Porting vs. Polishing vs. Both

[@reallifehardtruth4465]

Just my two cents but you can argue till the cows come home on the theories of flow verses velocities, this young man is definitely on the right track but my comments are on the quality of his video work. Great production quality and concise and articulate narration. He has a future, a great future in this kind of work. I have subbed. Coming into my golden years now but I can say that I have raced, won,lost,built, blew up and destroyed just about all of it and had a great time doing it.

[@ericthered9655]

The point of porting and polishing is to create an air flow that is as laminar as possible. Anything that deflects air molecules from a straight line of travel, reduces flow. As the molecules speed along, they reflect off a surface at the same angle they strike it - think pool balls with no spin on them. The angle of incidence = angle of reflection. Your task is to provide a surface that will deflect each molecule by the fewest degrees possible. This means no rough edges that will cause a radical change in direction. Creating turbulence is bad because it changes the direction of molecules, which in turn collide with other molecules increasing the effect and causing pressure which reduces flow. Atomization of fuel is never a problem because the air will be plenty turbulent by the time it passes the valve, and it is entering a very hot environment. The mistake many make is in making the port as large as possible, but creating bad angles in the process and causing restrictive turbulence. When porting, think of microscopic BBs being shot through the port, and how the surfaces would disturb the path of the BBs as little as possible.

[@skipstalforce]

Laminar flow is a virtual impossibility given the geometry we're dealing with.

[@sil-zk8061]

Laminar flow through relatively straight runners. It's a non issue at the point of turbulence

[@msk3905]

We are not talking about surfaces that are so rough in an intake making much of a difference to worry about them or worth talking about them, what is important is making them as straight as possible and paying attention to volume trying to keep large to small as you enter port. Spend time on blending or removing things like vlv guide that stick into port, make a smooth turn radius where port turns (never get a straight port), unshroud port where meets bowl and give a good valve job. In my experience unless racing and you have to use specific head not worth paying for porting one (or doing yourself) when you could buy a better flowing head for about the same money.

[@Mitutumuch]

I paused at 6.49 just to say. My question was "I wanna go fast, Ricky Bobby fast, I'm real serious about it" this great man says to me "that's all great in theory, but heres what we run into, come take a look" you myguy earned a subscription

[@camillosteuss]

As someone who hones their knives with sandpaper of very fine grit, 5000 at minimum as a finishing grit, on a bock of marble or a slab of glass, depending where i do it in my house, I will definitely go manual mode with my ports, as there are no electric tools that guarantee the quality and safety that a hand with wetpaper does, also, you can feel everything and can therefore get the most nominal shape with least curves in your work, whereas with power tools it may look great but still be uneven to the touch, and the air at high speed will notice even more than you will by hand, but then, thats why we polish it with powertools... Also, polishing my friend is the step done with the polishing paste and cotton pillows, so dont say that you are polishing it roughly, as polishing implies a mirror finish, that is why you can polish metal with powertools, as polishing can not create a hole or remove a bunch of material... Sanding or cutting or abrading away is what leaves "brushed" look and finish and that is done with sandpaper, powertools that use sanding bits. The porting is the roughest cutting with tools that do not abrade to cut but rather use a physical blade of whatever scale to remove thin layers, be it diegrinders with carbide cutters, dremel tools or any other highspeed rotary device...

[@blech71]

We found best results for our heads; cross hatch semi rough on intake and mirror on exhaust. Size was tailored to horsepower/torque curve desired. With the new injectors in market where we can change injection angle will change our approach quite a bit.

[@3rd-eye-neenja563]

100%

[@zososldier]

Knock off mold lines/ sharps, port match if needed and run a 80 grit sanding wheel. Anything more and you need a flow bench.

[@farimannorozizadeh9811]

By far the most compleat video about port n Polish thank you

[@LeKelsor]

So... port injection ='s port no polish and direct injection ='s port and polish. Makes sense the way this young man explained it. Great video young blood. Bright future ahead of you

[@EricFixalot]

Some of the best engine builders have said “Port finish doesn’t really matter, just get the shape right”.

[@OGbqze]

Who?

[@jonalarcon8564]

Eric Fixalot exactly it's TRUE

[@Louis-op4zj]

There was a bloke out there once upon a time that used to somewhat randomly tack weld his cylinder heads/air paths to the heads to create tumble in the airflow and he used to get mythical results. Not sure who or how, I'd have to ask the old man. My only reckoning is that the volume would have to be similar volume/pattern for it to produce good results on multi-cylinder engines. My understanding is it's (abstractly) a bit like shark skin and water.

[@Louis-op4zj]

That's for carb'd engines.

[@Louis-op4zj]

If you want to know more I will ask the old man when I see him next, just send me a direct message and I'll send you any info I get.

[@bainracing]

Sorry but there's so much wrong with this I wouldn't know where to start! I would suggest some SAE white papers on laminar friction factor equations to relative roughness values. This will help you understand boundary layer ratio thickness to relative Ra height. Also how the viscosity of the air and its environment effects optimal port Ra. Intakes with boost should be limited to 60-80 grit, far from a mirror finish especial on the intake side with a limited flow velocity of around 700 ft/s. Exhaust on the other hand is quite stable to 1300-1600 ft/s and our gas is very viscous at 800-1000C due to the density change and speed of sound in that environment. for these reasons mirror in the best finish for exhaust. Another important point that seems to be missed is, porting has nothing to do with making a big whole! its about velocity matching. finding the chock points and balancing flow. I've done and been involve with countless back to back test over the last 20 years with our race heads and plenty of others. On most late model twin cams, there's very little need for added CSA. They do not need any increase in window CSA, some actual need welding up. The ports or intake MCSA's is what needs to be match to improve engines VE's. Valve throat size should be similar to the port window CSA if you want good area under the curve. This video is very naïve and shows a huge lack of understanding in the very basics of physics around air flow and its function and science behind a good port design.

[@thatoriginalguy]

Thank you for this comment. This video is an EXTREME oversimplification of port and polishing. This young man speaks confidently about this process! If I didn’t know any better, I’d think you’ve been doing this for years. First off, I’ll give you credit for making a video that covers the entire port and polish process. I mean that. I have mad respect for people who post stuff on here that attempts to help the masses. I’ll stick to the biggest issue I have with your content in this video. In all my years as owner of a automotive rebuild and remanufacture shop, I HAVE NEVER heard of a cylinder head being ported and polished a certain way up until the point of the fuel injector, then done another way after the fuel injector. My company port and polishes every engine we rebuild/remanufacture, and have not have any issues to date. If you have data that supports this method, I’d really appreciate it. Thanks and good luck.

[@bainracing]

@@thatoriginalguy Yes that seems to be the problem with lots in the industry, They "believe" so much that isn't based in any facts or physics. It's not an over simplified video, it's plain wrong.

[@timarnott4483]

You are spot on sir, young lad here doesn't understand certain things.....you cant just open it up, you SHUDN'T polish (persay).....and he doesnt mention reversion at all (he probly dont know what that is).....if you do certain things to your exhaust port, you will enhance reversion...WHICH IS THE LAST THING one wants in getting a nice % of VE!!........ah youth......boy, give em a smart phn, and all of a sudden with have a genius......UGH!!

[@blackdeck9112]

I have a little tip for you. When you're trying to educate people who are much less knowledgeable about a certain subject, then don't use acronyms or at least explain what they stand for. When you use big words or acronyms, only people who already know what you're talking about will understand it and it goes over the peoples head who could actually use the knowledge.

[@tristenboatman8581]

The man is just explaining the process as well as the benefits and drawbacks. Obviously he's not a genius on the subject matter but he knows enough to educate other people while you see fit to put him under scrutiny because "he didn't do it right" grow the hell up.

[@thisislargemouth5566]

I always heard from the old engine builders, port the intake, port and polish the exhaust. You want a rougher finish on the intake to help atomize fuel.(carbureted engines ofc)

[@sportsmansparadice42]

Actually it depends on the fuel delivery. A rough texture is typically better for a carburetor or Throttle body configuration. Port fuel injection a smooth polished works best. Keep in mind biggest doesn't necessarily mean more power. Research that particular engine, and find out where is the choke point. That may consist of intake manifold or the exhaust manifold. Some engines you could loose power from over porting.

[@seventytwo4728]

Dafuq u tokin about throttle bodies are fuel injection

[@sportsmansparadice42]

@@seventytwo4728 Old throttle body injection for example Gm crossfire injection system. A newer style multi port injection where you have an injector nozzle for each intake runner.

[@gregcameron6047]

Excellent video, easy to understand. White board, works well.

[@twinturbom20]

This is such a nuance subject. There are SO many variables that will change depending on the application. For example the induction system, the purpose of the application, the types of camshafts used in the application. In a street application, the low end torque loss, in my opinion, might not be worth the gains up top. But even that theory does not apply to every motor. Like I said, every application has Sooooo many variables.

[@skipstalforce]

JUst my two sense, if you make it too smooth you create an area where the flow sticks to the side, known as the boundry layer. Ruffer creates a faster flow because there is little to no boundry layer close to the surface, sailors have known this about fluid dynamics for centuries

[@aaronchadwick2682]

For all those who think they know check out engine masters. They don’t show how to port and polish but they test on a dyno and debunk all these stupid things. Port and polish all of it. Higher volume means less struggle which totally out does velocity. When you have velocity you add pressure. If you want to prove volume out does velocity just blow through some tubes of different sizes. The engine will get what it needs. Port and polish gives it that easier allowing the engine to not work as hard to breathe

[@brandondavey2398]

Leaving a little roughness rather than polishing to a shine is most beneficial

[@oliverscorsim]

Sooo a rough finish flows much better were it's wet in the intake so polish upstream from the injectors but emery cloth 60-80 grit for the wet. Reason is fuel sticks to the walls and hurts flow and fueling. You could polish the combustion chamber and exhaust port but these days I ceramic coat all that works better for less effort if you ask me. Have fun

[@sleepwalker29]

I had mirror polished heads on port injection and made 30hp on the dyno all motor 3.0L 3000GT. Kids a want a be. You can also buy over size head gaskets to port the combustion chamber larger, and you can make your own intake gaskets to port it any size.

[@wynnyoder5605]

There is an abrasive mud than can be pumped through with great results. High dollar castings are surfaced that way.

[@sheheensumad]

Very informative this video just helped me. Got my head back from the machine shop and was wondering why isn't my intake port polished just ported and got that brushed finish. I thought it was a bad job lol

[@drtb69]

Most new direct injection engines now have both direct and port injection both now...so it keeps the valves clean 2018 and up.

[@kerrymccaughey5506]

Leave the oem "cast roughness" on the intake ...polish the exhaust if you want to polish something.

[@jumpsuite]

any one who has done porting knows where and how to port the head or intake you learn from mitakes and gaines and some heads and intake only benifit from blending and port macthing and some lite polishing so if you dont know learn cause the out come could be much less hp with stock heads intake than you started with. but if you do your porting clean and clean and againe you dont want lose meatal in your rings and cylinders walls.and if you are thinking of porting look at the vavle it might be your problem that lip changes alot of flow it there to cause turblance so the mixture stay atomized.so do your home work before you grind.oh ya dont inhale the dust from grinding get a mask on or get sick from the dust the big Canser.

[@slammedhachiroku8530]

What about carburetor? Should I polished it?

[@ravenguirao9081]

what is your say about putting dimple finish in intake ports just like on a golf ball?

[@user-neo71665]

First thing I will say if you do not have a flow bench and can actually test things is ONLY GASKET MATCH. You can ruin a set of heads or intake hogging it out without flow testing. You can port the hell out of a poorly designed plastic intake. It is easier to grind than anything else.I wanna see flow bench numbers to prove me wrong or OP admit you spouting off internet crap you read. Here is your kicker. I have a flow bench. I've played with plenty of heads and intakes on all kinds of racing crap since 1987. Go carts to 1200hp v8s. What you are spouting off is so generic it is almost old school, even then it's only about 1/4 right.. welcome to about 1989

[@fredrikrapp]

neo 71665 Word!

[@AmericanThunder]

Nowadays, with the ease and accuracy of CNC porting, I don't see the benefit of home porting stuff anymore.

[@bryanroupe8646]

American Thunder a cutter that knows what he is doing and has a bench can out do by 10x a CNC ported head.

[@AmericanThunder]

@@bryanroupe8646 You would rather sit down, and hand port your heads, instead of simply sending them back to the company who made them for CNC porting? Or are you referring to extreme applications, such as top fuel?

[@GroovesAndLands]

Gaskets usually have much bigger port openings than the ports themselves. In this case do NOT gasket match. Instead, lay out the joint and PORT match.

[@autotek7930]

Wait so on my jeep the fuel injectors are right at the head, so I need to port and polish the intake to get best results? I'm installing a 4.7l stroker and I planned on doing the throttle body and intake

[@JzLyfe]

Awesome man was waiting for this video since the last one you posted of the block. I asked about the port and polish vid and you said it's on the way :)

[@milanmastracci]

Ohhh yeah don't you worry :D

[@HalferLandPerformance]

Post a video when you do yours so I can watch you duck your shit up to LMFAO

[@bluegizmo1983]

A mirror polish on any part of the intake system should actually REDUCE airflow not increase it due to the Coanda effect, which is the tendency for airflow to stick to smooth surfaces, causing a dramatically slower boundary layer of air sticking to the smooth walls.

[@richard-mai]

Is it safe to polish the head's combustion chamber surfaces on a direct-injected system?

[@SoaringEagle1]

Ahem......most all OEM & aftermarket racing suppliers / experts have already spent the time, money, & have done all the R&D work for you.....save your money and just buy the "go fast goodies" they already provide, be safe, & have fun....but that doesn't mean you shouldn't learn and understand it, especially if you are on a design team, need that extra little edge as a privateer, or are in a niche class such as antique / vintage / classic, etc.........by all means.....1. Study, Study, Study (Air / Fluid / Thermal Dynamics, Geometry, Boundary Layer, Flow Bench, Dyno, modeling software, CAD, etc, just for starters). 2. Always make / save more money, you're gonna need it. 3. Determine the end result you really need & know your limitations before you start. 4. Obtain all component blueprints if possible, but accurately measure all stock components regardless - get your base line (Flow Bench, Dyno, & mock-ups are a must). 5. Talk to an expert in your OEM / Aftermarket fields......take extensive notes. 6. Go "pick" the local junkyards for some cheap stock parts that you are already using BEFORE hacking on & ruining your good parts. 7. Measure, flow bench, practice, flow bench, practice, practice, flow bench, dyno, document....destroy some shit, DOH!....start over....flow bench, practice more, dyno, etc (but remember failure = learning). 8. Spend money (make more & save more). 9. Test runs / proving grounds - reliable consistent results? something else gonna fail because of these gains? 10. Modify your good parts and go hit the track (or street, dirt, air). 11. Retain & document everything you've learned, but always remember and accept that what you accomplish now will most likely be obsolete very quickly, something or someone faster always comes along........if that's a problem - then create a niche class, or master a specific application, and be unique.

[@sarahelgin8082]

Porting good. Polishing chambers and exhaust ports good. Keith Black found 6% hp increase over entire curve with chamber/piston polishing. Polishing exhaust ports has a small gain, but mainly keeps carbon from sticking. Polishing intake ports is a waste of time. Wet flow happens in both polished and ported. Focus on velocity and swirl/tumble.

[@_Livid_]

Question, what if it’s an older car that used indirect injection? Would porting and polishing not have a benefit in that case?

[@dragan3290]

Rough and smooth for different applications

[@cetriemmmmm7177]

Is this a Peugeot 2.0 16v engine? 100 kw?

[@philistineau]

A fluid mechanics class would make everyone realize that polishing is not detrimental.

[@mightyeagle]

The receiving side should be larger so as not to cause back flow and what others have said if you don’t flow test bench your guessing ,cleaning small imperfections I agree

[@youngelz79]

I’ve seen this video like 5x and I have to ask what motor that is it looks identical to my motor the K24w series

[@gregmf9427]

Matched, ported and polished was POWER for engines Pre 2001! It was also CHEAP! The blocks are totally different! Made for fuel economy now

[@junechris]

Yeah, I'm doing my 1995 S Series with .20 over and 3rd gen crank and tie plate, etc dual intake cams, etc, not all the mods but yep, you would be correct. I know the difference between even the earlier Saturn engines vs the 1999-2002, even though technically the same engine, the later years, the put roller rockers on the head, but used smaller intake ports and added all kinds of emission restricting features to the exhaust manifold, etc, u can't even find a header made for the 1999-2002 years around. I have a 1995 and a 2001 SL2 in my yard that is going to be the donor car for the 5 speed manual for my 1995 SL2 amd going to add a MFactory limited flip and lighter flywheel, etc.

[@meowtrox1234]

Does this apply to carburetor engine?

[@billyjack8119]

Smooth is like watching water roll across a windshield with rainx on it. Fuel needs to break up and tumble on a rough surface with the correct shape for maximum velocity

[@henriklassen3435]

Try to get the air to be not turbolant. It is impossible

[@FordGTmaniac]

What about dimpling the intake ports and manifold? There's mixed opinions about it, but not really a solid yes or no as to whether it improves performance.

[@thetruthpal]

Does nothing

[@tylerphelps4868]

There's nothing wrong with mirror finish in the intake port on a mpfi system. Your argument is more relevant to throttle body injection or carb systems where fuel is introduced at the manifold inlet and needs to stay atomized. In a mpfi system the much higher air velocity at the moment of fuel introduction combined with the short travel distance makes it a negligible benefit in atomization leaving some roughness to runner. You'll benefit more by mirror finishing and flowing more air in. The smooth port in modern plastic manifolds is a perfect example of this

[@milanmastracci]

Without the use of a flow bench, there isn't a way to test what I'm saying vs. what you're saying. By removing the nasty castings, I think we can both agree that is where the most amount of power will be extracted from. By going the extra step to go for a mirror polish is negligible for both systems.

[@tylerphelps4868]

milanmastracci actually i think you'd be fairly surprised by the difference in flow turbulence can cause, especially when there's really no need for it

[@tylerphelps4868]

Granted most of that will be seen at higher rpm but on smaller higher revving engines you can certainly benefit

[@userpike]

generally mirror finish the exhaust port purely to prevent carbon build up, you never polish the intake ports EVER even on direct injection. The mirror finish actually slows airflow down. You leave the intake ports rough like about what 80 grit sandpaper would leave for a finish. The rough surface traps air and allows the intake air to flow with less resistance due to the air on air contact instead of the air on port wall contact.

[@keinoclarke4581]

userpike nice explanation.

[@messyjessy2148]

Gasket matching is a thing and its usually done in older engines, new engine use that new type of gasket

[@jamest4363]

You want turbulent air in the intake runner to make the fuel and air mix better but inside the combustion chamber you want the air flow smoothed out to aid in exhaust gasses being expelled. You can make the intake port too large before it hits the intake hole on the cylinder head which will cause a drop in incoming air velocity so you need a restriction from the intake runner to the valve. You don't want to loose too much velocity.

[@wilfredoortiz4038]

awesome very in-depth and educational thank you

[@_-KOEN-_]

Was waiting for this video... very nice

[@TU-TOF]

DO you think that we can mox polish in oil motor ?

[@ghettoflyer]

When are you going to cover dimpling intake, exhaust runners, and combustion chambers?

[@acmadniturner1668]

dimpling isnt really viable, only creates unneeded turbulence.

[@Novi347]

It's all about proper velocity to induce a tumble/swirling effect.

[@dinosshed]

You need to make the ‘combination’ not just change one thing. That head is a late model design optimised for street duty, porting it without changing cams, intake, exhaust, compression, rev limit and tune will drop the velocity. More flow always requires the combination to be optimised, that’s why the turbocharged method is best, no porting required.

[@ChuckHaney]

Doesn't sanding down all those bumps on the intake contradict what you said about rough intakes being better?

[@fiys567]

Sanding down with a low grit like 60 grit will still leave imperfections encouraging fuel atomization so no it doesn’t really contradict what he said

[@ginanjarprestigema307]

How about turbo direct injection engine? Is it any difference with non turbo? In terms of efficiency etc..

[@richardmaurer1409]

smooth allows liquid fuel to flow into the chamber possibly getting on a plug tip and a misfire,,,,

[@916pickups]

99% of porters are doing it wrong. Do not ever use a pneumatic grinder unless you like oatmeal. Take intakes up to 80 grit polish the exhaust to whatever. Watch the short side radius. Use a stone on the ssr if your not Mondello level porter. Do not chase casting seems. Raise the roof , and just clean the floor. Pull your radius and straighten up walls. CNC is for heads that are popular sbc , honda. Even then a porter should clean up cnc work with a stone. For the home gamers. Get yourself a dimmer switch and plug in a metal box with extention cord and a Makita straight grinder. The dimmer will control your speed. To keep your carbide clean USED motor oil is best. No need for fancy cutting oil.

[@electech_5495]

You said mirror finish only when gas isn't there trying to 'stay atomized' but I heard the opposite-- air actually clings to the mirror finish-thus decreasing velocity? ..I do believe the theory, because well I just thought of this, but Look at a golf ball for instance, it makes sense.

[@WarriorOfEden3033]

4.6 2v is notorious for having horrible flow. You can see a 50-100hp from porting high end is CNC & a full job low end it just matching up.

[@Jenuin]

Awesome introduction to port and polish. I’ll be doing this soon. Thanks.

[@paulnichols943]

You can't be serious??? Who is dumber? The person that makes a video that doesn't have any real experience,? Or someone that watches the video and takes their advise?? Casted?? Really??

[@Jenuin]

I felt I’d practise. Learn. On an engine that isn’t to be used. Test it. Then when I get aluminum heads plus a ton more education on my part I’ll probably think about doing mine or find a performance shop. I did my cr500 Honda back in the day. But one cylinder is easier then 8 and mine was obviously 2 stroke. Left it rough.

[@nicoleibundgut534]

There are a lot of people telling complitly different stuff about enlarging,polishing etc. I think enlarging ist just nessesary if you go up with power in general like with a Turbocharger. What about an N/A Engine? I have seen a Video where they test the flow of a Cylinderhead with 4 Different ports. Original,Enlarge,Polish and Golfballport. The difference of the best one(Golfball) is just about ~5% thats not alot. Is there really a Power difference in the hole powercurve for a NA engine like my 1.6 Honds crx?

[@charlieb5793]

Don't sand blast or glass bead ohc heads! There is a chance you won't be able to get some out of the oil galleys. Find someone with a soda blaster

[@jeffstone7912]

I bet a occasional aerosol seafoam treatment sprayed in to the intake in the engine on a direct injection system would keep the carbon deposits from getting really bad. I’ve seen a couple of videos on KZbin where this is done and it has made quite a bit a difference. One video even used a borescope to show how much carbon was removed from the back of an intake valve.

[@blainemacdonald6929]

Jeff Stone I do my directed injected engine every oil change so far no issues

[@dohc22h]

Put dimples inside the runners... Like a golf ball. = Golden

[@Robert-vp6xf]

Go back and learn before you impart knowledge.... Listen.... Dont take advice from a guy who sandblasts his head period. Now Milanmastracci.... Let me school you on one of the most highly controversial subjects in tuning. 1. never sandblast... Tank it or use boiling soap and water. sure it takes longer but its more consistent and safer. 2. Unless your running a carb you want to mirror polish the whole port. Heres why" A rough surface makes turbulence which is controversial in gains at best. A rough surface is also a bed for contaminents to stick to which is a huge issue in VW direct injection engines... duh... A smooth port again is a clean port. Also a smooth port has a great drag coefficient. Sure dimpling wins on a flow bench but not by much. 3. Steps are never good. cutting that carbn ring area down or fitting a tighter gasket is a win win. 4. good injectors atomize enough and a rough surface allows fuel pooling which is never good. 5. no port job should be quick enough to last a few hours. Old experts take hours like 80 is avrage for a great port job. 6. If like me you dont haved a bench you should be using water. You can cc the runners just like ccing the head and it does help keep flow even. 7. Unless your placing in new valve guides any porter should tape up the guides and use extreme caution in this area. 8. The exhausts can be cut to an extreme. IE the guides can be cut right off leaving a perfect polished tube. 9. if this makes no sense I am porting my lotus 910 head now and would be glad to take photos the only catch is they will be on mightycarmods forums. Also note I am glad you realize that FSI engines should be smoothed right to the valve seat. Good on you.

[@HalferLandPerformance]

Wow didn't see his video on blasting his heads LMFAO. Check out hid video he mirror finishes ONE valves as if they're aftermarket titanium and then advise everyone else to and that it's the perfect way to do it!! This kid is so lost, worse of all spouts the shit as if scientifically proven SMHF

[@HalferLandPerformance]

DAmn auto correct. `mirror finishes OEM valves

[@JC-11111]

@Robert DeHart You need more education, also. Rough surfaces don't allow pooling. Mirrored surfaces do. That's why no one polishes ports on a carb'd application. That's the only thing I'm addressing but it's not the only thing you're wrong about. Wanna learn real speed secrets and how it actually works? Leave those garage hacks, mightycarmods, and go check out speedtalk. Spend a month reading. You'll see just how much you don't know. These are top guys in the racing industry. People like John Kaase, for example. David Vizard. Darin Morgan of Reher Morrison. People like him that design cylinder heads. John Marcella, who makes Marcella Manifolds. Guys that have known names in the racing industry. Go learn there. You'll see just how wrong mcm is about whatever it is you've learned there.

[@JC-11111]

When every dyno test shows power picked up with intake ports roughed in with a carbide burr vs sanded smooth with a cartridge roll, why would you want smooth ports? You can, keep em, and stay at the back of the pack.

[@JC-11111]

Just like the people that think "bigger is always better" as far as port size is concerned. If it's bigger, it must flow more! You got a flowbench to check your work? Porting without one is like doing surgery blindfolded. You can increase the port size yet decrease to total cfm and never now it because now the velocity of the air slowed down. Now, it doesn't fill the cylinder completely and you've lost 15hp yet you don't know it because you assume bigger is always better! Go to speedtalk. Stick around for a while. You'll learn quite a bit from the guys who do this daily, for a living. And make a good livi g doing it. Why? Because they're good at what they do.

[@paulsalvestrin7253]

Take it from somebody that has spent 35 years and thousands of hour on the flow bench and dyno. Polishing ports does nothing for performance or flow and in fact it reduces flow. You are young and still learning buy some good books on airflow dynamics and a flowbench and then after 20 years of learning and testing then you can make a KZbin video that is correct. Oh just a tip study up on a thing called boundary layer effect its very interesting.

[@SoaringEagle1]

I totally agree......knowledge is power, not to mention proprietary in some cases. A flow bench, Dyno, understanding of thermal / airflow dynamics, geometry & 3-D measurement, proper tooling, patience, time, money, extensive knowledge of the particular OEM's / set-ups you are working with, & testing is absolutely critical.....and that's just the beginning, lol. I've been at it for 25+ years in my little world on my own engines (which isn't really saying much other than it works for my particular application).....I've only personally met 2 individuals in my 47 orbits around the sun that are truly masters in this subject (maybe you're the 3rd, that'd be kewl)...but both own a flow bench and dyno, both have been doing it 30+ years (One does Chrysler, the other Harley Davidson....and that's ALL they do)....both are engineers, own their own shops, and both have storage areas with catalogued / organized racks of sleeves, pistons, carbs, intakes, heads, & exhaust parts from all the R&D / data collection they've done over the years (and yes, even some expensive catastrophic failures).....the only reason I was fortunate enough to even meet and work with these fine gentlemen is I'm a certified CMM tech (coordinate measurement), certified in NDT (Level II UT/MT/PT/VT), and my welding certs (all processes & CWI / CWE)......which are really just small parts of their final "non-disclosed" equations (mainly for inspection data, testing, & repairs).......you typically only find these guys by reading the record books, and not necessarily by name either......but by their final numbers / results.....not in some KZbin video.

[@RICHIE_RICH89]

Yup slightly rough is better. Smooth it sticks

[@JO3haNsum]

Great stuff!

[@milanmastracci]

Glad you think so!

[@saadsiddiqi3861]

You said in the start of the video that porting means equalling the size of the intake manifold port, to the headers port size. That is porting. And usually, the header has a smaller size of port than the intake manifold, so in porting you usually increase the size of the header to match the manifold. Later on, in the video, you said that increasing size of the header does not really matter. Can you please explain. How is increasing size of header not going to make any difference?

[@sigops]

awesome videos man, im learning a lot

[@fabiovitagliano5334]

Your not hey's a fucking idiot

[@johnjones4096]

If your intake manifold is plastic, it's smooth already, and there's no need to polish it.

[@donatibb]

Nice man hope you get this beast finished soon ✌

[@204_mod_shop]

Yes all in theory . Your tune instead tuned for that added fuel/ air so there for it would probably run like poo , and if your porting and polishing your heads you probably go with a bit bigger injectors ext

[@timdegroot4159]

There is not that much theory in it. This guy does not understand or know anything of fluid mechanics.

[@JC-11111]

Polish combustion chamber and exhaust on carb'd applications. Fuel needs to stay in suspension. With polished ports, fuel sticks to smooth surfaces, coming out of suspension and pudding in the port. Not what you want on a carb'd app. If you're injecting into the port, anything above the injection point can be polished also, to put it simply.

[@siegfredvisitacion736]

Is it ok to port the exhaust?

[@ronchinoy]

I have been using the shark skin finish since the 80s. Only on the intake side though. It will take you some time to find the right kind of stone to achieve it thought. I use a brand called cool stone. Used in dental work.

[@EliminatorPerformance]

Great vid 👍

[@joshw3539]

It’s all in your head. Pun intended 😆

[@Goldenhordemilo]

you should look into dimple porting

[@jasongreen2179]

Ok late to the party but how about vapour blasting ports. A middle ground finish. Anyone got any thoughts on that.

[@Manuqtix.Manuqtix]

I think my turbocharger is going Because i always find oil on my boost hoses My intake manifold is full of sludge will porting ever work for me?

[@nmtints1153]

Your videos are awesome

[@coreyjamesjernigan9751]

What is your opinion on epoxy finish on the intake port?

[@tinypurplefishesrunlaughin8052]

I have found a quick 80 grit pad wrapped around a flexible hose slightly smaller than the intake driven slowly by drill from both sides making ridges against the flow gives similar results to dimpling on two stroke engines

[@erik61801]

Mirror on the exhaust.. velvet smooth on the intake. Gasket match the whole tract.

[@dublininnis9695]

This guy gets it

[@JC-11111]

Velvet smooth? I'd rather have mine gone over with a carbide burr. Contact some good head porters like Chad Speier or Larry Meaux. Ask them what they do. They won't say velvet smooth. Or even Darin Morgan at Reher Morrison Racing Engines. Ask him. Or look at any of the hundreds or thousands of heads and intake manifolds they've done.

[@youdontevenknowwhatyoudont7657]

True but are we talking carburetor or fuel injection? Big difference in how the fuel must

[@coolissimo69]

Of course we would like to see the next video.

[@___Eldritch]

I want actual numbers produced by sensors from a thing called technology. I don't want theories.

[@proudtitanicdenier4300]

dont talk

[@sicsol]

Lets get this motor back in the Mini

[@superduper2024]

Sounds fun

[@BilgePump]

Unless you can do a before and after dyno pull it’s all conjecture.

[@arnulforeyna6848]

Where did you get them sanding wheels ?

[@milanmastracci]

amzn.to/33lOlRx

[@mitchhuested6244]

Does'nt anyone use extrusion polishing anymore? Companies used to run an abrasive paste material through the ports that would give a nice finish to the port. Depending upon the time and amount of this paste material that was forced through the runners, you could get a mirror finish or just a smoothnes of 100 or so(which is what he is describing here). Just asking if anyone knows of any companies who stilll do this type of polishing............

[@paulsalvestrin7253]

Its good to see young guys having a go and learning and you have to be commended for that. But i do think you may need a couple of thousand hours in front of a flow bench and the same on the dyno. Some of the things you talk about are correct but there is a lot that is not,and theory is great but in the real world of cylinder head porting and testing it is proven wrong! Cylinder heads are funny things and the physics involved needs to be understood correctly, but if i can offer you some advice it would be to do some reading up on boundary layer effect and airflow dynamics. Also ports are great but most of your gains will be found in valve seat profiles. Anyway keep going with it and keep learing but just don't get set in your ideas and thoughts as applying real world testing and science my change your mind.

[@kelvinleong915]

Rough better rite?

[@dereknadeau2401]

How much horsepower gain would you get doing this?

[@Halsafe]

In a port injection setup, do the valve seals wear out quicker? Love your videos, Milan!

[@Trinibad718]

u sound like you have a bmw

[@adamhiggins3786]

Casted?

[@ls6nova398]

Lol

[@VndNvwYvvSvv]

"flow more". Only at certain (high) rpm. You want narrower, longer runners for low and mid-range where you spend 99% of your time.

[@thetruthpal]

Except for when you're racing you're spending all the time in the higher RPM

[@MegaReddevil71]

Rough and smooth on exhaust port

[@rhino1211]

Hiya milanmastracci. Once you start putting the mini back together are you looking to install a oil catch can? (Which i think i would go for) Or a pcv delete? As if you don't you will surely get carbon bulid up again. P.s. love the vids. Your amazing at what you do.

[@willis23jm1]

Unpolished area doesnt improve mix.... thats more determ8ne by angle of fuel entrance as oppose to piston.... dome and penthouse shape piston help to improve mixing. Those small rough area areas won't improve nothing...if you can polish everything then do so

[@riflemanjim]

Removing casting flash does nothing for power reshaping the ports and blending the short side radius as well as the valve pockets is where you spend your time. Don't pay for polishing....smooth to dimpled ports and finishes may help power. Without proper spark timing and cam timing you will never see max gains.

[@jameshatfield6814]

Great video!!

[@ambareeshtr7316]

Dremel Tools which is handy power tool ,works great alternative best option than drill .