I can not tell you how much I am enjoying your videos, the opportunity to experience "Data" rather than "tribal knowledge" and the experience of 60 something years is something we would all be foolish to ignore. I look forward to every video and have told all my gearhead friends about your site and never miss an opportunity to like them. Thank you and keep it coming. Please.

I started Drag Racing in 1967... David Vizard's books were my Bibles back then... I'm very glad to see that you're still at it... I'm 73 years old now...I'm still at it too... I've only been building High Performance Harley Engines for the last 20 years... I stopped building automotive, diesel and marine engines back then... CrazyHorse Speed Shop NJ

@tayloralvidrez4342

8 ай бұрын

High performance Harley... That's an oxymoron

A Guru breaking it all down for you free of cost.

This is literally a free engineering-level course in cylinder head flow dynamics. Thank you for making & sharing this!

David, Thank you so much for sharing your knowledge. It is greatly, greatly appreciated. No amount of thanks would suffice I think, but rest assured i'll at least help share your insights with others.

Hands down the best book I have ever purchased, cover to cover gold. My 1st port job was after reading your book port & flow test the engine was a dirt speedway ford 6cyl 250ci crossflow for Australia. The car won everything it was entered into for 2 years on the same build until I built a competitor car motor, the 1st race they were both in 1 x new 1 x refreshed they ended up 0.3 apart over the finish line and 3/4 lap ahead of the field. I have always wanted to thank you for all the shared information you have learnt in your many decades of building/racing and shared with the greater racing/engineering community. I have recommended and quoted you many times since, only just found you today on KZread. Wish you were in Australia I would gladly work for you as a learning experience Looking forward to the next videos in the series Thank you David for sharing

Respect to those that share their acquired skills and knowledge, which most definitely includes you David, Thank you. Had to reply to the malicious keyboard warrior previously, who, I believe is stuck in a world of hate. In reply, today we have an exponential volume of knowledge, led by Dr Google, good bad and indifferent. However principles remain constant and are enduring. Remember over a century ago twin cams, multi valves etc were already being manufactured. In the US mass produced car engines didn't reach a hp per ci till mid 50's. The evolution of fuel, alloys, man made fibres, casting techniques, machining and most of all, in recent times, silicon (as in computing) have revolutionised our world including automotive engineering. I will put my faith in a human being that has honed (punn intended) his skills over half a century and is prepared to share them. Thanks again David.

I took a full course on engine tunning for racing a few years ago and I'm proud to know that my professor explained to us the same as this great man here. This channel is Gold. So many people talking nonsense nowadays, but this man is great!

Smoky Yunick claimed the point of greatest restriction is at the valve. So valve/seat angles and the 1 inch above the valve is where to find the power. Of couse much work has been done since he was in the game. I have great esteem for David Vizard and Smokey Yunick.

@johnfairchild3421

Жыл бұрын

Smokey done. Almost genius work

Usually I skip over old timers, because some of the guys I've met or watched haven't the slightest clue how things actually work. They just have their ideas and theories. That may have won at the local sportsdrome lol but in today's engines they are lost. "Too many wires blahhh" lol There's still old guys saying 305 heads on a 350 is the way to go. (It's not, you lose so much cfm flow in the runners it's crazy) Then u have those guys who say they tried vortec heads on a sbc. They're junk. I ask em which cast it was. They said it came off a 90 Chevy truck. 😂😂😂 bro that's swirl port. Worst possible head out there. They think the center bolt valve covers automatically mean vortec heads 😂😂 Anyways My point was... this old timer right here knows some shit and I like his channel already. Subscribed.

You wrote your first book 7 years before I was born!! Outstanding, love this. Like watching my old chemistry teacher talk about machining. Thank you!!

Learning more than I knew existed for decades in head flow and porting!

My friend Corky Bell once described David as the best combination of a genius and a practical man.

@johnfairchild3421

Жыл бұрын

He is a Gearhead lol

Great info here. DV is a gold mine!!

Hi David I just came across this video and found out about your daughter Jacque's passing. Once learning of your beautiful daughter, I need to give my condolences to you and your wife. I read about how she was an engine builder and what a great soul she had. So I just wanted to say that I feel your sadness for her. She is in good hands with our great Lord Jesus Christ !

what a great Wizard, I am a retired 71 years old, and just got inspired after watching this genius give us his lifelong experiences, I just tore my engine down, sent it to the machine shop for my first major rebuild and blueprinting I will be doing myself, thank you sir for all you do, the world could use more gentlemen like you!

I saw your KZread videos - excellent work ...I have some of your original books from the 1960s and 1970s Keep on going Mr. Vizard

Very interesting. Especially as back in the day we just used to just port match to the manifold and kid ourselves we were making more powa

Born in 68 I love your knowledge, churning these lectures like candy, probably never gonna build another small block again, but you are feeding my dreams

@bravohomie

Жыл бұрын

It's never too late bro

If only these shows were not available in the 80's man do I wish they had been what an incredible amount of dyno time you have outstanding job ol man

@arealassassin

Жыл бұрын

They had these things called books back then; one read them, and applied the information gained to the problem. I have as many of the greats as I can get my hands on- Smokey Yunick, Phil Irving, David of course, Carroll Smith...etc. Nowadays people watch something on YT and consider themselves instant experts. This video does nothing more than reinforce the concepts David was writing about decades ago, as he says.

Wow, got so many of your books, the Mini one, and HP books "performance with economy" - from what, 40 years ago???? I learned so much from those books, and it helped so much. Good to see such a legend on here.

I would like to have seen a before and after picture of that 91% valve seat done on an actual cylinder head to get a better understanding of the theory.

#1 of the 5 COMMANDMENTS from David Vizard's porting heads! A true Genius "Number$ don't lie, BS does and also walks (takes a hick)"

your a loved man David vizard many thousands.... we appreciate you and all you do

I’ve been watching your videos this week and have learned so much, your teaching is so spot on. Thanks so much for your instructions 👍🏻👍🏻👍🏻

Excellent CFD visualization David, thank you!

Thank you David for the information and direction to improve my knowledge and skills needed to be successful in creating a cylinder head that will improve the overall performance of my project engine. You're a lifesaver and I mean this sincerely, thank you!

I've had so many questions recently about 4-stroke engines after doing a fair bit of research on 2-stroke engines in terms of performance and flow efficiency, while it's definitely alot to take in this video delivered well beyond my expectations and already answered alot of questions I had regarding improving said efficiency and flow. Thank you so much for this, I cannot wait to learn more through your videos

Excellent!!! I have been "amateur" porting for many years but have kept it simple as not to cause more harm than good. Having the exact contours and a base measurement to shoot for is a really big help in taking my porting to the next level.

Pretty educational stuff here. My takeaway is that any work done further up in the port should probably be to provide enough of a straight shot to the valve to utilize more of the "shrouded" short side and reduce turbulent flow up until the air gets to the valve seat and beyond, at which point, inducing turbulence and mixture motion will hopefully even out any pockets of rich a/f mixture and contribute to a quicker/more complete burn.

@DavidVizard

Жыл бұрын

Intake ports are totally turbulent from idle up. There is no getting rid of it!

Always the best resource for serious tech info

When a legend of performance speaks, it is wise to listen.

Thank you David. I really appreciate these videos. Thank you for sharing your time and expertise. Have a good day Sir. Take care, Ed..

I am surprised David has only got 15000 subs. In a hundred years time this will be the only record of this type of knowledge.

@vikenlink

Жыл бұрын

It won’t matter in a hundred years…. One of two things will happen. 1 …No more internal combustion engines will be in service due to technological advances and or 2- no human beings left alive to talk about it because we ported our heads out of existence over oil….destroying any chance of survival by killing our planet 🌎

@vikenlink

Жыл бұрын

Sometimes it’s better not to make any comments…. Too many sensitive people out there trying to learn how to port cylinder heads. Fact is every cylinder head is different, every performance engine build is different. Porting cylinder heads is just the tip of the iceberg for horsepower and torque. What’s your compression ratio? What’s the displacement of your engine? Are you running headers and what size? Are you running a performance camshaft and what’s the duration? Are you running a aftermarket intake manifold… which one? Where do you want your power curve for 99% of the performance fans that drive street cars .You can port a cylinder head to perfection and then use the wrong size camshaft or wrong intake manifold because the one you bought looks cool…. But what ever you gained porting and contouring your intake and exhaust ports was lost because you used a bad combination like a sheet metal intake with short runners and a cam that wouldn’t idle below 1000 rpm’s . Great I got 650 hp peak at 7000 rpm’s. But lost 60 foot pounds of torque and 50 hp where I’d prefer to be enjoying it … 2000-6000rpm Headers without considering the primary diameter for your engine displacement and static compression ratio. Lots to consider when diving into a project.

Thanks for the video I really appreciate your time in showing me this.

Excellent information and explanations what works and why, instead of just hogging out ports especially in a vortec style head

Dave, I did the rule 3 calculation of the weight of air in an average school gymnasium... i came up with 1.6228 tons.

Love how you explain things

Great channel old school tuning legend

Great science-based info ...thanks for posting !

I can’t wait till then. That’s was a great job .

Thank you for the nice lesson.

This is owesome oldskool stuff presentation. Just love it

Again thank you for videos God bless you sir.

Im very proud of my self to figure this out my self! And see how right i was on my project watching this video now 😌

Thanks again David. ✋🏻👍

David Vizard was th einspiration for my career in modifying cars and engines . I bought '' How to modify your Mini '' in the seventies . What alegend !

@herseem

Жыл бұрын

I got his 'A' series engine book. It's encyclopaedic. I spent a fortune modifying my allegro estate, and it was all worth it

@fraud3647

Жыл бұрын

Always learning something new when listen him unique knowledge how to modify ports, seats, valves and chamber. Probably he is one off the best headmaster what I know.

Love these videos, but I always change the playback speed to 1.25x

@d.thorpe2046

Жыл бұрын

I wish youtube would go above 2.0x sometimes.

Thanks a bundle sir! So many myths dispelled! So much data!

Thanks for knowledge!

Harking back and watching once again..

Great to get this technical education on KZread👨‍🎓🎓🎓🎓🎓👨‍🎓

Thank you David.

i really appreicate your informative videos. thank you sir!

I wish i would had this kind of info around 2004 when i was building CA18DET and RB26DETT engines in my carage shed :D Would have been much more than 408hp from the CA and hell of a lot more from the RB... Well, i guess today its more like plug and play tuning for youngsters with addon parts only.

@Kryndon64

Жыл бұрын

I don't have access to proper tools so I wasn't comfortable with messing the the valve seats on my RB20DE Neo, but what I did do is polish the comb chambers up to 2000 grit completely smooth and also took off material off the short side to help with tumble. Additionally I smoothed out 95% of the entire intake plenum which should help a tiny bit as I did not like the casting on the inside. I just wish I had a proper dremel and bits so I could have gone deeper and more precise. Also lapped the valves which ended up really nice.

Thanks David for your tutorials as they are very informative .! I Have an issue with the LOUD MUSIC playing while trying to listen to you ! I have TINNITUS , ( ringing in the ear ) and between trying to hear you over the MUSIC and the EAR RINGING is extremely hard to do ! If you could cut the MUSIC VOLUMN by 50 % , it would be much better for anyone trying to concentrate on your talks . The content of your tutorials are far more important than the background music and that is why we're here listening to you ! Thank you again !

Love all the info

Back in the 90's, when 'Roadsters' was the end all be all website/hub for performance companies it lead me to Vizard! He's a badass dude! I printed out all the 'Performance Professor' articles! Felt guilty I didnt have to pay for them! Best freebees ive ever got pertaining to race engine!~

Thanks for sharing the illustrations! With the cfm from the cutouts in mind makes you wonder if it's worth touching the rest of the runner lol. Would be interesting to see something similar on a stock casting for comparison

great graphics from the Port Velocity at different lifts.

Great insights!

I would love to see a series on home building flow benches. I am about to get a shop vac and a manometer and go to town testing!

@billshiff2060

Жыл бұрын

Built several. If I did it again I'd consider a leaf blower or 2. The best is a roots blower.

Thanks DV.

Thank you David Vizard!

The minuet I saw the lightning I hit the subscribe button, like. This has to be good!!

Great video!!

When porting the cylinder head one should note concentrating on having the highest port flow average rather than peak, and know that it’s just part of the equation

Mr. David Vitter I can't tell you how much I enjoy watching your videos. I never ported heads before. I have a pair of Pontiac #13 heads I would like to street pocket port but not ruin them. I am nervous and need to watch as many of your videos as I can to gain confidence. I am trying to build a 400hp 400 cu.in. Pontiac. I am running reproduction ram air three exhaust manifolds and stock four barrel quadrajet intake what do you think?

Sure wished you had finished by your explanation on areas of efficiencies of the seat .can't wait to see how this works out ..

Legend 🙌🏻

an interesting perspective

Vizard the porting wizard ❤

Thanks for your sharing

Thank you David for this video! I'm still trying to understand the porting process as in the past my brother would do all my heads for me because he knew the process inside and out but, he was killed by a drunk driver and I'm on my own now trying to learn the porting process. Do you also have books that I can purchase from you?

I hope you do a whole episode on offset seat profiles

Thank you

David Vizard is on youtube!?!?! Thumbs up!

Hi David . I get asked a lot about the valve Guide . And is it ok to cut the part level with the port . Is it ? Thank you your knowledge is a gift to us all !!!

Hey, thanks for the valuable information, can you give an opinion on port matching...in application of 4cyl/6cyl engines...where the intake manifold/ exhaust manifold mating to the head can have a step up or step down creating turbulence, i was taught to try best to create a smooth flow surface for both entry and exit of the cylinder ..is it worth the hassle?

Point 3. 7 port heads. A massive weakness

Love the great information your making available for the public. You're being a true gentleman. Unfortunately when describing the seat angle, your hand was blocking all the important pick work you were demonstrating! Also we want more on polyquad heads. Who still drives boring old 2 valve heads?

@raymondguzman5083

Жыл бұрын

Lmao i drive 2 valve heads and tons of other people do as well

That's something new, offsetting the throat diameters!

Going ba k and watching again King David:)

I’d love to see what Mr Vizad would do to a Gen 5 LT1 head

super info🤩

@David Vizard: Could you make a 3D animation of the different radius's of the valve seats? Then it is more clear what you mean with the 92, 93, 88 radius along the valve seats. Thank you.

Too bad I didn't find your stuff years ago (except much of it didn't exist yet). I am playing with LS engines these days. But all the principals still apply.

Thanks !

Wjere is a good place to get 1/8 inch or 8mm shaft carbide burr bits i would like to use a dremmel so I have more controle until I get it down thanks

Well, I wish I’dve watched this before I spent 5 weekends porting and polishing my heads.

Thank you.

Very interesting

I was just swiping through, and saw the Chevy head from the chamber, and thought, what if the valve angle were to be reversed? So intake would be similar to the heads being installed backwards, using the intake as exhaust, and exhaust as intake, with the valves reversed, seems high lift flow would be higher, possibly, low lift could be hurt, with the valve opens, the air should have a straight shot into the cylinder. The swirl may be hurt also, but tumble should be greater, but with optimized chambers could inverted valve angles in a wedge chamber, any thoughts?

@dale116dot7

8 ай бұрын

The main reason that the valve sizes are what they are is that the intake valve has atmospheric pressure pushing the air into the cylinder and on a naturally aspirated engine any restriction at all in the intake system generates a power loss. The exhaust valve has pressure from the piston pushing the exhaust gas out, and exhaust valve restriction mostly generates internal EGR and reduces scavenging a bit both of which creates a power loss, but not by the same amount. Intake needs to have priority in a naturally aspirated engine. In a turbocharged or supercharged engine it is possible that reversing the valve sizes might be helpful but with the exception of I think some race-prepped nailheads, I don’t think it’s a common way of doing it.

Hi David , great video! Can you still get really good flow on Vortec heads with the 1.94" Intake valve or do you need to upgrade to a 2.02"? I have a set of Dart Vortecs going on a 355 SBC.

@DavidVizard

Жыл бұрын

I have done a goodly number of vortec heads and I seem to remember that in most cases of aftermarket heads they do almost as well on a 1.94 intake as they do on a 2.o2 so, for cost sake, stay with what you have.

@xlr8r3VA

Жыл бұрын

@@DavidVizard thank you sir, I appreciate the response!

Obrigado

Thanks alot

Are you from that lil part of America where their accents mixed with Cornish?

Go until you hit water jackets...🤣🤣

@fraud3647

Жыл бұрын

There is no any reason open port too much, velocity is King!

@PhilipUnderwood-oy9tv

8 ай бұрын

I agree with you 100%

So basically. High-ratio rockers and camshafts go first before i ever think about porting. Just get the valve out of the way of the air.

Nice 👍