Coming from the NASCAR world. You'll be surprised on how much air filter height and the base of the air filter works I've seen 20-25 horsepower on a chassis, Dino!!
As long as a filter has enough capacity to not restrict, it can often smooth the flow through the carb giving a better more consistent signal to the venturi..
@@woods-garage I came to the comments to say this exact thing. I worked at a local drag strip for a few years and watched many 1/8th mile index racers looking for 1 tenth or so and can't find it. Then they slap an air filter on and break out by a tenth+. It's crazy that the things they we assume will hurt power will actually help make more power.
Way back in the mid 80’s I ran a tall filter kit by Moroso that I felt the difference in performance. It was about 5 in tall but fit under the hood and had a much more dramatic radius curve in the base pan, to help it fit under a hood.
Agree with most of the airflow comments below. That cyl. head intake combo looks awesome. Engine sounds sweet. Nice combo , would be good to see one that Steve can tweak more. Many thanks.
Back in the early 80s I built a iron block 490ci 385 series BBF with 429CJ heads and a built 750 carb flowing 780+ she pulled 823 hp @8500-9000 on good pump gas on the dyno and it had a big stacked air cleaner on it to and yes those BBFs like rpm and will live thru it.
Steve, it actually makes a bit of sense that the filter helps it. If the filter is super non restrictive, I could see how it would improve. Think of a gas lense in a tig torch. It evens out the airflow and causes it to be laminar instead of turbulent. In this case, it’s probably smoothing out the way the air is entering the carburetor. With the amount of air that engine is moving, it’s almost definitely turbulent due to the air velocity. However, not all turbulence is the same (think small and big bumps when riding in an airplane). If it’s reducing the amount of turbulence entering the engine, the fuel mixture and distribution are probably a lot more consistent and evenly distributed due to the lensing effect of the air filter. Interested to hear your thought on this idea.
Agree. I love the deep tone of a well built BBF. Such a unique tone. I used to be able to ID one at the strip just from the sound. Now I’m just old! 🤷🤣
Agree with the smoother air flow comments. With the filter media I believe the air flow gets very laminar and the engine is able to digest more CFM as a result. Love your content - thanks for sharing.
I love to see you working on the NA stuff! It's so awesome hearing you talk about the old cup engines and pro stock stuff, because it was a time of innovation and finesse in engineering.
One of my friends had a nearly identical combination (his was 513 cubic inches, single 1050 Dominator). It pushed a 67 Mustang fastback deep into the 7s.
So it must be fairly light,well under 3000 lbs.I raced a 3500 lbs Malibu with blown 538 bbc and calculated that even high sevens would require well over 1200 hp.What is deep sevens more accurately?@@owggarage723
The filter allows just enough airflow to slow/settle down for it to be more evenly distributed throughout the intake at the same time allowing for fuel mixture to optimize more evenly. All wile creating a bigger vaccume
The plate creates what is called the Coanda effect and the air filter creates diffusion thus making the fuel vaporize more (droplet break up) making the fuel burn better.
More Ford Content! Great feature. People constantly overlooking the BBF in favor of the BBC, it's the hidden gem of the motor world lol. I would also say a few things with respect to the power gain: 1) did you run the "Base Combo" again? I would be interested to see if it picks up power after a few runs warming the oil and settling the cam and rockers in. 2) One hypothesis is that the Filter acted almost like another manifold, slowing or sort of trapping air and therefore making it easier for the carb to pull it through. I see you turned the fans on right before each run, they appear to be pushing air out of the room? If that is the case that would also pull air away from the engine (which would make sense that a large filter which traps air and slows it down would make more power)...This affect would probably happen even if the fans were pulling air from outside and pushing it into the room. I could also be very wrong though. Great video either way BBF FTW!!
I believe the reversion that comes all the way out of the carburetor hits the air cleaner lid and helps with pulse wave tuning, just like header length matters. It picked up throughout the whole curve. But what do I know
The filter gives a better signal to the carb, and its enrichening the mixture just the right amount, or somehow the restriction helps lol. Or a combo of all three or just two. Enjoyed the vid
The inlet manifold may be a little excessive for the application, and once the filter is applied, it creates a better Venturi effect, causing the power to be increased
Steve you have to be the most down to earth man. You seem like my brother or best friend the way you teach us about your engines, which are more superior then them all. I love your channel please keep the videos coming. Thanks for sharing and God bless you and your family and friends.
Weeeeeeell someone applied their master's degree in fluid dynamics appropriately !!! Great job to whom ever designed the initial blueprint and air inlet carb set up etc. I'm sure tuning has a little to do with its success but the design and initial blueprint got you there so credit is definitely due there !
Awesome Thanks for Another great Lesson professor Morris!! Thanks for sharing, Also love seeing sugar Momma in the intro !!! Great Channel Keep up the Amazing Work !!!!
Ive actually read some awesome studies about this very thing back in the day. Theres been tons of research done about the effects different filters have on the fuel delivery/atomization through carburetors. Its amazing how different filters, spacers, and of course intakes effect atomization of fuel. You can adjust a spray nozzle into a perfect mist, but when you spray it into a fan on high, everything changes. Sorry to ramble, just a very interesting subject i dove into years ago while dirt track racing. Every little bit counted when it came down to the stringent rules given for the class i ran. A good filter will actually help power by improving the atomization of fuel delivered by the carb. A nice clean burn is good for power. That can be achieved by stopping turbulent air and cleaning up the delivery. Lots more goes into this, but thats a very quick amd dirty synopses.
I believe having just the base on would be creating a better path for air into the carburetor. Then adding filter could make the air entering more uniform and can syphon the fuel better. It might also help how the fuel is mixed into the air for better distribution to the cylinders . I wonder if the EGT temps were more even with the filter. Great stuff .Thanks for sharing.
filter raises the peak flow point to half way up the filter for better inflow. you can see the sand fabric pull in deeper concave at the mid height point on the filter... higher flow velocity as air is detached from the plate.
With limited air intake (one carburetor) you get very high speed air which can cause some "stand off" and air disturbance above the carburetor. I think the cover over the top of the air filter and the quality filter are helping "smooth" the air flow which is giving a more consistent signal to the boosters in the carburetor.
The base improves because of the rounded edge, the filter improves it because the restriction lowers afr slightly, meaning carb could be richened up a bit maybe. Ive had it happen with my motorcycles 🤷♂️
The air filter is a vary small restriction witch causes laminar airflow.The venturies respond with better atomization and distribution increasing horsepower. Nice build !
Like others, I believe there may be air vortices when run w/o the base, and the base smoothes out the flow and then the filter adds more favorable smooth air flow.
Engine masters tested different attachments on the carburetor and the salad bowl shape made the most power, by a good bit if I remember correctly. Does anyone else remember better than I do?
Much like we used to do in the early to mid 90s to improve ait flow for maf engined, rather smoothing air flow when going from say a 65 mm throttle body to a 90mm unit. The air becomes extremely turbulent causing a power production issue. Was magnified with boost We would put chicken mesh before the maf which stabilized the air flow into the maf causing power protection to be more tunable and resulted in more power. The carb on that motor has a massive choke hole causing turbulent air. The mesh from the filter smooths the air flow causing stable tuning resulting in more power production. Or in your case allowing the tune to be stable and the engine to utilize all of what your feeding it
K&N had those carb velocity adapters, back in the day, for carbs with and without a choke. I tried one and definitely helped my car run smoother while cruising.
I had a 2bbl claimer engine that picked up 3 when I stacked a cpl of air cleaners on it. And another one with a proper tall filter. My theory was that the tall filter provided enough air to not be a restriction but cleaned up the turbulence into the carb.
love the dyno pulls! But I would like to see/hear the pull from outside the building. Yeah, where the exhaust goes out. Bet it sounds awesome! Just my weirdness coming out.😆
When I've run into the more HP from a air filter, it was because the 4 outer cylinders were running slightly lean and the inner 4 were rich, but the overall mixture was good. That is taken care of in a dual carb engine, but not in a single carb one. Port or direct injection usually doesn't have this issue except to a minor degree. The only way to tell for sure is to have 8 O2 or 8 EGT sensors installed.
The filter acts as a intake resonator which helps with intake pulse harmonics. Mazda does something similar with their gen 2 skyactic engines with a large internal volume intake everything, but then chokes the very front snorkel.Think flywheel but for your intake air. Thats my guess. You can test by mathing out the intake runner harmonic orders, then pay attention to those RPM ranges for performance. The white line on the graph you showed displayed better peaks at certain RPM ranges. Try different shape/size air filters and pay attention to those peaks.
Stated in other comments also, buy my idea is that w/ no filter, the area an inch or so above the venturi's is very turbulent and the filter prevents the air from getting 'dirty' just before it is pulled in the carb.
That looks like a wire filter, so it probably has little to no flow interference. I would say it straighten out some of the air turbulence, which helps maximize the air speed coming over that radius on the air filter base, gives a cleaner reading to the carb too
Air speed, a restrictive component can speed up the average airspeed and that added airspeed above the valves can match up with the resonance of the long tube intake runners.
The lid on air filter and height to top of carby has great effect on air turbulence directly above carb which in this case resonates a few extra HP from the stable flow into said carby at those RPM..
Perhaps the air filter reflects a little more of the pressure wave making it act like a combo of some runner length and plenum volume. Could be why the effect seems more dramatic at the lower rpms
The filter and base are both changing the Venturi effect each pleat in the filter is making stream lines like a shower head allowing for a more compressed volume to enter the carb
Hi Steve , Interesting that you got more power with the filter on, I have the same experience with bike engines, best I can figure it out is that the filter straightens the airflow and takes out the turbulence in the airflow cleaning up the signal for the carb and the base stops opposing airflow from the bottom confusing everything !!
one of 2 things either cam lobe timing was allowing to much air fuel mixer to go out the exhaust valve and the restriction of air in was allowing more fuel air mix to stay in the combustion chamber or more likly the air stream was cleaned up allowing a more efficient flow in the system like stopping some turbulence in the instake
So as all have said it smoothed the air flow slowing more air but would also as a side affect get a better and smoother vac signal to the power valve letting it be more efficient.
I would think that the filter and hat force more air to be directed across the base increasing the venturi effect. Maybe test with a simple spacer in center to hold hat and base without an element to see if its actually the filter or addition of the hat effecting the power numbers. You could also add a smoke stream and a clear hat for visual conformation on what is happening to airflow
![Ford 460 7.5 Liter: Everything You Need to Know [Specs & More]](http://i.ytimg.com/vi/-k9_HfJpSVA/mqdefault.jpg)
Nothing better than a NA big block revving to 9000rpm. Im a chevy guy but can appreciate Ford stuff like this.
Ain't nothing like Ford power💪🏿
Are there any Ford part numbers on this beast?
I like big Fords and I cannot lie.
Those other brothers cant deny!
I'd love to put a motor like this in my 72 1.5 ton super duty!
When a car rolls by wit an itty bitty base and big block in yo face you get sprung!
Nothing has the deep tone of a BBF. Very distinctive.
Me too!!! 👍🇺🇸👍🇺🇸
Coming from the NASCAR world. You'll be surprised on how much air filter height and the base of the air filter works
I've seen 20-25 horsepower on a chassis, Dino!!
We need more fords
to replace all the broken ones?
@@korn38ktmIt’s obvious you know NOTHING about Fords!
@@korn38ktm I know you really meant to say to finish shattering all you morons hearts...... I see you have seen way too many Ford taillights!
@@korn38ktm He said more FORD'S, not LS ...
@@korn38ktm you misspelled Chevy wrong twinkboy
The addition of the filter and the LID gave it a smoother air flow creating a venturi affect?
thanks Steve, love your channel!!! Ford power baby!!!
The filter gave it a medium to align the air to flow smoothly over the Bass
Stabilized the air wich created better atomization of the fuel. ... but you were close
@@mcintyretyler89 I was going with the filter is helping clean up the air flow through the carb.
agreed
@johnhufnagel air flow should be cleanest with out a filter.... no restrictions....but a carburetor runs off vacuum
It's the difference in pressures that make them work
Reminds me of a episode of “engine masters” where they tested a bunch of different filters..
And the salad bowl kicked ass.. 😂😂😂
Thank you so much for doing a Ford motor
Thanks for the Ford content!
Thanks Steve. S,M.
As long as a filter has enough capacity to not restrict, it can often smooth the flow through the carb giving a better more consistent signal to the venturi..
The filter stabilized the air wich atomized the fuel better
Which?@@mcintyretyler89
Yes, and it’s possible the flow went from turbulent to laminar.
@@woods-garage I came to the comments to say this exact thing. I worked at a local drag strip for a few years and watched many 1/8th mile index racers looking for 1 tenth or so and can't find it. Then they slap an air filter on and break out by a tenth+. It's crazy that the things they we assume will hurt power will actually help make more power.
Way back in the mid 80’s I ran a tall filter kit by Moroso that I felt the difference in performance. It was about 5 in tall but fit under the hood and had a much more dramatic radius curve in the base pan, to help it fit under a hood.
Filter cleans up the air turbulence. I’ve experienced it before and it makes perfect sense.
Now here is a comment with some thought behind it..
Its simply atomizing the fuel better brother
I agree and I think the filter cfm capacity is much larger than the carb
The blue oval on the thumbnail got me excited! 😃 I love this channel, but also love Fords!
Yeah, would love to see lot more Big Block Ford stuff with Steve.
Killer build, and video! Love the 385 series!!!
Big block ford!!
Nothing better!!!
Well maybe a smx!!!
Being a ford guy , love my BBF’s
Being a SME guy, love the smx!!
Great work SME!!
As always!!
Best part about being a Ford guy is not having to talk about how you love BBCs.
Now…imagine a SMX version of a BBF. Billet block and all. WOW 😎
billet block/head BBF’s have been available for years.
1 of the best sounding engines to roll through your channel
Agree with most of the airflow comments below. That cyl. head intake combo looks awesome. Engine sounds sweet. Nice combo , would be good to see one that Steve can tweak more. Many thanks.
Back in the early 80s I built a iron block 490ci 385 series BBF with 429CJ heads and a built 750 carb flowing 780+ she pulled 823 hp @8500-9000 on good pump gas on the dyno and it had a big stacked air cleaner on it to and yes those BBFs like rpm and will live thru it.
Steve, it actually makes a bit of sense that the filter helps it. If the filter is super non restrictive, I could see how it would improve. Think of a gas lense in a tig torch. It evens out the airflow and causes it to be laminar instead of turbulent.
In this case, it’s probably smoothing out the way the air is entering the carburetor. With the amount of air that engine is moving, it’s almost definitely turbulent due to the air velocity. However, not all turbulence is the same (think small and big bumps when riding in an airplane). If it’s reducing the amount of turbulence entering the engine, the fuel mixture and distribution are probably a lot more consistent and evenly distributed due to the lensing effect of the air filter. Interested to hear your thought on this idea.
Great to see a BB ford. Very underrated engine.
Maybe drag racing, BBF is legendary, arguably on the top in mud racing/truck pulling
That ford sounds AMAZING!
Don't they all, nothing sounds better than an old foxbody 5.0 with exhaust
@@turbo-jm8hk- Meh. Only to 80’s guys.
They always do!
@@turbo-jm8hk A Cleveland sounds better than the little 5.0 😉
Steve, that is a wicked BBF, nothing sounds like it, Great job Steve Morris Engines
Agree. I love the deep tone of a well built BBF. Such a unique tone. I used to be able to ID one at the strip just from the sound. Now I’m just old! 🤷🤣
DragBoss351Cleveland I watch and love your channel and content also!
@@jerrywaston6842Thank you my friend, I appreciate it. More on the way, working on carb adjustment video series. Stay Tuned
Agree with the smoother air flow comments. With the filter media I believe the air flow gets very laminar and the engine is able to digest more CFM as a result.
Love your content - thanks for sharing.
And it is still running a distributor. LETS GOOOOOO!!
I love to see you working on the NA stuff! It's so awesome hearing you talk about the old cup engines and pro stock stuff, because it was a time of innovation and finesse in engineering.
I love to hear them sing around 9 thousand RPM and you build a mean motor!! 👍
One of my friends had a nearly identical combination (his was 513 cubic inches, single 1050 Dominator). It pushed a 67 Mustang fastback deep into the 7s.
Must ve been very light car if you are talking 1320 ft numbers.
@@teknoaija1762 square tube 4 link chassis built in the 90s.
So it must be fairly light,well under 3000 lbs.I raced a 3500 lbs Malibu with blown 538 bbc and calculated that even high sevens would require well over 1200 hp.What is deep sevens more accurately?@@owggarage723
Love seeing fords
Love the new intro, BBF’s and truck pulls. Triple win❤ Thanks Steve for another awesome video!!
Thank the lord for the big block ford!
Gold!!!
The filter allows just enough airflow to slow/settle down for it to be more evenly distributed throughout the intake at the same time allowing for fuel mixture to optimize more evenly. All wile creating a bigger vaccume
More Ford!!!!
The plate creates what is called the Coanda effect and the air filter creates diffusion thus making the fuel vaporize more (droplet break up) making the fuel burn better.
The intake on that big boy is a piece of art
More Ford Content! Great feature. People constantly overlooking the BBF in favor of the BBC, it's the hidden gem of the motor world lol.
I would also say a few things with respect to the power gain:
1) did you run the "Base Combo" again? I would be interested to see if it picks up power after a few runs warming the oil and settling the cam and rockers in.
2) One hypothesis is that the Filter acted almost like another manifold, slowing or sort of trapping air and therefore making it easier for the carb to pull it through. I see you turned the fans on right before each run, they appear to be pushing air out of the room? If that is the case that would also pull air away from the engine (which would make sense that a large filter which traps air and slows it down would make more power)...This affect would probably happen even if the fans were pulling air from outside and pushing it into the room. I could also be very wrong though.
Great video either way BBF FTW!!
I believe the reversion that comes all the way out of the carburetor hits the air cleaner lid and helps with pulse wave tuning, just like header length matters. It picked up throughout the whole curve. But what do I know
That big block looks clean - almost simple. Nice stuff.
I do like you work. That is 1 fine quality Ford. I like that you will work with all manufacturers. Keep up that great work.
Maybe the filter is acting almost like a choke, causing it to use a touch more fuel? I wonder if that would show up in the air fuel ratio data log
Thank you. The filter straightens the air going in.
Awesome sounding ford
Beautiful engine and the sound...!
You definitely nailed the cam profile....
Right?!
The filter gives a better signal to the carb, and its enrichening the mixture just the right amount, or somehow the restriction helps lol. Or a combo of all three or just two. Enjoyed the vid
The inlet manifold may be a little excessive for the application, and once the filter is applied, it creates a better Venturi effect, causing the power to be increased
It stabilized the air atomizing the fuel better
Steve you have to be the most down to earth man. You seem like my brother or best friend the way you teach us about your engines, which are more superior then them all. I love your channel please keep the videos coming. Thanks for sharing and God bless you and your family and friends.
That big block sounds crisp... 👍🏻
Glad to hear the SMX is still sweet🙏🏻💪🏻👍🏻
Weeeeeeell someone applied their master's degree in fluid dynamics appropriately !!! Great job to whom ever designed the initial blueprint and air inlet carb set up etc. I'm sure tuning has a little to do with its success but the design and initial blueprint got you there so credit is definitely due there !
It straightens out the air flow to curve down in there because of the base plate of the air filter housing
more than likely forces the air to come down straighter ,reduce turbulence over the radius, changing approach angle entry into cab bleeds/boosters!
The air filter with a well designed base plate is shaping the air allowing smooth transition into the carb.
Awesome Thanks for Another great Lesson professor Morris!! Thanks for sharing, Also love seeing sugar Momma in the intro !!! Great Channel Keep up the Amazing Work !!!!
Thanks
Steve do have v12 they 300zx init
Ive actually read some awesome studies about this very thing back in the day. Theres been tons of research done about the effects different filters have on the fuel delivery/atomization through carburetors. Its amazing how different filters, spacers, and of course intakes effect atomization of fuel. You can adjust a spray nozzle into a perfect mist, but when you spray it into a fan on high, everything changes. Sorry to ramble, just a very interesting subject i dove into years ago while dirt track racing. Every little bit counted when it came down to the stringent rules given for the class i ran.
A good filter will actually help power by improving the atomization of fuel delivered by the carb. A nice clean burn is good for power. That can be achieved by stopping turbulent air and cleaning up the delivery. Lots more goes into this, but thats a very quick amd dirty synopses.
I believe having just the base on would be creating a better path for air into the carburetor. Then adding filter could make the air entering more uniform and can syphon the fuel better. It might also help how the fuel is mixed into the air for better distribution to the cylinders . I wonder if the EGT temps were more even with the filter. Great stuff .Thanks for sharing.
🤔
filter raises the peak flow point to half way up the filter for better inflow. you can see the sand fabric pull in deeper concave at the mid height point on the filter... higher flow velocity as air is detached from the plate.
That thing just sings beautifully through the entire rpm range.
I reckon the filter smooths the airflow out, giving it a better velocity through the carb.
It's just like the Bell on the front of your turbo
With limited air intake (one carburetor) you get very high speed air which can cause some "stand off" and air disturbance above the carburetor. I think the cover over the top of the air filter and the quality filter are helping "smooth" the air flow which is giving a more consistent signal to the boosters in the carburetor.
With the filters put on top of the base it has more fuel in areas in the RPM sweep. Because decreasing the amount of air getting into the engine.
The base improves because of the rounded edge, the filter improves it because the restriction lowers afr slightly, meaning carb could be richened up a bit maybe. Ive had it happen with my motorcycles 🤷♂️
It's a ford it's just badass
First On Race Day baby.
😁👊🏻
@@stevemorrisracingwat kind you look foor car
@@stevemorrisracing Do you know what truck its in so we can whatch?
The air filter is a vary small restriction witch causes laminar airflow.The venturies respond with better atomization and distribution increasing horsepower. Nice build !
Maybe by putting the filter on it creates more vacuum at the mouth of the carb and cfm goes up. Just a thought
Watch how much the filter "sucks in" when under load. I'd be little concerned about the filter getting sucked thru the carb when it implodes.
I’d be interested to know if it’s possible to do is put a vacuum gauge on the hat with the filter just for curiosity
All the changes improve the air turbulence and the fuel mixes better, which increases the burning speed
That in a lightweight ford with a liberty 5 speed shifting at 9k would be a bad ass combo. 👍🏻
In a badass galaxy with carbon bits... yeah.
nah everything you said in a small tire(28.10.5 tire)maverick. That little sucker would rock😂
That motor would think an F500 is a lightweight ! Lol!
Like others, I believe there may be air vortices when run w/o the base, and the base smoothes out the flow and then the filter adds more favorable smooth air flow.
Engine masters tested different attachments on the carburetor and the salad bowl shape made the most power, by a good bit if I remember correctly. Does anyone else remember better than I do?
Thats what I was going to say, test the salad bowl! The flipped lid did suprisingly well too
The filter is changing the signal over the Venturi in the carburetor and is allowing it to work more as designed.
While driving near Quincy Illinois I saw a Steve Morris wagon pulling a Live stock trailer , laughed my arse off
The filter smooths out the airflow.
Is that the new EZ access Roadmaster wagon? I know you want to go faster but, the weight reduction has to stop somewhere! 😂
Much like we used to do in the early to mid 90s to improve ait flow for maf engined, rather smoothing air flow when going from say a 65 mm throttle body to a 90mm unit. The air becomes extremely turbulent causing a power production issue. Was magnified with boost
We would put chicken mesh before the maf which stabilized the air flow into the maf causing power protection to be more tunable and resulted in more power. The carb on that motor has a massive choke hole causing turbulent air. The mesh from the filter smooths the air flow causing stable tuning resulting in more power production. Or in your case allowing the tune to be stable and the engine to utilize all of what your feeding it
Dewey must be on vacation. 😃
K&N had those carb velocity adapters, back in the day, for carbs with and without a choke. I tried one and definitely helped my car run smoother while cruising.
The wagon looks like it is trying to identify as Leroy lol
Steve going cart mode while Leroy gets a body lmao. What is going on?!?1
My guess is that the filter smooths and aligns the airflow, acting as a bit of a buffer to changes in air flow around the engine. Very neat though.
The restriction can easily affect the atomization of the fuel. A little restriction isn’t always bad with carburetors.
I had a 2bbl claimer engine that picked up 3 when I stacked a cpl of air cleaners on it. And another one with a proper tall filter. My theory was that the tall filter provided enough air to not be a restriction but cleaned up the turbulence into the carb.
love the dyno pulls! But I would like to see/hear the pull from outside the building. Yeah, where the exhaust goes out. Bet it sounds awesome! Just my weirdness coming out.😆
When I've run into the more HP from a air filter, it was because the 4 outer cylinders were running slightly lean and the inner 4 were rich, but the overall mixture was good. That is taken care of in a dual carb engine, but not in a single carb one. Port or direct injection usually doesn't have this issue except to a minor degree.
The only way to tell for sure is to have 8 O2 or 8 EGT sensors installed.
Same thing I was thinking makes sense
The filter acts as a intake resonator which helps with intake pulse harmonics. Mazda does something similar with their gen 2 skyactic engines with a large internal volume intake everything, but then chokes the very front snorkel.Think flywheel but for your intake air. Thats my guess.
You can test by mathing out the intake runner harmonic orders, then pay attention to those RPM ranges for performance. The white line on the graph you showed displayed better peaks at certain RPM ranges. Try different shape/size air filters and pay attention to those peaks.
Some times there is a pressure wave that could include the intake above the carb. Similar to a single cylinder engine intake snorkel setup.
Stated in other comments also, buy my idea is that w/ no filter, the area an inch or so above the venturi's is very turbulent and the filter prevents the air from getting 'dirty' just before it is pulled in the carb.
That looks like a wire filter, so it probably has little to no flow interference.
I would say it straighten out some of the air turbulence, which helps maximize the air speed coming over that radius on the air filter base, gives a cleaner reading to the carb too
Air speed, a restrictive component can speed up the average airspeed and that added airspeed above the valves can match up with the resonance of the long tube intake runners.
Started the stream with a dyno pull and my sound at full volume in my headphones. Thank You Steve!
I think the plenum volume in the top above the runners creates a pressure drop or hi vacuum with a restriction above the carb.
The lid on air filter and height to top of carby has great effect on air turbulence directly above carb which in this case resonates a few extra HP from the stable flow into said carby at those RPM..
Perhaps the air filter reflects a little more of the pressure wave making it act like a combo of some runner length and plenum volume. Could be why the effect seems more dramatic at the lower rpms
The filter and base are both changing the Venturi effect each pleat in the filter is making stream lines like a shower head allowing for a more compressed volume to enter the carb
If adding the filter increases power, there’s probably 1 or 2 cylinders that are slightly lean when intake is less restrictive
Hi Steve , Interesting that you got more power with the filter on, I have the same experience with bike engines, best I can figure it out is that the filter straightens the airflow and takes out the turbulence in the airflow cleaning up the signal for the carb and the base stops opposing airflow from the bottom confusing everything !!
On NA the restriction of the filter creates a slight negative pressure in the intake that causes it to pull more fuel from the carb.
I believe adding the filter causes a vacuum on the intake side of the carburetor, increasing the ventury effect and pulling more fuel from the jets.
Thank you are right, made it run richer
one of 2 things either cam lobe timing was allowing to much air fuel mixer to go out the exhaust valve and the restriction of air in was allowing more fuel air mix to stay in the combustion chamber or more likly the air stream was cleaned up allowing a more efficient flow in the system like stopping some turbulence in the instake
Cool video. I believe the numbers improved because it makes the whole package look cooler!!!! Enjoyed watching ✌️ 😎
Can’t wait to see that on the track hopefully I might get to film it this summer depending on who they pull with
So as all have said it smoothed the air flow slowing more air but would also as a side affect get a better and smoother vac signal to the power valve letting it be more efficient.
My thought on the filter is that it takes the turbulence out of the airflow going into the carb and getting a better air fuel mix as it passes through
I would think that the filter and hat force more air to be directed across the base increasing the venturi effect. Maybe test with a simple spacer in center to hold hat and base without an element to see if its actually the filter or addition of the hat effecting the power numbers. You could also add a smoke stream and a clear hat for visual conformation on what is happening to airflow