Air speed limitations in 2 valve IC engines

[@autonomous_collective]

I heard of you through David Vizard. Produce more video's please.... Thx for sharing....

[@rageracing6435]

Very nicely done! I heard of you through David Vizard. I will keep watching your channel. Thank you for putting out this useful information.

[@coolguy112286]

I think a good inerita ramming demonstration would be to take a straw, hold it vertical, place you finger over the top hole, dip it in water, then momentarily lift the top finger letting water flow up the straw, then capping the straw again when the water reaches its highest point. The velocity, and inerita, of the water flowing up the straw will bring the water level in the straw above the level of the water in the cup. I do this "game" at restaurants all the time! If you catch it right you can get the water in the straw significantly above the level in the cup. Im sure theres a cam timing lesson in there as well... the intake closing point is #1 cam timing point as I think you and others have also confirmed. Thanks Darin!!

[@WesAdams-HillsideAuto]

Great valuable info!!! Thanks Mr Morgan for sharing your knowledge with us!

[@robertfontaine3650]

Cam over and subbed from Vizard. Great to see knowledgeable people putting in the time to share.

[@kurtadelman272]

Thanks for taking the time to post Darin, very interesting and I learned a lot, especially the discussion around the LS7 port design, I always scratched my head a bit on the design of the short side radius, I now have a better understanding of the design intent.

[@nathanhouse7277]

Darin, do you have plans on doing a 4 valve video? Seems to be a very different animal in so many ways even if the principals are the same. I k ow I'm not the only one that would love to hear/see a video specifically on the 4 valve layout. Keep it up sir! You're helping many of us tune our knowledge and the way we critically thing about airflow.

[@darinmorgan3520]

I have a lot of plans and visiting 4 valve design criteria is one of them. Yes, different animal but the same rules apply. Just a slightly different approach.

[@colinpringle8705]

yes i agree with you. as im one of thow people looking for info, im playing with the ford Aussy Barra engine 24 valve head. any help/info would be grate

[@bobbyhaskell2048]

Same. There's just not that much out there for 4 valve stuff.

[@dennisrobinson8008]

It's still airspeed, 4 valves have a benefit of much more low lift flow up to about .400" and lighter valves which can be more easily controlled.

[@johnzuggster375]

Thanks a million Darin! Knowledge is power. wish to meet you someday!

[@shanemorris702]

Thanks Darin for the lesson.
Probably gonna watch it another 20 or 30 times to help it sink in. 😄

[@Stelios.]

I really would love to see a video that you completely nerd out and break down all the math that is involved before you grab the grinder, that will be the perfect video for me

[@b.c4066]

While I cannot pretend to understand 75% of what you are saying, it does give me a glimpse into what goes into quality engine development, and makes me understand the costs associated with going fast. Bravo sir, if more people in your industry gave info like this to the public, it would help the racer/street car guy make better decisions about who to have build their horsepower, and stop so much of the bargain shopper crappola. Thank you for the view into your profession dude!

[@gavmorgan1846]

Thank you for sharing Darin. I've been intrigued by wet flow for literally decades and these are the most comprehensive explanations of what actually happens I've ever seen.

[@jamielombardo5292]

Thank you that's very informative I'm building a stroker Cleveland with the 3v head and CFI intake

[@frankreyes3304]

Can't wait for the 4 valve version of this video!! Please make one for 4 valve heads

[@davidreed6070]

I have watched this and all other videos that you are speaking in. This is the third or fourth time for this one and still learning.

[@rolandotillit2867]

Thank you good sir, I love the consistency of aerodynamics, you showed me something that validates something else I'm studying!

[@tricky6344]

Love your work mate
Always a pleasure listening to you.
I remember at dinner one year at your place we were going on talking for hours & I had to ask you "no more lol"
I just couldn't take anymore info in lol
Cant wait to catch up again

[@1616Rotor]

Love this. So good to be able to learn from someone of this caliber! Im sitting here with a notepad, treating this like school.

[@jamesford2942]

Found you through Dragboss, thanks for all this information and videos.

[@wayneireland4802]

thankyou mr Morgan for sharing your experience I'm addicted to head flow work.I live in Australia you end a few other gentleman who I inspired to reach ya level I love this shit.peace

[@penname5623]

Absolutely brilliant I look forward to more of your content!

[@freesexyew]

Wow remarkable! This was very educational for me, thank you.

[@QXZ9027MKII]

Much obliged sir for the insight, scintillating indeed.

[@DragBoss351Cleveland]

Looking good Darin, thanks for the help.

[@andretorben9995]

Although nowhere near as critical I'd like to hear Darin's theories on exhaust port fundamentals. Wish Darin would put out more video's on his own channel. This guy is an engine dynamics genius.

[@darinmorgan3520]

Not a genius, just the only one talking about it and putting it into words everyone can understand. I have taken some time off but within the next year I will put out some more videos. Exhaust port dynamics is a great idea. Thank you for the idea

[@autonomous_collective]

@@darinmorgan3520 Share more ....

[@Baard2000]

After 30 seconds : great info , GOLD, and thumbs up!!!!!!

[@cacsrx1]

THIS IS FANTASTIC

[@theshed8802]

Darin. This is a great video, as are the ones that followed it. I sincerely hope that you choose to return to making videos. I've thoroughly enjoyed watching some of the other stuff that you have done, Drag Boss Garage being one, but your lecture type videos are priceless

[@bobbyhaskell2048]

Agreed 👍

[@tomanypedos1153]

Great Video,
Thank you

[@kizzerplowright]

very very useful, nice tip on LS CRITERIA FLOW.

[@IMMENGINES]

Awesome video!!!! Thank you.

[@user-id9ft8qv4x]

Thanks for video!

[@GrocMax]

Choke flow does occur on a centrifugal compressor, it occurs somewhat after the 'choke line' on a compressor map, at all shaft speeds the mass flow remains near constant at its highest level, but pressure ratio drops in a near vertical line because any additional energy put into the turbine does nothing but be absorbed. The local point of choke can be anywhere within the leading edge of the inducer (or a class-mandated restrictor) to the exducer tips. This is why you see the choke line on a published comp map as ~60% isentropic efficiency, after that it takes a large increase in shaft power to get any mass flow gains towards true choke conditions. This operating condition puts an extreme thrust load on the bearing system as well as that flexible rotor system going all wet noodle on you, so the turbo manufacturers consider this not within operating parameters.

[@darinmorgan3520]

Thank you very much for input. A great many people never even look at the adiabatic or isentropic efficiency for there super charger or even understand what they mean. I found this on Bells web site that will help .
kennebell.net/tech/supercharger-tech/supercharger-efficiency-explained/

[@darinmorgan3520]

Thank you for that insight. Good information is always welcome

[@GrocMax]

@@darinmorgan3520 Also remember speed of sound in an ideal or near ideal gas, for the most part, is temperature related, NOT density or gas composition related, so for dry air, or combustion products, rule of thumb is 60F=1100 FPS, and 1600F twice that, why exhaust area doesn't need to be near as large as inlet area.
As an example of gas composition vs speed of sound,, do the helium balloon, voice goes silly cartoon high, do a sulfur hexafluoride balloon, voice goes silly deep, those two gasses have a big difference in speed of sound, but for the most part air and air+combustion products have nearly the same speed of sound at the same temps.
Boggles my mind how much power you can transmit thru a 6mm or 8mm shaft turbocompressor, but then again there's some old rocket turbopumps were one inch shafts and 100K HP.

[@billanderson6089]

Very nice 👌... watching this gave me dejavu lol

[@raykaufman7156]

Darin, I hope you find this comment and feel it's worthy of an answer.
In 2004, My friend Tom Miller clued me in to your message board discussion of the 4/4 engine. I know it didn't work out on your pro stock combo at the time, but I built a 481 BBC with a custom Reed 4/4 cam for my asphalt supermodified. The stack injection mitigated the mixture robbing problem you had encountered. My driver loved it.
Could you go deeper into the story of why you did it and what the advantages were? I've never seen anyone else discuss trying it in a pro racing application. Thanks. Love the channel!

[@darinmorgan3520]

I have not discussed firing orders and flat plain cranks for over a decade but your right, its a realy cool story. That would make for an entire video. Thnaks, I needed a new topic.

[@raykaufman7156]

@@darinmorgan3520 awesome...looking forward to it. BTW, Steve Faria gave me a tune for the injector and it was so good we never messed with it. We could run the same gear at almost any track, the power band was so wide.

[@bobg3034]

I built a 358 SBC with Vortec heads and it had a VE of 110-120% on the dyno.

[@jackwillson8099]

I learn a lot by my mistakes & used the dykem trick many years ago & learned too use my ears too lol , but this man nows his shit

[@bill2178]

awesome awesome stuff

[@BOOT]

I rem reading something bout that ls ssr and now I know why, interesting

[@manitoublack]

Thankyou for uploading such a great lecture.
As for supersonic flow. I always thought that flow past the exhaust valve was supersonic shortly after it lifts of the seat? Before quickly decaying back to sub sonic.

[@rolandotillit2867]

After a lot of research, I have come to the conclusion that it is intuitive, if you think about it the right way. Hyper critical turns make recirculation bubbles, which deflect flow. In other words airflow itself creates virtual port geometry that the bulk airflow goes around.

[@groomlake51]

Thank you!!!!

[@davidreed6070]

Daren we need some more from you, is it has been good but not enough.

[@theredwedge9446]

Now this is the good stuff right here

[@approachingtarget.4503]

Can you enforce the depth or the roof of the bowl area. Are shorter bowl area better for reversion?

[@djbassmyass]

Flukesman was actually so smart!

[@Bbbbad724]

I primarily mess with Ford FE engines. I was really surprised when you said that the FE engine was on the drawing board in 1938. I think it is really cool to see people still using and racing them. I have found them to be a durable engine and the heads that I have ported have reached a stable and quiet 308 cfm from iron heads with 2.19 valves in a 4.11 bore intake and 205 cfm with 1.65 exhaust. They are very durable and clean chambers. They fit the bores well. I plan to build a 451 stroker 4.11x 4.25, with a 6.7 rod. I have the Harland Sharp shaft rocker system and a Bullet roller cam 246@.050 and .600 lift. I would like to see 600/600+ from this. I have a PortoSonic intake and 780 3310. But I am open to more as needed. What might you recommend? I expect to have to run up to 7000 for this , but any suggestions you have would be appreciated. I really appreciate the informational videos.

[@job1bf]

super interesting. It sounds like a good example in the extreme of what you describe - would be a 351C 4bbl head with and without the intake floors filled. Perhaps? Have any experience with a comparison like this?

[@savagefabrication795]

I came across a diesel in detonation. Nitrous assisted. What makes the photo taken by Jason sands really over the top is that out of the turbo’s exhaust there are no shock cones but out of the waste gate on the manifold the shock cones are very much defined and visible. Something I thought was not possible on diesel fuel due to its flame speed being so slow.

[@bcbloc02]

Nitrous is violent and makes diesel much more explosive. I would say the Cummins blocks split at 30% less power with a bunch of nitrous versus an all boosted application.

[@roadrunner4404]

Greatness

[@billshiff2060]

4:20 Explain how detonation, which occurs at TDC, can appear at the exhaust outlet, 90 crank degrees later and 20 inches down the pipe. The detonation event is long since over and since detonation generates LESS overall cylinder pressure due to heat input into the combustion chamber, there is less than normal pressure venting to the pipe. No, that photo shows something else, not detonation in the chamber. Additionally, it takes only 12.7 psi to generate sonic flow in normal air, more than that will generate choked flow with respect to the source pressure but can be super sonic with respect to a lower pressure down stream. You can easily see that with any shop air hose held up to the light, you will see shock diamonds there. So I think you may very well see LOCAL super sonic flow in exhaust ports.

[@luckyPiston]

So youre saying detonation in the cylinder wouldn't manifest at the end of the pipe like that , what if detonation is to violent and rapid to create flow on its own and what we are seeing manifested at the pipe ends was actually transported by normal gas flow and not the detonation event itself ? is that possible or something like that i wonder ?

[@billshiff2060]

@@luckyPiston What usually is seen , when detonation is bad enough, is quick puffs of black smoke in the exhaust. It is soot from the incomplete burn/detonation. Only on individual pipe exhausts can it be easily detected.
That photo SEEMS to show what appears to be a super sonic flow with something combustible in it.
Maybe it is just a misfire where all the combustion takes place in the pipe giving the POP sound that can be heard when it happens. You know the POPing sound when you let off the gas... vrooom BAAAAAAA. That is fuel burning in the pipes.
I'd like a better explanation or a video with sound but I can't see detonation producing that picture.

[@luckyPiston]

I agree with u 100% , how are we gonna see detonation on the power stroke when the system is fully closed ? .... is the only explanation then that it is happening at some place and time other than what would be typical ? with the SR71 exhaust flow is constant and it happens at point of exit but with a 4 stroke engine you have a different operating principle , so how are we seeing the evidence of detonation when supposedly it happened in the previous cycle ?
Is it possible that the instantaneous pressure created by the detonation event still has enough residual energy (1/2 - 2/3 power cycle later) that at the instance that the exhaust valve opens we have supersonic flow ?
How about this, the instant the exhaust valve opens the residual pressure wave from the detonation event blows open the valve and supersonic flow occurs ? just thinking outside the box with this last idea ...

[@GTRliffe]

wouldn’t a few positive dimples encourage fuel too turn if placed just before the turn- or on the turn?

[@clarkmcmahan1595]

Like your detailed explanation on H.V.LP and port velocity with flow loss .I would love to sit down and pick your brain one day..how can this be achieved ??yo

[@samstewart4807]

hi, love your videos. The LT heads will run fine without direct injection. Why is that? AND who bought the Dart 60 k floe bench?

[@NoferTrunions]

25:42 Pure Gospel

[@jimkillen1065]

Thanks I watched this a few times and its a eye opening event . Yes sir I watched George at star racing videos also . Many years ago I bought a set of cylinders heads off a Monza that had a lot of work done to them and built a motor around them . I learned that in my option cylinder head flow and of course design is where hp made and the place to spend money . Back in that time I was also told that not going to mention there name but some folks in the Fort Worth, Dallas area had told my friend that the big block oval port head with the proper work done to them was the way to go at that time

[@samstewart4807]

Hi, love your videos. If the LT heads were not designed for wet flow, why do they work so well with standard EFI intak manifolds? or???? dont they work as well as they could? if they were designed for wet flow?

[@dustinarchdekin1537]

This is gold. Thank you. What do you have to do differently in situation where the restriction is underneath the throttle blade?

[@darinmorgan3520]

On an engine that is restricted upstream at the Carb venturi or with as restrictor plate takes a different approach to the volume ratio of the intake tract as well as the air speed/ cross sectional area. Since the manifold pressure is so low, charge density is low and the harmonics and inertia supercharging effects can be almost wiped out completely! Granted, wave action and inertia still takes place but the extent of the restriction will dictate how bad its diminished. The design changes to the system are relative to the size or amount of restriction as well as the heads and manifolding being utilized. If you have a OEM or comparable copy of a 23° iron head and dual plane manifold set up like a claimer engine with a 390 carb there is very little you can do other than make the system as stream lined as possible because you cant change the system dramatically enough to effect the small gains available to you.. If your dealing with high port heads and single plane manifolds like a restricted NASCAR engine, you have a lot of room within that architecture to make large changes in the over all design of the intake tract. If your not able to effect large changes to the system you wont achieve the small gains available.

[@dustinarchdekin1537]

@@darinmorgan3520 Thank you for taking time out of your Saturday for the explanation. This is a rule in our FSAE race car for our university team. We run a Honda 600cc 4 cylinder. The rule is a 20mm restrictor. We pull 2.0 PSI of vacuum at peak rpm.

[@darinmorgan3520]

@@dustinarchdekin1537 WOW! Now THAT is a restriction! Experimental development is all your left with I am afraid. You can analyze and simulate the system mathematically till your blue in the face and only get so far. After that, its dyno time baby! Experimental development. Get on the dyno, make small changes, evaluate the trends, exhaust those trends or changes and find another trend to exploit. There isn't anything you can do after the choke takes place. Your job is to develop the broadest most powerful curve under the choke point. Get it on the dyno and listen to what the engine is telling you. it will let you know what it wants. Just takes a lot of time.....

[@tkostang]

I finally found out who you are. Supposedly you’re the guy who “hand ported” my cylinder heads in 2016. I not sure if Rehr Morrison passed them on to you or what. Hell, I don’t even know if you actually did the work. I was told they were ported by you. Can you confirm? They were a set of DOHC Ford modular heads….. wasn’t cheap $$$ for me

[@darinmorgan3520]

That was me.

[@ambershade8583]

What about inline engines with 180 degree turns in runners? Some of those seem to work pretty well, and while turbocharged intakes sometimes do have short and straight runners, naturally aspirated ones most of the time have long and curved ones. Greatly curved. How bad is this, or is the air just "bounce off" the outer wall as I feel it should?

[@samstewart4807]

hi again, Are there companies who do CFD work for independetns? if yes who might you suggest?

[@09sez]

Here because of David vizard

[@AndySomogyi]

I’m running some simulations, (openfoam, compressible steady state, 28” water pressure ), and I’m seeing supersonic flow in the valve seat area at low lift.

[@darinmorgan3520]

Are you using a static pressure for your simulation?
I will have to look at the data on what the actual pressure is during overlap and intake opening. The pressure at this piont is very low as there is little piston movment. Dynamic flow through the chamber using exhaust and intake tract pressure waves are the only means to move air through the chamber at this piont. Simulating a fast changing dynamic condition with static modeling methods is difficult. The flow bench is a prime example.

[@AndySomogyi]

@@darinmorgan3520 Yes, I’m using a static pressure gradient of 28”, and using a steady state solver. It is wildly inaccurate above about Mach 0.7.
I’d have to work out the math to get real numbers, but if the lift is low enough, and intake flow is sufficient, there will be a small region at the valve seat area where flow is supersonic. Now this area will be very small, probably not much larger than the valve seat itself, as the volume rapidly diverges once flow enters the cylinder.

[@TheJohndeere466]

I am developing a head for a 6 cyldiesel pulling tractor. Is has no fuel in the port but it does have water for water injection. It will use roughly 3 quarts of water in 45 seconds. The water is being injected into the intake at about 1000 psi. Does it still need a short turn like a gas motor to prevent the water from coming out of suspension

[@darinmorgan3520]

I dont know. I have never dealt with that situation. I could only speculate as to what is happening under those conditions.

[@luckyPiston]

At 1000 psi is the water near vapor form ? sounds like on the right track at any rate

[@samstewart4807]

Hoe does putting the fuel injector in the back of the bowl effect the short turn aka@18.50?

[@DANTHETUBEMAN]

that big block short turn radius was news to me. 😮 i never herd that information before, i wonder if i lost low end from rounding the short turn radioys on my chevey vortec heads? 🤔

[@luckyPiston]

I had heard that was an issue with the BB but on the exhaust side not the intake , i wonder if that is what he was referring to ?..

[@luckyPiston]

On your vortec heads , if you were just cleaning up that area where the plunge cut part of the seat transitions into the short side and you didnt mess with the basic geometry there you should be alright.

[@doctorwhodj]

Watch listen pause let it sink in - rinse lather repeat🔁 📺👀

[@1960fl]

Darin i hope you leave this post up. Rick

[@darinmorgan3520]

not only will it remain up. I am working on another video dealing with wet flow

[@YouCantSawSawdust]

Doesn't turbocharging or supercharging make all this theory obsolete?
If someone came into engine development with no experience or preconceived ideas, the immediate thing they would suggest, to make an ICE more efficient, would be to artificially push air into the engine.
It's just common sense.
Why would you rely on relatively weak atmospheric pressure to push the air in.
It makes no sense at all. 🤷‍♂️

[@darius9521]

I'm here because David Vizard

[@ThunderAppeal]

'If youre not listening to George Bryce youre doing yourself a disservice'.
(heads straight to Bryce.) Be back later.

[@luckyPiston]

Does he have a youtube channel ?