Interesting video, but yes we would like to see engine dyno with different heads: polished, wavy, dimpled, etc.
@ericthered96553 жыл бұрын
Dimpling doesn't increase flow. What it can do is bend the flow. That's what golf balls do. Dimpling a sharp radius should make the flow hug the radius rather than bounce off at the angle of reflection. I bet a semi-smooth port with only certain areas dimpled would flow even better.
I understand dimples like golf balls create better airflow. But more material is removed which means a larger chamber too. And each port could have different sized chambers from the factory.
@alancollard89396 жыл бұрын
this needed a wet flow to see the difference in atomization , as the port forms are more likely to affect that than increase in port flow
@GREASEMONK3 жыл бұрын
Also,.. how about fuel injetced engines?
@jongillies48712 жыл бұрын
What about GDI engines? 🤣
@panda909TV2 жыл бұрын
@@GREASEMONK yown si sir tax hehehe parang dabest talaga si dimple sir pero sa carb type siguro to na test sir ??? di ko masyadong naintindihan pero mas mataas si CCFM jan
@theo77093 жыл бұрын
It shows a tendency but given that the intake of the port is made from clay and by hand makes this experiment less valuable. the intake has a big impact on the flow and therefor should be identical for each test. Maybe a 3D printed intake would make sense.
@erzincanli8 жыл бұрын
I've never seen before cnc builder making these tests before. Congrats!
@tazgrant45217 жыл бұрын
People might understand it better if you explained what the fuck the numbers mean as it's in Spanish.
@shaunroberts40706 жыл бұрын
Taz Grant i would have liked to hear a conclusion all i see is a bunch of shit numbers video sucks ballz
@blindabinda12346 жыл бұрын
Right. Not a word of any part or what the clay I'd for or explanation.
@MrHBSoftware6 жыл бұрын
its not Spanish you iliterate fucktard
@SL9SH6 жыл бұрын
Hugo Barbedo lol 😂 then what is it then? Armenian?
@blindabinda12346 жыл бұрын
Shaun Roberts right. I'd at least like to know why they got fackin gumby stuck onto the head.
@riflemanjim8 жыл бұрын
not really a valid test that clay doesn't provide a consistent radius at the entry. I ran into that problem years ago,I had to make a radius plate from lexan to keep things accurate.
@ZoDDyXXX7 жыл бұрын
exactly!!
@nickritter19927 жыл бұрын
I did the exact opposite and experimented with the clay on the outer rim on a ls1 head and it made no difference !
@MrElPoderozo16 жыл бұрын
James Okello. Thats what I was thinking!👍
@trabadix6 жыл бұрын
All the experiments done by any person always have failures, but they can always improve, however, the data obtained is still only for reference, because even NASA can not perform experiments so precise that they tell them that everything works perfect, most of the things we learn all is based on failure and error, "to win you have to lose" and things like that, is a test, but if we want to find variables not covered in the test, there are too many, and in the end it would be such an expensive test and so delayed, that simply nobody would want to do it and much less, pay for it.
@TheRoguelement5 жыл бұрын
I always wondered could we mount the Intake manifold we are going to use to see what effects port work have on velocity number's / air speed Vs CFM Or what intake runner's tend to lean out on Carburetor motors and what can be adjusted to aid in that ..issue ..
@YouCantSawSawdust11 ай бұрын
Just give it forced induction. Turbocharging or supercharging. Then all this flow bench nonsense becomes obsolete on redundant.
@andredesousa967 ай бұрын
As much as I love N/A and optimizing them, I admit your point is super valid. This chase for CFM does become obsolete once you throw forced induction in to the equation.
@henryhayes17438 жыл бұрын
This is why golf balls don't suffer from friction until the air speed drops, then the ball does..
@tazgrant45217 жыл бұрын
Most people wouldn't know what the numbers mean they just want to know what flows the best!
@rmt58202 жыл бұрын
I'm one of them 😁
@learningchristian8206 жыл бұрын
Couple of things worth considering as well; in real life an intake flow is not linear as it is on a bench it is a series of very fast pulses more like a church pipe organ. Each closing of the inlet valve causes a high pressure pulse to pass backward along the induction path. It is possible to set up eddies in these pulses that act as restrictions to the overall flow by having poorly worked inlets. It would be interesting to see these tested in a harmonic flow test.
@poncoolride5 жыл бұрын
Id be more interested in seeing a dyno run, and id be willing to bet there isnt enugh difference to matter. I was lucky enugh to see back to back dyno runs of polished ports verses the rough finish ports that they have been selling us on for years.. guess what? The polished port, in this case DID make a small increase in power.
@alexhu7655 жыл бұрын
@@poncoolride I'm sure the polished port would be better flowing but the reason why porters do not polish the intake runner is because if they were to polish the intake runners the fuel will form droplets and start to puddle in the runners. That's why porters leave the intake runners rough, so the air and fuel mix better and atomize.
@RicHowe5 жыл бұрын
@@alexhu765 This is of course for engines that are not directly injected.
@alexhu7655 жыл бұрын
@@RicHowe Can you be more clear? I did not talk about direct injected engines. If it were I'm guessing that a polished port would be better for fuel injected engines.
@RicHowe5 жыл бұрын
@@alexhu765 direct injected intake runners will not pool or have gas droplets because the gas is not injected above the valve
@VndNvwYvvSvv6 жыл бұрын
And you left out a rough ground surface? Looks to me like they're just trying to sell a product/service rather than find the truth.
@singletrack_king77005 жыл бұрын
Yeah rough up intake and smooth exhaust easy and works.
@Stale_Mahoney5 жыл бұрын
@@singletrack_king7700 true but the dumpling/golfball intake means a lot less turbulence as it creates air pockets in the dimples that the center air rides on, meaning less turbulence and actually bether flow, and since it's always the air in senter that is fastest means you get more accurate fuel delivery and can run more advance on timing on less fuel, a friend of mine had a ported head he sent in for a cnc ported dimpling and he picked up 25hp compared to the smod ported on the exact same compression and setup, for the daily tuner it's no need and a light port jobb will give great results, but if you want to race the dimpling make sure you get the most of the engine, he even had his intake manifold dimple ported, for a daily i guess it means you can lean it out even further and still retain the same to a slight increase in power if you care about economy driving.
@pauloconnor79513 жыл бұрын
@@Stale_Mahoney That's essentially FREE horsepower. Better efficiency in other words. Why wouldn't you ?!!!
@Stale_Mahoney3 жыл бұрын
@@pauloconnor7951 expense vs gains more or less, i dont remember what he paid but it's not to cheap, and it's at higher rpm the dimpling increase the effectiveness so it's not a flat gain from low rpm, so for diesels and the likes of low rpm cars it's next to useless.
@ilyas57083 жыл бұрын
@@Stale_Mahoney so bigger brap with a rotary?
@jasongrote13496 жыл бұрын
So is this dimpling is supposed to mimic the surface of a golf ball I'm guessing where it makes the air pass over it better and faster?
@d3tach3d5 жыл бұрын
id spend my own time doing the dimples with a dremel instead of paying the added costs. thats just me though
@informediatech-bruno57663 жыл бұрын
Wasnt dumplings british food?
@sroljosro70155 жыл бұрын
Thank you very much for making and sharing this comparative test
@makoycasa79844 ай бұрын
wa the fuck was that number tho. we dont know which is better on that 3
@ze_german29214 жыл бұрын
I need to try this on my lawn mower, my grass is getting very high and I can’t afford a more powerful mower.
@broughttoideas4 жыл бұрын
I kid you not I've done it lmao but your gonna want to be able to adjust rpms for safety reasons lol
@pauloconnor79513 жыл бұрын
You do that !. Let us know how it goes :)
@gbart78573 жыл бұрын
There is a healthy aftermarket & builder community for that! I'm here because I'm polishing up a head for a 212cc honda clone engine for a kart, figured it was a great inexpensive way to play around with engine performance mods. The head I'm working on would bolt right on to a 5-6 horse mower. Check out gopowersports, ombwarehouse, and redbeards garage!
@Elaba_3 жыл бұрын
Buy some elbow grease.
@kym3933 жыл бұрын
Adjust your governor up a few rpm's
@warrenlucier5796 Жыл бұрын
Build the engine with this head, tune it, dyno it and monitor the EGT of each cylinder.
@sprbkmike16 жыл бұрын
Looks like a crock of shit to me, yes does it really make a difference is what one wants to know. Any HP and flow gains?
@stuartjakl7 жыл бұрын
Like others, I was initially excited to see this test but dismayed to see the use of putty/clay to radius the ports. That seems less scientific. Could you please do the test again with a radius plate?
@1jzracing8 жыл бұрын
I own a flow bench too and as someone else stated not a valid test when you use clay as the intake radius.... get a little piece if plywood and make an inlet radius plate you can use on each port.... I have a box of then for almost any engine now. I dont doubt the dimpling affect we have done that manually for years.
@oskarjohansson83137 жыл бұрын
But i feel like its better in some applications but not for everything, lets say we got a head that we need to increase the area of the runners but cooling channels and otherstuff are very close to the runners so you cant increase the size to much would dimpling still be better or would a smooth ported runner be better? English might be rusty since its not my main language
@dinukap43 жыл бұрын
Post some videos mate would love to see
@Deftonesdsm6 жыл бұрын
I WANA SEE THIS WITH WET FLOW!!! PLEASE
@iava19815 жыл бұрын
I want to see the same!!!
@danatkins67513 жыл бұрын
I want to see it wet flowed !
@TurboJohn746 жыл бұрын
Velocity probe will tell the tale. I would guess that the boundary layer would become slightly constricted, and velocity will be up.
@FiteTheGoodFight7 ай бұрын
Even IF the dimpled ports flowed slightly less, they would still make more power because of better atomization of the fuel mixture.
now what would happen if you, polished, waved, and then dimpled a chamber... or did a combination of the 3 or 2 of these methods...
@Mastermindyoung145 ай бұрын
preferential dimpling would be the best. You can tune velocities in specific areas with that technique
@adancs39976 жыл бұрын
You should say whats gonig on, otherwise people only see a couple of numbers turning
@MilesPrower694205 жыл бұрын
in another language, too.
@XyberZyen6 жыл бұрын
Vídeo foi bom mas n precisava de tanto tempo e a escala final podia ser mais visível. Mas bom tópico bom vídeo. Obrigado
@31rus996 жыл бұрын
Где русские бл
@опаснаямалая675 жыл бұрын
здеся
@tracylewisperformance13282 жыл бұрын
Well proven and documented. From racing bicycle wheels to every surface on the intake side of an engine.
@kcampbell40987 жыл бұрын
whats this supposed to prove w/o valves in the way moving constantly??????? oB
@99silverstreak4 ай бұрын
What was the density of the air on each configuration flow is not the only factor to look at
@JRkota3187 жыл бұрын
Even without the use of a proper radius plate the dimpling only out performed the polish by 1 half cfm. For the amount of money it would cost someone to get the dimpling done it definitely isn't worth doing. If you were in a race class and had tons of money to throw around then by all means have at it and get that tiny bit of gain.
@BoubbieVagee7 жыл бұрын
Evil Opti Z i think thats specifically who its for
@mceperformance89787 жыл бұрын
Dry flow testing (what most of us do) doesn't tell you anything about how the dimpling affects the wet flow (fuel and air mixture). The dimpling or texture, creates a boundary layer that cannot be seen by conventional flow testing. A wet flow bench will show how fuel falls out of the mixture and sticks to the port walls.
@Deftonesdsm6 жыл бұрын
MCE Performance EXACTLY dimpling may have a huge atomization benefit
@TheJagjr44506 жыл бұрын
BINGO MCE and DEFTONES this is what I believe will result in most gains... complete or more complete burn of the intake charge.
@Robert-vp6xf6 жыл бұрын
I want to point out for street engines especially direct injection Dimpling is a really insanely bad idea. everyone forgets about EGR and more importantly crank ventilation turbo leak ect that cause carbon and sludge. Dimples do no good full of carbon. Also all non carb engines need no surface roughness. The argument on dimpling sucks air through a plastic bag because it has no real world benefit... Also if you are spending all that time then just cut that much more material out and run a bigger valve.... The throat and seat are way more important than the runner.... Unless your runners are real bad. Mine were but I still had more bowl work than the whole rest of the port job.
@MasterChief-sl9ro6 жыл бұрын
Dimpling the port does not increase flow. They do it to increase fuel economy. Same reason they dimple heads. And this shit is not just random. Its all computer controlled.
@duniafana2913 жыл бұрын
That mean the air passage is really smooth then. Correct me if im wrong
@MasterChief-sl9ro3 жыл бұрын
@@duniafana291 They dimple the ports and heads to keep the fuel from pooling up on the walls of the intake runners...And NASCAR used it for years. To get better fuel economy...As they said one team was cheating. Said they had extra fuel hidden some where in the car. So they protested the Vehicle..Which means NASCAR impounds it. Then they disassemble it. To see if they were... Only to find the heads with strange dimple patterns on them...They used a computer program to tell the engineer where to dimple it and how deep... Now all the teams do it....Now water injection is the new cheat.. As you get better fuel economy. Longer lasting engine. And cleaner burning...
@drake95916 жыл бұрын
So basically even a basic port and polish is really the only substantial gain.
@mtmgymtmgy7 жыл бұрын
Why did you carve the waves perpendicular to the port? Because those waves or dimples increase airflow by generate vortex, and the airflow is always in same direction in a port, I think parallel waves may be better just like vortex generators on the wing of airplane. Unfortunately, I don't have such machines to text my opinion. I wish I can hear your opinion and the reason of the work.
@rationalmartian6 жыл бұрын
Parallel waves would I think make no difference at all. They would not alter the flow, they would essentially be invisible and not alter the flow. The idea is to break up the smooth surface to disturb the flow nearest the surface, this creates less drag as each level of the flow is made slightly more turbulent detaching it slightly from the slowed down flow at the surfaces, allowing for a greater flow of air/mixture overall.
@GentiluomoStraniero7 жыл бұрын
You need to mount the intake to get a proper reading.
@rationalmartian6 жыл бұрын
Strictly speaking, for a true reading and measurement. This however really is merely a side by side; literally, evaluation/test. As such I would imagine it is reasonably representative. As testing anything in isolation will only give results within a margin.
@Liveforeever6 жыл бұрын
This video is ridiculous
@gunmspec7 жыл бұрын
i can see this as beneficial only to cars that spend their life at WOT and not useful for street or street/strip due to the needed airspeeds required to take advantage of the dimpling effect just like golf balls.
@rodriguez39397 жыл бұрын
jesse dominguez turbo cars perhaps?
@mattallen39407 жыл бұрын
Michael Dean just a thought but with a turbocharged car does it really matter at all? Your pressurizing the cylinder at that point rather than using flow or vacuum to move the air correct?
@LeveesGamingandReactions6 жыл бұрын
Matt Allen Turbochargers still factor in flow. Boost is the measurement of restriction, not air flow. This is why turbos are rated in CFM or flow rate. If you increase the flow, you get the same power at lower boost levels, so when you crank it up, it makes that much more.
@skippy29875 жыл бұрын
@@mattallen3940 I wish that fallacy would die, but unfortunately on first glance it makes sense. What actually happens on a boosted engine is you have an increase in pressure and density at all points, including residual gases in the combustion chamber. The net result is that the *volumetric* flow rate (which defines air speed) stays largely the same, meaning the port acts exactly the same way. The only big difference is on a mechanically supercharged engine scavenging on overlap becomes more effective because of the pressure difference between the inlet and exhaust ports, and while you have both valves open you have higher flow through them than before.
@cassandraclark85682 жыл бұрын
Just a band aid for a poorly designed port
@martinhulse74027 жыл бұрын
i read these comments about the clay and this is true and would make the test inconsistent but the lift is measured at % of valve size Porcent and they are not the same .in the last test they lift the valve 2% more
@peraltamenta7 жыл бұрын
Muy profecional tu trabajo, como consigues el efecto dimpling, con que herramientas? Muchas gracias, por tu trabajo y enseñarlos a la comunidad de fierreros Carlos desde estrasburgo, Francia
@buildingracingvideos47146 жыл бұрын
Those flow numbers must really suck with the valves installed like they're supposed to be. A stock untouched head shows huge cfm gains just by removing the valves.
@veicomerengineperformance6 жыл бұрын
Is not true. The cylinder under test has the valves installed. greetings
@MrHBSoftware6 жыл бұрын
he didnt read the video description...poor dumb fuck
@s302jzget3 жыл бұрын
What about the clay? It’s not the same from port to port, you were better off testing with no clay at all.
@reistje7 жыл бұрын
Very interesting video!
@LawrenceOrsini3 жыл бұрын
@veicomer please do it again wet flow. Makes no sense to do it dry flow, the benefits are gained from keeping fuel in suspension at transition points above 7deg.
@dinukap43 жыл бұрын
Do a Wet flow test, this really doesn't prove much.
@Senne_Maebe2 жыл бұрын
The numbers Mason. WHAT DO THEY MEAN?
@КлинЗатворов4 жыл бұрын
гугл перевод надписи в конце "мы обращаем внимание на тот факт, что ямочка имеет лучший результат, несмотря на то, что все направляющие клапана и отполированы, и имеют волнистую отделку отрезанных направляющих клапана"
Any way you cut it each application may need somthing a little different and all porting takes a hell of alot of time. Without dyno numbers you never really know. Usually ide rather have less air moving faster than the other way but 2 stroke outboards can be the trickiest of all. No gearing or clutch to hide the loss at low end so you can scream at 10 grand on the top. Its always a trade off.
@woofersonfull7 жыл бұрын
Amigo se puede hacer el dimpling manualmente ? Donde te encuentras ?
@zeroswings24 жыл бұрын
flow is very nice after this... but I've seen endyn/Larry Widmer p72 flow quite a bit more... still very impressive nontheless
@motorworks10355 жыл бұрын
fake news... que sucede con la alzada??
@antonioaaron188 жыл бұрын
where is the shop.? I'm from Philippines. i need to port with dimpling my motorcycle cylinder head my bore size block is 68mm
@jlsautoworks23287 жыл бұрын
so for best flow and reliability in a forced induction application dippled would be better
@4tee1816 жыл бұрын
Ford coyote5.0 ,I need to know the factory exhaust valve angle ? It looks like39.5 or 40
@bobthompson43193 жыл бұрын
Should have put itb on it
@TheCabdriver0368 жыл бұрын
Really liking your work. Haven't seen anyone in the US that provides dimples as of yet. Do you have spec sheets like this for K20 heads?
@rz70936 жыл бұрын
In U.S. they call it cellulite
@blindabinda12346 жыл бұрын
Are you guys mute or something? A little explaining what each piece does or doesn't do would be nice. What is the red gumby for? I'll rate this video a 2 ball's in a vice.
@jorgesalcedo56142 жыл бұрын
Conclusión final del autor?
@bobthompson43193 жыл бұрын
It's all in espanol
@HighOctaneExtreme4 жыл бұрын
Where is flow rate ?
@rolandoabella76778 жыл бұрын
do you guys provide services for people in the US?
@CreeperOnYourHouse3 жыл бұрын
how does that compare to stock cast?
@abctinh54846 жыл бұрын
bạn đoi lat nha minh lam bang dt nên hoi lâu
@bowwow2554 жыл бұрын
NYPD Labs.
@fredhether16102 жыл бұрын
Awesome
@kreativeorthodox12826 жыл бұрын
Is it just me or did some of the ports have more valve guide exposed then others.
@blaqlabspodcast58163 жыл бұрын
Yes... The stock and the dimple unit do have more obstruction from the guide shroud. Which further solidifies the gains from dimpling..but.. Beware.. The depth and radius of the dimples can hurt the port if it's not correct. There is a frequency established by the depth and radius of the dimples. I once did a test where I sandblasted a port with about 70 grit garnet from a precision blast wand and that thing was amazing.. I'm still working on an apparatus to blast polish ports instead of using rotary tools.. Don't try the dimpling without a CNC because the results are a bit unpredictable and it takes forever... Your wrists and hands won't live through it lol you won't be able to get dressed the next morning. 🤣🤣
@nicolasaporta66617 жыл бұрын
você é do Brasil?
@sandraaguilar83108 жыл бұрын
lo que me quiere decir es que son tres tipos de portiadas y que la mejor para aplicar es dimpling, aque se refiere con valvula original
@guilhermegaburro17727 жыл бұрын
si exato
@Gaark7 жыл бұрын
does this machine just haul as much air through the ports as possible and give a litres/sec reading or something?
@pauloconnor79513 жыл бұрын
That's the CFM. Cubic feet per minute I think.
@strawtech13576 жыл бұрын
What the number it for??
@YACIK-z2 жыл бұрын
Класс!хорошее подтверждение практике!
@alwan4066 жыл бұрын
Whats kind of machine u r using to test the air flow
@veicomerengineperformance6 жыл бұрын
Hi, Its a Saenz model J-600
@bjarnieinarsson34727 жыл бұрын
For what stands each number?
@4tee1816 жыл бұрын
Any help will be appreciated
@alltheboost53636 жыл бұрын
Hmmm that really interesting
@lcmotor6 жыл бұрын
Hablan español?
@76kingkiller7 жыл бұрын
Who win ? pls
@mohdfarhan57086 жыл бұрын
Which type is the best.
@januszboras55437 жыл бұрын
Ok!
@luizcomet19696 жыл бұрын
O aparelho é brasileiro?
@zeroswings28 жыл бұрын
can I send in a cylinder head and have work done?
@veicomerengineperformance8 жыл бұрын
Yes of course
@zeroswings28 жыл бұрын
cool! it's not a cylinder head that is usually ported/polished but fortunately enough I have cut-away or cross section drawings that I obtained from a forum member-so I think it has potential
@mattmoilanen38134 жыл бұрын
Ah, comparing flow numbers for a modification never intended to change flow. The process of applying a rough surface to an intake passage is for better fuel atomization and has zero to do with flow for goodness sakes. But hey, you sound smart to dumb people and it may make you some money doing unnecessary work on someone's heads!
@pabloanab8 жыл бұрын
muy bueno, gracias por subirlo, cual sería la mejor opción a su entender? gracias
@veicomerengineperformance8 жыл бұрын
+Pablo Anabitarte Lo Dimpling mejor
@pabloanab8 жыл бұрын
bárbaro, lo probaré entonces, muchas gracias!
@chimpun1979 Жыл бұрын
@@veicomerengineperformance Haz hecho alguna prueba porteando el cuello/pocket/bowl y anadiendo dimples en el bowl pero solo en el area de la valvula? Todo sin incrementar el tamano de la valvula.
@pmAhavasi6 жыл бұрын
I just dont believe this. I think this is just marketing, showing the expensive product as better than the cheap. Theres no way a dimpled port flows better.
@nanathannvw6 жыл бұрын
And this represents a vehicle how....? Hardly a valid test when you blow air through a port.
@josephbauer90526 жыл бұрын
A flow bench machine sucks air through a port. An engine is just a large air pump, sucks air in one hole and blows it out another hole. Dry testing is not as accurate as wet testing, unless the engine is direct injected. The purpose of testing an intake, exhaust or cylinder head for flow is to isolate what impacts fluid dynamics. If you can design an intake, exhaust or cylinder head that creates less friction, that component will have a high CFM. The higher the CFM, the more efficient an engine could be, if everything else such as valve size, valve seats, pistons, etc are the same. The whole purpose behind this is to create more power from the same engine, by increasing volumetric efficiency. More air means more fuel which means a larger combustion. Or sometimes the improvement keeps the fuel suspended better, so more fuel winds up in the engine, allowing for better metering of the air and fuel provided, so less fuel is wasted and this often increases power output too.
@david259159 жыл бұрын
im really hope to se long machining videos from block to end
@Vdubin4life8 жыл бұрын
what about a VR6 head from vw
@axelriet3 жыл бұрын
Well, it does not work. 10mm is a good practical lift for a road car and the from between the 1st (stock) and the last (full "dimple") the flow is *exactly* the same. There is a *small* gain of about 1.2% at 12mm (about 0.500) lift, which is where the valve spends the less time (at the tip of the cam) and this is also the practical lift limit for most engines. Beyond that value you run into interference problems with the pistons (you can only make pockets a certain depth) and issues with coil binding requiring longer springs, and issues with high-speed valve float etc, etc, etc. The conclusion I make, looking at this test, is the *unmodified stock port* is exactly as good as the fully "dimpled" one for all practical purposes. Waste of money :-)
@ZoDDyXXX7 жыл бұрын
There are so many wrong with this clip.. First the clay, they clay is not constant, the difference is huge just by change it a little bit with the finger... the second, the valves are not in. The correct flow performance needs the valves and also the intake manifold to see if there are any bad turbulence. The whole intake system needs to be in place to get the real world and valid numbers. Tried this so many times and it always shows the same. Dimpels rely on the "magnus effect" Its easy to google it to read more about it.
@Motor-City-Mike7 жыл бұрын
ZoDDyXXX airflow is being measured at 1mm. steps - see the top of the head, there's an actuator there.
@bouny017 жыл бұрын
to my opinion dimples should only be put on concave surfaces. It pulls the air towards the surface. On convex surfaces it will generate turbulance on the port surface. so the advantages of the concave dimples are zerod by the negative effect of the convex surface dimples.