The guy that sent the head in is my hero! I am a professional head porter and still I would not have big enough grapes to have my heads publically assessed by another pro. Allthough I wish I did. I know it would be helpful. I am sure I would learn from it also. I just wouldn't. So good for who ever that person is to be willing to do that. 👍👍👍👍👍👍
@matt gammell I have never tried or tested dimpling. I believe in some instances it would be a change. But good or bad change? I suspect it would be very application specific. I highly doubt it would ever help win a race. I would never aproach port area sizing or wet flow that way. So I can say its unlikely I will ever test or have an experianced opinion other than it looks super cool.
@matt gammell if a tangable airflow gain is yeilded. The MAF will likely show it. But I wouldn't invest to much time in port texturing of any kind. Especially anything more than 4 or 5 inches away from the injector location.
Before I hop in the dragster and get busy I wanted to watch this. I been racing my entire life. I have met a ton of engine and cylinder head guys. Basically some of the biggest names in drag racing at that. Not one of those guys have said anything so in depth and knowledgeable. It's weird because it's TH-cam, but I'm very seriously considering sending you my dart pro 1s. Anyway thanks for the video. Great way to start the day.
Yes, I'd have to agree with ya there. Eric does a very good job at explaining and showing thing to do with head porting. From what I've seen in his videos, is a man that takes great care in his work and profession. I have a set of Brodix -12's for a sbc that have been very well ported, and flowed good #'s by the two different guys I had run them on their flow benches. I'd love to send them to him to get an accurate flow,as his two different bench deal he does. Before I change from my current 23* set up to the 15* of these -12's, over this winter, as this is for my v-drive flat bottom lake/river hot rod. So I can get a good idea of just how much more power the change will make. I love watching his very informative videos.....
Man, I hope this guy has you do a good valve job and backcut on those intakes. Brodix did not do him any favors there... Would be interesting to see what his port work is actually capable of without those handicaps
In reality, at these resolutions, the only way to know if a head is better is to run it on the dyno. To experiment and find what works. CFD analysis and benching only narrow it down. And most builders aren't very keen to talk about what works after trashing 100s of heads.
Like you said, it took a ton of guts for this guy to send these in. However, it will have been money well spent. Kudos to him on making himself vulnerable in an effort to learn as much as he can. Best of luck to him.
Great constructive criticism Eric. You're certainly correct with "starting out". We all suck starting out or at anything new. How we translate the criticism is exactly how we will succeed or fail. I can remember the first head I asked an instructor to flow and evaluate 20 years ago. My pride shrunk, but I took what he said and dove right back in till I had a badass head.
I really like the video, and you are right: a golf ball is different as an intake. But, it has a different effect on the golfball then you mentioned. It has to do with the spin of the golfball, pulling air behind the ball, causing an unwanted effect on the backside of the ball. The little vortexes created by the dimples make sure there is a better flow around the ball, preventing flow separation. We don't have anything to do with flow separation (unless you have really bad edges inside your intake side). As far as my knowledge goes: every head has a different optimal way to improve it. Different methods get different results on different heads.
What would be cool to see now are the effects of doing the recut valve job and the Ferrea valves with the existing porting. BIG kudos to the individual who sent this head in so we could all learn!!!!!
The thing about the golf ball is, the turbulence on the surface does not actually reduce friction. What it does do is essentially give the ball vortex generators on the trailing edge, reducing the wake size, and thus the drag force on the ball. It has no application for cylinder heads, car bodies, etc. There's a reason no one does it.
@@zakksragea piston moves up and down pulling and pushing air, a port surface is static and serves to allow air to flow across it. These are two different applications of air flow and don't use the same principles to achieve results.
I port 2 strokes, But a few pennies dropped for me watching this. I have been tinkering for several years but recently I have been getting some serious gains and if I was honest I'm not exactly sure why. Watching this has helped my understanding and I really appreciate you taking the time to make this video.
Props to this guy. I did learn quite a bit from this video, having recently attempted to port my first set of Big Block Mopar heads. I wish I would have examined the short sides better on both intake and exhaust. I was honestly scared to alter them too much. Now I have a better idea on what to do on the short side radius of the next set I do. Great video Eric. Thanks for the info.👍
I don't have much experience in porting at all, but there are things that made sense. I did some work on a motorcycle head once, and my goal was mostly to make all the intakes be as close to each other as possible. The intake shapes on that head varied quite a bit between each cylinder. I do think that the intake side is the most important, but aside from the valve seat itself the area inside the cylinder is also important since if there's a wall for part of the flow then you'll lose a significant area for the gas flow.
I believe from now on i wont grind on my heads other than grinding minor imperfections off! Ive probably killed flow on all my heads! After watching your videos your a true artist in my opinion!
What lots of people do that screws things up is cut into the valve job. One set of heads I saw was bowl blended right out to the valve seat. That's the worst. If you want to hit your heads with a flap wheel its pretty hard to screw it up
The rough finish inside of a tube increases the rugosity and the surface coefficient, resulting in turbulent flow. In engineering, we use the Reynolds number to determine if a fluid or gas will be in turbulent or lamina flow. The goal is to have the ports designed to eliminate as much resistance as possible to the flow of gasses. There is a relationship between pressure and flow whereby the easier it is for a gas or liquid to flow through a tube, the lower the pressure becomes. The point of porting is to optimize the flow so having a rough surface finish will result in turbulent flow which would be counter productive. You could argue that this would help atomize the fuel however the problem is that as soon as the fuel vapor enters a low pressure zone of the eddy, it will become a liquid again. The best option is to have as smooth a finish as possible to reduce any restriction to flow so that you reduce high/low pressure regions allowing the fuel to remain in a gasseous form and flowing as efficiently as possible.
ive been porting for years i started about 35 years ago and spent some money taking joe mondellos course that guy taught me a lot ! i can tell just by listening to the ring of a grind tool how close you are to going through a head into water ! ive even dimpled ports on intakes and heads for specific situations dimpling actually works well if done right
porting my first heads. Wish I would of seen your video first. Learned a lot. Thank you. Going to have to go back and look at my work. Think I made a few of mistake. Figures crossed that there are minor.
I’ve had / have heads from Meaux and from Morgan. Both are so different… I don’t know what to believe. I’ve had CNC heads from the big 3. Both the Meaux and Morgan’s seem better for the application I used them for. One set looks like it was ported with an ice skate and a brick. One set are ported so nice I wear them around my neck on special occasions and when I get dressed up to go to Sonic. I have had both sets flowed by an individual that claims that he could fix them for me. Thanks for these videos. Keeps a guy thinking.
Awesome video Eric. I learnt more about porting from your analysis here than anything else I've read or watched. Thanks for taking the time to help out us amateurs who do this for fun, but want to get as good a result as we possibly can. Equal thanks to the guy who was brave enough to sent you the head. Doing so has probably helped more people than either of you realise!
Eric, I think you handled this in the best way possible. Good, constructive insights which will allow this person to actually progress and become a better head porter.
Regarding the burr finish (or not) affecting fuel vaporisation. One difference between a port and a golf ball is the temperature. A golf ball operates at relatively low temperature. A cylinder head operates at a temperature well above the vaporisation point of fuel.
It was really educational reviewing porting like this. Most videos run through doing it correctly and there is so much assumed knowledge that you don't learn anything unless you are simply duplicating the work on the exact same head block combination kind of thing. thanks for the video.
This right here is what makes TH-cam an awesome resource!!! A chance to get free expert advice from a professional! You can literally look over the shoulder of a master as he works and gives you advice. This is priceless👍
I was lucky enough to meet and hang with my mentors mentor in the mid 70's. His name was Jocko Johnson ( Heads by Jocko) a gearhead who considered himself an artist Harley Klentz my mentor and Jocko taught me basics of head porting and ive been useing their by "seat ot the pants" knowledge and technique to port my own heads. You Sir have revealed the intricacies and technical measurements required that have escaped me ever since. Im like a little kid again gorging on your expertise and knowledge . It's all well delivered and understandable. Thank You....
That’s Awesome! I have faith I’ll be able to say something similar when I’m done, even though it’s diesel heads with helical intake ports. Fingers Crossed
Beautiful explanation! I am currently reading/watching everything I can to get ready to do some head work on my first engine - a little 2.0 Toyota 2S i know it's not amazing but it's what I've got - and this is probably the most informative video I have found thus far. Thank you
Good stuff here!! I give the guy who sent his head credit for having guts to do it! I remember my first port job and it was ok but I really had a twist when I did my first tumble port design. 4 valve direct injection motors are radically different. Go too big on the flow numbers and it kills power from lack of fuel distribution unless you convert the car to port injection. It can’t be done on alot of cars so it’s not easy finding a balance between them to make power. A lot of good tips here. The short side shape makes a big difference with direct injection engines as well.
Helical intake ports dealing with a boosted application? I’m porting a set of 00’ 7.3 Powerstroke diesel heads, most of the way done, nobody has a flow bench to test these within a 2 hour drive of Fort Mitchell, Alabama, not very many videos on anyone else doing the port work or ways to improve the factory ports or limited valve diameter, I feel like I’m from outer space for thinking outside the box. Whoever finds a way to improve the dinosaur design to achieve better efficiency, better low end torque and cool the EGTs down will have a formula that will appeal to a massive market of diesel enthusiasts that apparently love spending money on the endless rabbit hole that comes along with the diesel community. Although it’s a different animal, some of these porting tips do apply to airflow, especially the valve seats and back cuts. I’d go out on a limb to say boosted compressed air flows a lot faster than an air/fuel mixture that relies on vacuum to charge the combustion chamber. PSI of Boost has to be responsible for the increase of low end torque along with a tighter wedge at TDC that increases compression ratios that are nearly double of NA gas engines, Then factor in the fulcrum leverage because of having a longer stroke. I dig gas engines, got a 73’ Stingray with a 350 SB and it’s a fun car, but the work gets done by a big heavy dually truck that needs a paint job, lol
Excellent video! And kudos to the sender. The perfect learning material. That head contained basically all the normal mistakes that can be made while porting, and you found all of them and added ways to fix them. Everyone makes mistakes, only better ones learn from them.
As an older guy I remember when the Bow Tie heads first came out and everyone hated them and said they did not work. They were cutting the floor down like the old 461 and 292 heads were done and shooting the flow across the back of the valve in a narrow stream. At the shop I worked for we went higher and wider with the port as it approached the bowl. We left the floor high allowing the flow to spread over the valve diameter. This cylinder head appears to be an updated version of the original Bow Tie heads. You pointed out the push rod area as a place that is easy to over grind. Crower cams made rocker arms that were offset allowing a builder to cut through the pushrod wall, reweld it and make the port .100 wider for a straighter port. Over the years GM tried to overcome the problem of the siamesed intakes by rolling the heads, changing the valve angle and raising the top of the port to improve the approach to the back of the valve. Back in the early eighties a top Nascar engine was 625 to 650 hp. Tonight I watched some videos of LS engines making 600 hp to drive on the street without drastic modifications. Taking a sanding roll loose from where it is glued together and making a flapper will allow a porter to smooth a ridge on the short side radius of a port without removing a lot of material.
We called those rags. By cutting a slot down a 6" 1/4" piece of rod you can wind any grade of sand paper around it enough times where locks in . Emory cloth with cutting oil creates an exhaust port with a mirror finish from out of this world.
Recently ported and polished my first heads to for the build my channel is centered around. Learned a lot , wish I knew more people locally that had experience porting heads to get more of an analysis from.
We all start somewhere I wish I had someone like you explaining head work when I was a apprentice, great video, all the best to you and your loved ones
Really nice port work.... polish the exhaust ports to a mirror finish and they will flow really well...if you put a super charger or turbo charge the engine then you can also polish the intake ports the same way....
I've been messing about with this stuff for years, mostly old british iron, and I've learned many of these lessons the hard way! and your video sums up really well some of the most overlooked aspects of porting, and it's not overly specific advice either, as most of this applies to almost any engine. There's a lot of porting 'experts' that don't get the basics right, and will argue about the silliest things. This is just humble and honestly won experience distilled, Very nicely done. Thanks Eric!
If you're not totally honest, the customer doesn't get their money's worth. I say you did a great job in evaluating and pointing out their work, without insulting them. That's the very reason I would have someone critique my work, so that i could learn more without being beat up about it. I think this customer got well more than their money's worth.
I hand ported a set of 327 heads back around 1975. Back then I was told the drag racing rules only allowed porting 3/4" deep from both the intake and exhaust ports. It took me about 80 hours with a Dumore grinder and I ported them all the way from the ports to the valves and I polished them too.... these were cast iron heads. Back then, the concept of leaving a "reversion dam" in the bottom of the intake side was supposed to be the latest and greatest in cutting edge design... and the real conversation back then was whether or not to make just a single damn or leave a double dam by leaving around 1/8" to 3/8" past the 1st damn to the next dam was actually better than using just a single damn. From your video I would have to assume that the reversion dam idea has been dropped.
It would be awesome additional information if the owner asked you to put a proper back cut on the valves and smooth out the apex of the ssr removing the burr finish in that area. Then reflow to see differences. Thanks for your videos Eric. I appreciate those that are confident in their craft to share information.
That does take guts to have your work checked by someone else like this. You done a great job of explaining what could have been better with out being negative. You've earned even more of my respect. I have ground on a few heads and used to modify 2 stroke chainsaws. It's been a few years though. I'm getting ready to work on a set of GM 128 L98 heads for a little 339 (305 with 3.75" stroke) I'm building. This info is priceless for me to get on the right track to get some decent flow out of those heads.
Why should having your work checked need guts? I do it all the time in my job. Quality control, which is involves having your work checked and tested, it is a basic step in making quality work.
@@sepg5084 You have to. That is a part of your job. This guy had a go and had it critiqued by a professional. He could have ended up looking like a dick. We can all learn from his small mistakes.
On did my first mild porting job on a set of 993 gm heads 10 years ago on a set of heads I bought in 95ish from Arrowhead, I ended up with a small bump on my short side radius I was like oh wtf that's not good so I cut a dynafile belt in half and just pulled it back n forth until it was a nice smooth radius, fortunately I didn't do it on all of them I caught it pretty soon. Arrowhead (a division of Indy cylinder head as far as I know) did the pocket port for $100 extra I opted for (along with optional $100 2.02/1.60 s/s valves and $50 screw in studs) so it was already done all I did was a small bit of smoothing to reduce ridges because it was pretty crude, looks as if they got the correct shape but not a lot of attention to detail. They actually make pretty nice power for mild SBC. I did see the bigger valve can actually hurt flow without some deshrouding but with only 9:1 I wasn't Shure which was more benefitial....more compression or bit more flow.... But I'm rebuilding it and I'm buying pistons with a mildly domed pistons so now I can do some de shrouding and still have 9:5/9:75. I know I could just use vortec heads and make more power but I think making decent power with old iron has a cool aspect and it's always run really strong in current configuration so why go through the hassle of modding vortecs and changing my intake even tho you said the Torker 1 is mehh and I agree not optimal it seems to work fine, it does have a 2" spacer...helps don't know. But I smoothed all the runners, guide boss radius,polished exhaust runners and de-burred chambers work good for first mild porting.
@@WeingartnerRacing the life of a buick 3800 enthusiast. We don't have aftermarket cylinder heads on one of the world's most produced motors. Had a aluminum set that one or 2 companies did but were 3 thousand plus. Probably closer to 4 with shipping and what have yea. Living in Canada it's tough. Now they've all stopped production so iron it is I guess
@@WeingartnerRacing That is most of us.....especially living in the eastern part of Tn. making less money than most.......thanks for the attention/little guy
I ported the heads on my 1989 Ford Bronco 2 and port matched the upper and lower intakes. Factory casting finish and upper to lower intake match on those little 2.9L engines are terrible which caused restriction and turbulence. The work done made the engine run smoother and had quicker throttle response. May have made a very slight uptick in HP or TQ but not really noticable. What was noticable was #1 throttle response and #2 engine running smoother.
6:58 from my understanding of fluid dynamics and aerodynamics I just want interject something here. Turbulation, with the coarser burr finish the flow is staying my turbulent and keeping the fuel in suspension. It is impossible to get laminar flow through a cylinder head intake or exhaust. So making the flow as turbulent as possible it will keep fuel and air charge well mixed.
That was probably the most educational head porting video ive ever seen , and ive seen ALOT of them ! Nice job . Curious , if u had to guess , how much power is being left on the table between running his heads as is , and changing rhe things that u talked about if u had to make a rough guess based on your experience with these heads ?
Excellent presentation. Fuel separation/drop-out seems to be almost entirely from 'dead air', where there was a bad port shape and/or bad metal removal that resulted in the airflow leaving the port wall. The valve and valve seat makes a HUGE difference on lower lift street engines, I've seen some 'know it all' wannabe home porters making a horrendous job with large amounts removed apparently at random and with very wide seats which choked the marginal flow - compounded by worn guides!
The best thing to modify to gain flow is the shape of the valve head. Most valves are shallow cone shaped,, a steeper cone will reduce turbulence and increase airflow.
As a professional skydiver, and a damn good mechanic, I can totally appreciate all the physics in this video that I dont understand, yet totally do, lol!
Racers will do all kinds of wierd stuff. We used to knurl crank throws on 2 stroke bikes to turbulate/ possibly increase air flow. Grind and polish and knife edge cranks and rods.
Please do a video on valve jobs and flow. I've seen so many different thoughts on this from narrowing the seat, pushing it out on the valve, five angle and more.
I like cutaway views. A big cutaway view of a good multiangle valve job with the transition through the throat and the transition into the chamber helps visualize the way a correct valve job should be.
Best information video Your Best Video Best Video to help shops that still build first generation small block Chevrolet. Also shows your depth of knowledge. Thanks.
Used to be a mechanic, one of the shops I worked at would offer this service so had alot of practice. Had a customer that was NOT happy with 60 grit, or 240 grit, we had to get intake AND exhaust to 20000 grit and polished to a mirror... He later never paid his bill after the boss let him pay it off slowly. I'll freely admit it took me forever to get it to his desired finish, from memory 2 weeks of basically 8 hr days as id think surely this is good enough...NOPE he would find an imperfection or it wasn't mirror like enough. We even had to tig inside to fill casting holes countless times, grind it out, buff it up, then he would see a tiny and I mean tiny casting hole. If my boss hadn't talked me out of it and bribed me a few times I think I'd have quit by the second "not good enough". Hate to know how much materials alone went into it, let alone the man hours he didn't charge for (seriously the whole job was only 800 a head he complained alot but 2 weeks is stupid long and pretty sure the boss stayed late alot to help, and ik I done a few very long days as I was in the groove and lost track of time) also don't be that guy/girl that expect that kinda finish, let alone doesn't bloody pay.
Once upon a time I was a 1/8” dremel grinding kid, making things bigger and shiny. Fortunately with all the variables of street racing, my hog-wild approach was lost in the “noise”. They’re probably some of those heads on a blow engine in a rusted out carcass patching a farmer’s fence.
I must say that this man knows his shit. That shit being making power with airflow tuning. The in depth explanation from years of experience is apparent to say the least. Im an amateur racer just looking to make as much power with what i got. I got a 4 banger and a brain. Thats a start.
one thing you got confused: air going on the tightest part of a corner - that's the slowest moving air. Because the fluid dynamics will always try to "equilibrate" the atmosphere, therefore the air moving the longer distance will have to move faster to balance pressure. AKA air on the longest side of the corner will be going faster. Just like over an airplane's wing.
Measuring with a velocity probe you will find the slower speed at the top of the port not the bottom. The fastest section is the floor over the shortside. The probe confirms this everytime.
A tube 2 units diameter will flow 16 times as much air as a tube 1 unit diameter. A small reduction on any port makes a far bigger difference that the measured size would suggests.
You are giving out gold hear Eric,, I would weald or epoxi in the short turn area and buy the best valves I could for this head. back cut and under cut stem.
Just so you are aware, I engineer for a major auto manufacturer. The cast / burr finish is preferred because fuel will cling to the port walls until they are saturated if they are smooth. This is why my ported heads on my mustang cause a poorer startup, and cleans up after about 15 seconds.
Hmmmm, don't forget that many engines have a secondary air injection pump that operates for at least 15-30 seconds (or longer) after startup which can be noisy during that time. See my other comment regarding the burr finish on the floor of the intake port.
Interesting video Eric. One suggestion though. I believe it would be really beneficial to annotate your results tables with percentage differences when making comparisons. Eg plus or minus percentage flow differences. +1.2% is fairly insignificant, + 9.2% is huge. I find I keep having to scan back and forth and mentally do the percentage calculation very quickly while the video plays. An additional 3cfm on 100cfm is far more significant ( and worth while) a change than 3cfm on 300 cfm for example . Also another forlorn request please for a good video on porting 4 valve heads. I think there will be demand. Thanks anyway for your video presentations. Mark
Maybe we should start using another term to describe "turbulence". All combustion engine airflow is considered to be highly turbulent. Turbulent airflow is actually crucial to the combustion process (swirl flow). When you described fluctuations in velocity (sharp changes in flow direction) you mentioned that the flow will become turbulent. The flow would technically become "extremely turbulent".
This may not be helpful and I don't want to speak on whether Eric meant this, but the wall turbulence is the boundary layer turbulence. Swirl, eddy and flow turning are considered large scale turbulence, which do not really relate to boundary layer, unless you get boundary layer separation. With regards to boundary layer thickness you have thicker boundary layer with higher velocities and rougher finish but like he says the surface finish affect is minor compared to velocity. I am not a serious porter, just an engineer. Eric, I really appreciate you honest/open thoughts on head flow, they are very insightful and make a bunch of sense and don't disobey any laws of fluidynamics. Engine flow is so complicated, really hard to grasp all that happens in there, but you certainly have the best "book" of knowledge I have seen. Thanks for everything you do. From a fellow A-fibber
@@jeffmays930 I was referring to the short side radius. This port has somewhat of a peaked short side rather than a gradual change in direction. He mentioned that this could cause "turbulence". We need to apply the fundamentals here, as all combustion engine air flow is highly turbulent.
@@seahorse5677 We may be talking past each other, but if the main surface has drastic flow direction changes that may lead to large scale turbulence. If large scale turbulence occurs on a sharp radius turn it is because the boundary layer actually separates from the wall causing a partial wake (like a bubble) and subsequent losses because the flow has to turn more abruptly into the valve opening. Hard to fix on a short radius, but if the bowl is sufficient to slow the velocity (known as a positive pressure gradient due to the Bernoulli principle), it will prevent the separation. But Eric nailed it, that any change in direction or speeding/ slowing of the inlet air results in reduced flow. Managing that is the key. My $0.02
One of the most important issues not addressed here is the valve guide clearance, material of the guide, shrink fit installation, valve micro finish (super polished)and generation of the valve seat from the valve guide. If not addressed then you wear out valves on the seat and stem, allowing for oil by-pass and wear of the seat.
Are we forgetting about the “Boundary Layer” the port texture creates? The boundary layer actually helps by creating a layer/cushion of air to help the fuel/air charge flow with less restriction and stay suspended. At least this is the theory I’ve followed with success. JD
I’d love to see you do some 4 valve stuff. There’s very little info on porting them. You have a little less freedom because of how small it is around the valves & from factory the bowl blends are often pretty bad.
Smooth finish is not necessarily going to create an increase in flow. Some roughness to create a boundary layer, like the dimples on a golf ball, actually increase flow (decrease aerodynamic drag). Larry Meaux did a test years ago, back to back test on ported big block heads. Engine was dynoed with the ported heads then the heads were pulled and Larry purposely bent the shank of a ball grinding burr and used it to dimple the surface of the ports as best he could with such a crude tool. Dynoed on the same engine, power increased by 10 HP with the dimple port heads.
Years ago a friend had a good running 350. Blown head gasket so he decided to port them. Yikes what a irregular chopped up mess. Damn thing ran like a stripped as ape after. I'll bet +30 hp. Fluke? Beats me. 😱😱
Eric Weingartner + David Vizard = Genius?! I was able to put together two very important tidbits from this video and one of David Vizard's videos regarding port roughness. At 8:08 Eric states never to make the apex of the floor rough. Consistent with this, in PowerTech 10 Episode 28 @ 36 : 55 (th-cam.com/video/FBpf9nYyu6g/w-d-xo.html) David notes that the floor of the port starting from the opening of the port--up to but not including the apex (as he illustrates)--should be rough. He additionally hints "that is NOT so for the ceiling" implying that the ceiling should be smooth. I suppose the rough floor leading up to the apex will help slow down the air near the floor so it can make the sharp turn... plus benefits of fuel atomization? Anyway, I'm thinking this just might be the ultimate recipe for the finish of an intake port. Would love to hear your feedback!
That burr finish will not create eddies. There is not enough of a change in surface level for it to effect the airflow that much. it's also too chaotic of a pattern to have a predictable effect on the air current, It probably does not help with atomization either, but if it does that would be due to the increased surface area which again is hardly noticable but maybe at a molecular scale it could cause more fuel to re-vaporize. I would put money on no noticable impact in either case, and it's entirely in your head.
I never take anything as you being harsh man. What I understand is that you know what you're talking about, you wanna get the point accross and teach and there are way to many hard headed people out there who think they know when they don't actually know. I Think one of these days i will ship my ead to you just to make a video on and hear your thoughts. It might be great or it Might suck lol. I'm pretty good on my Short sides, bowl to seat blending and reshaping around the guides. But Like I said I am not pro but I try to be.
air pushing is way different than air being sucked, it acts different as well. they pull the air through a wind tunnel. pushing air through the tunnel creates turbulence and they wouldn't be able to use the smoke stream. i don't think dimples would help at all with air being sucked over the top. airs not being pushed to create a vortex swirl.
Nop just nope pressure is important for flow of gases but The air dosnt make a difference between pusch and pull inside a tube because it is just moving to the lower pressure Too the dimples of a golf ball his explanation is ok but the why has a Golfball dimples they are to reduce the low pressure areas behind the ball there layer seperation is possible the littel swirls help to curve the air behind the ball so his explanation with the apex isn't perfect if you get layer seperation after a sharp bend (I think no head after 1950 should have such spots) right after the apex a littel swirl will improve flow around the 90° edge
makes sense for burr finish making more torque, I believe at lower speeds fuel will fall out of atomization faster, however find it easier to become reatomized at lower speeds? I think?
Once fuel falls out of suspension it never goes back in. I guess people don't realize the air direction inside that port changes direction multiple times per second.
The guy that sent the head in is my hero! I am a professional head porter and still I would not have big enough grapes to have my heads publically assessed by another pro. Allthough I wish I did. I know it would be helpful. I am sure I would learn from it also. I just wouldn't.
So good for who ever that person is to be willing to do that. 👍👍👍👍👍👍
Do it
You can always teach a old dog new tricks
@matt gammell
I have never tried or tested dimpling. I believe in some instances it would be a change. But good or bad change? I suspect it would be very application specific. I highly doubt it would ever help win a race. I would never aproach port area sizing or wet flow that way. So I can say its unlikely I will ever test or have an experianced opinion other than it looks super cool.
@matt gammell if a tangable airflow gain is yeilded. The MAF will likely show it. But I wouldn't invest to much time in port texturing of any kind. Especially anything more than 4 or 5 inches away from the injector location.
Would this also apply to a 6.5 hp small ending cylinder head as well ?
Before I hop in the dragster and get busy I wanted to watch this. I been racing my entire life. I have met a ton of engine and cylinder head guys. Basically some of the biggest names in drag racing at that. Not one of those guys have said anything so in depth and knowledgeable. It's weird because it's TH-cam, but I'm very seriously considering sending you my dart pro 1s. Anyway thanks for the video. Great way to start the day.
Yes, I'd have to agree with ya there. Eric does a very good job at explaining and showing thing to do with head porting. From what I've seen in his videos, is a man that takes great care in his work and profession. I have a set of Brodix -12's for a sbc that have been very well ported, and flowed good #'s by the two different guys I had run them on their flow benches. I'd love to send them to him to get an accurate flow,as his two different bench deal he does. Before I change from my current 23* set up to the 15* of these -12's, over this winter, as this is for my v-drive flat bottom lake/river hot rod. So I can get a good idea of just how much more power the change will make. I love watching his very informative videos.....
Eric is famous. Great work top of the class.
Man, I hope this guy has you do a good valve job and backcut on those intakes. Brodix did not do him any favors there...
Would be interesting to see what his port work is actually capable of without those handicaps
It just goes to show... It's those that are in the right place at the right time...
In reality, at these resolutions, the only way to know if a head is better is to run it on the dyno. To experiment and find what works.
CFD analysis and benching only narrow it down. And most builders aren't very keen to talk about what works after trashing 100s of heads.
Props to the guy who sent it in. a few small changes and the ports will come alive.
Like you said, it took a ton of guts for this guy to send these in. However, it will have been money well spent. Kudos to him on making himself vulnerable in an effort to learn as much as he can. Best of luck to him.
Im sure his next set will be better.
Great constructive criticism Eric. You're certainly correct with "starting out". We all suck starting out or at anything new. How we translate the criticism is exactly how we will succeed or fail. I can remember the first head I asked an instructor to flow and evaluate 20 years ago. My pride shrunk, but I took what he said and dove right back in till I had a badass head.
I really like the video, and you are right: a golf ball is different as an intake. But, it has a different effect on the golfball then you mentioned. It has to do with the spin of the golfball, pulling air behind the ball, causing an unwanted effect on the backside of the ball. The little vortexes created by the dimples make sure there is a better flow around the ball, preventing flow separation. We don't have anything to do with flow separation (unless you have really bad edges inside your intake side). As far as my knowledge goes: every head has a different optimal way to improve it. Different methods get different results on different heads.
What would be cool to see now are the effects of doing the recut valve job and the Ferrea valves with the existing porting. BIG kudos to the individual who sent this head in so we could all learn!!!!!
The thing about the golf ball is, the turbulence on the surface does not actually reduce friction. What it does do is essentially give the ball vortex generators on the trailing edge, reducing the wake size, and thus the drag force on the ball. It has no application for cylinder heads, car bodies, etc. There's a reason no one does it.
False. The new Dimpled pistons for diesels are gaining Hp and mpgs
@@zakksragea piston moves up and down pulling and pushing air, a port surface is static and serves to allow air to flow across it. These are two different applications of air flow and don't use the same principles to achieve results.
I port 2 strokes, But a few pennies dropped for me watching this. I have been tinkering for several years but recently I have been getting some serious gains and if I was honest I'm not exactly sure why. Watching this has helped my understanding and I really appreciate you taking the time to make this video.
Props to this guy. I did learn quite a bit from this video, having recently attempted to port my first set of Big Block Mopar heads. I wish I would have examined the short sides better on both intake and exhaust. I was honestly scared to alter them too much. Now I have a better idea on what to do on the short side radius of the next set I do. Great video Eric. Thanks for the info.👍
BBM have horrible shorts and very limited for improvements.
I don't have much experience in porting at all, but there are things that made sense. I did some work on a motorcycle head once, and my goal was mostly to make all the intakes be as close to each other as possible. The intake shapes on that head varied quite a bit between each cylinder.
I do think that the intake side is the most important, but aside from the valve seat itself the area inside the cylinder is also important since if there's a wall for part of the flow then you'll lose a significant area for the gas flow.
Where were all of these fantastic informational videos back when i was building engines? Ahhh the 80's. What a different planet that was lol
And better times for the most part.
I believe from now on i wont grind on my heads other than grinding minor imperfections off! Ive probably killed flow on all my heads! After watching your videos your a true artist in my opinion!
What lots of people do that screws things up is cut into the valve job. One set of heads I saw was bowl blended right out to the valve seat. That's the worst.
If you want to hit your heads with a flap wheel its pretty hard to screw it up
The rough finish inside of a tube increases the rugosity and the surface coefficient, resulting in turbulent flow. In engineering, we use the Reynolds number to determine if a fluid or gas will be in turbulent or lamina flow. The goal is to have the ports designed to eliminate as much resistance as possible to the flow of gasses. There is a relationship between pressure and flow whereby the easier it is for a gas or liquid to flow through a tube, the lower the pressure becomes.
The point of porting is to optimize the flow so having a rough surface finish will result in turbulent flow which would be counter productive. You could argue that this would help atomize the fuel however the problem is that as soon as the fuel vapor enters a low pressure zone of the eddy, it will become a liquid again.
The best option is to have as smooth a finish as possible to reduce any restriction to flow so that you reduce high/low pressure regions allowing the fuel to remain in a gasseous form and flowing as efficiently as possible.
ive been porting for years i started about 35 years ago and spent some money taking joe mondellos course that guy taught me a lot ! i can tell just by listening to the ring of a grind tool how close you are to going through a head into water ! ive even dimpled ports on intakes and heads for specific situations dimpling actually works well if done right
great that you have a willing customer to offer their craft work up for analysis for us all to observe.
great insights and great content
It is nice that he wanted this done.
One of the best videos you have made!
Thanks.
porting my first heads. Wish I would of seen your video first. Learned a lot. Thank you. Going to have to go back and look at my work. Think I made a few of mistake. Figures crossed that there are minor.
I’ve had / have heads from Meaux and from Morgan. Both are so different… I don’t know what to believe. I’ve had CNC heads from the big 3. Both the Meaux and Morgan’s seem better for the application I used them for. One set looks like it was ported with an ice skate and a brick. One set are ported so nice I wear them around my neck on special occasions and when I get dressed up to go to Sonic. I have had both sets flowed by an individual that claims that he could fix them for me. Thanks for these videos. Keeps a guy thinking.
Its very rare to have two head porters have the same design. We all do things a little different.
Bob Morgan sr?
@@peterchristlieb Darin Morgan
@@WeingartnerRacing I've said that to friends and clients for 20 years....they just don't grasp the reality of it.
Awesome video Eric. I learnt more about porting from your analysis here than anything else I've read or watched. Thanks for taking the time to help out us amateurs who do this for fun, but want to get as good a result as we possibly can. Equal thanks to the guy who was brave enough to sent you the head. Doing so has probably helped more people than either of you realise!
Thanks for watching.
Eric, I think you handled this in the best way possible. Good, constructive insights which will allow this person to actually progress and become a better head porter.
Thanks.
Regarding the burr finish (or not) affecting fuel vaporisation. One difference between a port and a golf ball is the temperature. A golf ball operates at relatively low temperature. A cylinder head operates at a temperature well above the vaporisation point of fuel.
Great information. It gives me more to think about when I look off into nothing and become consumed by deep thoughts of how things work.
Thanks for wathing.
He's got guts but he's smart learning all the trick from you .thank you for sharing your knowledge thank you
Thank you. I find the information useful and reinforces what is important and what is not.
It was really educational reviewing porting like this. Most videos run through doing it correctly and there is so much assumed knowledge that you don't learn anything unless you are simply duplicating the work on the exact same head block combination kind of thing. thanks for the video.
This right here is what makes TH-cam an awesome resource!!! A chance to get free expert advice from a professional! You can literally look over the shoulder of a master as he works and gives you advice. This is priceless👍
I do the same thing with sand paper by hand lol been porting for 25 years and your spot on!
I was lucky enough to meet and hang with my mentors mentor in the mid 70's. His name was Jocko Johnson ( Heads by Jocko) a gearhead who considered himself an artist
Harley Klentz my mentor and Jocko taught me basics of head porting and ive been useing their by "seat ot the pants" knowledge and technique to port my own heads.
You Sir have revealed the intricacies and technical measurements required that have escaped me ever since.
Im like a little kid again gorging on your expertise and knowledge .
It's all well delivered and understandable.
Thank You....
First pair of heads I did was on my own truck. No misfires leaks or nothing made about 30 more horses to the rear tires.
That’s Awesome! I have faith I’ll be able to say something similar when I’m done, even though it’s diesel heads with helical intake ports. Fingers Crossed
Beautiful explanation! I am currently reading/watching everything I can to get ready to do some head work on my first engine - a little 2.0 Toyota 2S i know it's not amazing but it's what I've got - and this is probably the most informative video I have found thus far. Thank you
Very good video. Thanks to you and the guy that sent the head in.
Im glad he sent it in.
Good stuff here!! I give the guy who sent his head credit for having guts to do it!
I remember my first port job and it was ok but I really had a twist when I did my first tumble port design. 4 valve direct injection motors are radically different. Go too big on the flow numbers and it kills power from lack of fuel distribution unless you convert the car to port injection. It can’t be done on alot of cars so it’s not easy finding a balance between them to make power.
A lot of good tips here. The short side shape makes a big difference with direct injection engines as well.
Thanks for watching.
Helical intake ports dealing with a boosted application? I’m porting a set of 00’ 7.3 Powerstroke diesel heads, most of the way done, nobody has a flow bench to test these within a 2 hour drive of Fort Mitchell, Alabama, not very many videos on anyone else doing the port work or ways to improve the factory ports or limited valve diameter, I feel like I’m from outer space for thinking outside the box. Whoever finds a way to improve the dinosaur design to achieve better efficiency, better low end torque and cool the EGTs down will have a formula that will appeal to a massive market of diesel enthusiasts that apparently love spending money on the endless rabbit hole that comes along with the diesel community. Although it’s a different animal, some of these porting tips do apply to airflow, especially the valve seats and back cuts. I’d go out on a limb to say boosted compressed air flows a lot faster than an air/fuel mixture that relies on vacuum to charge the combustion chamber. PSI of Boost has to be responsible for the increase of low end torque along with a tighter wedge at TDC that increases compression ratios that are nearly double of NA gas engines, Then factor in the fulcrum leverage because of having a longer stroke. I dig gas engines, got a 73’ Stingray with a 350 SB and it’s a fun car, but the work gets done by a big heavy dually truck that needs a paint job, lol
Excellent video! And kudos to the sender. The perfect learning material. That head contained basically all the normal mistakes that can be made while porting, and you found all of them and added ways to fix them. Everyone makes mistakes, only better ones learn from them.
Yep
As an older guy I remember when the Bow Tie heads first came out and everyone hated them and said they did not work. They were cutting the floor down like the old 461 and 292 heads were done and shooting the flow across the back of the valve in a narrow stream. At the shop I worked for we went higher and wider with the port as it approached the bowl. We left the floor high allowing the flow to spread over the valve diameter. This cylinder head appears to be an updated version of the original Bow Tie heads. You pointed out the push rod area as a place that is easy to over grind. Crower cams made rocker arms that were offset allowing a builder to cut through the pushrod wall, reweld it and make the port .100 wider for a straighter port. Over the years GM tried to overcome the problem of the siamesed intakes by rolling the heads, changing the valve angle and raising the top of the port to improve the approach to the back of the valve. Back in the early eighties a top Nascar engine was 625 to 650 hp. Tonight I watched some videos of LS engines making 600 hp to drive on the street without drastic modifications. Taking a sanding roll loose from where it is glued together and making a flapper will allow a porter to smooth a ridge on the short side radius of a port without removing a lot of material.
We called those rags. By cutting a slot down a 6" 1/4" piece of rod you can wind any grade of sand paper around it enough times where locks in .
Emory cloth with cutting oil creates an exhaust port with a mirror finish from out of this world.
Recently ported and polished my first heads to for the build my channel is centered around. Learned a lot , wish I knew more people locally that had experience porting heads to get more of an analysis from.
We all start somewhere I wish I had someone like you explaining head work when I was a apprentice, great video, all the best to you and your loved ones
Thanks.
Really nice port work.... polish the exhaust ports to a mirror finish and they will flow really well...if you put a super charger or turbo charge the engine then you can also polish the intake ports the same way....
Awesome info!! And ty for the guy that sent in his head for the evaluation. Just saw my last comment . I’ll be rewatching this a few more times .
I've been messing about with this stuff for years, mostly old british iron, and I've learned many of these lessons the hard way! and your video sums up really well some of the most overlooked aspects of porting, and it's not overly specific advice either, as most of this applies to almost any engine. There's a lot of porting 'experts' that don't get the basics right, and will argue about the silliest things. This is just humble and honestly won experience distilled, Very nicely done. Thanks Eric!
That was really informative! Thanks to Eric for making the video, and to the viewer for sending in the head. 👍
Thanks for watching.
Great science and teamwork you will increase my skills... thank you and porter for this inside info !
Your welcome.
If you're not totally honest, the customer doesn't get their money's worth. I say you did a great job in evaluating and pointing out their work, without insulting them. That's the very reason I would have someone critique my work, so that i could learn more without being beat up about it. I think this customer got well more than their money's worth.
I sure hope they do.
I hand ported a set of 327 heads back around 1975. Back then I was told the drag racing rules only allowed porting 3/4" deep from both the intake and exhaust ports. It took me about 80 hours with a Dumore grinder and I ported them all the way from the ports to the valves and I polished them too.... these were cast iron heads. Back then, the concept of leaving a "reversion dam" in the bottom of the intake side was supposed to be the latest and greatest in cutting edge design... and the real conversation back then was whether or not to make just a single damn or leave a double dam by leaving around 1/8" to 3/8" past the 1st damn to the next dam was actually better than using just a single damn. From your video I would have to assume that the reversion dam idea has been dropped.
I don't do it.
It would be awesome additional information if the owner asked you to put a proper back cut on the valves and smooth out the apex of the ssr removing the burr finish in that area. Then reflow to see differences.
Thanks for your videos Eric. I appreciate those that are confident in their craft to share information.
Its not in the cards for this head.
That does take guts to have your work checked by someone else like this. You done a great job of explaining what could have been better with out being negative. You've earned even more of my respect. I have ground on a few heads and used to modify 2 stroke chainsaws. It's been a few years though. I'm getting ready to work on a set of GM 128 L98 heads for a little 339 (305 with 3.75" stroke) I'm building. This info is priceless for me to get on the right track to get some decent flow out of those heads.
Why should having your work checked need guts? I do it all the time in my job. Quality control, which is involves having your work checked and tested, it is a basic step in making quality work.
@@sepg5084 You have to. That is a part of your job. This guy had a go and had it critiqued by a professional. He could have ended up looking like a dick. We can all learn from his small mistakes.
I don’t think you check someone’s work and post it online.
Why the 305 block?
@@stevenbelue5496 just building something different.
On did my first mild porting job on a set of 993 gm heads 10 years ago on a set of heads I bought in 95ish from Arrowhead, I ended up with a small bump on my short side radius I was like oh wtf that's not good so I cut a dynafile belt in half and just pulled it back n forth until it was a nice smooth radius, fortunately I didn't do it on all of them I caught it pretty soon. Arrowhead (a division of Indy cylinder head as far as I know) did the pocket port for $100 extra I opted for (along with optional $100 2.02/1.60 s/s valves and $50 screw in studs) so it was already done all I did was a small bit of smoothing to reduce ridges because it was pretty crude, looks as if they got the correct shape but not a lot of attention to detail. They actually make pretty nice power for mild SBC. I did see the bigger valve can actually hurt flow without some deshrouding but with only 9:1 I wasn't Shure which was more benefitial....more compression or bit more flow.... But I'm rebuilding it and I'm buying pistons with a mildly domed pistons so now I can do some de shrouding and still have 9:5/9:75. I know I could just use vortec heads and make more power but I think making decent power with old iron has a cool aspect and it's always run really strong in current configuration so why go through the hassle of modding vortecs and changing my intake even tho you said the Torker 1 is mehh and I agree not optimal it seems to work fine, it does have a 2" spacer...helps don't know. But I smoothed all the runners, guide boss radius,polished exhaust runners and de-burred chambers work good for first mild porting.
I like that you spent time to work with what you had.
@@WeingartnerRacing the life of a buick 3800 enthusiast. We don't have aftermarket cylinder heads on one of the world's most produced motors. Had a aluminum set that one or 2 companies did but were 3 thousand plus. Probably closer to 4 with shipping and what have yea. Living in Canada it's tough. Now they've all stopped production so iron it is I guess
@@WeingartnerRacing That is most of us.....especially living in the eastern part of Tn. making less money than most.......thanks for the attention/little guy
I ported the heads on my 1989 Ford Bronco 2 and port matched the upper and lower intakes. Factory casting finish and upper to lower intake match on those little 2.9L engines are terrible which caused restriction and turbulence. The work done made the engine run smoother and had quicker throttle response. May have made a very slight uptick in HP or TQ but not really noticable. What was noticable was #1 throttle response and #2 engine running smoother.
6:58 from my understanding of fluid dynamics and aerodynamics I just want interject something here. Turbulation, with the coarser burr finish the flow is staying my turbulent and keeping the fuel in suspension. It is impossible to get laminar flow through a cylinder head intake or exhaust. So making the flow as turbulent as possible it will keep fuel and air charge well mixed.
That was probably the most educational head porting video ive ever seen , and ive seen ALOT of them ! Nice job . Curious , if u had to guess , how much power is being left on the table between running his heads as is , and changing rhe things that u talked about if u had to make a rough guess based on your experience with these heads ?
Thanks for watching.
This is gold thanks a ton eric and whomever it was that sent these in. :o)
Excellent presentation.
Fuel separation/drop-out seems to be almost entirely from 'dead air', where there was a bad port shape and/or bad metal removal that resulted in the airflow leaving the port wall.
The valve and valve seat makes a HUGE difference on lower lift street engines, I've seen some 'know it all' wannabe home porters making a horrendous job with large amounts removed apparently at random and with very wide seats which choked the marginal flow - compounded by worn guides!
. I enjoyed every minute of this instructive video, thank you Eric !
Glad you enjoyed it!
The best thing to modify to gain flow is the shape of the valve head. Most valves are shallow cone shaped,, a steeper cone will reduce turbulence and increase airflow.
As a professional skydiver, and a damn good mechanic, I can totally appreciate all the physics in this video that I dont understand, yet totally do, lol!
Racers will do all kinds of wierd stuff. We used to knurl crank throws on 2 stroke bikes to turbulate/ possibly increase air flow. Grind and polish and knife edge cranks and rods.
I use to knife edge cranks as well.
Please do a video on valve jobs and flow. I've seen so many different thoughts on this from narrowing the seat, pushing it out on the valve, five angle and more.
Maybe but it is really head dependent.
I like cutaway views. A big cutaway view of a good multiangle valve job with the transition through the throat and the transition into the chamber helps visualize the way a correct valve job should be.
Best information video
Your Best Video
Best Video to help shops that still build first generation small block Chevrolet.
Also shows your depth of knowledge.
Thanks.
Thanks
Used to be a mechanic, one of the shops I worked at would offer this service so had alot of practice.
Had a customer that was NOT happy with 60 grit, or 240 grit, we had to get intake AND exhaust to 20000 grit and polished to a mirror...
He later never paid his bill after the boss let him pay it off slowly. I'll freely admit it took me forever to get it to his desired finish, from memory 2 weeks of basically 8 hr days as id think surely this is good enough...NOPE he would find an imperfection or it wasn't mirror like enough. We even had to tig inside to fill casting holes countless times, grind it out, buff it up, then he would see a tiny and I mean tiny casting hole. If my boss hadn't talked me out of it and bribed me a few times I think I'd have quit by the second "not good enough". Hate to know how much materials alone went into it, let alone the man hours he didn't charge for (seriously the whole job was only 800 a head he complained alot but 2 weeks is stupid long and pretty sure the boss stayed late alot to help, and ik I done a few very long days as I was in the groove and lost track of time) also don't be that guy/girl that expect that kinda finish, let alone doesn't bloody pay.
Once upon a time I was a 1/8” dremel grinding kid, making things bigger and shiny. Fortunately with all the variables of street racing, my hog-wild approach was lost in the “noise”. They’re probably some of those heads on a blow engine in a rusted out carcass patching a farmer’s fence.
I must say that this man knows his shit. That shit being making power with airflow tuning. The in depth explanation from years of experience is apparent to say the least. Im an amateur racer just looking to make as much power with what i got. I got a 4 banger and a brain. Thats a start.
Good job both you guys. Bravo!
one thing you got confused: air going on the tightest part of a corner - that's the slowest moving air. Because the fluid dynamics will always try to "equilibrate" the atmosphere, therefore the air moving the longer distance will have to move faster to balance pressure. AKA air on the longest side of the corner will be going faster.
Just like over an airplane's wing.
Measuring with a velocity probe you will find the slower speed at the top of the port not the bottom. The fastest section is the floor over the shortside. The probe confirms this everytime.
another great video from Eric. Lots of good info ! and props for that guy who send the heads !
Thanks.
A tube 2 units diameter will flow 16 times as much air as a tube 1 unit diameter. A small reduction on any port makes a far bigger difference that the measured size would suggests.
Great Video! Awesome information.
I think all of us are looking up to this brave man
You are giving out gold hear Eric,, I would weald or epoxi in the short turn area and buy the best valves I could for this head. back cut and under cut stem.
Thanks for watching. He just needs to round over the short side.
@@WeingartnerRacing as soon as I saw your drawn profile, I was like rut ro,,,
the ski jump looks better to me,, clay one up and test it.
@@DANTHETUBEMAN it may look better but it doesn’t have enough area and limits rpm which limits power.
So he actually did a good job of porting. Some better valve and seat cuts should help as you said. Thanks Eric!
Not horrible.
Heard the big chief mention your name. Hopefully we get a video on his heads
I did meet up with him. You never know maybe.
Awesome info!!! I would like to port one of my heads and send it in one day.
Eric's work is great. I watch a lot of your videos and lean a lot. I also follow you on Speed-talk Keep up the great work.
Too bad we couldnt get the valve job done by you and see the numbers improve too. Great tips really helps
Just so you are aware, I engineer for a major auto manufacturer. The cast / burr finish is preferred because fuel will cling to the port walls until they are saturated if they are smooth. This is why my ported heads on my mustang cause a poorer startup, and cleans up after about 15 seconds.
Hmmmm, don't forget that many engines have a secondary air injection pump that operates for at least 15-30 seconds (or longer) after startup which can be noisy during that time. See my other comment regarding the burr finish on the floor of the intake port.
Interesting video Eric. One suggestion though. I believe it would be really beneficial to annotate your results tables with percentage differences when making comparisons.
Eg plus or minus percentage flow differences. +1.2% is fairly insignificant, + 9.2% is huge.
I find I keep having to scan back and forth and mentally do the percentage calculation very quickly while the video plays. An additional 3cfm on 100cfm is far more significant ( and worth while) a change than 3cfm on 300 cfm for example .
Also another forlorn request please for a good video on porting 4 valve heads. I think there will be demand. Thanks anyway for your video presentations. Mark
I do sometimes but this video was already long.
Maybe we should start using another term to describe "turbulence". All combustion engine airflow is considered to be highly turbulent. Turbulent airflow is actually crucial to the combustion process (swirl flow). When you described fluctuations in velocity (sharp changes in flow direction) you mentioned that the flow will become turbulent. The flow would technically become "extremely turbulent".
This may not be helpful and I don't want to speak on whether Eric meant this, but the wall turbulence is the boundary layer turbulence. Swirl, eddy and flow turning are considered large scale turbulence, which do not really relate to boundary layer, unless you get boundary layer separation. With regards to boundary layer thickness you have thicker boundary layer with higher velocities and rougher finish but like he says the surface finish affect is minor compared to velocity. I am not a serious porter, just an engineer.
Eric, I really appreciate you honest/open thoughts on head flow, they are very insightful and make a bunch of sense and don't disobey any laws of fluidynamics. Engine flow is so complicated, really hard to grasp all that happens in there, but you certainly have the best "book" of knowledge I have seen. Thanks for everything you do.
From a fellow A-fibber
@@jeffmays930 I was referring to the short side radius. This port has somewhat of a peaked short side rather than a gradual change in direction. He mentioned that this could cause "turbulence". We need to apply the fundamentals here, as all combustion engine air flow is highly turbulent.
@@seahorse5677 We may be talking past each other, but if the main surface has drastic flow direction changes that may lead to large scale turbulence. If large scale turbulence occurs on a sharp radius turn it is because the boundary layer actually separates from the wall causing a partial wake (like a bubble) and subsequent losses because the flow has to turn more abruptly into the valve opening. Hard to fix on a short radius, but if the bowl is sufficient to slow the velocity (known as a positive pressure gradient due to the Bernoulli principle), it will prevent the separation. But Eric nailed it, that any change in direction or speeding/ slowing of the inlet air results in reduced flow. Managing that is the key. My $0.02
Correct and thank you.
You helped him a bunch, and me also.
@24.00 you can go taller if you use spacers in between the manifold and the heads, then you can raise bottom with epoxy!
High speed because that's the smallest part of the port ,like putting your finger over the garden hose does that make sense
One of the most important issues not addressed here is the valve guide clearance, material of the guide, shrink fit installation, valve micro finish (super polished)and generation of the valve seat from the valve guide. If not addressed then you wear out valves on the seat and stem, allowing for oil by-pass and wear of the seat.
Although great points I was only evaluating the porting.
@@WeingartnerRacing I can help you with the data, so you can add it to your "porting and polishing" expertise.
Love this off his first advice
Are we forgetting about the “Boundary Layer” the port texture creates? The boundary layer actually helps by creating a layer/cushion of air to help the fuel/air charge flow with less restriction and stay suspended. At least this is the theory I’ve followed with success. JD
That cushion takes up space. The head still needs area.
properly undercutting valves then swirl polish can help enough to mean winning or loosing too !
I’d love to see you do some 4 valve stuff. There’s very little info on porting them. You have a little less freedom because of how small it is around the valves & from factory the bowl blends are often pretty bad.
I don’t do 4valve stuff. Most of the time it seems they make them to large.
I would like to see you make a video of how to properly make the measurements correctly.
I 0ort r53 mini cooper cylinder heads , intake manifolds , intercooler horns AND throttlebody and it makes AWESOME power gains
Smooth finish is not necessarily going to create an increase in flow. Some roughness to create a boundary layer, like the dimples on a golf ball, actually increase flow (decrease aerodynamic drag). Larry Meaux did a test years ago, back to back test on ported big block heads. Engine was dynoed with the ported heads then the heads were pulled and Larry purposely bent the shank of a ball grinding burr and used it to dimple the surface of the ports as best he could with such a crude tool. Dynoed on the same engine, power increased by 10 HP with the dimple port heads.
I did the same thing on an intake manifold. Once I smoothed up the burr finish it gained power.
Years ago a friend had a good running 350. Blown head gasket so he decided to port them. Yikes what a irregular chopped up mess.
Damn thing ran like a stripped as ape after. I'll bet +30 hp. Fluke? Beats me. 😱😱
WOW! I JUST LEARNED SOO MUCH FLOW TECH. Thank you for this video. Now where did I leave those Jag v-12 heads? SUBSCRIBED!
A true word: "I'm a professional because I get paid for it".
"Roast my cylinder head"
Good video Eric , and that is why I would leave porting expensive heads to the experts , LOL .
Thanks.
Eric Weingartner + David Vizard = Genius?! I was able to put together two very important tidbits from this video and one of David Vizard's videos regarding port roughness. At 8:08 Eric states never to make the apex of the floor rough. Consistent with this, in PowerTech 10 Episode 28 @ 36 : 55 (th-cam.com/video/FBpf9nYyu6g/w-d-xo.html) David notes that the floor of the port starting from the opening of the port--up to but not including the apex (as he illustrates)--should be rough. He additionally hints "that is NOT so for the ceiling" implying that the ceiling should be smooth. I suppose the rough floor leading up to the apex will help slow down the air near the floor so it can make the sharp turn... plus benefits of fuel atomization? Anyway, I'm thinking this just might be the ultimate recipe for the finish of an intake port. Would love to hear your feedback!
That burr finish will not create eddies. There is not enough of a change in surface level for it to effect the airflow that much. it's also too chaotic of a pattern to have a predictable effect on the air current, It probably does not help with atomization either, but if it does that would be due to the increased surface area which again is hardly noticable but maybe at a molecular scale it could cause more fuel to re-vaporize. I would put money on no noticable impact in either case, and it's entirely in your head.
I like the way you speak brother
I never take anything as you being harsh man. What I understand is that you know what you're talking about, you wanna get the point accross and teach and there are way to many hard headed people out there who think they know when they don't actually know. I Think one of these days i will ship my ead to you just to make a video on and hear your thoughts. It might be great or it Might suck lol. I'm pretty good on my Short sides, bowl to seat blending and reshaping around the guides. But Like I said I am not pro but I try to be.
Thanks for waching.
air pushing is way different than air being sucked, it acts different as well. they pull the air through a wind tunnel. pushing air through the tunnel creates turbulence and they wouldn't be able to use the smoke stream. i don't think dimples would help at all with air being sucked over the top. airs not being pushed to create a vortex swirl.
Nop just nope pressure is important for flow of gases but The air dosnt make a difference between pusch and pull inside a tube because it is just moving to the lower pressure
Too the dimples of a golf ball his explanation is ok but the why has a Golfball dimples they are to reduce the low pressure areas behind the ball there layer seperation is possible the littel swirls help to curve the air behind the ball so his explanation with the apex isn't perfect if you get layer seperation after a sharp bend (I think no head after 1950 should have such spots) right after the apex a littel swirl will improve flow around the 90° edge
makes sense for burr finish making more torque, I believe at lower speeds fuel will fall out of atomization faster, however find it easier to become reatomized at lower speeds? I think?
Once fuel falls out of suspension it never goes back in. I guess people don't realize the air direction inside that port changes direction multiple times per second.
Smooth finish should create a laminar flow. Laminar flow SHOULD always flow better than a turbulent flow. That's the physics. Your milage may vary.
Great Engineering.!
I am also modify & tune motorcycles engines for RACING in INDIA.
I appreciate your Good work..!!