CFM IS SO IMPORTANT. We are not discussing Density and some of you Do Not Understand the Difference.
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- Опубликовано: 8 фев 2025
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There is a place and time for everything. APPLICARTION DICTATES DESIGN. CFM and Density are 2 Different things and are not to be confused.
Air flow or CFM REQUIRED = Engine size X RPM ÷ 3456 x volumetric efficiency
Once again thank you Brian. From you I've learned once you have the CFM. Then you can worry about the air density. And that are density is just a small player. Until you maximize the CFM did I get it right?😊
So Brian is there a formula for cylinder head flow that will relate back to engine rpm? For example if I have a 400ci engine and my intake port flows 300 cfm at peak cam lift, given intake is not limiting, what is rpm capability of the combination? Thanks😊.
Thank you Brian Salter my only question is what volume metric efficiency number should I put down like a good race engine either on a 2 barrel 500cfm carburetor or a big 4 barrel carburetor I don't know if that has to do with anything but I thought I ask you
@@chevyrc3623 yes the average race engine can be like 85 and as high as 120% or even higher volumetric efficiency
If the heads in the camshaft are done correctly the higher you rev the engine the more efficient it becomes
Also remember that not all eight cylinders are firing at the same time so that's why you're able to turn 8 and 9,000 RPMs with a 390 Holly for example
Anyway I am going to talk about this an upcoming videos
@@SalterRacingEngines ok thank you
like DV says, "give the engine what it needs, not what you think it needs"
I think restrictor plates
kinda prove your point too.
I touch the throttle a quarter inch and my little edelbrock boosted 355 sbc and it goes instantly to 6500rpm on the chip hehehe. 850cfm quick fuel b2 blower carb is too small at wide open get 1.75 inches vacuum below the carb. Heads are ported and solid roller cam fun. Love the channel, you know your stuff!!!
Boost shows the amount of restriction! Good cylinder heads will drop boost! Great stuff Brian!
I love messing with people and telling them my goal for their heads is to make super low boost numbers with their fancy blowers. The look on their faces is priceless until I explain. 😂
Brian,looking forward to more content,im a big N/ A guy,in the process of buildind a drag engine 421ci sbc,trying to pick the right components, cylinder heads,ect that will get me to the 850-900 hp range reliably, keep up the great content
Brian i and a amateur engine builder for my self , n/a engine . Your channel is in valuable to me i do not work in the industry , so the bits of information i get from you helps me a lot ! I can get as cranky as you when i try to explain some thing to some one who won't listen. ( i don't no must very often ) keep up the good work .
Kit from down under
There are so many crusty old-timers with crusty old beliefs that don’t end up being true. Yes, sometimes the old-timers know what they’re talking about but sometimes they don’t. Sometimes they’re holding on to traditions that have no basis in fact. My experience is that those old-timers who get frustrated and annoyed when you doubt them or ask questions are the very ones who don’t really know what they’re talking about, they just want you to bow to them.
Iv only just found this channel but it is so on point info. Thank you for sharing your hard earned knowledge
I got to say l love your logic we are talking real wold situations here the only way you get this information is from real world experience listen & learn ! This guy is real !
Love the information i get from the channel. As a parts changer most of my life i never really got the jist of how all the parts work in theory. But after just a few of your posts ( starting with the distributor video) i understand my carburetor and every screw on it, i understand my timing events whether its locked out or not and now i understand in totality what makes my engine breathe. The best parts is I GET IT😂😂😂 Sometimes i dont so i rewind the video and listen again just cause i want to understand what im doing. Thank you for sharing your knowledge 🏁🏁🏁
Why would someone question you with your success. This guy is only 2 years older than me and I been wrenching for 40 years this year I'm still at it very successful. I listen to this guy because he knows the science I know the mechanics. I started when fuel injection was a myth carbs was it 1984. Take it from a tech this guy rocks listening to him brings me back to the good old.days this guy is hardcore he almost killed himself to make people happy. Take a true dude for that and I thank him because I'm the same way never quit
I’ll admit…your passion on this is great!
Buddy i love this shit you should do a school for us old timers or guys that have been working on engines enough that what you're saying makes sense. Small crowd but I'd pay to get learned
The best way I heard it is that if someone says everyone has it wrong and this is best you should next see if they are selling a solution to it?
I appreciate the content you put out, the knowledge you freely share and hope it pays dividends for you to do it.
Thank you
Thanks Brian, Airborne All The Way!! So much to understand in such a short video!! Make as much power N/A as possible then add density (I.e. boost). A turbo/blower/pro-charger does not increase or improve flow, they increase density by compressing more air into the same space.
I love the passion you show in your videos, and for sure if you mistake air volume with air density you even missed the bus going to the boat. I would like to point out that it is not engine vacuum that sucks fuel out of the venturies but vacuum created by the air flow. Which makes the carburetor superior to any fuel injection for power if the tuner knows his shit. It fuels the engine with mother natures laws. If engine vacuum fueled the engine, the engine fuel flow would be highest at idle. I know you understand this, but when people doesn’t understand airflow from density, I would just mention it.
Increasing CFM as measured through a carburetor, intake manifold or cylinder head intake port is a metric we can use to show that we have decreased the restriction on the inlet side of the cylinder. For that purpose, CFM is an easy to understand and valuable measurement. The older I get and the longer I do this though, the more I’m leaning away from imperial measurements and seeing the benefits of metric units, but that’s another discussion.
The reality is we are actually dealing with pressure drop in the engine between the induction system and the cylinder itself, and the less pressure drop remaining at the end of an intake stroke, the more complete the cylinder filled. If we do our job as engine builders correctly, we can actually generate greater than atmospheric pressure in the cylinder at the end of the intake stroke which is how we achieve greater than 100% volumetric efficiency.
As the piston moves down the bore it creates a low pressure void space (a depression), if you monitor cylinder pressure with a transducer, the pressure drops. This is what everyone likes to call “vacuum” but it’s actually just a variable lower pressure than atmospheric pressure. High pressure (atmospheric) wants to move to the low pressure (cylinder) and that’s what creates the air flow, NOT THE PISTON!
If you cycle a piston at a constant speed in a sealed cylinder, the pressure will change but no flow will occur. If you vary the inlet flow, you will vary the flow or CFM because you are changing the restriction and the resulting pressure drop.
I agree that CFM is a great tool for quantifying parts. It should not be used as a tuning tool though. And once a typical OHV performance engine is built, the maximum air flow for the engine at any given RPM will stay relatively the same because the cylinder head and cam profiles are fixed, meaning that only the throttle plate(s) impact CFM. I will say that if you look at the pressure drop between relative atmospheric pressure and the working manifold pressure (vacuum) you can estimate airflow fairly accurately for any given pressure drop at any given RPM.
Love your channel Mr. salter, I’m not even a Pontiac guy but we restored a 1961 Pontiac Catalina original 267 HP 2v and put an old offy 2x4 intake on her with on old speed pro cam, 2 500 edelbrock AVS carbs and this old 389 loves It! It runs like it did then, around town but man Mr. Salter you jump on this thing and It gets after it! My point?? CFM matters, the same damn engine wet from 267 hp to 303 with nothing more that a carter 4 v yea thank you sir Air flow absolutely matters before “air density “ ✌️✌️
Salter Racing Engine
Absolutely well said
This man is so very smart...
To prove what you are saying, I stick a vacuum gage on the engine and it as hard as it will go. If it makes vacuum at wide open throttle below what you want the the carb is too small.
I think they are trolling you, or they are just lost. Don't let them trigger you. Most all of us are thankful to the info you share! The laying back of valve reliefs was a light bulb moment for me.... so obvious once seen.
Yes I agree 100%. My example is a Quadrajet carburetor. I have to learn to adjust the secondary air valve for the cfm and fuel that the engine needs. Even if is an 800 cfm or some that I modified to do more mostly on the primary side.
Brian .Thank you for sharing your knowledge
You said it about as clear as it can be said. I don't know why some people don't get that pumping losses are present regardless of the air density
Love learning from you Sir. Thank you!
@6:36 "how much air can we pull in". Exactly, how much air can we pull in to the fixed volume of a cylinder to increase the fuel/air density within the cylinder. We want to cram as much air mass as possible into the cylinder of a fixed volume, that way we increase the operating pressures and therefore power output. Density is the measure of mass quantity in a fixed volume. CFM is a measurement of volume over time. It doesn't tell us how many molecules of air (it's oxygen we want) is in that geometric space, not without knowing the likes of the temperature of that air. We want a high level of mass flow into an engine and I'm sure this is what Brian means. Tiny heads for a given cubic inch engine reduce available or potential mass flow that our language incorrectly refers to as CFM. Remember; Mass is the physical quantity that signifies the amount of matter in the body of an object. Volume is the evaluation of how much 3-dimensional space is occupied by the object. Mass is the physical value. Volume is the geometric value. CFM is a volume or geometric measurement. We want the physical air.
I’m pretty sure this is what Brian said. In a n/an engine density is a given condition Mother Nature gave us. The amount of air the engine can suck and trap is fixed by the engine builders talent.
@RoyOlsen-mm4fm all mother nature does is assist in the density of the air/fuel charge in the cylinder. Mother nature is not 'the' density in the cylinder. The amount of air the engine can suck and trap is literally how dense with air and fuel we can make the cylinder. Engines don't operate off volume as volume is the measurement of space. Engines operate off mass flow - the flow quantity of air and fuel particles, and how much of those air/fuel particles are in the fixed volume of the cylinder - density. More air/fuel particles in the fixed volume of the cylinder then more oxygen and hydrocarbons to combust so more power. Mother nature helps by how dense the air is before it enters the engine but ultimately it's the throttle that controls the density of air/fuel charge entering the cylinders. The industry is so fixated on flow that it has become accepted that the throttle blades control air flow. They do control flow, but it's mass flow the throttle is controlling, not volume.
The engine builders talent is how dense with air and fuel he can make the cylinders. CFM is a tool that is used that does not need correction to know how much mass flow the induction system is capable of.
excellent show, thank you, 👍👍👍
Great content Brian!!!!
Having enough CFM gives dense air the greatest opportunity to show its effect. Lacking CFM gives little room for dense air to show its effect.
Looking forward to the 4.84 car and content
Once again, great info.
He is talking about cubic feet per minute not density. A cubic foot of air is a cubic foot of air. It's size does not change with density. It is ALWAYS 12" x 12" x 12" no matter how many air molecules are in it, or what its mass is. A cylinder head or port doesn't flow more or less CFM at different temperatures and densities. Yes, there will be more air molecules in it at lower temperatures but it is still one Cubic Foot of air.
Application dictates design, Precision of the build out weights the parts. 🏁
I remember many years ago when Cup cars were running 16/1+ compression ratios on their restricted engines to try to cheat the power up high in the rpm range because of lack of airflow. They were creating their own air density until NASCAR said no…
The air density thing is related to boosted applications...!!!
Temperature IMO is by far the biggest thing that affects power. Humidity is almost a non issue, very humid air staves off detonation. So even if it's a little less dense than pure dry air. It's essentially a non-issue. Temperature, however, will limit power by lowering air density and making it easier to knock.
If I could step into the ring and just continue the discussion
First of all anything I say I cannot back up, I don't have a flow bench or have I ever used one. I dream and think about this stuff day and night and wish I had the opportunity to work on these awesome pieces of equipment.
However
I see them Both as equally valid metrics. On a flow bench, CFM is the standard metric so it makes sense to keep it that way,
however you absolutely could use air density to measure flow. In some ways I can see merit in it as air density takes into consideration the air temp and I understand that on a hot day on the flow bench vs a cold day if you are going full ham accuracy you'd make small calibration changes to keep results equal. Air density measurements do this automatically.
When you are assessing a port on the flow bench at any given ambient temp a CFM of air will weigh something, so measuring mass air flow could easily be converted to CFM and vice versa.
I believe both methods would yeild absolutely identical results all other things being equal.
Given the comparative minimal change in temp on any given day in the workshop where the flow bench sits, setting up special equipment to measure density is an absolute waste of time, but under the bonnet of a running driving vehicle, density measurements are where it's at.
With all respect I cannot see how there is a right and wrong way here. I promise I've listened to the video. Peace, and happy new year good sir.
If I could take my flow bench up to 30000 feet and flow a cylinder head using both standard CFM and air density, both I believe both benches would need to be calibrated to take into consideration the ambient conditions, and therefore both, all else being equal, could be made to work.
@isaacandruthruss90 I understand what you're saying and I appreciate your comments but the context of what I'm talking about is the mechanical ability to move air
When I look at density I have to separate the two meaning density and CFM. The reason I separate the two is because I want to talk about density as a tuning tool and as a benefit to getting my intake and exhaust system correct. You create more density than you start with in a naturally aspirated engine by getting the intake port and camshaft correct. And it is very difficult to talk about a mechanical machine moving air and calling it density and then using density in a whole other subject matter later on. There is no doubt that when we use a mass air flow meter we can calculate how much air speed or air volume is coming through but that is not how the industry works that's not how we sell cylinder heads and that's not how we talked about cylinder head flow. This all started because somebody said that CFM was outdated and has been obsolete for decades. And that's just not true. When we flow a cylinder head we're not just looking at how much Air or CFM travels through it, we are looking at is it Disturbed, is it moving up in the port or down in the port or in the middle of the port does it have dead areas does it have turbulence. And none of those areas have anything to do with density that's why we don't use density when we describe cylinder head Flo. I made another video about people taking what I say out of context because they get triggered when they're so hell-bent on calling something density and not CFM or they feel like you stepped on their hero. They start bringing Gail Banks into the conversation I have never said nothing but good things about Gale Banks but I can 100% guarantee you that Gail banks will agree with what I'm saying quite frankly if he doesn't I still don't care. I have just told you the reasons why we call it CFM and why we separate the two so I hope that makes sense as to why I say it the way I do. I think the main reason that Banks diesel made that comment was because they are mass-producing intake systems on vehicles for bolt on air induction components and they sell the tunes for them and they have to know the mass air flow traveling through that tube so that they can properly tune the computer. But their using gigantic pipes which is an increase in CFM the engine must know how much oxygen is in the air flow because it is not drawing across a booster mechanically pulling fuel the computer has to know how much fuel to mix with that amount of air and that's why they're using mass air flow meters to test the density. It is not the same conversation as what I am doing because I am talking about the mechanical ability to pump air and where the air is in the port and the other reasons I stated above.
@@SalterRacingEngines I am really sorry, thank you so much for taking time to reply. I thought about it a bit more and realized I was wrong. I've just come back to the computer to see your reply. would it be right to say air density is sort of a static ambient thing? I am confusing air density with mass air flow which is more than just pressure and air temp.
thank you for taking the time to reply to me, I know you have much better things to do with your time than to respond to keyboard warriors.
Appreciated back
I thought scfm generally assumes a temp of like 70* f and 14.7 psi pressure. With the density part held constant you can just use the volume cfm for comparison or measurement of airflow. Seems pretty straight forward to me.
Is that a correction correction? 😮😅😅
Good information 😊
Air density is irrelevant on a N/A engine, it's even somewhat irrelevant on a turbo engine.
You can't change the temps of air by much.
The example of where you gain the most is an intercooler.
Other than an intercooler it's basically cold air intake, but you are stuck with what the temperature is so it's a moot point because you can't change that.
Like if we could everyone would be running -250c air temps.
So this is why you look at CFM only because the temp is what it is.
Have a good new year 🎉🎉💥
I am increasing the MCSA on some heads right now, so the new longer duration camshaft can properly RMP and make the additional power. The math gets over my head super fast. However, online calculators make it easy. It's not really for the novice, though. I have to admit it's a little fun seeing you wound up. I have, similar passion. But not a RUclips channel. I would pop a main breaker. 😂
Hey Brian,
Tim here, the DENSE part is the commenter.....CFM is what ALLOWS the motor to perform......WHY do they make a cool can then??.....its to INCREASE DENSITY.....why do they make scoops??....TO INCREASE DENSITY........NONE of it is for CFM.......if we don't have enuf CFM.......we aint goin ANYWHERE!!......get the RIGHT CFM for the combo, add a cool can and a scoop, and WE WON the days battle at the strip......CFM IS WHAT MAKES AN ICE PERFORM........density is just the quality of our incoming charge.......wish these dudes understood ICE.....b4 opening their mouths.....PEACE my SMART brother!!
Id love a dyno test showing at what point too much cfm is bad. Like how mismatched can you get
CFM ratings are points on a curve. They are useful only for comparing items. 4bbl Carbs are measured at 1.5 inches of mercury. Cylinder heads are measured at 28 inches of water. The intent is to compare the parts under reasonable engine operating conditions. For max power, 1.5 inches of mercury is too much restriction. A 600 cfm 4bbl will flow less than 500 at 1 inch, and 350 at 0.5 inches. So when making these calculations, consider where on the curve you want to be.
"I'll just put more boost too it."😂
Density is an important component. Your engine can make x hp at sea level with standard air conditions. That same engine at altitude 14,000 ft makes less hp at same carb setting due to less dense air.
Less 02.
Love your youtube channel please keep them coming.first thank you for your service to are country respect
i have a010 sbc Gen 1 block im wanting to build this motor for a 4x4 chevy truck for towing boat, plowing snow,pulling small camper , what cc heads would or head recommend for this application every body wants race motor i just want something that will pull a boat on step boat ramp
Seems like common sense, engine wise to me. I mean that’s what I’ve always thought. Cfm means rpm, density means how much fuel needs added. I follow mbe and they shoot for 3 hp per cube at least I think that was said.
Thx brother.
It’s mass flow that’s important not volumetric flow. This is why an engine makes less power at high altitude despite the engine still sweeping the same cfm at a given rpm. Cfm can tell you effectively the same on a flow bench as mass flow since compressibility effects are low due flow bench velocities being relatively low compared to a running engine
@@dmc5681 sorry I misread your comment
You are correct
listening in from Australia...i don't need any information on this blokes experience. In minutes i can tell this guy knows his stuff, if i lived near him and needed an engine id use this guy
its not always how much you know but more the case of who's your source?
Ive learned a lot from your vids, and i think some people dont understand it is not just the piston drawing a vacuum that causes air and fuel to enter the engine, but 14.7 pounds per square inch of air pressure that helps, so i just have a question ? Does barametric pressuure along with alltitude affect jetting very much ? Because a pulling truck runs great off and on, he runs it between 700 ft. And 1300 elevation ?
@@PeggyParrow yes every 3,000 ft the oxygen changes it's not a lot but it is a change
Can you have too much cfm for engine size, great video I have forgotten some of the basics
Density doesn’t put itself in there! ❤ game, set, match.
Thanks forsharing i need a formula to calculate port cfm times engine size to know if i need to make ports bigger to match cylinder required do you have one i would really appreciate that thanks
Thank you Brian. Something I have been trying to get through peoples head is the value of rod to stroke dwell. The extra dwell of the long rod allows the combustion event extra time to build force. Folks argue that TDC dwell doesn’t matter. Just mock up a cylinder with a long rod short piston and a shorter rod and taller piston, then turn it and watch it. The longer rod short piston compared with the other can be seen. The dwell keeps the piston in the pressure wave longer than the other creating more pressure at the critical pressure wave. How do I better explain it. Am I wrong?
@@Bbba724 somewhere on the internet someone (Stan Weiss maybe) has graphed out the motion of a long rod and a shorter rod. The long rod doesn’t behave much differently at the TDC region. Ignore the Pete Saueracker fraudulent magazine article from maybe 30 years ago. It was complete made up rubbish. From being around a bunch of people with a lot of dyno time, I have seen that the rod ratio doesn’t really matter as long as it’s above 1.45 maybe. Sonny’s made mountain motor pro stock motors with maybe a 1.36 rod ratio. Other things matter a lot more.
@ I agree that it’s not a primary concern but it is a small thing that helps. A light piston with a longish rod is good for addressing design issues that exist in some engines. 1.7 is as long as it needs as long as the piston is stable. Gale Banks has a video that shows the advantages of some engines that benefit from the extra dwell rising to and pulling away from TDC. It’s kind of a between remedy. If you’re stuck with a lazy chamber that final little bit of real estate you crutch helps. Some engines benefit from shorter rods. I’d narrow the range to 1.6-1.7 as best among factors for longevity. I don’t want to start a food fight over this it is just my preference.
@@Mpcoluv I am confused is there a fixed value or a variable value that goes with various elements? Can you enlighten me. I don’t see it as an absolute, but long rod wedge engines seem to thrive along side short rod poly angle engines. The side pressure and angular velocity would make a parasitic drag that some engines can ill afford. I am here to learn not to teach, but I have 50 years experience under my belt and I know I don’t know everything, so please enlighten me.
@ pick your perfect piston design, pick your ideal crank stroke and then a rod that connects the two (within reason). Seriously for my non-max effort builds I try to stay above a 1.45 ratio. I think my next build is 1.50. A lot of newer OEMs are 1.7. Supposedly long rods help poor flowing heads, short rods help heads with the CSA that is too large. I know folks that are chasing the last possible HP use longer rods because of friction.
For me I pick the stroke, and the piston compression height that seems reasonable (over 1.10 IMHO) and then use what rod fits. So Im using a 4” stroke, a 1.200 CH piston and a 6” rod for a 9.2 deck.
@@Mpcoluv The FE usually squares up at 10.16. So I take a 410 and turn it to 4 inches from 3.98 and it is actually better than the stock journal overlap. Then my block is a D4TE cast at MCC with robotic core setters and the 3 rib CJ mains. Crossbolt 2 and 4 mains to not have to fight with the thrust main. Do the oiling system well and clean the main edges with a deburr to the slots and run the long bit down the center main passege and the oil pump feeds block the lifter gallies with plug with a small .080 hole drilled in them. Put hose nipples in the valley drains and clean up the front and rear returns. The nipples allow crankcase pressure out and oil from roping on the crank. On my 4 inch 410s they rev like a 327. After sonic I bore it to .122-.125 walls between the bores. I use blocks that are .160 wall on the sides and bore to 4.115 for a .105,;: wall between. .150s minor and .190 major thrust. A 425.57 displacement. It is what I used to do in high school and never hurt a block with a fill to the bottom of the water pump, cycling the heads and top ring area. Anyway I used 7.005 HD Slant 6 198 rods and 1.15 ch 4032 forgings at 11.3:1. I had a 2x4 Shelby PI 428 intake and a pair of 600s or 750 3310s with 600 bowls. I ran it and stomped many of my “better’s “ in the middle of the night on a 32 mile run on “bloody 13” a red primer 67 Mustang fastback I tricked out. They usually disappeared from the rear view at 15 miles and showed up to beg me not to take the car or title. Never underestimate the FE C6AER 2.15/1.63 valves and a close ratio top loader. I’m old now and blind but I have one more 3/16 drill bit tested block and a set of C6TE-Gs and headers like what I had. Itchy trigger finger 😆
I get what you’re saying. I have a question? My friend races street stock round rounds. One of the rules has to be a 2 barrel carb. He’s mad cause it’s not pulling at the end of the straightaway. So I asked what gears? Tire size? I looked at him and asked what rpm is that? He’s trying to go 6500 on a stock 350 motor. I told him he can not pull that much air with a 2 barrel carb. I am asking you am I wrong? I told him to run it around 4500! I mean the motor will run there but he’s got no power. Just like you said. You have to have the cfm to make power. I would love to hear from you on this subject. Thank you.
@@richardmoerke9329 yes you can make power with the two barrel especially if it's the 500 Holley 2 barrel. But in order to do this everything has to be right the cylinder head work meaning the proper valve job and squeezing all the compression ratio you can out of it getting the carburetor spacer correct and then last but not least the most important thing is the right camshaft for the application. And almost forgot getting the right header to pull the exhaust out to help pull the intake charge in.
I do those types of builds quite often and you need a very fast camshaft rocker arm combination.
@@SalterRacingEngines I agree with all you said. This is what I have been telling him. You can’t take a 350 out of the junkyard and expect to win races and run 6500 down the track with it. Also they can’t run the 500 Holley.
Truth.
Sounds like one of your viewers is taking Gale Banks out of context.
That guy needs to pull his head in, he puts out so much miss information to try and sell diff covers, intercoolers and oil pans.
@@shanerorko8076Gale is talking sense, but its not specific to this NA conversation.
@@shanerorko8076 i think ive only disagreed with Gales information once, and he always goes the extra mile to prove himself. Can you give an example of what he said that was incorrect?
@jtrill2 well just recently, he's trying to sell oil pans, and claims that the manufacturer has screwed up.
But he fails to understand that most manufacturers build oil pans to retain some old oil.
This is because the oil is designed to work dirty not clean.
Many people don't realise that some additive packs actually change chemically when the contamination is in the oil.
So manufacturers will design the oil pan to leave a couple hundred millilitres to help start the chemical reactions within the new oil.
There's a few other things he's stated that are wrong. I wouldn't mind so much except he acts like he's the God of the automotive world.
Oh yea he picks people out for having black smoke at the drag strip.
He's correct in that the less black smoke the cleaner the burn, but he fails to understand what performance shops are doing at the drag strip when they overfuel.
They're doing it on purpose to get the EGTs up quicker to help spool the turbos.
I've been in the automotive game for 18 years, many old guys don't like to learn new tricks.
There's an old saying I live by, there's more ways than one to skin a cat.
I've seen guys do things differently to me, I don't criticise, I watch and learn and adapt my behaviours.
There's always one aspect that is overlooked by people watching and until you actually try and do it yourself you should just try and learn.
One of the most based guys in this way is the guy that own Harrel engine and dyno. He seems like the type of guy that is willing to learn new ways.
And he's one of the humble ones like Eric weingartner.
I also like Darrin Morgan.
@@shanerorko8076 right on sir. I am impressed with your insight into the oil pan design and kicking off the additive package and hats off to engineers who designed in that feature. Its too bad oem's have done blindingly obvious negative things with cars so much that us consumers are not suprised when we see another f up even on tech thats decades old and even to the point where people and aftermarket go around it because we have to if we want to actually fix it. But it seems like Gales team got ahead of themselves on that one. Cool on the name drops. I know Pete's real good at doin stuff, Erics all over them cams and Darins got those port velocities movin. Well its good to see you on Brians channel keepin it real and not just a blind follower of what pros say. Have a prosperous day!
Excluding 80's fuel injection, fuel supply is pretty much a non issue. The name of the game is getting as much oxygen inside the cylinder as possible.
As far as density. Well, no matter what the density is, it still flows through the ports exactly the same. Even boosted, your air wants a clear path to follow. Shit, with more dense air, it probably needs a clear path even more. You're trying to pass more molecules down a path in the same amount of time
We always make more HP when we run the engine with cooler air. Of course, without enough cfm the engine won't rpm
Thank you for your time. I look forward to all your vids as I live in Australia worth or weight in gold. Sir, do you think that if there is moisturiser in the air, I give the engine a degree or 2 of timing to help with a bit water in the air? What do you think thankyou peace
CFM and Density are 2 Different things just like horsepower and torque are 2 Different things but it is ridiculous to think of them as separate. You can't have one without the other in either case. They are 2 sides of the same coin.
I would like to know how to make over 150 HP/litre with a pushrod engine. Please share 🎉🎉🎉🎉
If you have a ¹/⁴ inch hose with really nice dense -200°f air going into one engine and a pair of 88mm turbos pushing 500°f air into another engine, which one would make more Clydesdales? Pretty simple
Neither engine would make power because they would not start.😆🤣
-200° will freeze some of the gasses in the air into a solid thus stopping air flow through the 1/4" hose.
500° air will auto ignite gasoline and even methanol before it makes it into the cylinder.
Someone needs to explore the pors n cons of both of the 6paks
Your engine prefers brawndo. It has electrolytes!
It has what yo engine needs!!😂😂
I was thinking of CFM at 25000 feet CFM of what?
Which video has the required CFM formula?
i went to look in therd factory long time i see those on a 302 and it run but only a few second so i dont really know if it would be running for a 100k
Hello Brian I don't think about density. Your competition will have the same air quality and I would have to be able to change the weather 😆
Brian, way to really simplify stuff.
How much of info in these series can be applied to 4 valve heads?
@@joeclone2686 all of it. I'm going to get to that
It's just my opinion but I've always felt like superchargers and turbos can be a crutch. Old school NASCAR and NHRA Pro Stock engine builders know their sh*t on N/A and nitrous power and cylinder head design.
👌🏾❤️👌🏾
Whom ever doesn't understand this basic principal maybe smoking something that's not good for their brain 😄
Hey brian do you know a formula for how much cfm flow thru a given valve size? 2" valve at .250 what its max flow would be?
Superflow has in the instruction manual of the sf110 tables if I remember correctly with max cfm for a given valve diameter and lift.
It also can be calculated as discharge coëfficiënt are calculated.
The formula your looking for is in a video made by Adam his channel is Cattledog Garage & Racing, it's in bolth his recent camshaft/optimal valve event timing videos as part of the coefficient of discharge calculation, which ever one you watch i would watch the whole video because its loaded with information. I've seen the longer 3.5 hour version of the video at least 10 times lol. Hope this helps.
I know which video of Adams your talking about, bolth versions of that video were awesome!!! All the Dyno data, the valve event calculations, Discharge Coefficient calculation and ya can't forget the in cylinder, Intake & exhaust pressure dynamics chart relative to ivop, overlap, evcp, ivcp, evop, crankshaft rotation, psig, psia, psiv, the explanations and the knowledge Adam gives about Optimal valve events is top notch. Best valve event timing information ive come across ever.
Sounds like sum body is lacking data flow due to they dense ity.
A power adder can cover a lot of sins when it comes to making power --- but these NASCAR naturally aspirated engine builders have to do a lot of research to get that few extra horsepower here and there as Professor Salter does, y'all. 🧐
Do you fellow try to run the coats rotary valve?
@@MrMrBigro I saw it up close in 2005 but I've never messed with it
As far as I know, the Coats doesn’t run. My mechanical engineering senior project in 1989 was a RUNNING rotary valve
@@Alaska_Engineerthe rotary valve is so difficult to seal . The humble poppet valve and spring is very , very good.
The Mazda rotary is another example of a very difficult engine to get right. Its design is sort of nearly like having a 2 inch bore and 18 inch stroke. Fundamentally inefficient.
Density matters for boost, for naturally aspirated you're not changing the density of air, so CFM matters. A cubic foot of air will have roughly the same amount of air in it as any other cubic foot in the same environment(humidity, temperature, etc).
Hell CFM works with boost too cause if you're moving more cubic feet per minute and those cubes have more air density in them, then more air and power.
CFM to RPM ....sounds like a tee shirt
Hi Brian. I have something I have wondered about for a while and it is relevant to this video. You said that cfm is required for rpm and I believe that, however how the heck do they get restrictor plate engines to rev as high as they do? I don't know the size of the bores in the restrictor plates but they seem quite small, too small for a 358 to rev to about 9000 or so. Thanks.
Andrew
@@andrewburlock2653 hey great question and to answer your question they are not too small. The main reason is because of the very short stroke we use. Most of The strokes are between 2.850 and 3 inch and those little short strokes do not require a lot of air so the restrictor plate works just fine.
It cuts to horsepower back that's for sure but it is an affair to turn that many RPMs.
Consequently if we were using a 4 1/2 or 5 inch stroke it would struggle
Hey fellas, I have been running 2bbl classes (ashpalt street stocks) and have wanted to try a 3" stroke for a while. Thumbs up or down? Thanks
@@turbo1438 I'm all for it. 3 inch to 3.250
@SalterRacingEngines cool! Just seems like the 3.48" runs outta breath about 6200. A ton of people run under this type of 500cfm rule carburetor, maybe a video about some ya know "tricks" wink wink. Thanks again and see you next episode
@@SalterRacingEngines Hi Brian. Thanks for the reply. I didn't know the stroke was that short but it makes perfect sense. I need to look outside the box a whole lot more. 350 some cubes and I automatically think 3.48 stroke. Andrew
CFM makes rpm.
Density dictates how quick RPM is achieved
The air density is what it is at that time of day or night you tune to air density