with those flow #'s, how much metal is left in the ports? i would think, really thin.

Some areas are no doubt thin....I have found.....wink wink....a lot of the areas that simply cannot get any larger.....this is one of the reason why I have so much time in R&D and also specify that I am not sure how it will translate to a 'real' port....

I would guess that you subscribe to the intake port mach effect as you have a target MCA.....just as this theory has many propponents it has many opponents....there are those that say this theory only applies to the exhaust port and the intake does not become limited....like I said....if theory was law this would be easy....I do however quite enjoy our debate....there are no hard feelings on my part and you mentioned that Ford before....sounds awesome!....hope it works out!

Actually however, there are areas of the port that responded better and gave me greater results.....much greater....when material was added.....not just for the sake of adding but to reshape the port and 'direct'(as much as it is not the proper term) the flow....the port is not concentric, it is not geometric and it certainly isn't pretty....but to paraphrase what a wise porter once said "if we could attach a piece of string inside the port and make it stay we would, if that would flow better"....

it is no theory that minimum int cross section limits cylinder filling in the comp stroke, thus limiting the peak engine speed of the engine,, you cannot "cam" the motor to run past where the int port will peak,, though many think you can and try to do it causing you to loose power everywhere,,

i have a dyno here,, and see it,, as with talking with my friends/customers who race nhra,,, super stock,, comp,,, or pro stock

Jeff if he is ever willing to verify these flow numbers on another bench I am willing to offer my bench. I will throw a test plate on to verify my bench and we will then use his bore adapter and do the test. I will do this FREE of charge as long as he agrees that I post ALL findings. All flow number will be posted along will bore adapter size. I am located 35 miles NE of Pittsburgh, Pa. if he is interested.

I appreciate your offer....as stated previously....once I have a finished product with which I am happy I have someone about 15 miles away with a Flocom SF600 that will verify my results....our benches flow very similarly....as calibrated Superflows should...so I am not concerned with differing results....the one thing I find peculiar is that Jeff tells me my low lift numbers are down but my high lift cannot be that high......seems as though my bench has some odd ability to both increase and decrease numbers at different lifts in the same test according to what others believe they should be.....I would think either numbers would all be up or all be down across the board......

Assuming this 'theory' has validity....I believe it was Darin Morgan who said it is not correct....you are assuming that the air column is 'seeing' the port in the same dimension as you....we look at the cross section physically...we take measurements and calculate a uni-dimensional volume for that very specific point in the port....that is dine assuming that the air is moving.perpendicular to that point...however air very rarely flows with such 'proper' direction...if the line of flow is skewed any amount from perpendicular then it will 'see' the window at an angular view effectively making the area larger....again....science is not exact or cut and dry.....this may be the reason that Darin said this theory lacks a level of validity because we are wrongly interpreting the data....

Quoted from a thread relating to CD...

) Can it be too high causing something to sonic choke at the SSR? Yes it can choke but NO it cant Sonic choke. There is no such thing as Sonic choking in an intake tract. They operate at a maximum of about.5 to .55 mach 600+ft/sec, which is far below Mach. If the mean velocity in the intake tract where to exceed mach .55 the power would drop off dramatically. Sonic only occurs on the exhaust side and usually at lower lifts in super charged engines.

Darin Morgan

Not saying he is right or wrong....although he is head of cylinder head development.at Reher Morrison....just illustrating my point that the theory has its.opponents as well....

darin is correct for the most part,, but what he said and what i said arent the same,, read it again,, i never said the intake ports go sonic,, exh ports can,, beacuse of the pressures in the cylinder when the exh valve is initially opened.. the intake port cross section will just limit how high the engine will peak at,, everybody knows that....... and pro stock trucks used w-9 heads when they were slow,, they used p-5 heads when they were fast,, also,, a "good" pro stock truck w-9 flowed just about 390-400,, which is enough to make 950hp,, he is claiming 470,,, see my point yet???

also,, i have a cnc machine,, and computer software for it,, i can see the ports on my computer screen and slice them wherever i want,, not use calipers and guess,,, plus like i said,, ive worked on engines along with others,, and witnessed peak power at a predicted rpm based on minimum int cross section and runner length

I don't know where to go from here....I am not 'claiming'....it is what I have achieved on a calibrated and verified bench....I don't claim it will work or make power....I am simply posting my results.....I expected there would be some naysayers....Jim I respect you for what you have done and all your achievements...it is too bad that instead of being reciprocal you need to try to convince everyone that these results cannot be as you have never gotten them.....I remember the days when a 350cfm port was considered astronomical....I am just glad that at that time there were people who felt there was still room for improvement and not that since that is all the porters of the time were getting that that must be all that is possible....

It is the same....the whole reasoning behind this theory relates to the MCA controlling the velocity....that at a specific cross section and RPM the air will be travelling at a given velocity based in what the port flows....that this velocity...if it reaches a certain speed will sonic choke the port thus making power drop off after this point....the intact tract length controlling RPM is a different theory and relates to the range at which.sonic pulses will aid in cylinder filling based on the timing of the pulses to be synchronized with the intake valve opening.....

If not for its ability to influence velocity...then what other reason would there be for the MCA to control where an engine will make power?

What I have found....and this is just me....is that the as cast bias of the intake.port is not conducive to very high flow numbers....perhaps the PS heads were ported on the factory bias and thus the reason they were limited to around 400....I in no way claim to be a better cylinder head buy than anyone, let alone the PS guys, I just try different things to see what works rather than rely on conforming my design to what everyone else says works.....

the mca,,,,, will effect the ports pressure on the cylinder during filling in the compression stroke,,, when you have a port that flows extremely well,, its obvious the filling in the intake stroke will be enhanced,, therefore when the piston starts comming up, compressing that mixture there will be more charge in the cylinder, causing more pressure,, the point at which the pressure of that compressed mixture becomes equal to that of the inertia pressure in the intake runner becomes equal,, you must close the valve,, inertia increases as engine speeds comes up, or gets higher to the point that the mca restricts it, causing it to stall, and not produce anymore,, therefore anything past that speed will push charge back into the runner if the valve is open longer, loosing power

its not that "I" cant get your numbers,, nobody on the planet,, but you,,, can,,,im not saying they arent true,, id just like to see you validate them with somebody else,, its not like you got 440 out of them,, which would be a high number,, but maybe possible,, you got 470,, that number is so high,, higher than anybody has heard, got,, etc...

According to this explanations a high flowing port with a smaller MCA will make more power than a like.flowing port having a larger MCA as the smaller port will have more velocity and consequently higher inertia allowing more charge to RAM the cylinder, the valve.to stay open longer and the piston to be higher in the bore before the pressure in the cylinder equals or exceeds the inertia ram...

no,, you missed it

Quite the converse of what you were attempting to illustrate....by this definition it could be argued that the best power would be made with the SMALLEST MCA possible while still providing adequate airflow to fulfil the demand if the engine at the RPM you are trying to make power.....as too large an MCA will kill velocity and inertia and require the valve to close sooner before to avoid reversion.