How good is a totally vertical down draft port??

[@Comet-hn3gm]

"If it was simple we wouldn't need a flow bench" True words.

[@V8Lenny]

Pro teams dont use flow bench

[@Comet-hn3gm]

@@V8Lenny Which professional teams are you talking about ?

[@V8Lenny]

@@Comet-hn3gm F1 , MotoGP

[@adrenaholic1]

Richard H. He gets most of the blame for my nose being stuck in hot rod mags throughout high school. Sure wish these videos were around back then, thanks DV.

[@bumpstart21]

Thanks for summing up the discharge coefficient!! That straight port looks like a great setup to explore valve/seat effects.

[@briantayes2418]

Absolutely fantastic content. I get smarter every time I watch your videos. Thank you!

[@hunnybunnysheavymetalmusic6542]

Interestingly, the fact that the air is coming into the cylinder sideways, to a slight extent, helps get past the problem of the valve drag and turbulence.

[@79beans347]

Your gaining subs super fast, I gained some really good info from that, Its nice to learn a lot of usabe info from a legend such as yourself

[@michaelvoigt724]

I learn more every time I watch your videos, Thanks David!

[@rondrew2857]

Omg, you are making becoming a pilot look easy.

[@richardsmith-qy6vl]

Yes richard holder does alot of testing and I watched the test he did with the big block heads on the 468 and the heads that worked out and made most power were the afr265 oval port so I watched and the 468 made 622 hp so I had a 427 and I bought a set of the AFR 265 heads and picked a Howard's hydraulic roller duration was 235x241@50 and 618 lift and the lsa was 108 I told Richard I was hoping to make 550 hp on the dyno he said the cam was to small and the motor is a 30cc dome and the combustion chamber is 113cc and it is a 427 60 over well it made 661hp and 605 torque I told Richard and he is still not believing it I sent the dyno print out and he never responded back so I made 40 more hp with 20 less cubic inch. Love your videos

[@dannoyes4493]

Well done. One of your best! Thank you!

[@bcbloc02]

I knew porting was complex but this takes it to an even higher level. 😊

[@markhowley6537]

I am really enjoying all your knowledge sharing.

[@JG-kv4oi]

Excellent presentation Dave, and thankyou. I'm about to build a flow bench like your original ones to test flow on performance mufflers up to 3" tube diameter as I've done exhaust for a living since the mid 80's and am interested in the flow of different brands. I may need more than a shop vac lol. Thanks again!

[@magnusdanielsson2749]

It would be interesting also with a video on how the chamber influence port recovery in relation to port, valve and the flow. Darin Morgan have stated that the SB2.2 chamber is one of the best examples on a chamber with good recovery that hes seen.

[@bicylindrico]

Wow, amazing video David. One of you best and so insightful. Really love what you are doing, thank you.

[@michaelblacktree]

Great video! Now I'm curious to see if a typical intake port can be made to out-flow the straight tube you showed in the video.

[@bikeaddictbp]

I am wondering whether a straight but angled (let's say 30-degrees off the centerline of the valve stem) could out-flow this. Reason: With the straight-line configuration shown in this video, all of the flow needs to turn as it goes past the valve, no matter how much you open the valve. Having it angled - aside from actually being more practical and allowing space for valve springs and camshafts and the like! - allows at least some portion of the flow to go straight past the valve without turning a corner. Reference examples: late model sport-bike heads (Ducati V4, Kawasaki ZX10R, etc), Formula 1, and Toyota "Dynamic Force".

[@lesgaal4017]

Hi David great to see you again mite want check i thought you went missing but I checked and I had been unsubscribed by u tube. Great video. Australia.

[@TheInsaneShecklador]

David lost his old channel and is now using this one. Were you subscribed to this one or the other one?

[@Scarlet_1971_cuda]

Loving the content and education. Keep it coming. Thank you!!!

[@hunnybunnysheavymetalmusic6542]

I've been subscribed to Richard for a long time now... Maybe 5 years?

[@cam3002]

Thank you DV, suggest multi-valve heads for a future topic. There are quite a few 4 valve heads, a few 5 valve heads, and I've heard of 6 and 7 valve engines.

[@alejandro52612]

I second this request.

[@TheInsaneShecklador]

3 valve too.

[@alejandro52612]

Anything having to do with multi valve heads really. Especially how to make torque down low

[@evotoadracekartscars.6738]

Dave, glued to your video as usual, but please cover RAM CHARGING, I've forgotten how to make the carburettor boost sensitive. Kart engine loves it but I can't stop it weakening of at high rpm. Biland SA250 4stk twin. Just a short one please please please 😊👍🇬🇧

[@hotrodray6802]

This is a repost if a year and half old video. Hope DV sees your comment 👍

[@mcintyretyler89]

I wonder if David has ever seen the Perkins engineering crew. Interesting stuff for sure!

[@hunnybunnysheavymetalmusic6542]

That's fine, I already did all the fluid dynamics classes while learning how to design and build turbojet engines.

[@kaboom4679]

Richard H will Dyno test anything , then stick a turbo on it and flog it some more . Love his content .

[@pdr5926]

David, could it be that increasing the taper of the straight port increased its flow efficiency? Let´s say 30% larger cross-sectional area at the input than the area of the valve?

[@slackthompson6984]

great lecture professor

[@HPRaceDevelopment]

I think the actual flow area opening is greater at low lifts than being calcuted due to seat and valve design. a venturi IS where c\d benchmark of 1 comes from…

[@KompressorPete]

Question regarding valve diameter measurement. Is it the largest diameter you can measure or is it the actual diameter where the seat and valve meats? On fx my old volvo B20 these two values are quite different. And again - thank you for sharing. !

[@BCzepa]

hi david, its good to find your videos, im liking the explanations of all the various aspects of engine physics. im designing a completely new engine configuration that has never been done to my knowledge. im not an engineer or architect, but im a tradesman and i think in engineering terms. QUESTION: (for this purpose assume forced induction on a single cylinder) if there is room to allow extra air pressure on the opposite side of the valve from where the pressure is being generated/delivered, can this result in a big gain in flow? i would be calculating the optimum volume based on flow as pressure is increased in a fairly linear way. this could be like a timing chain passage which is sealed from the crankcase. i might contact you by email later with more detail.

[@johnnyhonda7576]

Can you do a video on Volumetric efficiency

[@hunnybunnysheavymetalmusic6542]

11:40 That is because the VALVE is in the way! There is no way that air will flow at its optimum with a big parachute in the middle of the path.

[@hisab-n8c]

Will a anti reversion cones in exhaust "port" improve efficiency (less back flow)

[@hunnybunnysheavymetalmusic6542]

Sadly, there is no way I could possibly travel to attend classes. If I could I would certainly go!

[@Dr_Xyzt]

What about raised ports like on a 2017 Yamaha YZ450F?

[@johnshackelford6965]

I'm not telling I bleep blooped. 2.02 hero

[@Drunken_Hamster]

You wanna know what I'm getting from the combination of this video and the camshaft timing stuff you've done? I'm starting to think that manus should make asymmetrical camshafts and that systems with VVL or otherwise having multiple profiles should have two RADICALLY different profiles. For instance, based on the flow test of this straight port, I'd want to have a VVL system where the economy lobe is around 0.400 lift, and the performance lobe is 0.700 lift. Feel free to correct me if I'm wrong.

[@iansmith6728]

And Honda says "Hold my VTEC beer!"

[@markpierce366]

DV, I would like to purchase your IOP software. Can I do that at your seminar website? Also, are there any minimum computer requirements? Thanks! Great video btw!

[@hunnybunnysheavymetalmusic6542]

@David Vizard: What is your take on 180 degree headers?

[@DavidVizard]

The cross over pipes are too long to get any good results.

[@tips3377]

Can you please share with us/me what the correct number is in regards to your 128 formula with a relatively common set of LS heads like 243s. I will be having a cam ground soon and I'd like to maximize it's potential with your formula.

[@mcintyretyler89]

Richard is a guy who can't take criticism very well. I'm a lot like Richard. But I can admit when I'm wrong.

[@uhfnutbar1]

love it :)

[@MrMrBigro]

Is your cam formula work with v6 engine?

[@alexlandsberger1423]

It would be different 128 is small block Chevy

[@hotrodray6802]

🔔😎. 👍👍👍

[@cstavro]

Of course a port won't flow as much as an orifice plate. An orifice plate is made to calibrate the flow bench, not as a benchmark for port flow. If the flow chart is erroneous, it follows that the Cd, and port energy charts are also wrong. Did you use this rig to find optimal seat and chamber shape? You made me think of a new seat geometry.

[@StefanRügamer]

An engine is a very complex air pump - I'll educate my teacher next time he will say that.

[@TheSilversheeps]

David so if find "discharge co-efficient" an interesting topic would using the term ports "friction factor" be a good analogy? 17:17 is so interesting a12% recovery.... How do we maximise this effect and increase the range of valve lift area this could apply to? its like saying how can we get the most venturi effect over the longest extensions... Would looking at how they do rocket nozzle designs and altitude pressure recovery seal level to near vacuum be helpful? For example, that exploits a dual convex curve feature that separates the expansion edge be helpful? CFD could help... and then test some old valves out... hmmm. {the curve shape would be absolutely critical and only a few thousand of an inch.}... kzbin.info/www/bejne/ombPZHZ-jNR7ias&ab_channel=ScottManley see 6:49

[@jackwillson8099]

I always wonder about that the perfect port lol ! there isn't one

[@davian157]

🤌🤌🤌🤌👌👌👌👌THANK YOU!!!!! ------ITS NOT A AIR PUMP-----

[@OgamiItto70]

"An engine is just a simple air pump" is schoolboy-level thinking on the processes of induction, ignition and exhaust in an internal combustion engine. An internal engine *_is_* an air pump, but it's not a simple one. It's an air pump *_plus._* And in that *_plus_* is The Devil and all his Details. "An engine is just a simple air pump" is a way to *_begin_* thinking about the aerodynamics and, shall we say, "pyrodynamics" of an internal combustion engine, not the be-all, end-all of thought on the subject.

[@andypdq]

The metric system is much less complicated, LOL.