I think you answered your own question about the huge experimental change in plenum volume, there at the end. As far as I can tell, this is virtually the same as speaker cabinet design. And if I'm right, from my experience, you will see minimal effects until you decrease the volume past a critical point. Runner size and length should be comparable to speaker port length/volume, and/or horn length/volume, and would be very sensitive to changes.
Well, an simple way to figure out the engine frequency is to put a mic in and see the peak in an audio spectrum. Then build a "dram" that's resonant @ the frequency
Richard, anytime you say in a video "what do you guys think, should I test it?" EVERYONE watching instantly says YES!!! Thank you so much for all your hard work and for sharing your knowledge.
You raised a lot of questions and did a fine job of answering them. When you mentioned fuel standoff the first thought I had was could this be caused by some form of resonance. Later in your discussion you answered that question. That also confirms why some combinations respond to increased plenum volume and some do not. You make people think and that’s a good thing. The more we think the more possibilities exist that we might just be the blind squirrel that finds an acorn. Great video. I always learn something from you. Please continue the series.
Disappointed that the dyno chart didn't look like a shark. That "flamingo leg" intake looks awesome too! Do a video on that. In terms of beer kegs they're pretty darn utilitarian. My aluminum foundry is made from a keg. Wait till you start making mufflers from freon jugs you'll know you're set then.
Love the testing you do and scientific way you go about it. I did have another idea on potentially another plenum volume test. My thought was the testing you’ve shown lately, and forgive me if you’ve shown this and I just missed it, is all about adding volume. What about less volume? Small block mopar magnums for example had an option of a 2bbl single plane manifold that could be bought direct from mopar. That manifold had a fairly small plenum volume to it compared to more conventional intake. And while the runners have been shown to flow within 10cfm or so of the 4bbl version that was also available, general consensus is that the 4bbl is a much better option for anything that sees boost, nitrous our big cubes despite often using the same 2bbl throttle bodies. Factory they came with a large keg style intake and Dulcich alleged to it during the engine masters episode on volume but a lot of guys go to great lengths to reduce the volume. While that engine specifically may not be the greatest option for taxing the intakes just based off cylinder head options and variables that are difficult to make consistent, maybe a stroked 4 banger like a Honda B or H or K series would be a good test. Lotta guys go to great lengths on those to increase volume so it begs the question that, while too much is not much a problem it seems, maybe too small is? One of those things where testing just leave ya with more questions lol
This was a neat test, a couple graphs comparing open and 4 hole spacers on a dual plane would prove the point. The issue you maybe ran into with the Holley Hiram is the plenum is already pretty huge. It would be possible to test a reduction in plenum volume. The dual quad top is pretty tall, a flat plate like was used under.the m90, drilled for the perimeter and dual quad pattern would cut the plenum by about half. It's a tuning factor and even the best guys have to put their theories to the test because it's so abstract. I also don't believe this is Helmholtz resonance, it's still resonance but doesn't use non pathway airsprings.
Back in 91' I remember my little Escort GT with the Mazda BP 1.8 had both dual length runner intake manifold and a Heimholtz resonator in the intake tube; I suppose Mazda was trying their best...was a fun little car and zero issues. Just mentioning this since Richard's vids have been on the subjects.
If you ever saw a dyno run of the last carbed 600cc sportbikes with the airbox removed, you would begin to understand the reversion, and fuel fog standoff Mr Holdener is talking about. Just below the torque peak, the fuel reversion was incredible!!! It gave you a ton of respect for the men engineering the carbs
we ran a 600 with no air box on the chassis dyno standing next to it with a video camera and a strobe light to see the fuel past the valve and the fuel stand off-it was awesome
I remember seeing that intake you made on Engine Masters. It is still the greatest and funniest intake. I was hoping for a power increase. It's interesting that plenum volume doesn't really make a differenece unless you get the formula right. Great video, keep up the great videos
One thing not mentioned between the single and dual plain is firing order and port sharing. While negative pressures are shared between all 8 cylinders on a singke plain. The dual separates them. Hence the old pratice of using a larger carb on a dual plain. A open spacer may improve volume. It does not improve the approach of the negative pressure to the ventries. Older single plain intakes with a spread bore plate sometimes used a dividing wall. And some that even shared all runners to the same side bank. Tunnel rams still give you the best of both worlds.
I like it. I know that Propane was really popular across Europe for years. It's a challenge to directly compare octane, even on the same engine on different days. I have never understood why high pressure port liquid propane never caught on in North America. LPG is really similar but is a mixture, i would really like to see a boosted test.
LPG is still popular. and much cheaper. 1 liter of gasoline here is about $ 1.70 and LPG is $ 0.80. LPG injection has also been tried, but the pumps break down quickly. with newer cars they use g3. I am a fan of the impco line and now use the 300 evaporator and 425 mixer for my 5.7 vortec. am now working on an l92 and use up 2 425 mixers with a dual port intake. but to get information about for example dual plane or single plane or which camshaft for max torque is quite difficult
@@arjenvandrie7705 lpg would work really well in front of a turbocharger compressor intake?? Right as a pre cooling air inlet temperatures and for supplement and fuel supply ?? Ps. I’m not big on NO2 laughing 😝 gas spray but I’ve been told it would work the same way ish
I ran a mechanical fuel injection Bird catcher on a Tunnel Ram ( large plenum volume) when you would lift and close the butter flies the engine would slowly drop R.P,M back to idle. compared to the Carb's
Kegalodon!!! I LOVE Shark Week. I've watched it every year since the beginning!!! Back in 1988 I would set up vhs tapes to tape it in case I missed an episode!
A problem I saw with this on EM was the plenum was on top of another smaller plenum and the smaller one closer to the runners would have made the biggest changes, So effectively the keg was just far too up stream and it was like having the door open next door vs having it closed for all the difference it would make, The plenum actually has to be directly attached to the runners themselves not through a smaller secondary plenum is what i'm trying to say. . I think also the main benefit of a plenum is the resonating pulses in the intake have a less dramatic effect on the chambers vacuum signal, So one cylinder opening its valve is not effected by the prior cylinder closing nor does it effect the next one about to open afterwards, The cylinders get to work more individually. Of course runner length has a dramatic effect on this as always and on a carb engine while the vacuum might be more consistent the distance from carb to cylinder might mean worse throttle responce but given a turbocharged application especially with multi port EFI (so imports with 2JZ's etc) its probably not much of a concern. If you look at past or modern turbo F1 engines the plenums tend to be the same size as the engine block! . I think the short runners on that FAST intake have a huge problem that they are effectively drawing from the space directly in front of thier neighbour and that makes every cylinder suffer, the second their throats pass each other in the medium length suddenly everything gets better and it surprises me they didnt pick up on this.
Hi Richard, I love your videos, and your channel, you've got tons of great content. I think what this test shows, as other comments have mentioned, is that the plenum volume on the manifold as designed by Holley was more than adequate for the engine combo. I'd be really interested to see results on a test starting with a severely undersized plenum, and gradually increasing volume until no further gains are seen with increased volume. Thanks for all the effort you put into all this stuff, and keep up the great work!
If you are gonna test the carburetor and multi port is it also worth it to throw a TBI system on as well? Because from how I understand it the fuel is still injected at 50 plus psi so it wouldn't be affected like a carb would be based on how the engine is signaling. Just some thought
Surely the heat isolation effects of a carb spacer can have a positive effect, particularly on old cast iron intakes. I'd love to see a comparison on a street/strip motor, dual plane intake, carb. A variety of spacers trialed - open, 4 hole, tapered and in two different heights, say 1" and 2", see if there are any trends.
Maybe intakes and runners should be optimized and will look something like a two stroke tuned pipe. The easiest to do would be "stacks" for individual port injection. Wouldn't that look wild.
It needs a hinged lower jaw with a vacuum actuator from a vacuum opening exhaust valve so at lower rpms the mouth is mostly closed and opens as rpm's rise
Sorry my device or RUclips kept eating my comment so I ended up retry 5 + times gerr that’s why It’s edited more than once . Yes do like the idea of testing the same intake with a carb or moving all 8 efi injectors up top or mechanical injectors vs down at the ports. I do like the idea of retesting the kegladon at a lower RPMs and add a carb ( for 2 different runs higher again and lower ) on top of it and leave the rest the same way as the last testing procedure aka keeping the Throttlebody bolted on just shut when testing the carb part ( and the same way with testing the injection testing just shut the carb blades off ) of the testing to see if it makes any difference or not to really drive your point home 🏠 . Heck I’d try it out on the dyno temporarily to learn but my engine isn’t ready yet and I’m biased to cross rams 🐑 ( do you Richard have any dyno stuff from the mopar 60’s cross 🐑 that you showed in the video and I think 💭 it might make a good content ) and I like my OG hood without a big hole in it or skipping having a bonnet . . I’d love to learn when to spray and were to spray as my intake has more than one injectors set of 8 sequential efi injectors ( and one Direction direct injection set of 8 inside of the combustion chambers for a spray pattern aka GDI/diesel 5000 psi / 350+ bar set because the parts number looks the same if I’m not mistaken but the pumps are different than or the settings/setup ) and two mechanical constant electronically adjustable ( ecu by way of a ball valve servos ) spray bars in the plenum ( / mounted to the ) sides pointed at the super chiller HX / intake ports and 2 mechanical ( same setup as the bars as custom efi units are expensive to buy and bulky to use and this was my fix ) nozzles after the turbos to supplement extra fuel ⛽️ in. . I have questions about how helmholtz frequency affects camshaft timing ( fixed and unfixed ) / VVT,VlSA( variable lobe separation angel ),VVL or how variable intake ( or fixed length ) ( and I guess exhaust two well where on the topic ) runner length and how it effects the tune up / tuning strategy aka spark tables and fuel tables and or the firing 🔥 order timing as helmholtz frequency can change cylinder to cylinder scavenging I think 🤔 💭
I put a 1” spacer on my 350 Performer rpm duel plane with holley 750. bore 20 over flat top aluminum pistons stock crank and rods mild-medium comp cam. 194 stock heads that I ported and cleaned up as much as I could. Hooker headers and swap to Hei. Runs strong but I’m pulling the motor soon to build something a lot nastier and this is the matching numbers engine so I don’t want to blow it up so I’ll oil it wrap it up and put it in a corner for the future. I’m third owner of the car it now has 110k miles. I have had it since 64k I went through whole car during my first time having cancer and doing chemo treatment. All that said the spacer definitely gained some power the engine liked the increase fall for sure.
I’ve always wanted to know if the abrupt end of the carb throats and transition to the open plenum (even the half-plenum of a dual plane) does, versus a gradual blend. My guess is that there’s a lot of turbulence, but that might be a good thing for vaporization and distribution. If there’s room below the carb for the air to mix up with the fuel in the turbulence. I’m also really glad you mentioned the visible fuel reversion out the top of the carb. I’ve seen that so often, but nobody ever talks about it. Putting on my acoustician hat (my degrees were signal processing, but I took three graduate acoustics classes): that happens because mass of the air/fuel mix the 4 throats of the carb is the one of the vibrating masses of the helmholz resonator. The simplest helmholz resonator is a hollow ball with an open neck, and the resonance is the “spring” of the compressible air in the ball acting on the “weight” of the mass of air vibrating up and down in the neck. As you said, a manifold is a very complex helmholz resonator because it has a volume plus 8 runner masses, plus 4 masses of air in the carb... but ALSO because there is net mass flow through the system, not just resonance of a fixed mass of air in a simple helmholz resonator. It’s all really cool stuff, and throwing the mass flow into the mix makes it a lot harder to either solve mathematically or model on a computer than a simple resonator.
Richard Holdener after I wrote that, I had the “forehead smack” moment where it occurred to me that even with a smooth blend, there WILL be a ton of turbulence just below the carb when the throttle blades are in any position except wide-open. I see your point about it only being an effect that you’d see at very high flow... but I guess my point is that even then I’m not sure you’d WANT to eliminate that turbulence since it might help even out fuel distribution.
I think Kegalodon needs boost! A little more than the CO2 produced when flowing liquid bread (yes, the result will be the same curve just higher--right?). Maybe that test should try to swell the keg with mega boost. Very interesting topic for sure. I've always wondered what kind of artificial tornado exists in a V-8 single plane intake at 8K RPM.
I seen this before and at the time I did not know what was going on except I fixed the problem with the fuel over the carb a 750 holly the problem is the pressure wave bounces back of carb and and it picks more fuel as it goes back in again . I fixed the problem by changing the exhaust and the change was instant . I was a kid back then an Pete who had a record holding Manza told me about the signal to the carb and how manifold design and port size ect effected that signal . Many hours were spent there watching him work on his Monza . I listened to him chat about the cylinder head design and making hp . Long time ago back in the Sheppard days
Thanks for educating us as jim I was curious if the exhaust side messed with the intake side if only one side was changed or if both changes at the same time on runner lengths and everything else motor and drive line wise was the same. Guess now I know helmholtz frequency can change pinging/ knock resistance and how the exhaust vibration can affect intake feeding of air and fuel into each cylinder firing event as I’ve never heard of your exact carb problem and how you fixed it. I have heard of some intakes being picky before but a quick change to a different carb ( / or Throttlebody ) or changing the intake to a different one fixed it
Wha wha Wha wonderful!!!I do a lot of collision work and the imports and their resonator chambers added to the intake tract are all about what your talking about.I have left them off when destroyed and to save a friend a few bucks and I must say the cars have more intake noise and I swear they might be down ever so slightly on power. Maybe it’s in my head?
When the throttle body is restrictive for the engine, then additional plenum volume becomes more valuable. When the TB is oversized, then you can get away with very small plenum with little loss.
You were talking a lot about the differences is spacers on signal vs duel plane intakes any chance you'll throw a video up on it I'm looking at getting a tapered or open spacer for my non airgap duel plane I would really find you're advice helpful
i found on my b20vtec that going from a 1 litre plenum with a 70mm throttle body and 2.5 inch cold air intake to a 5.5 litre plenum with a 90mm throttle body and 4 inch cold air intake there was an average tempreture drop of 20 celcius/68 fahrenheit, but also an increase of air flow of 18% at the topend 9500rpm of course AFR's need adjustment and were corrected. also what i had found was putting a 65mmX2.5 inch long restrictor inside the 4' CAI on the 90mm throttle body with the 5.5L plenum it picked up response and better throttle transition. and on the VE tables pretty much from 2000rpm till 9500rpm it was in the 105kpa column @ WOT when compared to the original set up maxing out to 102kpa @ WOT.
@@richardholdener1727 although the motor is naturally aspirated I think it has something to do with the expanding inside a larger plenum allowing it to cool down
Given intake runner length tunes for a given rpm, has anyone made variable runners, something like a trumpet that slides in as rpm goes up, much like cams on modern engines are variable.
I think the plenum volume ofnthe ram style intake was all the engine wanted. In older 2x4bbl pro stock development, my understanding is that those engines will keep showing dyno gains as you add ridiculous amounts of plenum, but that on the track they fall flat. Another example of the dyno lying. I also suspect fuel injected vs carb makes a big difference here. You touched on that here.
Love the content rich. I've brulee dulcich and yourself talk about the signal to the carb. I was wondering if you do a video (I know I'm asking maybe with animation or drawing) explain what you mean by signal. Is it the vacuum created by the valve opening? Air bouncing around? I'm just not sure on what you mean cheer?
How about a test on a Dual Plane, where you run a spacer, say 2", of open design, verses a four hole spacer. Particularly on a Dual Plane that is totally divided.
Interesting, I always thought fuel standoff ( same as double carburation ?) was only a concern on old 2 strokes without reeds on intake. So the rpm range with fuel standoff richens up that area of the RPM curve when the air passes through the carb 3 times before it ends up in the cylinder same as an old 2 stroke? Is this the primary emissions advantage of direct injection? If so, how do VW direct injected TSI intake ports get loaded with carbon? Maybe they're opening injectors too early trying to give fuel some time. Thanks for all the testing!
You're thinking about plenum volume in the wrong way. A plenum is supposed to be a quiescent space that maintains a steady pressure to allow all of the cylinders to breathe equally. It is the runners that have to be calculated to resonate at a certain frequency selected by the engine designer to maximize volumetric efficiency at a definite engine speed. This is the purpose of the Helmholtz calculation, and defines where peak torque is achieved. The plenum volume must be a multiple of the runner volume to decouple the resonant frequencies. Once upon a time, I was working on a V12 marine engine project where it had been designed with uneven firing intervals; 30-90 all the way through the firing order, instead of 60-60. We were brainstorming ways to improve performance, and theorized that the odd-bank cylinders were robbing air from the even-bank cylinders. To test this, we modified the plenum with dividers to make the cylinders breathe in four sets of three, by dividing the engine into quadrants. The power output dropped by about 50 hp out of 860. Then we took the lateral divider out, so the engine would breathe like two inline sixes, but the power only came halfway back.. So we were totally wrong in assuming one bank was robbing the other, and concluded that plenum volume should be about double the engine displacement. I would like to see you do tests in the opposite direction: take a Holley high ram EFI manifold, and cut its volume in half. Then see if it reduces power.
Is there a test you can do in which you can limit reversion ie: some sort of fluting that offers resistance to outward flow. I have always wondered what a set of runner mounted Read Valves would do in a back to back test, with and without.
If you've ever played around with subwoofers, you'll understand Helmholtz resonance a bit better. Also a ported sub box reacts kinda like the resonance chambers in factory air inlets
@@richardholdener1727 Anton had the same line of thinking I did... change the port shape or size dramatically and you can feel the difference in the air coming out of the port, so much as to actually hear it chuffing if the port isn't big enough, and you're trying in most cases to tune the box to a specific frequency. The chuffing (port noise) could be analagous to fuel stand off? Just spitballing here, but that's what came to mind when you discussed fuel standoff.
Hey Rich,love all the content 1st off. My question is i seen the episode of Engine Masters, where you guys tested different intake manifolds on the 360 Magnum,i wanted to know if for my daily driver(absolutely no racing just cruising)is the modified kegger and throttle body worth spending over a grand on my truck( that I barely do 90-100mph at any given time except Vegas runs😊) it's bone stock but i do plan on using the same cam if not the 216/224 duration cam instead? I appreciate you input thanks.
Id imagine theres a tipping point where the plenum is large enough. But below that might there be changes? For the 2.8 and 3.1 60 deg v6 the plenum is around 0,5 liter. On the later 3400 engine its 1 liter. The still later 3500 engine its atound 1,5 liter. In the 3900 they have a active wall in the plenum that divides it into two chambers at certain rpms. I think its open in low rpm, closed in mid and open again at high rpm. But those are fuel injected engines of course
I think you missed the magic of the plenum "volume". You want to havea column of fast moving air, the faster and longer the better... like an intake runner. The kegeledon has tons of volume but it is not being sped up... its like hogging out intake ports too big. Less volume and more length is better. You are wanting the inertia of the moving air to keep the air moving even after the valve closes so that when the next valve opens the air is still moving. Also if you can add your fuel before the plenum extension you will get the benefit of the increased weight of the air caused by the weight of the fuel. This dramatically increases the weight of the charge column. If you replaced the kegeledon with a 4inch pipe x 4 feet long that might do better... you need to tune that so maybe have a 3 inch and a 2 inch and a 1 inch and 5 inch and 6 inch pipe to show the extremes?
Why not test a single-plane manifold, and a dual-plane manifold, with something like Holley's Sniper injection system ? That way, you're only testing the manifold, not the change in carb to efi. Will a Holley Sniper run on a dual-plane manifold ?
I expected a better bottom end, and now I'm questioning evey decision in life haha. Just kidding. Im really surprised though. Ice always thought that short runner/low volume was the recipe for increased power up top and vice versa.... i wonder if this was a port velocity issue where the plenum was so large that it acts as a buffer/great equalizer.
This is gold. Best Automotive RUclips channel hands-down
Richard has been knocking it out of the park. One of the few channels I immediately click on.
Richard..not sure if anyone has told you..but THANKS! Thanks for the videos and sharing your knowledge!
Glad to help
I think you answered your own question about the huge experimental change in plenum volume, there at the end.
As far as I can tell, this is virtually the same as speaker cabinet design. And if I'm right, from my experience, you will see minimal effects until you decrease the volume past a critical point.
Runner size and length should be comparable to speaker port length/volume, and/or horn length/volume, and would be very sensitive to changes.
Are you also known as, shocker mike?
@@supercoupe28 Not to my knowledge. Michael A is not my actual name.
Very interesting to say the least. I hope you touch on this again.
Well, an simple way to figure out the engine frequency is to put a mic in and see the peak in an audio spectrum. Then build a "dram" that's resonant @ the frequency
Why is it not sticking out of the hood of a car,or a rat rod yet? Coolest intake ever!
I'M SENDING IT TO GARRET-HOPE HE CAN RUN IT
@@richardholdener1727 Lol, it's big enough to mount the turbos inside it.
A c-3 corvette mako shark would be perfect
Because it is for a boat engine Einstein
@@daleearnhardt817 I don't think so...
Richard, anytime you say in a video "what do you guys think, should I test it?" EVERYONE watching instantly says YES!!! Thank you so much for all your hard work and for sharing your knowledge.
I picture them all chanting yes, yes, yes (with pitch forks and torches to storm the castle)
You raised a lot of questions and did a fine job of answering them. When you mentioned fuel standoff the first thought I had was could this be caused by some form of resonance. Later in your discussion you answered that question. That also confirms why some combinations respond to increased plenum volume and some do not. You make people think and that’s a good thing. The more we think the more possibilities exist that we might just be the blind squirrel that finds an acorn. Great video. I always learn something from you. Please continue the series.
I would love to see a dyno comparison between the mopar long runner intake and a single plane duel carb on a bb mopar.
Disappointed that the dyno chart didn't look like a shark. That "flamingo leg" intake looks awesome too! Do a video on that.
In terms of beer kegs they're pretty darn utilitarian. My aluminum foundry is made from a keg.
Wait till you start making mufflers from freon jugs you'll know you're set then.
The 2 cycle engine enthusiasts will be able to discuss this topic in length. Great information keep it up!
Love the testing you do and scientific way you go about it. I did have another idea on potentially another plenum volume test. My thought was the testing you’ve shown lately, and forgive me if you’ve shown this and I just missed it, is all about adding volume. What about less volume? Small block mopar magnums for example had an option of a 2bbl single plane manifold that could be bought direct from mopar. That manifold had a fairly small plenum volume to it compared to more conventional intake. And while the runners have been shown to flow within 10cfm or so of the 4bbl version that was also available, general consensus is that the 4bbl is a much better option for anything that sees boost, nitrous our big cubes despite often using the same 2bbl throttle bodies. Factory they came with a large keg style intake and Dulcich alleged to it during the engine masters episode on volume but a lot of guys go to great lengths to reduce the volume. While that engine specifically may not be the greatest option for taxing the intakes just based off cylinder head options and variables that are difficult to make consistent, maybe a stroked 4 banger like a Honda B or H or K series would be a good test. Lotta guys go to great lengths on those to increase volume so it begs the question that, while too much is not much a problem it seems, maybe too small is? One of those things where testing just leave ya with more questions lol
This was a neat test, a couple graphs comparing open and 4 hole spacers on a dual plane would prove the point. The issue you maybe ran into with the Holley Hiram is the plenum is already pretty huge. It would be possible to test a reduction in plenum volume.
The dual quad top is pretty tall, a flat plate like was used under.the m90, drilled for the perimeter and dual quad pattern would cut the plenum by about half. It's a tuning factor and even the best guys have to put their theories to the test because it's so abstract.
I also don't believe this is Helmholtz resonance, it's still resonance but doesn't use non pathway airsprings.
Back in 91' I remember my little Escort GT with the Mazda BP 1.8 had both dual length runner intake manifold and a Heimholtz resonator in the intake tube; I suppose Mazda was trying their best...was a fun little car and zero issues.
Just mentioning this since Richard's vids have been on the subjects.
If you ever saw a dyno run of the last carbed 600cc sportbikes with the airbox removed, you would begin to understand the reversion, and fuel fog standoff Mr Holdener is talking about. Just below the torque peak, the fuel reversion was incredible!!! It gave you a ton of respect for the men engineering the carbs
we ran a 600 with no air box on the chassis dyno standing next to it with a video camera and a strobe light to see the fuel past the valve and the fuel stand off-it was awesome
I remember seeing that intake you made on Engine Masters. It is still the greatest and funniest intake. I was hoping for a power increase. It's interesting that plenum volume doesn't really make a differenece unless you get the formula right. Great video, keep up the great videos
Had to click on this to make sure I wasn’t high ... 5 minutes in and still not sure.
That's a win/win
Christ Miles you didn’t use the 5 min very well then sir?
One thing not mentioned between the single and dual plain is firing order and port sharing. While negative pressures are shared between all 8 cylinders on a singke plain. The dual separates them. Hence the old pratice of using a larger carb on a dual plain. A open spacer may improve volume. It does not improve the approach of the negative pressure to the ventries. Older single plain intakes with a spread bore plate sometimes used a dividing wall. And some that even shared all runners to the same side bank. Tunnel rams still give you the best of both worlds.
I read about Porsche tuning their intake manifolds resonating frequency on the turbo engines. Seen some serious gains.
Would love to see a deeper dive including video and discussion on that fuel standoff/resonance phenomenon.
the Engineering Explained channel does a good job explaining it in the "variable intake manifold" video.
you can also do some tests with LPG, which is widely used here in Europe and has an octane of 103
I like it. I know that Propane was really popular across Europe for years. It's a challenge to directly compare octane, even on the same engine on different days.
I have never understood why high pressure port liquid propane never caught on in North America. LPG is really similar but is a mixture, i would really like to see a boosted test.
LPG is still popular. and much cheaper. 1 liter of gasoline here is about $ 1.70 and LPG is $ 0.80. LPG injection has also been tried, but the pumps break down quickly. with newer cars they use g3. I am a fan of the impco line and now use the 300 evaporator and 425 mixer for my 5.7 vortec. am now working on an l92 and use up 2 425 mixers with a dual port intake. but to get information about for example dual plane or single plane or which camshaft for max torque is quite difficult
@@arjenvandrie7705 lpg would work really well in front of a turbocharger compressor intake?? Right as a pre cooling air inlet temperatures and for supplement and fuel supply ?? Ps. I’m not big on NO2 laughing 😝 gas spray but I’ve been told it would work the same way ish
Super great info Richard!
I’d love to see you share more about that variable injector distance Honda test. That would be really interesting.
Cheers 🍻
I will
I ran a mechanical fuel injection Bird catcher on a Tunnel Ram ( large plenum volume) when you would lift and close the butter flies the engine would slowly drop R.P,M back to idle. compared to the Carb's
5.9 magnum motors are called “ kegs” huge debate over the m1 intake by hinges or the original keg ported .. adapter plate to an ls?
Keep the awesome content coming, you are so knowledgeable and a great speaker!
Kegalodon!!! I LOVE Shark Week. I've watched it every year since the beginning!!! Back in 1988 I would set up vhs tapes to tape it in case I missed an episode!
OG
A problem I saw with this on EM was the plenum was on top of another smaller plenum and the smaller one closer to the runners would have made the biggest changes, So effectively the keg was just far too up stream and it was like having the door open next door vs having it closed for all the difference it would make, The plenum actually has to be directly attached to the runners themselves not through a smaller secondary plenum is what i'm trying to say.
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I think also the main benefit of a plenum is the resonating pulses in the intake have a less dramatic effect on the chambers vacuum signal, So one cylinder opening its valve is not effected by the prior cylinder closing nor does it effect the next one about to open afterwards, The cylinders get to work more individually.
Of course runner length has a dramatic effect on this as always and on a carb engine while the vacuum might be more consistent the distance from carb to cylinder might mean worse throttle responce but given a turbocharged application especially with multi port EFI (so imports with 2JZ's etc) its probably not much of a concern. If you look at past or modern turbo F1 engines the plenums tend to be the same size as the engine block!
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I think the short runners on that FAST intake have a huge problem that they are effectively drawing from the space directly in front of thier neighbour and that makes every cylinder suffer, the second their throats pass each other in the medium length suddenly everything gets better and it surprises me they didnt pick up on this.
Plenum volume can be connected through the two carb openings as we used. Its like joining two dual plenum intakes that resonate as 1
Hi Richard, I love your videos, and your channel, you've got tons of great content. I think what this test shows, as other comments have mentioned, is that the plenum volume on the manifold as designed by Holley was more than adequate for the engine combo. I'd be really interested to see results on a test starting with a severely undersized plenum, and gradually increasing volume until no further gains are seen with increased volume. Thanks for all the effort you put into all this stuff, and keep up the great work!
Wow lol. That would look good mounted on the hotrod going to October fest.
If you are gonna test the carburetor and multi port is it also worth it to throw a TBI system on as well? Because from how I understand it the fuel is still injected at 50 plus psi so it wouldn't be affected like a carb would be based on how the engine is signaling. Just some thought
Is the Keglodon painted in blue dykem?
winner/winner
@@richardholdener1727 I love it!
Surely the heat isolation effects of a carb spacer can have a positive effect, particularly on old cast iron intakes. I'd love to see a comparison on a street/strip motor, dual plane intake, carb. A variety of spacers trialed - open, 4 hole, tapered and in two different heights, say 1" and 2", see if there are any trends.
an aluminum carb spacer actually transmits heat to the carb-alum is a very good conductor but a poor isolator
Maybe intakes and runners should be optimized and will look something like a two stroke tuned pipe. The easiest to do would be "stacks" for individual port injection. Wouldn't that look wild.
That is why factory intake systems have resonators on the intake system before the throttle bodies.
also for noise dampening-they are intake mufflers
It needs a hinged lower jaw with a vacuum actuator from a vacuum opening exhaust valve so at lower rpms the mouth is mostly closed and opens as rpm's rise
yes and a growl
Sorry my device or RUclips kept eating my comment so I ended up retry 5 + times gerr that’s why It’s edited more than once
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Yes do like the idea of testing the same intake with a carb or moving all 8 efi injectors up top or mechanical injectors vs down at the ports. I do like the idea of retesting the kegladon at a lower RPMs and add a carb ( for 2 different runs higher again and lower ) on top of it and leave the rest the same way as the last testing procedure aka keeping the Throttlebody bolted on just shut when testing the carb part ( and the same way with testing the injection testing just shut the carb blades off ) of the testing to see if it makes any difference or not to really drive your point home 🏠 . Heck I’d try it out on the dyno temporarily to learn but my engine isn’t ready yet and I’m biased to cross rams 🐑 ( do you Richard have any dyno stuff from the mopar 60’s cross 🐑 that you showed in the video and I think 💭 it might make a good content ) and I like my OG hood without a big hole in it or skipping having a bonnet .
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I’d love to learn when to spray and were to spray as my intake has more than one injectors set of 8 sequential efi injectors ( and one Direction direct injection set of 8 inside of the combustion chambers for a spray pattern aka GDI/diesel 5000 psi / 350+ bar set because the parts number looks the same if I’m not mistaken but the pumps are different than or the settings/setup ) and two mechanical constant electronically adjustable ( ecu by way of a ball valve servos ) spray bars in the plenum ( / mounted to the ) sides pointed at the super chiller HX / intake ports and 2 mechanical ( same setup as the bars as custom efi units are expensive to buy and bulky to use and this was my fix ) nozzles after the turbos to supplement extra fuel ⛽️ in.
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I have questions about how helmholtz frequency affects camshaft timing ( fixed and unfixed ) / VVT,VlSA( variable lobe separation angel ),VVL or how variable intake ( or fixed length ) ( and I guess exhaust two well where on the topic ) runner length and how it effects the tune up / tuning strategy aka spark tables and fuel tables and or the firing 🔥 order timing as helmholtz frequency can change cylinder to cylinder scavenging I think 🤔 💭
I think it has a lot to do with the atomization of the fuel too and how well it can get mixed in with the air
Great work, you could school US on boosters, strait, down or annular.
I put a 1” spacer on my 350 Performer rpm duel plane with holley 750. bore 20 over flat top aluminum pistons stock crank and rods mild-medium comp cam. 194 stock heads that I ported and cleaned up as much as I could. Hooker headers and swap to Hei. Runs strong but I’m pulling the motor soon to build something a lot nastier and this is the matching numbers engine so I don’t want to blow it up so I’ll oil it wrap it up and put it in a corner for the future. I’m third owner of the car it now has 110k miles. I have had it since 64k I went through whole car during my first time having cancer and doing chemo treatment. All that said the spacer definitely gained some power the engine liked the increase fall for sure.
How about a carb spacer test on throttle body fuel inject ie. Fitech or Sniper
I’ve always wanted to know if the abrupt end of the carb throats and transition to the open plenum (even the half-plenum of a dual plane) does, versus a gradual blend. My guess is that there’s a lot of turbulence, but that might be a good thing for vaporization and distribution. If there’s room below the carb for the air to mix up with the fuel in the turbulence.
I’m also really glad you mentioned the visible fuel reversion out the top of the carb. I’ve seen that so often, but nobody ever talks about it. Putting on my acoustician hat (my degrees were signal processing, but I took three graduate acoustics classes): that happens because mass of the air/fuel mix the 4 throats of the carb is the one of the vibrating masses of the helmholz resonator. The simplest helmholz resonator is a hollow ball with an open neck, and the resonance is the “spring” of the compressible air in the ball acting on the “weight” of the mass of air vibrating up and down in the neck. As you said, a manifold is a very complex helmholz resonator because it has a volume plus 8 runner masses, plus 4 masses of air in the carb... but ALSO because there is net mass flow through the system, not just resonance of a fixed mass of air in a simple helmholz resonator. It’s all really cool stuff, and throwing the mass flow into the mix makes it a lot harder to either solve mathematically or model on a computer than a simple resonator.
I don't think that is an issue unless there needs to be more flow
Richard Holdener after I wrote that, I had the “forehead smack” moment where it occurred to me that even with a smooth blend, there WILL be a ton of turbulence just below the carb when the throttle blades are in any position except wide-open. I see your point about it only being an effect that you’d see at very high flow... but I guess my point is that even then I’m not sure you’d WANT to eliminate that turbulence since it might help even out fuel distribution.
I think Kegalodon needs boost! A little more than the CO2 produced when flowing liquid bread (yes, the result will be the same curve just higher--right?). Maybe that test should try to swell the keg with mega boost. Very interesting topic for sure. I've always wondered what kind of artificial tornado exists in a V-8 single plane intake at 8K RPM.
Camera 🎥 time and maybe some lighting inside of the kegladon?? With it running? A dyno test
I seen this before and at the time I did not know what was going on except I fixed the problem with the fuel over the carb a 750 holly the problem is the pressure wave bounces back of carb and and it picks more fuel as it goes back in again . I fixed the problem by changing the exhaust and the change was instant . I was a kid back then an Pete who had a record holding Manza told me about the signal to the carb and how manifold design and port size ect effected that signal . Many hours were spent there watching him work on his Monza . I listened to him chat about the cylinder head design and making hp . Long time ago back in the Sheppard days
Thanks for educating us as jim I was curious if the exhaust side messed with the intake side if only one side was changed or if both changes at the same time on runner lengths and everything else motor and drive line wise was the same. Guess now I know helmholtz frequency can change pinging/ knock resistance and how the exhaust vibration can affect intake feeding of air and fuel into each cylinder firing event as I’ve never heard of your exact carb problem and how you fixed it.
I have heard of some intakes being picky before but a quick change to a different carb ( / or Throttlebody ) or changing the intake to a different one fixed it
Wha wha Wha wonderful!!!I do a lot of collision work and the imports and their resonator chambers added to the intake tract are all about what your talking about.I have left them off when destroyed and to save a friend a few bucks and I must say the cars have more intake noise and I swear they might be down ever so slightly on power. Maybe it’s in my head?
I've done lots of Honda air intake testing-they really respond
When the throttle body is restrictive for the engine, then additional plenum volume becomes more valuable. When the TB is oversized, then you can get away with very small plenum with little loss.
You were talking a lot about the differences is spacers on signal vs duel plane intakes any chance you'll throw a video up on it
I'm looking at getting a tapered or open spacer for my non airgap duel plane I would really find you're advice helpful
I was expecting to see a couple of carbs sat on top of the keg...
Can we get a plenum size comparison on boost? Would be awesome
i found on my b20vtec that going from a 1 litre plenum with a 70mm throttle body and 2.5 inch cold air intake to a 5.5 litre plenum with a 90mm throttle body and 4 inch cold air intake there was an average tempreture drop of 20 celcius/68 fahrenheit, but also an increase of air flow of 18% at the topend 9500rpm of course AFR's need adjustment and were corrected. also what i had found was putting a 65mmX2.5 inch long restrictor inside the 4' CAI on the 90mm throttle body with the 5.5L plenum it picked up response and better throttle transition. and on the VE tables pretty much from 2000rpm till 9500rpm it was in the 105kpa column @ WOT when compared to the original set up maxing out to 102kpa @ WOT.
you saw a change in IAT from a plenum change?
@@richardholdener1727 yes that's correct Richard
@@richardholdener1727 although the motor is naturally aspirated I think it has something to do with the expanding inside a larger plenum allowing it to cool down
How about covering the dyno test on whatever that was at 2:35? Looks intriguing.
I don't see anything at 2:35
Given intake runner length tunes for a given rpm, has anyone made variable runners, something like a trumpet that slides in as rpm goes up, much like cams on modern engines are variable.
yes they have
My poor brain+science=I’m gonna go grab a beer
So when is the Kegladon available for purchase
I think the plenum volume ofnthe ram style intake was all the engine wanted. In older 2x4bbl pro stock development, my understanding is that those engines will keep showing dyno gains as you add ridiculous amounts of plenum, but that on the track they fall flat. Another example of the dyno lying.
I also suspect fuel injected vs carb makes a big difference here. You touched on that here.
Love the content rich. I've brulee dulcich and yourself talk about the signal to the carb. I was wondering if you do a video (I know I'm asking maybe with animation or drawing) explain what you mean by signal. Is it the vacuum created by the valve opening? Air bouncing around? I'm just not sure on what you mean cheer?
“The mighty Kegladon... RAAAH”
excellent explanation of the resonance , awesome info as always thanks
wow so much information!!! very good video, thank you
How about a test on a Dual Plane, where you run a spacer, say 2", of open design, verses a four hole spacer. Particularly on a Dual Plane that is totally divided.
Very interesting good stuff clearing up all the myths great vid.
Sounds like you have some carb testing to do.
Too much science to watch on the run. Here's your well deserved 😎👍 and I'll watch the whole thing later.
Enjoying your content, always able to learn something.
Interesting, I always thought fuel standoff ( same as double carburation ?) was only a concern on old 2 strokes without reeds on intake. So the rpm range with fuel standoff richens up that area of the RPM curve when the air passes through the carb 3 times before it ends up in the cylinder same as an old 2 stroke? Is this the primary emissions advantage of direct injection? If so, how do VW direct injected TSI intake ports get loaded with carbon? Maybe they're opening injectors too early trying to give fuel some time. Thanks for all the testing!
no fuel going through the ports to clean them
A carb spacer would also likely increase fuel atomization due to time just like charge cooling that could also change the power output
Helmholtz would be proud!
Who won the cam? The higher the carb the better the atomization to.
Richard can you test cold fuel vs ambient fuel. Also test cold water methanol vs warm ambient.
Great video! One of your best.
You're thinking about plenum volume in the wrong way. A plenum is supposed to be a quiescent space that maintains a steady pressure to allow all of the cylinders to breathe equally. It is the runners that have to be calculated to resonate at a certain frequency selected by the engine designer to maximize volumetric efficiency at a definite engine speed. This is the purpose of the Helmholtz calculation, and defines where peak torque is achieved. The plenum volume must be a multiple of the runner volume to decouple the resonant frequencies.
Once upon a time, I was working on a V12 marine engine project where it had been designed with uneven firing intervals; 30-90 all the way through the firing order, instead of 60-60. We were brainstorming ways to improve performance, and theorized that the odd-bank cylinders were robbing air from the even-bank cylinders. To test this, we modified the plenum with dividers to make the cylinders breathe in four sets of three, by dividing the engine into quadrants. The power output dropped by about 50 hp out of 860. Then we took the lateral divider out, so the engine would breathe like two inline sixes, but the power only came halfway back.. So we were totally wrong in assuming one bank was robbing the other, and concluded that plenum volume should be about double the engine displacement.
I would like to see you do tests in the opposite direction: take a Holley high ram EFI manifold, and cut its volume in half. Then see if it reduces power.
runner length determines the effective operating range-Helmholtz Resonance is the resonating frequency of the Plenum volume as described
Need to find a place to make a clear acrylic intake manifold and run smoke or colored fuel through it to see how it flows??
Thinks about making a plenum and 1st thing he thinks about is a keg ? Now that's a mind of a master builder !
Stick with what you know-I/m actually not a beer drinker but a Keg of Raspberry Lemon Drops (the manliest of all the Lemon Drop Family) would work
Is there a test you can do in which you can limit reversion ie: some sort of fluting that offers resistance to outward flow. I have always wondered what a set of runner mounted Read Valves would do in a back to back test, with and without.
If you've ever played around with subwoofers, you'll understand Helmholtz resonance a bit better. Also a ported sub box reacts kinda like the resonance chambers in factory air inlets
sub woofers only resonate-they don't add pressure wave charge filling to improve power
@@richardholdener1727 I guess I meant more about how different volumes resonate differently
@@richardholdener1727 Anton had the same line of thinking I did... change the port shape or size dramatically and you can feel the difference in the air coming out of the port, so much as to actually hear it chuffing if the port isn't big enough, and you're trying in most cases to tune the box to a specific frequency. The chuffing (port noise) could be analagous to fuel stand off? Just spitballing here, but that's what came to mind when you discussed fuel standoff.
Does the extra time for a carb to mix the fuel with air over fuel injection the same as air charge temperature as opposed to port injection over TBI?
TBI add charge cooling like a carb, fuel atomization is already good with high-pressure injection
Fantastic information. 💘
I think you ment to say Jason from JT Fab lol. Recognized the work bench right away lol.
Hey Rich,love all the content 1st off. My question is i seen the episode of Engine Masters, where you guys tested different intake manifolds on the 360 Magnum,i wanted to know if for my daily driver(absolutely no racing just cruising)is the modified kegger and throttle body worth spending over a grand on my truck( that I barely do 90-100mph at any given time except Vegas runs😊) it's bone stock but i do plan on using the same cam if not the 216/224 duration cam instead? I appreciate you input thanks.
I would not spend the money on that mod-do a cam and springs and headers
@@richardholdener1727 Thank you kind Sir, appreciate the speedy reply and definitely the honesty,your the best rich keep up the great work bud!
Very kool and interesting information. Thanks again.
Is there a video of the Sonoramic Commando test you mentioned?
I wish
The Kegalodon would look awesome on a jet boat!!
Id imagine theres a tipping point where the plenum is large enough.
But below that might there be changes?
For the 2.8 and 3.1 60 deg v6 the plenum is around 0,5 liter.
On the later 3400 engine its 1 liter. The still later 3500 engine its atound 1,5 liter.
In the 3900 they have a active wall in the plenum that divides it into two chambers at certain rpms.
I think its open in low rpm, closed in mid and open again at high rpm.
But those are fuel injected engines of course
have you ever done a Filter test like engine masters did but with diffrent filters.. // Roger, sweden
I have not
I think you missed the magic of the plenum "volume". You want to havea column of fast moving air, the faster and longer the better... like an intake runner.
The kegeledon has tons of volume but it is not being sped up... its like hogging out intake ports too big. Less volume and more length is better. You are wanting the inertia of the moving air to keep the air moving even after the valve closes so that when the next valve opens the air is still moving.
Also if you can add your fuel before the plenum extension you will get the benefit of the increased weight of the air caused by the weight of the fuel. This dramatically increases the weight of the charge column.
If you replaced the kegeledon with a 4inch pipe x 4 feet long that might do better... you need to tune that so maybe have a 3 inch and a 2 inch and a 1 inch and 5 inch and 6 inch pipe to show the extremes?
What do you think about a carb spacer on an LS 4 barrel F/I intake with a throttle body elbow? Say 2-4" spacer?
it likely does nothing
never been this early before. Let's go Keglodon!
Love me some dyno testing!!
The Kegalodon Resounding!
love the shark theme it needs to be on a 78 stingwray.
Why not test a single-plane manifold, and a dual-plane manifold, with something like Holley's Sniper injection system ? That way, you're only testing the manifold, not the change in carb to efi. Will a Holley Sniper run on a dual-plane manifold ?
I've run plenty of single and dual-plane intake tests
@@richardholdener1727 With the Holley Sniper ?
Aren't we also seeing runner length again too rather than just plenum volume?
no change in runner length
I expected a better bottom end, and now I'm questioning evey decision in life haha. Just kidding. Im really surprised though. Ice always thought that short runner/low volume was the recipe for increased power up top and vice versa.... i wonder if this was a port velocity issue where the plenum was so large that it acts as a buffer/great equalizer.
Right on
Helmholtz resonance is when you blow across the top of a bottle. It's got no place with intake manifolds
That was crazy good info!
what were you drinking
put a super charger on the keg
So why no dyno results with/without carb spacers on single/dual plane intakes?
have not run that test yet
@@richardholdener1727 but,but,but,but....
That thing might look pretty good on a drag boat
agreed
Excellent information. TY🏁
"RAWR"
~Richard Holdner 2020
it was subtle-like the jaws theme