Port Velocity 101 - Part 1
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- เผยแพร่เมื่อ 14 ต.ค. 2024
- In this series of videos we look at how to -
Calculate port velocity
Calculate Mean Piston
How this effects port numbers
What this means for 'high velocity' porting
In this episode I go through how to calculate mean port velocity and how we come to these numbers.
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Hey Matt iv always been rubbish at equations and mathematics but the way you explain it relative to this makes me think I had some shite maths teachers.... Keep up the good work.
Damn it. He's making you learn Algebra again! IT'S A TRAP> RUN!.
gizzy nc , if he really wannnted to stealth them on algebra, it'd be..you get 40 kilometers per litre, and you have eight litres of fuel. How far can you go? No one knows that is algebra
I struggled with this shit in the 80's, doing ONC/HNC in Mechanical Engineering. The phrase, "ignore loss of head due to friction" comes to mind...this is why I stayed on the shop floor.....
You mate are an exceent teacher.,i will re omend you and follow your editoriaials.bmw tech hub
How fast will it make my bike go?
I'm excited to learn how some engines exceed 100% volumetric efficiency
Vincent Pampanin there are n/a engines with over 100% ve.
Jarek Nowak I know, I am excited to learn how they manage it.
Resonance, inertial supercharging.
Well above 100% ve.
Valve timing, intake + exhaust port geometry, and so on.
Regards.
Please correct me if I am wrong,
-but a port surface of 10m² equals 10,000,000mm² or a port diameter of 3,569.14mm, which is larger as the height of my kitchen door...
-a piston surface of 100m² equals 100,000,000mm² or a piston diameter of 11.286.64mm which is more as twice the average length of a car...
right.......so?
@ 11:15 I say this....
Hey Matt I was wondering whether or not two stroke transfer ports work the same?
In what way? Other than air flows through them
@@dirtygarageguy Since they are uncovered by the piston and the port durations are relatively smaller compared to a four stroke engines will a tapering inward port aid in flow.
Can you point to us, or if you know exact numbers what is optimum port velocity? Is better to be as slow as possible or we wont be able to mix gas and air? Is there some guide line for optimum?
Youre asking the wrong question. What is important is the best flow rate. And this changes over rpm.
@@dirtygarageguy Ok. Sorry, I did not want to write a book here :-). But you know if I am aiming for max torque at 5500 rpm how to optimize my ports? I can calculate amount of air that engine need, but velocity can be very different. I think that we need some optimum for good mixing. As you say, best thing for maximum cylinder charge would be to take of head and put it back, but than our fuel and air mixing with standard injectors would be poor, or not? Do you suggest that port can't be to big? Do you think that flow bench gives comparable results to the real world (dyno results), and if yeas is it important at what vacuum it can work? English is not my native language so maybe I am not so good at expressing myself. And BTW, your channel is awesome, you do what no one does, you do the math and physics stuff :-)
This is a question everyone wants to know.
@@dirtygarageguy hehe, I know. I tought maybe you know some good reference numbers. My expirence is not big as yours. I have made a flow bench, but I think that if my flow bench can not achive same speed of air as the engine will my results will not be comperable(especially if flow bench can make speed for turbulent flow) , what do you say?
Variable timing is to tune the opening to the resonance of the system
I love these videos. Please go indepth ( is that a correct word) btw i could not read the board its a bit blurry
You need to turn up the quality
You are right it was set to automatic
I have a question, so v2 is piston speed ? its that correct ?
Yes
@@dirtygarageguy so if we do porting polish on the A1 intake path will be greater, and the calculation results v1 will go down because V1 = A2 x V2 / A1 , is that correct ?
ok ok.. i have shitty 2 banger theory... what if u had a 2 stroke 2 cylinder and had a turbine on each exhaust.. and the turbines soul focus was to help pull exhaust gas form it adjacent cylinders exhaust causing a massive vacuum.. plus having a cylinder to its own crank case volume what maybe normal i havent check.. my thought is just vacuum turbos sucking air fuel- from exhaust side ahh iv had to many beers
Was that the cylinder head of your spaceship? An single cylinder 4t with and 100m² cylinder bore space bike! Some how you got to get to Mars in style, right?
Matt is this Bernouli? lookS like conservation of mass. I think Benrouli WOULD require all thoee energy considerations
Well, bernouliis explains for macroscopic effect of forces on fluid, while the movement of air from high to low pressure is due to the kinetic energy that posses by each molecule gets no surrounding where to transfer its kinetic energy but to transfer it into the cylinder (vaccum is created)... 😁 We can correlate, instead of finding out mistakes in our scientists efforts 😄
15:03 hahahaha eddy currents 😁
If the caravan goes quicker, I guess that would be called a fish tail.
LOL
It will reduce heat and gsin oil pressure snd exhaust gas exiting .hes 100 percent right .bmw fu ked him sround .suport a d recomend him and if you diont belive in it state why if you csn teach him teach.
why is the sound in the back ground so creapy
Now i can use variable nose runner to increase my volumetric efficiency of my lungs
I am sorry sir a bit too technical for me good video
Why go to college and learn this stuff when you can right here?
I've just "Ran"/"Run" Sorry Matt I can see it flying over me head. Wish i could get to gripp ?? Having now watched the vid 3 times me head is still spinning !!! Just born a thicko !!!! Me Mam always said
if i had brains i would be Dangerouse !!! also suffer with dislex diss lec disss Can't fucking spell !!!!!!!!!!!
Hi Matt, the video is blurry...
Bob Hancock hi blurry I'm Matt
Seems ok now Matt
never mind.Bernolli just showed up
If you don't believe Matt, read garage.grumpysperformance.com/index.php?threads/port-speeds-and-area.333/
uhoh. p and v cant be added
#360psquad