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 RUclips, 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.
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!!!!!
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.
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.
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 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
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
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'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!
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!
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
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.
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.
This right here is what makes RUclips 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👍
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.
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
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....
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.
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.
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.
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.
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.
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 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.
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
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
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.
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.
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 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.
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 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.
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!
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.
Question: Does porting affect CV carburetor slide lift? Thinking of doing mine unless it will mess cv carbs up because I know how finicky they can be with intake pressure and whatnot. Would you recommend it?
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.
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 ?
I have a pair of Pontiac 13 heads and I noticed that the exhaust port is a little offset to the valve pocket is that to create a vortex? I never ported heads and I am trying to learn as much as I can before I pick up a grinder and your videos are super. As a beginner I think I should just give them a street pocket porting nothing too drastic. I'm trying for 400hp out of a 400 Pontiac. Stock quadrajet intake and reproduction ram air three exhaust manifolds. Would Swirl polished under cut valves make a big or small difference
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.
On the subject of valve jobs. If someone sent in a head they ported with a stock valve job would you do a flow comparison of stock valve job and then do a valve u feel is correct? I would find that interesting to see
I have a question. I have a 5.5 ltr Mercedes m117 V8. Sohc 2 valve. There are no cams available for it (for reasonable money at least). It makes factory rated 227 hp and 290lb/ft. The best the same motor was rated in euro trim with higher compression, better(unobtainium) factory cams and no cats was 300hp. Same heads, compression increase is in smaller piston dish. It will be running no cats. At this low power level is there any point in doing any porting? Maybe more concentrate on combustion chamber side around the valve?
if you mill a thread pattern behind an intake valve (closer too the seat) would this encourage atomisation? i can imagine droplets parting way’s making contact with that
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.
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
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.
I’m building a 383 all scat stroker motor with DSS FX series forged pistons 040 over, 16cc dished. Looking to get 550 hp n good torque. What heads would you recommend ?
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.
Really interesting 👍 Regarding the exhaust. Some say they listen to the sound it makes when the air goes through. Is that something you do? Maybe something to try and talk/show in a video?
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
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.
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.
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?
Very constructive criticism Great video. I personally learned allot. 👍👍 I've ported a few sets of heads with decent results, Incidently my last name is Head 😄 .... go figure.
question, you mentioned exhaust reversion. Can you answer whether a small exit funnel at top of header (1/4 inch smaller dia, maybe 3/4inch length) will make a difference or just end up trading one thing for another?
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.
Great video ! Question... you said not to raise the roof, what if on a head you need to cut into the roof to port match the intake, would you do it or not? Never mind... answered my question in the video. haha :)
Eric, having a discussion with my brother about rectangle port intake used on an oval port BBC head. I say not good, he says lots of people did it back in the day. I would think air hitting a wall at the transition is not good. Whats your thoughts?
I am new to head porting. I am loving Eric’s videos. But, I feel like I am missing some of the basics I need in order to keep up. Is there some books or something I can read to get caught up?
When you were talking about back cutting the intake valves it reminded me of someone once saying a guy should front cut the exhaust valves. And that the cut should be a radius (rounded), have you ever heard of this? Does it help exhaust flow?
Thanks for the link to the end of the other video and your explanation, I can see your thinking now. It does raise another question though - Let's make an example - Head will have 700 lift on the engine, everyone wants to compare so test at 28" no problem. But wouldn't it be more realistic to do your stability test by staying at 700 lift and increasing vacuum ? I'd appreciate your thoughts as I'm trying to understand the practical re-creation of a running engine scenario to flow testing as applied on the flow bench ?
Yes I could raise the depression but it still will not match a running engine. Also running engine has violent increases in velocity the bench cannot duplicate that.
@@WeingartnerRacing Thanks Eric, both comments make perfect sense. I'm trying to read your mind about the black art part of flow testing and how you arrived at that idea of over-lifting ? Perhaps you've seen dyno results that didn't correlate to flow numbers ? Maybe you just woke up one morning and decided to try that as an idea and suddenly the dyno agreed ?? Everyone has a theory about what happens in a running engine, maybe you have had access to some specialized knowledge that has led to over-lifting as a flow bench cure ?
![MURDER DRONES Series Finale [TRAILER]](http://i.ytimg.com/vi/p6mhC5Iatns/mqdefault.jpg)
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 ?
Props to the guy who sent it in. a few small changes and the ports will come alive.
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 RUclips, 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.
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!!!!!
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.
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.
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 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
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
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.
One of the best videos you have made!
Thanks.
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!
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.
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.
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
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.
Thank you. I find the information useful and reinforces what is important and what is not.
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.
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
This right here is what makes RUclips 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👍
This is gold thanks a ton eric and whomever it was that sent these in. :o)
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.
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
another great video from Eric. Lots of good info ! and props for that guy who send the heads !
Thanks.
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.
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....
Great science and teamwork you will increase my skills... thank you and porter for this inside info !
Your welcome.
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.
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 .
Very good video. Thanks to you and the guy that sent the head in.
Im glad he sent it in.
. I enjoyed every minute of this instructive video, thank you Eric !
Glad you enjoyed it!
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.
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.
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.
Good job both you guys. Bravo!
That was really informative! Thanks to Eric for making the video, and to the viewer for sending in the head. 👍
Thanks for watching.
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.
I do the same thing with sand paper by hand lol been porting for 25 years and your spot on!
Great Video! Awesome information.
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
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 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.
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
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
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.
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.
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 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.
Thanks Eric for another nice video
Thanks for watching.
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 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.
You helped him a bunch, and me also.
Curious how that back cut affects atomization. I'm always timid to follow the flow bench instead of the dyno.
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.
Awesome info!!! I would like to port one of my heads and send it in one day.
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!
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.
Question: Does porting affect CV carburetor slide lift? Thinking of doing mine unless it will mess cv carbs up because I know how finicky they can be with intake pressure and whatnot. Would you recommend it?
Love this off his first advice
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.
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.
So the burr finish makes the port smaller more velocity more torque is that correct ? Im just trying to learn and under stand
I have a pair of Pontiac 13 heads and I noticed that the exhaust port is a little offset to the valve pocket is that to create a vortex? I never ported heads and I am trying to learn as much as I can before I pick up a grinder and your videos are super. As a beginner I think I should just give them a street pocket porting nothing too drastic. I'm trying for 400hp out of a 400 Pontiac. Stock quadrajet intake and reproduction ram air three exhaust manifolds. Would Swirl polished under cut valves make a big or small difference
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.
On the subject of valve jobs. If someone sent in a head they ported with a stock valve job would you do a flow comparison of stock valve job and then do a valve u feel is correct? I would find that interesting to see
I have a question. I have a 5.5 ltr Mercedes m117 V8. Sohc 2 valve. There are no cams available for it (for reasonable money at least). It makes factory rated 227 hp and 290lb/ft. The best the same motor was rated in euro trim with higher compression, better(unobtainium) factory cams and no cats was 300hp. Same heads, compression increase is in smaller piston dish. It will be running no cats. At this low power level is there any point in doing any porting? Maybe more concentrate on combustion chamber side around the valve?
if you mill a thread pattern behind an intake valve (closer too the seat) would this encourage atomisation?
i can imagine droplets parting way’s making contact with that
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.
Not to change the subject… but what do you think about the sbc Blue Print aluminum 195 heads ?
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.
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.
Awesome video Eric
Thanks!
I’m building a 383 all scat stroker motor with DSS FX series forged pistons 040 over, 16cc dished. Looking to get 550 hp n good torque. What heads would you recommend ?
At 35:45 a reference is made to "just smoothing it out" and a video was made. Any chance of putting a link up for that smoothing video please? Thanks.
So he actually did a good job of porting. Some better valve and seat cuts should help as you said. Thanks Eric!
Not horrible.
Too bad we couldnt get the valve job done by you and see the numbers improve too. Great tips really helps
Just a wild thought here, what if you adjust the shape of the port to create a vortex flow?
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.
Really interesting 👍
Regarding the exhaust. Some say they listen to the sound it makes when the air goes through. Is that something you do? Maybe something to try and talk/show in a video?
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
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.
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.
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?
Very constructive criticism
Great video. I personally learned allot. 👍👍
I've ported a few sets of heads with decent results,
Incidently my last name is Head 😄 .... go figure.
Good video Eric , and that is why I would leave porting expensive heads to the experts , LOL .
Thanks.
So I noticed in the Cylinder head down in the Chamber there 2 holes 1 looks like it has threads and other just looks like a hole what they used for.
question, you mentioned exhaust reversion. Can you answer whether a small exit funnel at top of header (1/4 inch smaller dia, maybe 3/4inch length) will make a difference or just end up trading one thing for another?
Ideally you want header tube bigger than exit on the head.
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.
WOW! I JUST LEARNED SOO MUCH FLOW TECH. Thank you for this video. Now where did I leave those Jag v-12 heads? SUBSCRIBED!
Great Engineering.!
I am also modify & tune motorcycles engines for RACING in INDIA.
I appreciate your Good work..!!
Question is how much would you charge or what should be paid to correct it to yours.??
Great video ! Question... you said not to raise the roof, what if on a head you need to cut into the roof to port match the intake, would you do it or not? Never mind... answered my question in the video. haha :)
Eric, having a discussion with my brother about rectangle port intake used on an oval port BBC head. I say not good, he says lots of people did it back in the day. I would think air hitting a wall at the transition is not good. Whats your thoughts?
Its not good but it was done a lot in the past because of the availability of manifolds.
I am new to head porting. I am loving Eric’s videos. But, I feel like I am missing some of the basics I need in order to keep up. Is there some books or something I can read to get caught up?
No. Most books have a lot of talk but very little info a person can use.
When you were talking about back cutting the intake valves it reminded me of someone once saying a guy should front cut the exhaust valves. And that the cut should be a radius (rounded), have you ever heard of this? Does it help exhaust flow?
You should almost never back cut an exhaust valve because it helps flow but especially in reverse making reversion worse.
I 0ort r53 mini cooper cylinder heads , intake manifolds , intercooler horns AND throttlebody and it makes AWESOME power gains
I think all of us are looking up to this brave man
Thanks for the link to the end of the other video and your explanation, I can see your thinking now. It does raise another question though - Let's make an example - Head will have 700 lift on the engine, everyone wants to compare so test at 28" no problem. But wouldn't it be more realistic to do your stability test by staying at 700 lift and increasing vacuum ? I'd appreciate your thoughts as I'm trying to understand the practical re-creation of a running engine scenario to flow testing as applied on the flow bench ?
Yes I could raise the depression but it still will not match a running engine. Also running engine has violent increases in velocity the bench cannot duplicate that.
@@WeingartnerRacing Thanks Eric, both comments make perfect sense. I'm trying to read your mind about the black art part of flow testing and how you arrived at that idea of over-lifting ? Perhaps you've seen dyno results that didn't correlate to flow numbers ? Maybe you just woke up one morning and decided to try that as an idea and suddenly the dyno agreed ?? Everyone has a theory about what happens in a running engine, maybe you have had access to some specialized knowledge that has led to over-lifting as a flow bench cure ?