5 Golden Porting Rules - real detailed porting tech!
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- เผยแพร่เมื่อ 28 ธ.ค. 2022
- In this, PowerTec 10. episode 59, Part 4 of Rule #1 DV explains why certain valve forms work better than others. Why intuition led engine builders astray for maybe as much as the first 60 years of the 4 cycle poppet valve engines existance. Useing computational fluid dynamics (CFD) diagrams the reason that what appears to be the leaast streamlined valve actually flow the best and make more power
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50 years ago the Mopar Engine modification book was pushing "nailhead" valves on the intake side and tulip exhausts. We ground our own valves(poorly) but they still made more power than stock. A pretty sharp cyl. head guy told us we'd pick up 20-30 hp with better seat concentricity and seal. Well, our junk parts turned on junk equipment were every bit as good as his $50 cost to clean up the seat angle(45°) and valves. I borrowed a fixture to cut the valve guides down 0.050" in order to run a 0.590'" solid cam and he cut the 16 guides down for free because his valve job made 0 extra power. Bought a cam and lifters from Direct Connection for $79 and dropped .4 sec in the 1/4mi. Car ran in the 114-116 mph range with a bunch of used junk on it. Great fun, and cheap, too.
You know Uncle Tony don't ya...
Would be entirely reliant in the way the port functions.
Alot of these mofos just want your money with no added benefits.
That's what it's about .. thinking, & fun factor ideas beating $$s
Your information is always appreciated. I have been following you through the books I bought. For over 20 years plus now! You put me in the winter circle. Thank you. What a coincidence. My NASCAR short-track number was. 50. At ODS Virginia. Thank you again
Thanks! David, and you are correct , nobody talks much about the finer points of valve seat work
Thanks again Mr. David Visard ! I re-read and re-watch your information regularly. I have put as much of your information as I can into practice. It has served me well.
I’ve personally always found that the lower the port floor, the less “tulip” angle on the back of the valve was needed.
Just wanted to express my gratitude for your knowledge thanks...also great thing your channels are doing for ST. Jude
The only words I can think to say are - THANK YOU DAVID
Thanks 4 sharing David.....!...this is a topic I can never get the same anser from different people...stay healthy David...looking forward to the up coming videos...thank u again...!
I’m always looking at objects under an electron microscope on TH-cam my curiosity of valves under one before and after you have worked on one is driving me nuts I doubt I’ll ever get to work on an engine but I’ve been reading about them a lot since 1968 it’s my main reading material I do own a small engine shop and am fascinated with all of this thanks for everything Tim
Although I'm retired and I've been a mechanic for 55 years in various forms I started doing heads on my own around 1980? Through the years I never had a lot of equipment or expensive equipment or fancy equipment but when I saw you back cut I would do a two angle on the seat on the valve grinder on the valve and then I tried to polish it with a roll and here I see you using a disc in a lathe which tells me I was on the right path 30 years ago plus and various ideas I had worked out but it's all about having tools which I never really had a big shop nor did I have money nor did I have fancy tools but the ideas in my head all seem to work
Your show is unique with knowledge and tips I've not seen before! You are paying forward a lifetime of knowledge to today's enthusiasts! In truth, your show is a contribution of subtle and profound points and details that help inspire others to get that EDGE; the winning edge! Thanks for all the experience and insight that keeps us looking for more!
Great tips. Very much looking forward to next installment(s), particularly the 30 and 39 deg faces and matching seats. Much thanks.
Excellent video David. Thanks very much. Have been waiting for the continuation of this series. Regards Greg
Thanks DV for the tips and tricks
Wealth of knowledge
I machine some waukesha valves on a lath years ago at a shop I worked at. The way they acted, I thought I was going to get fired.
I used a small lath to back cut my valves and polish them. The lath I had wasn't tight enough to do the seat area. My old black and decker valve grinder never let me down.
Got a Black & Decker from 1940ish does beautiful job. Right on the money.
I'm restoring a black and decker valve grinder. Unfortunately all the electrics were fried, but it'll look neat once I'm done. Maybe I'll get it working again one day.
DV- I see the dial indicator you are using has 100 thousandths per 1 rev on the dial. That is pretty coarse for chasing tenths. I have many indicators, and the one I use for chasing tenths, has 2 thousandths per 1 revolution of the dial, not 100. You can see so much better what is going on. You did not show it, but I am making the assumption that your 5C collet chuck is a set-true type, with 4 adjusting screws like a 4 jaw chuck does. Note that this is fine to adjust radial runout, but angular runout is governed by how good the collet chuck is. Since these chucks hold the collet out in front of the spindle, any angular runout in the system is multiplied. My point being, you can adjust radial runout with the adjusting screws, but because of any angualr runout that is present, your radial indicator reading is only good for one linear point on the valve stem. This can be a problem. One of the better solutions is to have the collet be held in an adapter that sockets into the spindle taper. (The spindle taper must be large enough to accept a 5C collet, like 5 Morse taper). The best situation is to make the adapter yourself, in the lathe, with final boring (or grinding) done in place, right in the spindle. This assures zero radial and zero angular runout, or as best as the lathe bearings will allow it to be. Some lathes (like HardingeHLV-H lathes) have a native 5C bore. These spindle sockets accept 5C collets directly into the spindle, and ground in place. This is a really good and accurate setup. I also assume you use Hardinge collets. If you are really fussy, you can order them in special accuracy. Not sure the price, but be sitting down for sure. Another option that affords less stick out, is to go with ER series of collets. You can buy an ER32 or ER40 closer chuck for not much investment. They mount to a face plate and have the 4 set-true screws for adjusting radial runout. To keep angular runout at a minimum, the stick out from the spindle face is INCHES less than the 5C closer chuck. As you might expect, you can get ER series collets in various quality levels as well, so buy good ones. Maybe I went into accuracy of lathe collet setup deeper than you desire here, but you for sure come across as putting accuracy in high regard. As an engineer and machinist, I do as well. So not trying to criticize, just trying to help, as I appreciate accurate work as well. I am not far from you. I have my shop here in Charlotte NC. I always watch your videos because I love to learn about engineering and engines. If you ever want to chat, shoot me an email. Best to you in this new year. ----Doozer
Honestly my camel hump heads ported like your book said with slight help from a old timer flowed enough for 9k rpm and 600 hp from race gas 355. No one believed it had 186 heads on it till I popped the hood
Thanks David great video
I very much appreciate you sharing your knowledge and experience with us. Thank you!
I'm 76 and I've always wanted to learn about this. DVs knowledge and willingness to share...WOW!
He exudes an air of certainty that's unmistakeable :Very moving! ( pun is humbly intended). Sir, thank you very much!
As always, thank you for sharing your knowledge. Priceless.
Awesome tips MR. Vizard , I have a tip for you I'm a long time machinist , try using Micro 100 lathe bits tooling way better stay Sharper, than those blue China junk bits your using, little more money but last ten times longer.
I recall reading something along these lines a "few" years back, from chapter 5 of a handy little book, called "Performance with Economy" I got back in 1982.
The author's name was a Mr D Vizard.
This is gonna be awesome thanks DV
This is good stuff! Thanks for sharing. 👍
I'm loving every bit of info you give us. Can't wait to make use of this knowledge when i get my car going again for SCCA racing.
I wish I had this info when I built my little airboat engine.
Excellent video. This is such useful info. Wish I could have seen this years ago. I have wanted a valve grinding machine for a long time, however I never considered using my hobby lathe as shown in the video. You are opening up some real possibilities in a practical way for even a (low budget) hobbyist like me. Cheers from South Africa.
I managed to use a small myford ML7 lathe with some copper shims on the jaws so I wouldn't damage the valve stems, held and clocked up as concentric as possible in a 4 jaw chuck.
I had a bit less sticking out than David did here to avoid chatter.
A very talented guy with loads of usefully information a pleasure to listen to .
Mr.David is a Great Tuner
Huge respect for your automotive knowledge. Your vlogs are slow and gaudy with random audio blasts, your 13min vid, half is filler. Instead of lightning and audio blasts with screen scroll how about more detail on the abrasives, your findings of the valve 15/18 degree back cuts, how the port biasing effects the CFD 2D image you show etc. The automotive detail you skip over being proficient is the detail us knuckle draggers appreciate knowing.
Very informative video. Can't wait to see the next video with more valve and seat info. Thank you for sharing your hard-earned knowledge.
Love all this information you share with us. Thank you!
Thanks! Can't wait for next video
Thank you for the information David
looking forward for the next episode. Very interesting stuff 👍🏻👍🏻
Very cool of you sir.
To show youngins we what a master craftsman.that is all you sir.tyank you sir
Thanks for sharing! Good videos on valves.
Thank you for sharing your hard earned wisdom
Very good Video, tank you Wisard 😊
I recently found your series. Good information. Shear with some friends. Thanks for sharing your years of experience
Thank you David.
I find your videos very interesting and I especially appreciate, when you show us the required tools for the job and how to use them. I have just ported a cylinder head my self with some basic tools. And now I really would like to see the equipment and how it's done by a professional.
Thank you for sharing your knowledge Mr Vizard!
Ive got twisted wedge trick flow heads for a sbc bault them brand new in 1998 i bet i dont have 2 thousand miles on them ran them on the street but they really picked up power they dont sale them that ive found but they have the intake twisted to the intake side and the ex twisted to the ex side look like big block valve springs off set by just looking at them they made the most power out of all the heads when i bault them !!
Ño felicito señor, lo conocí en internet en 2016, aprendí hasta ahora lo que quise saber en 33 años sobre los "misterios" de la trayectoria de fluidos bajo ciertas condiciones, gracias por su generosidad de compartir sus conocimientos y experiencia, Dios le bendiga y confíe en Él asi Ud podrá encontrarse de nuevo con su hija. Saludos desde Buenos Aires Argentina !
Thanks for knowledge!
David, you need to get setup as an amazon affiliate and put the links to your books in the description of the video. Not only will you sell more books but you'll get a tiny commission on each. Thank you again for your help.
🔔😎
Thank you again DV for what you're doing.
ST JUDES #1
😎😎
Thank you, sir.
Tsssss esas Válvulas te quedaron super, saludos!!!
David Vizard a Genius !!!
Your an amazing man!
Hello David,
Thank you for expanding out the detail section by section. I have ported only one engine head in the past, a Nissan PATROL TB42 N.A. daily driver running on LPG. Only info I used was what my fingertips told me about the shape of the port, big improvement in ability to rev and accelerate without stumbling. Currently rebuilding a Nissan TD 42 in an old cab chassis ute. My goal is to increase fuel economy by using manual technologies, without any high tech to keep it easily repairable. My reading over many years informs me that by using a variety of racing engine concepts there are some potential fuel economy benefits when driven as a normal vehicle. Thank you for your help with this project. Martin Falls
Great viedeo - and how to grind valves with good results
Thanks!
Even tho my machinist did a back cut like I requested, I still put the valve in a drill and with a sanding pad on an angle grinder smoothed it all the way around close to the seat. Alot based on what I had read on David's books all those years back.
Awesome information only important is to try fix the sound with cloth or foam it sounds like a empty room little echo is all
Thanks for sharing your go fast information
I really enjoyed this episode the simple mods for touching up valves. was good and helpful.
-What I would like to understand is what actually happens at supersonic flow. I can grasp the area rule. but what is actually happening to flow and why?
- I totally agree with your comments about the importance of radii for inlet entry and metal fatigue...
- What do you think about the topic of "wet flow" on a flow bench plus and negatives...?
In cad flows at my old work, at least in liquids I see 90-degree bends into two counter-rotating vortices that form after the center line hits the back wall and starts to fold away down the bend I can approximate that by running water out the kitchen tap and putting a spoon under it and observing the flow it corresponds quite well ( yeah i know pretty basic but does help in cheap and easy visualization I think...)
Thanks, Jm
As far as I can tell a head with more swirl is going to benefit from a flatter valve. Whereas for the straight shot I can not think of a steep enough tulip to interfere.
the little Smithy ,,,, on a collet THANK YOU THANK YOU THANK YOU
Very much looking forward to your finishing seats
I am garden tractor puller K 341 Kohler flathead
( nothing about blueprinting )
Just make it work :):):)
Thanks
Thanks
Yes - and as you can clearly see and hear, when you cut the first valve, it’s not concentric to a close enough tolerance:)
A few .000 - like .003 out of spec:)
The choice of valve shape is best determined by where the power is needed.Ultimately, the engine builder must first decide whether it is better to redirect airflow, or deflect airflow. Properly applied, the tuliped valve redirects airflow to the inside radius of the port most efficiently, as demonstrated by virtually all modern performance DOHC engines. When used correctly, the flat-backed valve deflects airflow to one side of the valve opening, in order to use that part as effectively as possible; frequently this is the only strategy possible with horizontal or near-horizontal port engines. In a dual swirl,modern low angle cylinder head, why does the ‘nailhead’ valve perform better? The answer is found in the unusual configuration of the porting: two ports supply each valve from equal and opposite positions, offset from the valve stem. Because of this juxtaposition of the ports, there is no need to redirect airflow to ‘activate’ the near side, as this is accomplished by the opposite port, so there is no benefit with a tuliped valve in this application.
if you have a ferrari or a Lamborghini v12 or a Bristol tulips are best. but chev v8 your right.
keep up the good work. really learn a lot.
I spent a lot of time on my valve grinder getting it to consitently chuck valves with less than .001" run out. It is not as easy as it would seem!
Have you ever did any port work or flow testing to Buick Nailhead cylinder heads?
Dear Sir . I did just discovered your videos . Love them as i learn a lot and watch them one after the other . You are a great teacher . Do you think that all your teaching can be apply to an aircraft piston engine ? I am going to start soon a Lycoming 360 rebuild 180 hp stock and look to get more power of it . I wish you a great day
Thank your David for the information so my question it do flat valve on only intake and tulip exhaust or both intake and exhaust do flat. I was curious on the exhaust side on which would be better
The best results are usually the opposite of conventional wisdom while still keeping it simple!
I wonder what effect would have on air flow if you dimpled it like a golf ball??? The intake port on the head even??? Could flow be increased on the "short side" if I used the correct terminology.
The dish on the face of the valve you were preparing appeared to be off center. is that an issue?
Most all get forged that way. Guess it's no big deal or DV would have trimmed it with the lathe.
David, how do you feel about "side gapping" spark plugs?
There is an earlier episode on this , trimming the strap short is better.
Addendum to previous: Could you please advise us on the valve timing requirements for the seat angle changes. Thanks much.
DV has explained that dyno tests determine the exact timing for each individual engine.
Thank you David! Always a great watch!!!
Didn't catch the back cut angle you used? Probably address in the next video..?
I understand the flat valve for the intake , but should the exhaust remain the traditional shape as you would want the exhaust to go up the valve , not across it ?
What are the special collets you use? I'm no expert but a collet is essentially a spring & if you push on the tool it will move.
Do shiny polished vavles of 40 or 60 grid swirl finish work on back of valve.
To better atomize mixing air and fuel droplits
On a flow bench the head is under vacuum so I can understand the flow wanting to move on the straightest path. What about under boost? Does it work the same? The restriction is still the valve but you will have 30lbs of air on the back of it. I guess the majority of the air is still going to want to take the easiest path.
I'm wondering why you don't use a 1/10th dti.
But my motor doesn't run when I get rid of my valves
I see you post Jacque's photo at the end of each video, I was just wondering what happened to her that she is not here with us? She looks just like you. Thanks David!
Due to major depression. She took her own life. Sad, very sad...
@@danawilkes6174 Tragic.
thanks for confirming what i have been doing is right ? ive been doing a lot of briggs and stratton ... the valves dont fit my grinder ? so i just used the lath and toolpost grinder ............... some how/ way i knew it was a better more accurate way to face them ... lapping always confirmed it
👍
Tulip valve works best in the 426 Hemi ports..
have u ever had to port the cam bearings so u can get a bigger cam in it which also takes some head work for the cam we did it to a 327 but ended up being over 400 cubic inch after we put over sized cylinders . then have u ever seasoned a block i know there no proff if it helps just everyone we have seasoned we have never had a problem with the cylinders and they seam to last longer. the pro built 327 that we built in the mid 9-'s still runs today and has been pushed real hard over 10,000 rpms many times when i blew the clutch it went over 13,500 rpms which was the highest the tach went to and we took it almost back to 0 on the tach . i thought the engine was dun but it kept on running just fine old man bell said it would handle 10,500 all day long which he was one of the first to build a hemi head for a bbc for top fuel . i have a set of hemi heads for bbc that he made but he said u need to be pushing 1500 hp to use them
Have done anything on small bore shrouding?
Look at 396 BBC.
D.V. check your email. Flow report on two different intake and exhaust ports using Dodge 302 casting for the Mission Impossible project. Thanks, Cheers!
The valve and the seat act as a second throat!
I thought you put an anti-reversion grove on the valve itself?
Do some video on exhaust side also I mean 3d output
It would depend entirely on the function of the port.
If I'm limited by terrible stock cams in a Mercedes V8, is head porting and optimizing things going to pick up much power? I'm not sure that it's really restricted by much besides reserved cams. 227hp 287lbft 9-1 5547cc .
I once picked an engine up 25% in power doing only cylinder head work. The cam was still the stock cam.
AWOO 🤙🏼
Sleeve Valve engines are better flowing than poppets, internet told me 😂
Not 100% sure what he means flat valve vs tulip. Could someone explain please?
Imagine the valve stem has a flat circle on top …. The other type of valve stem has a bowl shaped circle on top , like a samurai hat shape vs a more extreme top hat shape
DAVID!! Can you please add an email to your ‘about’ section if people wanted to reach out?
Is that a theremin?
I fihd your videos & experiences a wealth of knowledge that would otherwise take years to learn if ever. But who ever put across the screen to buy your wheels at harbor freight this contradict every thing you teach i have learned the high end wheels last way longer & cut way better including all grinding , polishing wheels & cut off wheels!!
The opposite has happened on the mission impossible 318. The flatter LS valves didn't not do a better job.
I would say from my 33 year as a machinist , use a dial test indicator 0.0001 , not a 0.001 , 1 inch travel you will be surprised your eyes will fool you, your probably out 0.0003 easy. I have shown people and they can't believe it
I'd believe David if he said the Earth is flat, no matter what they all say!!!!!! LoL, cause it looks flat to me & I'm the smartest guy I know, besides David! Haha....
.....always wanted Davids views on the OddFire PRV-V6 used in its anemic from I the Delorean & was Europe's SBC used in so many cars a.k.a. Peugeot, Renault, Volvo, & similar to the odd fire Buick Fireball V6.