a testo air flow / temp reader 😂

[@fredsteigerwalt6743]

As a TAB guy, the only way to get a good reading on the runners is to traverse them haha

[@Jeffsa12]

Rob, keep in mind that not all the inlet ports will be drawing in air simultaneously. Being a rotary, I'm way outside my wheelhouse but you'd be able to figure out how many ports will be drawing air at the same time. I'd avoid implementing any changes until this is taken into consideration and more testing is done. The test results would obviously be different.

[@Onedown5ups]

Crazy to see Rob using HVAC tools I use on the job but repurposing them for the 12 rotor.

[@87xfute]

Hey Rob, I'm no rotary expert by any means but I am a retire mechanical and automotive engineer and I think you may be over looking something. Starting with the setup maybe it's the camera angle but at 7mins 45secs the blowers look level BUT the intake does not, the runners that are getting the most air look like they are in a different section of the air stream and the plenum design itself I think is also contributing to the problem because it slopes down towards the back which will increase the air speed to the back runners due to the venturi effect, maybe it's me but I think these things need to be looked into especially the plenum design, it need to have a more universal and volumetric shape and design. I hope you get what I mean mate, maybe I've got it all wrong. Seeya Rob............from Australia.

[@alastairjanssens3238]

Really ready interesting and very informative. Can't believe how different and what changes flow so much

[@ThePointlessBox_]

That fly cutter had me squinting

[@Familytreewoodworks]

Since 3/4 of the rotors aren’t open at a time, doesn’t it need to be tested with only the ones that are open in the firing order?

[@negkdguarantee9881]

Agreed the flow of air will be dramatically changed in volume and pressure just by the ports being dead during compression and exhaust cycles. These readings are great to find the potential total flow of the intake but in a engine operation scenario the readings should also be taken port side like a vaccum instead of positive pressure from the throttle blade side. Though when the turbo is applied it will be a hybrid effect of some vaccum some forced induction.

[@regisztral]

Because the flow will change periodically there will be weird pressure waves in the intake. What is more worse, those waves will be different in every rpm scenario, with high and low pressure areas.

[@leohughes6921]

The thing is, the intake ports are essentially always open. because as soon as the end of the intake stroke of one of the rotor faces ends, the next rotor face is literally intaking air. every single time. Theres not really much of a wait at all.

[@zzzz1192]

hes not actually testing anything, the cfd and the leaf blower were all wrong. just disregard and read literature rather than watching a rich kid in a garage misleading the public

[@Familytreewoodworks]

literally nobody made you watch his video. Move along.

[@livinlikelarry8782]

Very good job with that overhead mill bravo!!🎉🎉🎉🎉

[@dwightsmith5174]

From the first time I saw that box/tube intake design, I knew it was not going to flow properly / equally to each rotor. Any successful hot rodder learned that in hot-rodding 101.

[@SvendsenWorks]

Using a boring head as a fly cutter 🤣

[@mandrakejake]

Not as odd as you think. I used to have a special boring head that was designed to face parts also, you held the 'adjuster' ring with an arm and it made the tool grow in diameter whilst cutting. It was probably so you can face a part like a cylinder barrel on a jig borer.

[@MrMaaaske95]

It’s not stupid if it works 💁🏻

[@yucannthahvitt]

@@MrMaaaske95 It worked well enough for DIY in a hurry, but if you are paying a machinist and you see something like this don't go back. Not only is the surface finish terrible, it's bad for tooling longevity.

[@MrMaaaske95]

Yeah true. But I think the problem already starts with the fixture. I looks like the main flange is only supported by the intake runners which are in no way stiff enough to machine a truly flat surface

[@json8172]

LOVE THIS BUILD, KEEP IT GOING.

[@Buckworth_]

Thank you for being kind in the Chick-FilA drive thru! I hope you and your family are safe from the fires, I couldnt tell if you had to evacuate or not

[@haigha-qb4kf]

2:30 what I commented months ago. Flow calculation etc. instead of simply building. But we can do it perhaps really professionally for the next project then.

[@Andrewlang90]

Just a machinist’s opinion. For a motor that expensive, I would suggest sending things like the manifold out to get surface ground rather then flattening with a fly cutter. Get a much better surface finish quality, and more uniform finish.

[@APEX.86]

There is no benefit in surface grinding a flange that uses a gasket. It just has to not leak. That's it. No benefits beyond that.

[@blueblood76]

@@APEX.86 Correct flat is flat

[@brettbernhardt7608]

I've researched decking heads a little and it seams like they like to fave the fly cut finish and I have not seen one pro using a surface grinder for a mirror finish.

[@TrevorChokey]

We are all super excited that your full steam forward with the 12 rotor

[@iamnickdavis]

Love the 3d printed doodad on the flow meter

[@Pitbike65]

I'm starting to think these youtube mechanics are sponsored by Harbor Freight. The product placement is so good they don't even have to say it. Best kind of advertisement.

[@Jefreeman13]

Good morning Rob👍🏼

[@lastminutetravels3034]

Always a blessing when rob drops new videos.

[@whitlcj1]

You can weld washers to screws with wingnuts. Insert them in the runners. Turn the washer like a ball valve to tune each runner. Then you can use that data to make each runner specific for its position in the manifold.

[@jsfcharlie]

cool rob but it will work difficult due to a vac from the routers

[@rude235]

My thoughts as well

[@wamanning]

i think you're seeing a difference L/R airflows because of the rotational velocity coming out of the blowers. both blower fans rotate the same direction, but the manifolds are L/R mirror-images.

[@gp8666]

im no manifold expert but im curious to hear from someone who does this stuff if this was actually helpful to the engine, wouldnt you want to simulate it in action since the manifold would be under pressure? and not all the ports will be open at the same time plus the pulse timing will affect the results

[@HughMessenger]

Should get Hims back as a sponsor for this one, with all those shots of Rob's luxurious hair blowing in the wind.

[@floridarednecks5061]

That’s bad ass dude i need that in my 05 5.3 crew cab

[@Bob0sModelFabWorx]

Can you imagine the HOURS and work it took people like Smokey Yunick to do the same thing? You make it look effortless while I know what it took back in the 70s - 80s.

[@WildEngineering]

rob you need to calculate what ports overlap and then block all the others, then pressurize the manifold. the only issue with this method still is theres no vaccum drawn on the intake ports that are unblocked and the atmosphere would be pushing back against the leaf blowers.

[@18_DriftBox]

This test has little to do with reality. I designed the intake manifold. The main mistakes: 1.) The cylinders suck in the mixture 2.) They do it one by one 3.) The most important thing is that air has weight. The larger the turbine, the higher the pressure it pumps air with, the greater its weight. It is amazing to watch how the distribution of the gas flow changes when the turbine reaches the operating pressure. If at low loads, as a rule, the first cylinders receive more air if we are talking about an inline 6-cylinder engine, but at high loads, the last ones receive more air, due to the mass and energy of the gas. And if at low loads, due to the fact that the cylinders SUCK air, the disproportion is minimal, then at high gas consumption this can be 5-10-15%.

[@18_DriftBox]

It would have been best to buy 12 lambda probes and 2 CAN controllers for this money. And make actual AFR. This was a waste of money and time.

[@Daniel-vh9lg]

It's mainly a Marketing video from his sponsors. I've noticed people don't make videos anymore because it's fun but because they have to according to contracts.

[@zzzz1192]

rob needs friends with actual knowledge, dude surrounded himself with simps and its just a bunch of whack "experimenting"

[@zzzz1192]

@@18_DriftBox 100% , this is what the internet and money does to your brain. Crackpot ideas.

[@CaptnWaffles]

The best power band is a wide one! No one is talking about the reflected intake pulses inside the manifold when the pressure isn't positive. The best way to test an intake manifold in on a running engine under all conditions. It's a game of compromises. Print the manifold. Test. Change. Compare. Repeat. Then make it durable (aluminum)!

[@keith_5584]

If you have to redesign, it might be worth it to build a way to get the turbos closer to the intake manifold. (Like make a cutout section) You might be able to build the intake and intercooler into one unit for when you will be compelled to put this in an FD. We are putting our faith in you Rotary Brother.

[@edwardscott3262]

If he rebuilds it it might be worth going to completely separate 4 rotor intakes and exhausts. So it's like 3 separate engines hooked together. People assume engines geared together or combined in some way require perfect matching and tuning but they don't. Internal combustion engines are really, really forgiving about it when combined together. The stronger engine will just help spin the weaker engine faster. The weaker engine will just help slow down the stronger engine. It's shocking how different they can be and still work great because the engines do the job of self matching. There was a guy in California who put a motorcycle engine in the back of a Prius. Despite having the motorcycle engine in the back pushing it took no tuning of the Prius part to make it work. When he wants more speed he just turns on the motorcycle engine and it does it's thing in the back while the Prius does it's part in the front. That's an extreme of two totally different engines working together. Making each 4 rotor like it's own separate engine would simply things and help with packaging.

[@keith_5584]

@ I am not convinced multiple Wankel rotaries would behave quite like that. Granted a 4 or 3 rotor have the best chance to, over for instance multiple sets of 2 rotors. I am willing to take your word for it though. I could easily see how a regular Ottocycle would behave like that though. Rotary Valves are actually really good compared to OHV. I dont know what that means for timing 3/6 sets of them that are apart. I think if they push/pulled each other it would create oscillations that would press on the side seals more. I am not sure it would help to multiplex them in the sense of saving space though. The injectors would be the difficult challenge of that idea or mainly the fuel rails. I think we need an iron with the turbo built into the center housing or a lovely tapestry of exhaust manifold with the hotside right in the manifold.

[@danielvelazquez8255]

You need to keep the anemometer in the same location for the 2 different output sizes. Even if the FT2 and CFM is the same, you’ll get different velocity readings by measuring in the center of 2 different shapes.

[@justpauls]

Great R&D work!

[@DangoNetwork]

You may need to test at different inlet air speed. There always a potential that the devider behave differently at different air flow rate.

[@MushFPV]

14:47 You know what else is MASSIVE?

[@Tactital]

Your mom

[@Roboseal2]

Bro ruined the comment section

[@Evert89kr]

Stop. Just stop.

[@Firefrei]

You sure this isn’t just a video to show air flowing through rob’s hair?

[@OBSESSED1954]

I have been waiting for this for a long time

[@AKzzonFAYYYAA]

This engine should definitely go on a corvette.

[@ralmslb]

If there is something that I will always be sad about this build is the horrible headers and intake plenum. So many ways it could have done better, specifically more compact

[@ralmslb]

2:15 Lol, I commented before watching the video, glad they admit it now 😅

[@liampousson1173]

They aren't meant to be permanent, just a start so they can build a baseline and then improve everything over time. A lot of the bulk is to allow space between exhaust runners and wires for air to flow

[@pyoshmusic]

Feedback is always good. I love to see Rob's doing something, I don't really know what's going on but him explaning things is really entertaining.

[@Watchmedome3017]

It’s just to get it running then make it look dope

[@christiangarcia8888]

Do a better one on your 12 rotor

[@3toedSloth75]

13:22 brought to you by Keeps.

[@TheSam123281]

measuring the resistance of the manifold you could do by measuring the consumed power of the two leaf blowers with and without the manifold connected and some changes to it

[@romanengland7036]

Gail Banks designed a manifold for Jay Leno’s Tank powered car that had expansion pipes that held boost. Reason for that design due to how much those giant aluminum heads/ runners expanded/warped with heat. Perhaps that’s something you’d be interested in looking into. Cheers Rob, great content, I look forward to the next upload

[@robbergerson4915]

Mr. Rob, please call Gale Banks. The turbo diesel god is the king of making air go into the right place at the right numbers....or better! We all know you want to figure this out yourself, and we love it. But nothing wrong from a lesson from a absolute master in airflow into air hungry engines😂😊

[@zzzz1192]

great suggestions, dude is so lost, he needs an educated friend, gale is a legend and ive learned so much from od books with his teachings.

[@robbergerson4915]

@zzzz1192 i would buy youtube red to watch thst rabbit hole go past the center of the earth with no adds🤣

[@jmazoso]

@@robbergerson4915 and a stone cold stud

[@DJchestr]

I wonder if putting the throttle bodies on the top middle would solve the inconsistency. More like a 350 chevy type shape.

[@Ryan_scott15]

Hope you are safe and doing well rob.

[@connorwolfe150]

Balancing a "spider" box like this will always reduce efficiency of airflow and cause chaotic currents in the manifold. Knowing you are planning on boosting this thing in which smoothness of airflow actually doesn't matter as much. If you truly wanted to have equal and smooth balanced airflow to all the runners you'd design a box with built in baffles almost like the inside of a muffler. Either way this thing is gonna rip! Excited to see what it makes on the dyno

[@Sam_9988]

Exciting to think we’re going to see this thing on a Dino again after however many years since Tyson’s video

[@brianpbedell]

Love it! This was cool to see!

[@seanbragg1696]

Think you need inlets of port tracts curved towards the throttle body inside the plenum so they scoop air in order

[@Darksurfr]

You guys should look at the way the composite LS manifolds are made. They have those ripples in them that pull the air down into the intakes. need the volume but need to upset the air to capture it to move it down. No slip conditions to cause air to go where it needs. Just talking in text.

[@travisballard1286]

Rob you can take that boring bar and carefully bend it downwards in a vise just a hair and it will clear the bottom of your boring head.. I do that with the cheap bars the boring heads come with. Just make sure you bend it the right way lol

[@AIM54A]

You're going to need a compressed air bottle to get some boost initially at startup until the turbo's have a chance to produce boost.

[@jacksonclinton349]

HVAC human here, love seeing Testo, you have good taste sir

[@Ezthereals]

Not the only thing getting blown

[@aidanspieler9239]

saw dahm vid had to click immediately

[@IStratz]

I always wondered how they would figure out how the flow in an intake is optimal, but I never thought it could be as simple as a couple leaf blowers and a wind measuring device lol. I always thought it had to be some super complex computer program only available to like car manufactures. Always cool to see how it can be done for the "normal" people

[@jakephilbrick7384]

Don't forget the low-pressure areas that will pull air in. That cylinder that wasn't getting air in the sim would be in the real world. The engine creates a low pressure area on intake, forcing higher density air to fill the volume. Air is not pushed into the plenum on NA. It is pulled in by the engine creating low pressure areas. Flow rate would be measured by the air you can pull through each individual runner. Not pushed through from the throttle body side. Remember, engines are air pumps.

[@SkunkieDesignsElectronics]

This

[@dpjazzy15]

Do you KNOW that difference in airflow will still appear under pressure? You're measuring air speed, which gives you an idea of resistance. The air probably wants to blow past the first intake and shoot straight to the back. If you had the whole system under 10+ psi, wouldn't the air just be forced where it needs to go? The rotors not at their intake cycle will be sealed and not accepting any air. Therefore it would have to redirect to which ever intake port is open for air.

[@danernest5084]

Not only this, but a rotary, like a piston, will be creating a vacuum while it is spinning. Wouldn't this draw in air when the engine is running?

[@_Everyone__]

Exactly, the system is not under pressure, the picture will change when the pressure build up.

[@leftnut7508]

The leaf blowers are replicating a decent enough pressure to simulate the air flow due to the vacuums created by the rotors. Everything is an approximation when dealing with the unsolved physics problem of turbulence.

[@ValentineC137]

The blocking and opening of intake ports generally cancels out. the ports getting less airflow will have less air available when they do open, the ports getting more air, will accept more air when they open. It wont be redirected to even out other ports.

[@bass_and_bass3323]

Eather way the changes will be more efficient. = hopefully happy motor

[@daltonterrell4860]

Should those turbos create a positive charge of air in the manifold which would solve your problem of low pressure in some runners and high in others? I could be wrong.

[@jowofoto]

Science teacher here, do the same test with a conical section for the meter instead of middle flow for my curiosity. Make the 3d printed flow adapter narrow at the exhaust end

[@chrisbacongaming]

Rob, throw a smoke machine behind those leaf blowers! The smoke will get picked up by the blowers and shot through the manifold so you eill be able to visualize the flow

[@figmentfire]

I feel like trumpets would make more sense on this build because you can control intake variability per rotor pretty easily, at the cost of more moving parts

[@BeckTools]

so maybe you should test these with actual back pressure. cover all the holes but one and test each one with all the other blocked off. I think this would give you interesting results that might be valuable.

[@wrexz]

You should definitely use thicker flanges so they warp less

[@ratboyiscool]

I don't like using a fly cutter for those surfacing jobs. Get yourself a nice round cutter with square or round inserts that's 4-6" wide and you will be much happier with the finish and time spent machining

[@JamesPerry63]

Hahaha! I clicked "thumbs up" before watching. The power of a clever thumbnail!

[@peripheral1258]

Hey Rob... you have to test the mammiefold right side up so that gravity acting on the air is accounted for... Of course you will have to lay underneath it so that all that heavy air is .... Never mind... thanks for another cool vid.

[@zzzz1192]

i wish this is sattire, but rob would believe this, PLEASE next video flip the manifold to account for gravity!

[@peripheral1258]

@@zzzz1192 that's right... set it up so when you are on a creeper it is exactly 6" above yer face...

[@OlofJansson755]

Best youtuber With the nicest projekts

[@jonathanallen9205]

Individual intake plenums may actually help more then hurt. Running a turbo to each intake with individual throttle body's. And probably wouldn't look so off. And be able to simplify the intake air pressure

[@lucianalamo5887]

Thanks to Keeps for that nice hair flowing more than your manifold.

[@TurboVisBits]

For something that is "puling" from a plenum does the CFD really matter?

[@eurohubert]

The hair shots!

[@zeadlots]

We are so back! 2025 is going to be nuts. I'm here for it.

[@krocketonboost5236]

Congratulations for still having a face. Interesting tool choice!

[@dogmoo]

I’m pretty sure once you get over a certain pressure ratio the flow characteristics go out the window. The CFD was done under NA and the leaf blower is moving little amounts of air. Boost pressure fixes crappy designs.

[@Cloud-Man-Racing]

Wasn’t expecting the video to end like that. 😂

[@100cotton0]

I know awhile ago it was mentioned that the elbow on 13b could cause the rear rotor to get more air than the front. With Rob's FC having intake pipe coming from below and not in front, it shouldn't have that same result. Would be cool to test out and verify.

[@peterga3658]

where re you man i missed you . happy new year 2

[@josephmatuszak3855]

lol, Rob figured out what chatter is.... it's an enemy of machinists, and there are varying ways to reduce it. But some jobs... you just know the engineer is a space cadet and the part is gonna have chatter marks all over it based on the design....

[@yucannthahvitt]

I don't think an engineer was present within a 2 mile radius when that manifold was designed.