Thank you David, as a engine builder 35 years , working cylinder heads, your books and information has help take me in many directions, , Peter McDonnell

Thank you David. In 45 mins you have offered up more info on non n/a heads than I've found in 2 years of book and web reading! Thank you again. All the best!

I’m so thankful that DV shares his amazing amounts of knowledge with us. Anyone that ever wants to learn how to make more power can learn from his channel. I’ve learned so much watching the videos and I save every single one of them to rewatch time and time again because it takes me watching a few times to absorb all of the great information in each video. I’m going nitrous for next year so this video was priceless to me. Thanks a million DV.

thanks a lot, David! your first book was read by me at the age of 20, it was in 2006! I have been assembling racing engines and porting heads, regularly finding something new in your writings. bow to you, good health and long life! from Russia with love!

The information in this video is absolutely priceless!! It's like having Albert Einstein as your todor!! Thank you DV!!

Im glad you mentioned the preformance with economy . MORE OF THIS !!!

I’ve really enjoyed this video. Building a Kenne Bell blown 5.0 would definitely be a lovely engine. A Gas as a British fellow would say:) The Kenne Bell blower and EFI combination. For GT 40 lower intake manifold. I’m would definitely enjoy the 10 days of high instruction from you DV. Having my thinking cap ON At all times:)

Great stuff David. Really enjoyed this episode. It is obvious that we are only seeing a small fraction of your knowledge and experience in these videos. Many thanks, Greg

Thanks again David, I really enjoyed this episode.

I watch every single video even most of them are very seen. Been through a lot of surgeries lately myself so hopefully I can make it back to one of your seminars. You mean a lot to us thank you for everything

Thank you for your knowledge David

Super informative and thought provoking. Much thanks.

I gain a lot knowledge every time I watch you video your awesome

amazing video as always david ,,, your explanation of what you are doing and why is second to none ,,, i watch all your tech stuff ,,, and so glad you do these for all of us to watch and learn ,,, THANKS so much David for all that you do for us

This man is full of knowledge well done sir and think you so much for this video you've really help me understand how to port cylinder heads and opening them up to flow better I've got more of an understanding now. Your definitely got my like and I've already subscribe.

🔔😎 Boost is a measurement of the restriction to flow. ****** Improve the heads, boost pressure goes down

And thank you david for helping the children also, bless you and loved ones, and loved ones in heaven.

I don't know what my career would be without him and grumpy Jenkins

❤❤❤ thank you so much for all your videos I'm learning so much just the right things I want hear and see I'm thankful for all the information I can get you are a true legend

outstanding info DV👍

Thank you for the great vidja 🤙🏼

Good stuff! Just got my first book of yours modify sbc chevy on a budget great read!

Thank you David Vizard for sharing your knowledge and expertise. What your giving all of us is priceless. But I do have a question about four valve N/A heads. Will the porting knowledge from this or earlier videos work on dare a mention a BWM N62B44 or N62B48 engines? I would like to get as close to 100 hp per liter as possible. I know of problems these engines have. But that being said, I like Ford engine in a Ford and Chevy in a Chevy etc etc...

Kenne Belle 5.0 - iron 302 cid Also 4.6 2V Fun, fun, fun

Good hp improvement......

David I just got your how to port cylinder heads and your how to tune your carburetor. I was wondering if you could do a video on porting a single plane intake and flow improvements on the carburetor itself. I'm in the process of maximizing my current 350 combo before I build the engine.

Very nice I’m loving your videos! now I have a question does this also apply when using nitromethane? I’ve recently started building a motor that I intend to run a 30% nitromethane mix(30% nitro 70%methanol) using a separate fuel system that kicks on above 5,000rpm below that the intent is to run pump gas on from the other fuel system as far as I know this hasn’t been tried before so any info would be greatly appreciated thank you!

25mpg is pretty good for a carbed V8. I've seen modified LS7 making near 700 bhp getting over 30mpg, albeit 12.5:1 compression and EFI (pump gas). I'm sure the CR helps the 41mm exhaust valve work better at part throttle. What do you think about the Ford Ecoboost 2.3L with 92% exhaust/intake valve ratio?

David could you please explain a Turbo head and camshaft in a future episode.I’m just a average guy trying to learn before I put my money down on a ported head thanks!

What intake manifold and exhaust valve size was on the 350 that got 25+ mpg? What were the @ .050 cam specs and LCA?

What about 351m 2v open chamber heads milled .015 and deck milled. 010 with a turbo, nitrous or a blower with zero deck forged pistons? Cam, rockers valve job mild port work etc...Closed chamber heads are expensive or very hard to find for iron heads. Aluminum need a lot of work. My budget is very tight. Thank you in advance Mr Vizard for any input you have or numbers you need to help.

In relation to the comment about economy towards the end; are you meaning the cam timing with short duration and mild lift? Also, could using a bigger rocker ratio for the exhaust side only, along with a bigger valve, produce more efficiency/velocity? Or is it limited to one or the other, in correlation with lift?

Anybody saying that says it doesn't matter on a boost engine is way off. Boost just amplifies the NA power. Yes To say boost will help out improve the potential of poor flowing heads is somewhat true. On roadkill garage they put a procharger on a bone stock cam and heads smog 350 thinking it will make power because that supercharger would drive it through but it didn't and it was a total pooch and also ran lousy.

I was confused at the exhaust valve seat drawing at 19:05, is the dotted line the way the air wants to go?

Hi Mr. DV, any relationship between your flow ball clearancing and camshaft lift? Thank you for sharing!!!!!!

thanks ,i have a 428 ford N2O engine.Im getting ready to take the heads to get them cnc ported.this info may help me out.thanks

Many of us don't have steady hands to bowl blend.

After doing the math david had about a 77.5% ratio. I think he was saying you could push it farther if the heads allow

What cam has 1 inch of lift. See the screen, I've seen that once on a cadillac 500.

Mr. Vizard, would using a ceramic coat (like what is used in pistons) in the intake ports be beneficial?

David,have you ever entered the engine masters challenge? i would like to see you show them how its done!

👍💪

So, since a boosted engine needs more exhaust valve compared to a similar NA engine and a high compression engine needs less exhaust valve than a low compression engine. Does a high compression boosted engine average itself out needing similar intake to exhaust flow as a NA 10:1 motor?

Do you build engines for the public?

Area rule this: Fact, I haven't got a dyno, , nore do I have the iop program but, what I can tell you is this: Given a similar weight car, You haven't got a chance with those heads. 😁 Your going to need to make 650-680hp true flywheel HP with ported trick flow Windsor heads to get in front of my hz Holden with my 379ci naturally aspirated street and strip pump fuel small block Chevy and a similar weight vehicle.. Don't believe me ? Power Nation recently built a 527 flywheel HP engine dyno tested small block ford, and it made 537 rear wheel HP installed in the car with the nitrous on uncorked. They ran 1 mph faster uncorked, than my eighth mile run. My run was with my full exhaust in place, (no cut outs, no trans brake). I have also run side by side within 2mph for the full quarter mile of a very well built 680hp dyno tested small block Windsor with ported trick flow heads, in a similar weight street strip XA XB XC falcon. Forget which model one it was. No turbo, No blower , no nitrous.

Too bad David doesn’t cover 4 valve heads or performance 4-6 cylinder engines

If all you guys read about 20 minutes about Jesus christ being the savior and that you need to call on him to avoid hell. Instead of watching these videos would give you eternal life. John 3.3, 3.16 kj bible