weak valve springs are the main reason valves float occurs at a lower RPM than you get your best power curve at. Of course push rods play a rule, just not as big. The harmonic resonance frequency is only what the valve springs do at a certain RPM and Comp Cams or whomever you buy the springs from should know when this happens. The biggest thing that affects it like I said was the pump up or pump down of hydraulic lifters. I can imagine though that too could be simulated by changing the valve lift and duration to see how the higher RPMs would react to this.

Air can only flow through a confined space so fast. I don’t know if some of those import companies are doing it, but here in the states, as far as I know, they don’t use variable runner length because it complexes the system more than it has to be for the average person and adds to the cost of the vehicle. Diameter is directly related to velocity. Long runners help the lower RPMs because after the port closes, it creates a high pressure near the port and pushes back out. The longer the runner, the longer it takes the wave to leave the runner and go down the next one that has an opening intake port, which is to say if it is even tuned to that next port. Long runners hurt you in the higher RPMs since you starve the cylinder taking in air because it still has a low pressure in the runner once the valve is closed which is filled by the intake airflow and the next cylinder opening gets even less air since it was diverted to the other one and as you can see makes it twice as bad. This happens because the mass of air inside the runner has to be accelerated and the more there is (longer runner), the more it has to move which is fine at slow speeds, but at high speeds, it doesn’t have enough time. diameter can offset this because air flows better and at a lower velocity. That’s why the upgraded TPI system has larger diameter runners. You will hit the same tuning and max velocities at higher RPMs. Vice versa goes for short runners. Diameter has the same effect though.
Also like I said before, every reflection the pressure wave takes, it loses power exponentially. Think of it as a water balloon hitting a wall. How much comes back to hit you? Air does bounce a little better because it’s lighter obviously, but at higher RPMs, it will splatter more as you could’ve guessed. I’ve also read the best way to tune the pressure waves is to have it so the wave hits the port right before it closes so you get that extra charge and more pressure to bounce out.

Single planes don’t have a resonate frequency. Find me a site that has one. They have “cross talk” which interrupts any resonate frequency they might be capable of. The only way to have it work, like I said earlier is to divide the intake into 2 (dual plane).

You would also need a computational fluid dynamics (CFD) program to simulate the airflow and by then you would’ve spent so much money and time it’s hardly worth it. It would be worth it to just get Dynomation, but for me, this program will do fine.

because some of the stuff I don’t know I can just look up and I am having a problem finding the compression values which I need if I am going to (re)build this engine. It’s not like I’ve got the money to do this right now. I’m hoping the tax return will be higher this year and I’m getting a higher pay grade soon.

HAH! I didn’t even get my first chevy till late 02. and it took almost 6 months to get interested in learning about it.

PS: please make sure you are right by checking your reply on the internet or a book or something before replying.

 

your really going to make me use google after all this

but fine let me look for smoething
ok I tried to find something for single planes and didn't yet. but here is something also
with a single plane vs a dual plane the pulses will come at twice the frequency. it would be about the same effect as if you took a dual plane and reved it up to twice the rpm range that it was running at. the effect might not be as strong but it should be relevent.

valve springs make a difference so does weight of the components on the valve train. heavy parts will tend to bring float about easier as well as should bring it in at a lower rpm range. still could be some other valve train harmonics causing issues that isn't all dependent on the valve springs. there are other factors that effect the harmonic resonant piont.


in the states there are cars that use variable runners just in a different setup. most of them are not a infinant adjustable runner but rather two runners going to the same port with a butterfly valve or something like that. how do you tune one runner to the next runner port? you do realize that if all runners are the same legnth they are tuned to each other right?now the question is frequency has been tuned. air flow at a lower velocity doesn't add as much to the ram effect going into the motor.

harmonics get weaker over each order usually. I've known that for a while when dealing with my electroncs and guitar stuff

as far as cross talk what do you think these resoant frequencies are between the cylinders. one port sending out a notice that it's port just closed and sends that pressure wave right back up.
it's all nothing more then crosstalk



hey I was talking about being accurate with the programs. sure a little overkill but the program you have could be al ittle more accurate without being too much more involving




blahblahblah

 

I’m not sure exactly how they tune the runner to the next port, but what I get from it is it should be pointed in the general direction of the next port about to close and it should follow the air that is being pulled down that runner since it has lower pressure and boost it while it creates another charge for the next port in line after it fully closes. Just look at the TPI intake. It’s “tuned” and as you can see the runners point at each other. The LS1 is the same way and GM even changed the firing order for better wave tuning, and a better idle or something. That couldn’t be more wrong. I haven’t really seen an intake with different length runners and that doesn’t at all mean they are tuned together. It’s called wave tuning. That’s what I said though… if the velocity is giving you the tuning you need at a low RPM, it will act against you at a high RPM.

it’s not really a harmonics though. It’s pressure wave tuning.

while one port is closing, another is just opening and yet another is fully open. That leads to turbulence in the manifold that cancels out any effect you are talking about. Prove me wrong, find a site.

 

gm changed the firing order for a smoother running engine. with the slight change it had less vibration
you can tune a inline 4 cylinder to have tuned pressure waves. btw they don't face each other


it is harmonics being that your tuning in a way not on the fundimental note itself but a multiple there of
the harmonics are what makes the pressure


the effect of a v8 running on a single plane at 2000rpms would be the same effect as a v8 with a dual plane or a 4cylinder spinning at 4000rpms.
can you prove that wrong?

 

Well for my first trick, I will attempt to make a ~10.96:1 SCR run on 87 octane. That's the compression I will make with a 58cc head and my current setup.

I'm done replying back for stuff that has no significance.

 

Thank goodness.

 

oh boo hoo