sometimes we forget that Steve is one of the best engine builders in the country. And then he pops out a video like this one and reminds us why he is in that category.
@@stevemorrisracingShame you despise NA stuff. You would build a fire Big Block dirt modified motor. A custom SMX wide bore Small block for Dirt Latemodel would not only be sweet but that’s also a massive consumer base. 950+ HP NA Carbureted motors.
@@stevemorrisracing With opposed valve location of the Hemi, the incoming intake charge helps push out the exhaust. Causes efficiency and emission issues at lower RPM, but full effort engines at high engine speeds, it's money.
Good Lord! I just caught myself answering Steve's questions and statements OUTLOUD!!! Thank You Steve. I'm a 75 year old performance addict and I'm STILL LEARNING stuff from you. I love your shop so much that I have a picture of it in my room, LOL! May God bless you and all you do for all high speed enthusiasts.
Wonder how much street able power and torque a SMX would make NA to run in a cool street car, that’s raced about as much as you’d race your stick c7 ? aid love to put one in a truck like a 2014 -2015 extended cab f150, and just have fun…or put it in a classic car..
We can't avoid Boyle's Law in physics. Volumetric efficiencies differ between the Hemi & Wedge head design. Simple analogy that most can wrap their melons around is you can take a gradual turn at higher speeds than you can in taking a 180° turn. Gases are on par with lightning in that they enjoy taking the path of least resistance. On another note, Dewey staring out the window yearning to chase a squirrel is always welcome. lol
most engine guys know the Hemi law, proline are the Kings of fast Hemi's Turbo, Pro charger, and NOS which ever way you want it pro line can do, they make 1000-1500hp more than the SMX when your talking over 4000hp to 5400hp is way harder to make an extra 1000hp, I like Steve but the SMX and Proline Hemi's are 2 different animals the fastest auto engines on earth is a Hemi that sits in a top fuel dragsters and funny cars, look at the street outlaw guys the fast guys use proline Hemi's Steve fixated on calling them promod their not they can come in all sorts of cars
@@LSturboguy pretty sure Steve stated this in the video. And what differentiates a 300k+ dollar tube chassis car from a promod? Proline engines are exactly that, promod engines!!
@@LSturboguy Please expand on "Hemi Law" and give a points of reference(s) that can be gleaned as there are no white papers in physics study that make mention of this 'Hemi Law' in published literature. This is the first time it's been mentioned by anyone.
@@LSturboguyplease Mr LS turbo guy. Please tell us all about this Hemi Law and who discovered and wrote this law. And since you're an expert on this platform tell us all about how the engineers at Proline designed this engine.
@@LSturboguySteve is referencing their use in ProMod because of fans incessantly comparing the two due to Cletus’s new engine. They see smoke where there is no fire and force Steve to respond. They have questions about the two. He’s repeatedly mentioned the other uses of a Hemi design. He’s also right, in the NA world No one runs Hemi. They just don’t. They make more power with a wedge style head. It’s not really debatable. Steve wasn’t making it about pro line. Obsessed fans are.
The hemi valves go into the center of the cylinder. The other regular heads that have big valves are shrouded on one side. Its really that simple. Air flow.
@@wingracer1614they don’t. Nhra crippled n/a hemi development early on with massive weight penalties and left the door open for wedge engines to progress…and they did. nobody has a platform to push n/a hemi development, if one existed, it would dominate.
I think ur spot on with the valve orientation with the hemi letting more air out of the valves being in the center. Its not the volume of air but the path it takes to leave.
As a former pro stock hemi builder I can tell you definitively why they work better boosted and not as well NA. Hemi's are capable of better airflow but for NA using high compression the chamber is a nightmare shape that burns like crap(shaped like half a grapefruit peel). Supercharged with lowered compression you can burn what you get in because the chamber is open and burns properly. High compression does not hurt a wedge nearly as bad as it does a hemi. At high compression the extra flow does not make up for the lousy chamber . To get a hemi to run at high compression you have to tighten up the chamber a LOT , that is what Ford did and also the gen 3 hemi.
I remember watching a super slow motion video of a hemi and how the explosion would burn . The way a hemisphere engine flows makes the burn just that little more complete and can put more volume just a little more.
I saw a great video of darin morgan at BES showing a nice drawing on the path air flows from the intake to out the exhaust in a wedge head ranging from a normal non canted in line valve head like a sbc so something like DRCE 2 head where the valves are highly rotated to a full hemi where the valves are straight across from each other and how the RPM capability of the head increases the more you rotate the valves and eventually land at a hemi. Interestingly it seems wedge heads will make more low and midrange torque and hp than a hemi. I saw an interview with the guys from proline comparing the 481x to the hemi and they mentioned the 481x will tend to out 60ft the hemi. The reason ive heard that makes alot of sense is at lower rpm the hemi valve arrangement over scavenges and hurts low to mid rpm hp and torque over a wedge. That's why the hemis shine at super high rpm which is why some say that when NHRA put the 10500 rpm limit on prostock the hemis dropped away
I did watch Darin Morgan interview at Engine Performance Expo. (Super Stock Hemi Cylinder Head Porting with Darin Morgan (Expo 2024 - Episode 20) It has interesting talk about Gen2 and Gen3 Hemi heads, even its from Super Stock NA point of view. Lots of info “dos”, “don’ts”, “hows,” and “whys”.
Steve, everything you said about HEMI vs Wedge air flow is correct. The HEMI has a Quality and Quantity of air flow the wedge just doesn't have. This is because as you said, the Wedge valves get close to the cylinder walls. The NA HEMI would also make more power than the wedge today if the cylinder head development had not stopped for NA GEN2 (426) applications in about 1974. NHRA threw the rule book at the 426 HEMI in Prostock, the only place the NA HEMI was still run. The Prostock HEMIs had to carry an extra 600 pounds of weight when the last driver parked his car in about 1974 and said screw it!!! NA Cylinder Head development continued on the BBC because guys were still running them, to this day. GEN2 HEMI Head development did continue for blown Nitromethane heads. Billet solid heads and blocks allow those engines to make 13,000HP. PS. Your SMX heads look like they have great ports. Give us some flow numbers sometime. I know you don't care, but let us know?
Not true. The weight break system was long gone in the 80's with the 500CI rule. The last competitive CHRYSLER hemi retired in 87(Us and Roy Hill) but Glidden used a Ford hemi which had a far superior combustion chamber for a long time after that.
Steve, I hereby dub thee Professor Emeritus of the Drag and Drive Horsepower. Please keep bringing these highly informative videos coming. I thought I had a fair handle on the internal combustion engine, but I always learn quite a bit from these videos. I'm the kind of guy that needs to keep learning, regardless of how old I get.
I hope everyone watching this picks up on the very subtle -- but extremely important -- differences between Steve's "drag and drive" SMX engines and Promod "drag only" hemi engines. Bravo!
If you study wet flow you will understand why the wedge is better N/A. I have spent 40 years working on wet flow thru and engine along with countless pulls on the Dyno. And what you see is the wedge will run with 8 to 10 degrees less total Ign. timing. So burn time is always faster on the wedge engine. The Hemi is better suited for slow burning fuel. I feel this is because of the lack of quench and the cross flow at overlap.
Stupid question, as a small plane pilot, I notice that we've got 2 spark plugs per cylinder. Redundancy is nice, but its mainly for power, we check each mag/plug before each flight and when you drop a mag you have at least a 50 RPM drop. I realize they've come a long way with ignition systems, but would you also benefit from 2 plugs??? Thanks, love your channel sir 🙂
In aviation the dual plug and dual magneto setup is primarily for redundancy not power. A plane would become a very inefficient glider if only one magneto went out AND you only had one. Small aero engines are still using basically vw bug engines so very old tech but modernization is at snails pace because those old engines are proven.
Love the technical explanations The water jacketing on the SMX heads is some terrific engineering. Hemi's have great airflow and absolute crap combustion chambers. So much so, that N/A the extra airflow isn't enough to make up the difference. (that giant dome is a killer) As you have pointed out, in boosted applications, squish/quench isn't as important (and can be detrimental) while N/A it is critical. (Love to hear more about your findings here) N/A Hem'is also require a heavier piston. Of course, 4V engines have the best of both worlds- hard to package on a giant engine though. One could speculate a billet 400 inch LT based 4V V8 would be a killer drag and drive engine just because of the increased reliability. Maybe something based on the new Z06 engine
Ford produced a cammer and then forgot about it cause they got banned from racing it and chev had nothing to match it.. the way forward would be OHC heads but where do we draw the line of insane horsepower.. better crankshafts , rods , pistons the list just multiplies to the point of more money wins..😂😂
I had this same thought too. It would be interesting to hear why Steve didn't go for a multi valve overhead cam cylinder head. Not so much for increasing power but improving reliability
I have a very very old 388 you built along time ago. Recently went to fuel tech and made 1290 wheel on a 70/30 meth/nitro blend with a gear driven procharger
Excellent information I like that you don't claim to know it all but are willing to take an educated guess and leave it open to other opinions and comments I think that's excellent thanks for the information and the great channel , been subscribed for a couple of months .
I wish this was PINNED to the top so all these bro science backyarders could hear a cylinder head design expert talk about heads and how the chamber shape and valve rotation effects everything.
I agree with you as to the hemi theory. I feel as when the valves move into the center of the cylinder, the gasses can escape faster as the valve has moved away from the port in allowing a faster path to evacuate the cylinder where as in a wedge style the valve is essentially still in front of the valve port, same deal with intake
but depending on the valve angle the hemi gives up a lot of cam timing with bigger valve size due to overlap constraints. It's all trade offs. I think the wedge canted valve is actually better for a host a reasons, the valve train is more stable at high rpm as seen with prostock stuff. It's a case of, nobody's really bothered yet. I think a solid block SMX with some development would likely be competitive in top alcohol, the chamber shape on the hemi has some advantages with nitromethane that a wedge can't compete with, namely spark plug location.
@@seancollins9745 Yes forsure, I agree with you as to the cam timing 100% but I was just comparing non canted to hemi, from one extreme to another and as to why I believe the hemi is more efficient. On a wedge style I feel like the exhaust gasses get bounced back so to say instead of limited restricted flow, also believe that hemi style kind of creates a tornado effect to help completely evacuate the cylinder.
The video of Darin Morgan explaining the ford jC51 cylinder heads is amazing….. that man has forgotten more about cylinder heads than any of us could ever hope to learn…
I’ve always been curious if ford made a coyote that was 500+ ci, would it make more power than a hemi or a bbc? From what I understand is the 4v is superior
I agree 100% valves that opens up intake and exhaust directly in the center of the bore can make a tornado effect and intake and execute air and liquids faster. That's why they take beer and shake it in a small circle make a tornado effect it comes out comes out much faster. That's my YouTub theory 😂
Listening to Steve describe the mass inherent to the cylinder heads does point to why moving the camshafts to above the valves is the go to for F1 engines
Good ol Steve always giving his fans new content. You would think he would run out of different stuff but he mostly does not run out. I have been watching since 20 k subs and I have never looked back. Great American. Thanks Steve.
I love the details, Steve. Rod specifications, bearing journals, valve angles and sizes, rocker ratios with identical intake and exhaust rockers is genius. Wow. Best video since the piston design video you did years ago. Thank you.
I always thought the advantages of a Hemi is the unshrouding (You mentioned this) and the short runner lengths with the valves sideways (90*) to a wedge, the runner can be lined up (both the intake and exhaust) to where the flow is maximized, as well as the shortest path possible through the engine. Under boost the combination of unshrouding, the inline flowpath as well as the much shorter runner length help to move everything in a more orderly fashion and much much quicker
Thanks Professor Steve, love the tech talk, Making sense of all the black magic, exhaust valve opens 83 per sec, so a top fuel car runs 3.70 sec on a run, the exhaust valve opens 307 times during a typical run, that is amazing.
I love it that you and Kevin (KSR) are doing such a collaborative production on Val's Camaro. This, to my mind, shows just how close nit the racing community is. Not to mention how much Cletus is doing to promote the entire industry. Some day, I'm gonna pop into your shop & show you what I'm working on...I'm currently working on revolutionizing the relationship between fuel & spark. I've already shown you a teaser with my 'plasma spark ignition system. Just remember when your receptionist says, The plummer is here & wants to talk to you.
Steve, you could honestly probably give a week long lecture about the hemi/wedge differences. Flame front propagation, squish band, thermal efficiency, all apart from the airflow difference you described. But you described it very well
hi Steve, I think as you rotate the position of the valves in the cylinder head you can achieve more rpm, the big advantage of hemi i think is that the intake valve opens and uses the cylinder wall as a continuation of the seat angles and the air doesn't become turbulent when the intake valve opens, good pressure recovery. the disadvantage for N/A application is I believe in the second generation hemi, the huge combustion chamber and the dome in the piston, and the piston weight. On the other hand the huge combustion chamber is very good for forced induction to control the detonation! there are a couple videos of darin morgan who explained this very well. regards from Argentina, your channel is awesome!
It’s after 3am and I’m hooked again watching another Steve video. I’m a dang electrician but these vids are so informative I get hooked. Thanks Steve, I don’t need to sleep.
Steve you make perfect sense. I’m absolutely with you on the desire for low maintenance, high performance. Who wouldn’t? But there are people who wouldn’t! That’s not me 😂 I’d like to hear your quench tutorial when you find the time thank you. Enjoy your weekend and I hope you achieve all you have planned from 🇬🇧
I had no idea of the difference. Thanks for explaining.. But I would love to see you max out the smx. Just to see how much it could put out. Awesome videos brother keep them coming
You’re exactly right I’ve done a lot of reading on this and Darrin Morgan and some others have said that Hemi is able to RPM better because the valve placement, wedge air has to make a dog leg. Hemi comes straight in and straight out it’s not even that cylinder head flows more either
The low down torque loss because of the nature of the flow of the hemi head against wedge heads. Hp = torque (ft lbs) x rpm ÷ 5252 So the higher torque at lower rpms of the wedge heads will yield a higher low rpm hp I notice far lower hp wedge motors are doing the 1,0 sec 60 fts but the high hp hemi's struggle on launch but blow everything else off once rpm gets up and the car is launched. Nature of the beast with loss of low down torque compared to a similar sized wedge motor.. Torque launches Hp runs for the back door Interesting to see top fuel 60ft times even with 12,000hp and then at 330 theres nothing to touch them
Steve thank you for sharing your knowledge, you always remind me of my brother in law who passed away before I could learn from him. He was a huge boosted LS guy. Had his own shop, dyno, and made turbo manifolds. RIP Kyle Brown, KB Racing. Fawk Covid
I love how Steve rubs his block like it’s his baby or patting dog without even realizing he doing it. He’s one proud mofo of his awesome creation and so he should be 💪
My guess would be because it is RPM targeted for 11000 & the valves are closer to roof of head, where thecplug is. That is the RPM that they are engineered to make max power. What are the different valve sizes between your heads & the Hemi's? Port size if you haveca sec? This really amazes me! I would be interested in hearing more about your exoxic SBC & displacement possibilities?
Wow love this video! The nuts and bolts along with theory. It doesn’t get any better for a motor head. Hope to see result on this sbc build. Love how quickly u determined cam lift plus valve lift. Would have loved to see na hp for this motor before rebuild.
I wonder how the hemi and the great SMX compare to a 4 valve per cylinder. Then there is a long belt or chain to deal with, so that sucks. I only dream of owning an SML or SMX. Perfect hobby Steve.
It works on motorcycles. Also can run shorter chain to a single gear on each head and have the cams gear driven. I think the 4 valve idea would make more power.
As far as cylinder combustion and head design I have never seen a head design better than the Honda hurricane head design, whereas the valve trains and cams are straight up and down and the intake and exhaust flow is straight into the cylinder, one should probably take a look at the reasurch they did on the development of that particular head design because it doesn't get much better than that
Steve, I truly find the information that you put out there incredibly interesting. I would definitely watch any “tech” video that you put out for all of us to watch and learn from! Thanks for sharing!
Steve you have a great mind ive had the same idea for a few years you were just able to make it happen ive always thought an open deck was a bad idea for a lack of terms
I believe your 100% correct on the hemi valve layout, proven best design for quicker in and out airflow, piston crown design in NA applications may not be ideal. Wedge style head valve positions require the air to change direction across the cylinder bore, however its intake port layout can add intake charge swirl or tumble that can improve mixture distribution in the combustion chamber. I'd love to see a solid SMX made for max effort, Methanol. Max cam 90 psi. Shut em up. Probably break your dyno. Love your work. Justin. Sydney, Australia
Great video love hearing your explanation on the gammit of what you do ! I agree on hemis the intake valves fill better and exhaust valves exit better being the air flow central to the bore the advantage is diffenately an advantage as the the air flows more in a straight line crosses in straight path over from Intake manifold through valve into combustion chamber straight out exhaust valve straight out to exhaust manifold in a straight line. What really makes this so effective is the timing of valves taking advantage of scavenging and fill happening with overlap events, for volumetric efficiency through the exhaust and intake overlap of valves. This is where the valve geometry really shines is its volumetric efficiency gains. But that's also what boost does is increase volume of air being filled that's the reason for it being so effective together and your top fueler guys go a step further when your fuel is being dumped in marginally close to hydraulicing because the fuel also makes its own oxygen as it burns. The fuel and valve system were meant for each other in top fuel funnies and dragsters.
Calculation of rocker frequency of actuation is correct - with the divide by two factor. However, the four stroke operation means the valve is closed for a lot of degrees of crankshaft rotation, which means the rocker is loaded much more violently than just the frequency of opening would imply.
Valve rotation affects the rpm range. Darin Morgan has a good explanation of this. Wedge style is lower rpm medium rpm is cleveland or big chevy or 385 series ford. high rpm hemispherical all day long.
Max effort Hemis do not have to worry about burning out the thin wall between the intake and exhaust ports i.e. Top Fuel thus have superior thermal properties compared to the wedge just saying.Kepp the cool vids coming,much enjoy !
Only a handful of people would want a full race/max hp engine. People like Steve and Kevin from KSR build ( in my opinion ) More obtainable cars and engines and I'm sure they sell more for that reason. Plus the knowledge Steve shares 👍❤ Thank you sir love the channel.
Like You Demonstrated Steve a True Old School Hemispherical Combustion chamber Intake valve opening is in direct tangent line over the exhaust valve. Exhaust valve opening is directly over the intake valve. Intake and exhaust valves both open during Overlap the fresh air fuel charge coming in has 90 degrees or less turn with crossover pulse energy drawing in more Fuel & Air Directional change Vs 180 degrees for A Wedge V8. Intake ports on a Hemi have a straight shot in. Hemi exhaust a much cleaner shot out.
Wow Steve just wow haha them water blocks are masterpieces. Do you find hotspots in the cooling systems? Seems like the cooling runs along the engine and then back.
...awwsome tech, Steve & thank you - I really want the video on 'quench' - I have stewed about it alot & want to learn the 'real deal' - again, thank you !...
This was another great video, and I learned a lot. As I watched how often you had to make quick calculations it brought me back to high school. I was at a technical high school with a lot of trades programmes. I would often hear guys (yes, they were always guys) say "I want to be a mechanic, why do I need math?". This video shows exactly why. If you want to be the best mechanic yyou can be you need more than the ability to spin a wrench. This video should be sent to every school guidance councillor that needs to answer the question "Why do I need math?"
I always chocked it up to the shape of the chamber. With the hemi being domed it is easy for air for flow in a less turbulent manner in and out. With a wedge the air has to hit a wall and redirect into the exhaust port. Air will flow around a sphere smoother than it will around a flat wall.
Yeah I love this video it really dose show the massive difference between a smx and a pro mod engine like drivability and making very close numbers but the face you can drive around the streets with 5000hp is insane
Awesome video on camshafts I always bought them from Jerry Haas that was for the motors i built for the cars my brother drove for me. Now the motors I used I had Leo Walter's ( Superchargers ) build my motors an tune them. The motors he built for me was filled Aluminum blocks. This was in the 2000s. There is so much change in motors from yr 2000 to now. I can't wait to see the Camaro to start making pass . Keep up the great videos.
So, my theory is what you said plus intake and exhaust port placement and desig. More direct alignment into center of cylinder. Volume of flow at crazy rpm. Seems like the efficiency of flow due to time available.
I’m definitely interested in a video about quench. I was also wondering why the hemi that Cleetus has doesn’t use captured lash caps like the SMX does.
Hemi head valves are placed across the cylinder bore and inclined toward the center resulting in better airflow than a wedge design in a relatively small package. You can run bigger valves in a hemi head without issues with valve shrouding from the cylinder walls.
I really enjoy all of your videos. You have so much knowledge of engineering engines for different applications. Keep up the great work. I look forward to it more soon.
you are correct with the hemi theory. draw a picture of a wedge from top down then draw a picture of a hemi top down and tell me which one has the easier airflow. i do alot of harley stuff and i would like you to check out hammer performance to see there research. they made a 28 degree reverse dome piston and a 30 degree machined head to make a small squish band while keeping comp down. the results work better than the competition and their stuff makes more hp and tq than anyone else.
The greater valve angle in the hemi allows a larger valve to be used (in relation to piston diameter ratio). These larger valves allow quicker cylinder filling for more high end power where that starts becoming a limitation.
Steve. We know that you could build a5000+ hp engine! But you have made your place in drag and drive engines. What would happen if you tried running an all out hemi on a drive and drag run haha. Steve we know your engine’s are the best for d&d runs … you are right were you should be …. We know the difference… But you are doing a great job of explaining/educating ..you’re the best!
No kidding. Poor Steve can’t let it go that garret bought that proline hemi. Now I get it Steve reads the comments and everyone is talking about it but don’t let it bother you man. Cleetus gave you couple hundred thousand followers overnight, just let it go
Another issue that I believe is far to often overlooked is the exhaust system back pressure holding the exhaust valve open at high rpm, and I realize that this might sound crazy but I think it's worth looking into and that is a vortex exhaust system, similar to that of a R/C model aircraft nitro motor, that literally vacuums the exhaust gasses off the head helping to close the exhaust valves faster and allowing for even higher rpm
![GT-R Powered 240Z - FIRST DRIVE [Ultimate Turbo Sound]](http://i.ytimg.com/vi/ATBLQj1yPIk/mqdefault.jpg)
![GT-R Powered 240Z - FIRST DRIVE [Ultimate Turbo Sound]](/img/tr.png)
sometimes we forget that Steve is one of the best engine builders in the country. And then he pops out a video like this one and reminds us why he is in that category.
Try in the World....🌎
When Steve Morris says something, smart people listen. Thank you for all the time you spend in your busy schedule to educate us.
He doesn't do it for free, lol. These videos make him money and increase sales which make him even more money.
Love how Steve is always taking us to school. Good luck to you and Tom in Le Mullets.
I love how you have engineered durability in the SMX. You and Val are delightful, I had an awesome time in Edgewater with you guys!
Thanks!
@@stevemorrisracingShame you despise NA stuff. You would build a fire Big Block dirt modified motor. A custom SMX wide bore Small block for Dirt Latemodel would not only be sweet but that’s also a massive consumer base. 950+ HP NA Carbureted motors.
@@stevemorrisracing With opposed valve location of the Hemi, the incoming intake charge helps push out the exhaust. Causes efficiency and emission issues at lower RPM, but full effort engines at high engine speeds, it's money.
Good Lord! I just caught myself answering Steve's questions and statements OUTLOUD!!! Thank You Steve. I'm a 75 year old performance addict and I'm STILL LEARNING stuff from you. I love your shop so much that I have a picture of it in my room, LOL! May God bless you and all you do for all high speed enthusiasts.
As always, thanks for the lesson. Such a smart, humble guy.
Wonder how much street able power and torque a SMX would make NA to run in a cool street car, that’s raced about as much as you’d race your stick c7 ? aid love to put one in a truck like a 2014 -2015 extended cab f150, and just have fun…or put it in a classic car..
We can't avoid Boyle's Law in physics. Volumetric efficiencies differ between the Hemi & Wedge head design. Simple analogy that most can wrap their melons around is you can take a gradual turn at higher speeds than you can in taking a 180° turn. Gases are on par with lightning in that they enjoy taking the path of least resistance.
On another note, Dewey staring out the window yearning to chase a squirrel is always welcome. lol
most engine guys know the Hemi law, proline are the Kings of fast Hemi's Turbo, Pro charger, and NOS which ever way you want it pro line can do, they make 1000-1500hp more than the SMX when your talking over 4000hp to 5400hp is way harder to make an extra 1000hp, I like Steve but the SMX and Proline Hemi's are 2 different animals the fastest auto engines on earth is a Hemi that sits in a top fuel dragsters and funny cars, look at the street outlaw guys the fast guys use proline Hemi's Steve fixated on calling them promod their not they can come in all sorts of cars
@@LSturboguy pretty sure Steve stated this in the video. And what differentiates a 300k+ dollar tube chassis car from a promod? Proline engines are exactly that, promod engines!!
@@LSturboguy Please expand on "Hemi Law" and give a points of reference(s) that can be gleaned as there are no white papers in physics study that make mention of this 'Hemi Law' in published literature. This is the first time it's been mentioned by anyone.
@@LSturboguyplease Mr LS turbo guy. Please tell us all about this Hemi Law and who discovered and wrote this law. And since you're an expert on this platform tell us all about how the engineers at Proline designed this engine.
@@LSturboguySteve is referencing their use in ProMod because of fans incessantly comparing the two due to Cletus’s new engine. They see smoke where there is no fire and force Steve to respond. They have questions about the two. He’s repeatedly mentioned the other uses of a Hemi design. He’s also right, in the NA world No one runs Hemi. They just don’t. They make more power with a wedge style head. It’s not really debatable.
Steve wasn’t making it about pro line. Obsessed fans are.
Can't believe how awesome this is!
The hemi valves go into the center of the cylinder. The other regular heads that have big valves are shrouded on one side. Its really that simple. Air flow.
True but that should be better for everything so why do wedge heads seem to be better NA
@@wingracer1614they don’t. Nhra crippled n/a hemi development early on with massive weight penalties and left the door open for wedge engines to progress…and they did.
nobody has a platform to push n/a hemi development, if one existed, it would dominate.
I think ur spot on with the valve orientation with the hemi letting more air out of the valves being in the center. Its not the volume of air but the path it takes to leave.
Been following you for ages, keep it up!
As a former pro stock hemi builder I can tell you definitively why they work better boosted and not as well NA. Hemi's are capable of better airflow but for NA using high compression the chamber is a nightmare shape that burns like crap(shaped like half a grapefruit peel). Supercharged with lowered compression you can burn what you get in because the chamber is open and burns properly. High compression does not hurt a wedge nearly as bad as it does a hemi. At high compression the extra flow does not make up for the lousy chamber .
To get a hemi to run at high compression you have to tighten up the chamber a LOT , that is what Ford did and also the gen 3 hemi.
I remember watching a super slow motion video of a hemi and how the explosion would burn . The way a hemisphere engine flows makes the burn just that little more complete and can put more volume just a little more.
I saw a great video of darin morgan at BES showing a nice drawing on the path air flows from the intake to out the exhaust in a wedge head ranging from a normal non canted in line valve head like a sbc so something like DRCE 2 head where the valves are highly rotated to a full hemi where the valves are straight across from each other and how the RPM capability of the head increases the more you rotate the valves and eventually land at a hemi. Interestingly it seems wedge heads will make more low and midrange torque and hp than a hemi. I saw an interview with the guys from proline comparing the 481x to the hemi and they mentioned the 481x will tend to out 60ft the hemi. The reason ive heard that makes alot of sense is at lower rpm the hemi valve arrangement over scavenges and hurts low to mid rpm hp and torque over a wedge. That's why the hemis shine at super high rpm which is why some say that when NHRA put the 10500 rpm limit on prostock the hemis dropped away
I did watch Darin Morgan interview at Engine Performance Expo. (Super Stock Hemi Cylinder Head Porting with Darin Morgan (Expo 2024 - Episode 20) It has interesting talk about Gen2 and Gen3 Hemi heads, even its from Super Stock NA point of view. Lots of info “dos”, “don’ts”, “hows,” and “whys”.
Steve, everything you said about HEMI vs Wedge air flow is correct. The HEMI has a Quality and Quantity of air flow the wedge just doesn't have. This is because as you said, the Wedge valves get close to the cylinder walls. The NA HEMI would also make more power than the wedge today if the cylinder head development had not stopped for NA GEN2 (426) applications in about 1974. NHRA threw the rule book at the 426 HEMI in Prostock, the only place the NA HEMI was still run. The Prostock HEMIs had to carry an extra 600 pounds of weight when the last driver parked his car in about 1974 and said screw it!!! NA Cylinder Head development continued on the BBC because guys were still running them, to this day. GEN2 HEMI Head development did continue for blown Nitromethane heads. Billet solid heads and blocks allow those engines to make 13,000HP. PS. Your SMX heads look like they have great ports. Give us some flow numbers sometime. I know you don't care, but let us know?
What you said about n/a hemi is false. (I know you think you’re right) As for the rest…thanks captain obvious for repeating him.
Not true. The weight break system was long gone in the 80's with the 500CI rule. The last competitive CHRYSLER hemi retired in 87(Us and Roy Hill) but Glidden used a Ford hemi which had a far superior combustion chamber for a long time after that.
Steve, I hereby dub thee Professor Emeritus of the Drag and Drive Horsepower. Please keep bringing these highly informative videos coming. I thought I had a fair handle on the internal combustion engine, but I always learn quite a bit from these videos. I'm the kind of guy that needs to keep learning, regardless of how old I get.
I hope everyone watching this picks up on the very subtle -- but extremely important -- differences between Steve's "drag and drive" SMX engines and Promod "drag only" hemi engines. Bravo!
Subtle? The differences are extremely vast. He literally 30 min discussing them in great detail.
They are very different yet those that don't know still won't know and those of us that do know we already knew.
If you study wet flow you will understand why the wedge is better N/A. I have spent 40 years working on wet flow thru and engine along with countless pulls on the Dyno. And what you see is the wedge will run with 8 to 10 degrees less total Ign. timing. So burn time is always faster on the wedge engine. The Hemi is better suited for slow burning fuel. I feel this is because of the lack of quench and the cross flow at overlap.
my guess would be the valve shrouding on a wedge heads effects on flow. and spark plug location being more centralized
Stupid question, as a small plane pilot, I notice that we've got 2 spark plugs per cylinder. Redundancy is nice, but its mainly for power, we check each mag/plug before each flight and when you drop a mag you have at least a 50 RPM drop. I realize they've come a long way with ignition systems, but would you also benefit from 2 plugs??? Thanks, love your channel sir 🙂
In aviation the dual plug and dual magneto setup is primarily for redundancy not power.
A plane would become a very inefficient glider if only one magneto went out AND you only had one.
Small aero engines are still using basically vw bug engines so very old tech but modernization is at snails pace because those old engines are proven.
Love the technical explanations
The water jacketing on the SMX heads is some terrific engineering.
Hemi's have great airflow and absolute crap combustion chambers. So much so, that N/A the extra airflow isn't enough to make up the difference. (that giant dome is a killer)
As you have pointed out, in boosted applications, squish/quench isn't as important (and can be detrimental) while N/A it is critical. (Love to hear more about your findings here)
N/A Hem'is also require a heavier piston.
Of course, 4V engines have the best of both worlds- hard to package on a giant engine though.
One could speculate a billet 400 inch LT based 4V V8 would be a killer drag and drive engine just because of the increased reliability. Maybe something based on the new Z06 engine
DOHC hemi might be interesting 🤔
It sounds like it might reduce some of the valve train issues, but it might introduce some others.
Came here to ask the same thing.
Ford produced a cammer and then forgot about it cause they got banned from racing it and chev had nothing to match it.. the way forward would be OHC heads but where do we draw the line of insane horsepower.. better crankshafts , rods , pistons the list just multiplies to the point of more money wins..😂😂
I had this same thought too. It would be interesting to hear why Steve didn't go for a multi valve overhead cam cylinder head. Not so much for increasing power but improving reliability
@@rogerbarnes9904 research and development would be a nightmare i guess.. tried n true pushrods and 2 valves doing pretty good so far at 5k HP..
It needs a k20 style head yes two more timing chains or I would like gear to gear matchup like diesels use
I have a very very old 388 you built along time ago. Recently went to fuel tech and made 1290 wheel on a 70/30 meth/nitro blend with a gear driven procharger
I would love to learn more about Quench, both boosted and N/A. Thanks for all the knowledge!
Excellent information I like that you don't claim to know it all but are willing to take an educated guess and leave it open to other opinions and comments I think that's excellent thanks for the information and the great channel , been subscribed for a couple of months .
Daron Morgan has some great videos on explaining the development of pro stock heads. Hemi, and wedge. Some great videos on Dragboss garage also.
I wish this was PINNED to the top so all these bro science backyarders could hear a cylinder head design expert talk about heads and how the chamber shape and valve rotation effects everything.
I agree with you as to the hemi theory. I feel as when the valves move into the center of the cylinder, the gasses can escape faster as the valve has moved away from the port in allowing a faster path to evacuate the cylinder where as in a wedge style the valve is essentially still in front of the valve port, same deal with intake
but depending on the valve angle the hemi gives up a lot of cam timing with bigger valve size due to overlap constraints. It's all trade offs. I think the wedge canted valve is actually better for a host a reasons, the valve train is more stable at high rpm as seen with prostock stuff. It's a case of, nobody's really bothered yet. I think a solid block SMX with some development would likely be competitive in top alcohol, the chamber shape on the hemi has some advantages with nitromethane that a wedge can't compete with, namely spark plug location.
@@seancollins9745 Yes forsure, I agree with you as to the cam timing 100% but I was just comparing non canted to hemi, from one extreme to another and as to why I believe the hemi is more efficient. On a wedge style I feel like the exhaust gasses get bounced back so to say instead of limited restricted flow, also believe that hemi style kind of creates a tornado effect to help completely evacuate the cylinder.
My son said " Is there a video Steve has made that he does not pet his engine, or engine parts?" lol. I just said, that is Steve's thing.
Thanks for taking the time to make these videos!
Darin Morgan explains the hemi vs wedge similarly.
Love the smx👍
The video of Darin Morgan explaining the ford jC51 cylinder heads is amazing….. that man has forgotten more about cylinder heads than any of us could ever hope to learn…
I’ve always been curious if ford made a coyote that was 500+ ci, would it make more power than a hemi or a bbc? From what I understand is the 4v is superior
Just by design a true Hemi chamber doesnt suffer from valve shrouding like a wedge
I agree 100% valves that opens up intake and exhaust directly in the center of the bore can make a tornado effect and intake and execute air and liquids faster. That's why they take beer and shake it in a small circle make a tornado effect it comes out comes out much faster. That's my YouTub theory 😂
Not quite right.. wedge heads swirl that way.. hemi flows 90 degrees to a wedge more like a rolling wave into the cylinder..
Listening to Steve describe the mass inherent to the cylinder heads does point to why moving the camshafts to above the valves is the go to for F1 engines
Good ol Steve always giving his fans new content. You would think he would run out of different stuff but he mostly does not run out. I have been watching since 20 k subs and I have never looked back. Great American. Thanks Steve.
Always super interesting and well explained!
I love the details, Steve. Rod specifications, bearing journals, valve angles and sizes, rocker ratios with identical intake and exhaust rockers is genius. Wow. Best video since the piston design video you did years ago. Thank you.
Steve giving engine builder secrets
I always thought the advantages of a Hemi is the unshrouding (You mentioned this) and the short runner lengths with the valves sideways (90*) to a wedge, the runner can be lined up (both the intake and exhaust) to where the flow is maximized, as well as the shortest path possible through the engine. Under boost the combination of unshrouding, the inline flowpath as well as the much shorter runner length help to move everything in a more orderly fashion and much much quicker
Thanks Professor Steve, love the tech talk, Making sense of all the black magic, exhaust valve opens 83 per sec, so a top fuel car runs 3.70 sec on a run, the exhaust valve opens 307 times during a typical run, that is amazing.
I think you’re spot on as far as the hemi air flow goes. We all know that a motor is basically an air pump- the more in the more out
I love it that you and Kevin (KSR) are doing such a collaborative production on Val's Camaro. This, to my mind, shows just how close nit the racing community is. Not to mention how much Cletus is doing to promote the entire industry.
Some day, I'm gonna pop into your shop & show you what I'm working on...I'm currently working on revolutionizing the relationship between fuel & spark. I've already shown you a teaser with my 'plasma spark ignition system. Just remember when your receptionist says, The plummer is here & wants to talk to you.
Steve, you could honestly probably give a week long lecture about the hemi/wedge differences.
Flame front propagation, squish band, thermal efficiency, all apart from the airflow difference you described. But you described it very well
hi Steve, I think as you rotate the position of the valves in the cylinder head you can achieve more rpm, the big advantage of hemi i think is that the intake valve opens and uses the cylinder wall as a continuation of the seat angles and the air doesn't become turbulent when the intake valve opens, good pressure recovery. the disadvantage for N/A application is I believe in the second generation hemi, the huge combustion chamber and the dome in the piston, and the piston weight. On the other hand the huge combustion chamber is very good for forced induction to control the detonation! there are a couple videos of darin morgan who explained this very well. regards from Argentina, your channel is awesome!
It’s after 3am and I’m hooked again watching another Steve video. I’m a dang electrician but these vids are so informative I get hooked.
Thanks Steve, I don’t need to sleep.
same
Steve you make perfect sense.
I’m absolutely with you on the desire for low maintenance, high performance. Who wouldn’t? But there are people who wouldn’t! That’s not me 😂
I’d like to hear your quench tutorial when you find the time thank you.
Enjoy your weekend and I hope you achieve all you have planned from 🇬🇧
the SMX is a redesigned billet BBC, he reinvented the wheel
I had no idea of the difference. Thanks for explaining..
But I would love to see you max out the smx. Just to see how much it could put out.
Awesome videos brother keep them coming
Gonna. Someday
You’re exactly right I’ve done a lot of reading on this and Darrin Morgan and some others have said that Hemi is able to RPM better because the valve placement, wedge air has to make a dog leg. Hemi comes straight in and straight out it’s not even that cylinder head flows more either
The low down torque loss because of the nature of the flow of the hemi head against wedge heads.
Hp = torque (ft lbs) x rpm ÷ 5252
So the higher torque at lower rpms of the wedge heads will yield a higher low rpm hp
I notice far lower hp wedge motors are doing the 1,0 sec 60 fts but the high hp hemi's struggle on launch but blow everything else off once rpm gets up and the car is launched.
Nature of the beast with loss of low down torque compared to a similar sized wedge motor..
Torque launches
Hp runs for the back door
Interesting to see top fuel 60ft times even with 12,000hp and then at 330 theres nothing to touch them
Steve thank you for sharing your knowledge, you always remind me of my brother in law who passed away before I could learn from him. He was a huge boosted LS guy. Had his own shop, dyno, and made turbo manifolds. RIP Kyle Brown, KB Racing. Fawk Covid
I love how Steve rubs his block like it’s his baby or patting dog without even realizing he doing it. He’s one proud mofo of his awesome creation and so he should be 💪
My guess would be because it is RPM targeted for 11000 & the valves are closer to roof of head, where thecplug is. That is the RPM that they are engineered to make max power. What are the different valve sizes between your heads & the Hemi's? Port size if you haveca sec? This really amazes me! I would be interested in hearing more about your exoxic SBC & displacement possibilities?
Every time I watch one of Steve's videos, I learn something and I'm taking notes for a engine I'm getting ready to build
Wow love this video! The nuts and bolts along with theory. It doesn’t get any better for a motor head. Hope to see result on this sbc build. Love how quickly u determined cam lift plus valve lift. Would have loved to see na hp for this motor before rebuild.
I think its evacuation the valves are sitting sideways so when the piston comes up, it pushes it in the runner instead of against the valve
I wonder how the hemi and the great SMX compare to a 4 valve per cylinder. Then there is a long belt or chain to deal with, so that sucks.
I only dream of owning an SML or SMX. Perfect hobby Steve.
It works on motorcycles. Also can run shorter chain to a single gear on each head and have the cams gear driven. I think the 4 valve idea would make more power.
Billet coyote based 5.8L engines are making well over 4000hp
@@knowbull5hit590 Are they lasting?
As far as cylinder combustion and head design I have never seen a head design better than the Honda hurricane head design, whereas the valve trains and cams are straight up and down and the intake and exhaust flow is straight into the cylinder, one should probably take a look at the reasurch they did on the development of that particular head design because it doesn't get much better than that
Steve, I truly find the information that you put out there incredibly interesting. I would definitely watch any “tech” video that you put out for all of us to watch and learn from! Thanks for sharing!
Steve you have a great mind ive had the same idea for a few years you were just able to make it happen ive always thought an open deck was a bad idea for a lack of terms
I believe your 100% correct on the hemi valve layout, proven best design for quicker in and out airflow, piston crown design in NA applications may not be ideal.
Wedge style head valve positions require the air to change direction across the cylinder bore, however its intake port layout can add intake charge swirl or tumble that can improve mixture distribution in the combustion chamber.
I'd love to see a solid SMX made for max effort,
Methanol.
Max cam
90 psi.
Shut em up.
Probably break your dyno.
Love your work.
Justin.
Sydney, Australia
Still hoping for a V10 SMX. Would sound amazing.
Thank you for always teaching and going into details!
Great video love hearing your explanation on the gammit of what you do ! I agree on hemis the intake valves fill better and exhaust valves exit better being the air flow central to the bore the advantage is diffenately an advantage as the the air flows more in a straight line crosses in straight path over from Intake manifold through valve into combustion chamber straight out exhaust valve straight out to exhaust manifold in a straight line. What really makes this so effective is the timing of valves taking advantage of scavenging and fill happening with overlap events, for volumetric efficiency
through the exhaust and intake overlap of valves. This is where the valve geometry really shines is its volumetric efficiency gains. But that's also what boost does is increase volume of air being filled that's the reason for it being so effective together and your top fueler guys go a step further when your fuel is being dumped in marginally close to hydraulicing because the fuel also makes its own oxygen as it burns. The fuel and valve system were meant for each other in top fuel funnies and dragsters.
I like to think of it as less pumping loss at high rpm/flow with the hemi that helps it make more power in all out boosted combos
Calculation of rocker frequency of actuation is correct - with the divide by two factor. However, the four stroke operation means the valve is closed for a lot of degrees of crankshaft rotation, which means the rocker is loaded much more violently than just the frequency of opening would imply.
Valve rotation affects the rpm range. Darin Morgan has a good explanation of this. Wedge style is lower rpm medium rpm is cleveland or big chevy or 385 series ford. high rpm hemispherical all day long.
Yet DM never designed a hemi head... he designed a twisted wedge... hmmm wonder why????
Max effort Hemis do not have to worry about burning out the thin wall between the intake and exhaust ports i.e. Top Fuel thus have superior thermal properties compared to the wedge just saying.Kepp the cool vids coming,much enjoy !
Only a handful of people would want a full race/max hp engine.
People like Steve and Kevin from KSR build ( in my opinion )
More obtainable cars and engines and I'm sure they sell more for that reason.
Plus the knowledge Steve shares 👍❤
Thank you sir love the channel.
I like this new schedule of videos being released. I like the longer ones that cover lots of topics, much more likely to watch the whole thing!
Like You Demonstrated Steve a True Old School Hemispherical Combustion chamber Intake valve opening is in direct tangent line over the exhaust valve. Exhaust valve opening is directly over the intake valve. Intake and exhaust valves both open during Overlap the fresh air fuel charge coming in has 90 degrees or less turn with crossover pulse energy drawing in more Fuel & Air Directional change Vs 180 degrees for A Wedge V8.
Intake ports on a Hemi have a straight shot in. Hemi exhaust a much cleaner shot out.
Please tell us more about cylinder head quench. 👍
Thanks Steve, appreciate that you take the time out of your busy day to explain this stuff. Super interesting.
Idgaf about HP numbers...How durable and reliable is it? Any motor can make all the boost...but can it take it for more than single pass
Another good vid "in my opinion". Enjoy the high horse engine specifications.
Remember steve it is always hard to explain that the sun is shining to people who keep thier heads in the sand...😊
Wow Steve just wow haha them water blocks are masterpieces.
Do you find hotspots in the cooling systems? Seems like the cooling runs along the engine and then back.
Loving these tech videos, Steve you do a great job explaining where its understandable and comprehendable. Keep em coming
...awwsome tech, Steve & thank you - I really want the video on 'quench' - I have stewed about it alot & want to learn the 'real deal' - again, thank you !...
This was another great video, and I learned a lot. As I watched how often you had to make quick calculations it brought me back to high school. I was at a technical high school with a lot of trades programmes. I would often hear guys (yes, they were always guys) say "I want to be a mechanic, why do I need math?". This video shows exactly why. If you want to be the best mechanic yyou can be you need more than the ability to spin a wrench.
This video should be sent to every school guidance councillor that needs to answer the question "Why do I need math?"
It's probably not cost effective but a gen 3 hemi for Mopar guys wanting a drag and drive car would love something like your sml
I always chocked it up to the shape of the chamber. With the hemi being domed it is easy for air for flow in a less turbulent manner in and out. With a wedge the air has to hit a wall and redirect into the exhaust port. Air will flow around a sphere smoother than it will around a flat wall.
I appreciate your discerption in your videos for a lot of us less knowledgeable viewers.🤔
Yeah I love this video it really dose show the massive difference between a smx and a pro mod engine like drivability and making very close numbers but the face you can drive around the streets with 5000hp is insane
Great video Steve, definitely want to here more about quench and softening up the combustion chamber for boost.
Awesome video on camshafts I always bought them from Jerry Haas that was for the motors i built for the cars my brother drove for me. Now the motors I used I had Leo Walter's ( Superchargers ) build my motors an tune them. The motors he built for me was filled Aluminum blocks. This was in the 2000s. There is so much change in motors from yr 2000 to now. I can't wait to see the Camaro to start making pass . Keep up the great videos.
So, my theory is what you said plus intake and exhaust port placement and desig.
More direct alignment into center of cylinder. Volume of flow at crazy rpm.
Seems like the efficiency of flow due to time available.
I’m definitely interested in a video about quench. I was also wondering why the hemi that Cleetus has doesn’t use captured lash caps like the SMX does.
Hemi head valves are placed across the cylinder bore and inclined toward the center resulting in better airflow than a wedge design in a relatively small package. You can run bigger valves in a hemi head without issues with valve shrouding from the cylinder walls.
I really enjoy all of your videos. You have so much knowledge of engineering engines for different applications. Keep up the great work. I look forward to it more soon.
It's just the way the air flows thru the motor between the 2 styles hemis flow better because of what you said with the valve opening to the center
It's completely next level when Steve says 'only 1500hp, nothing huge'.
you are correct with the hemi theory.
draw a picture of a wedge from top down then draw a picture of a hemi top down and tell me which one has the easier airflow.
i do alot of harley stuff and i would like you to check out hammer performance to see there research.
they made a 28 degree reverse dome piston and a 30 degree machined head to make a small squish band while keeping comp down.
the results work better than the competition and their stuff makes more hp and tq than anyone else.
The Valmaro? Freakin perfect Steve!
The greater valve angle in the hemi allows a larger valve to be used (in relation to piston diameter ratio). These larger valves allow quicker cylinder filling for more high end power where that starts becoming a limitation.
Steve. We know that you could build a5000+ hp engine! But you have made your place in drag and drive engines. What would happen if you tried running an all out hemi on a drive and drag run haha.
Steve we know your engine’s are the best for d&d runs … you are right were you should be …. We know the difference…
But you are doing a great job of explaining/educating ..you’re the best!
Cleetus seems to have a lot of influence on all of your YT channels... You are great! Thank you for sharing all this insights with us. V8 Rules 🙂
No clue why I don’t get it. Bunch of goofs to me.
@@daleolson3506Vids Of Cars You Build...?
@@daleolson3506 Becareful speaking the truth, it hurts Cleety Clowns feels and they cry like woke folk who lost the election.
Could it have to do with the law of motion. The hemi has straight 😮high flow through the combustion chamber.
No kidding. Poor Steve can’t let it go that garret bought that proline hemi. Now I get it Steve reads the comments and everyone is talking about it but don’t let it bother you man. Cleetus gave you couple hundred thousand followers overnight, just let it go
Another issue that I believe is far to often overlooked is the exhaust system back pressure holding the exhaust valve open at high rpm, and I realize that this might sound crazy but I think it's worth looking into and that is a vortex exhaust system, similar to that of a R/C model aircraft nitro motor, that literally vacuums the exhaust gasses off the head helping to close the exhaust valves faster and allowing for even higher rpm
Emblem for Vals camaro SSMX