Is Port Energy validation just around the corner?????

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Re: Is Port Energy validation just around the corner?????

Post by turbo2256b » Sat Sep 23, 2017 9:27 pm

Tickford did the first variable geometry intake their pat ran out and at some point I WAS Given the engineering design order to do one for ford. Had a couple ideas figured out and on CAD.

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Re: Is Port Energy validation just around the corner?????

Post by hoffman900 » Sat Sep 23, 2017 9:32 pm

From a strictly theoretical sense, read about variable area nozzles on jet engines. Obviously you can't have that in an internal combustion engine because the chamber does more than assist with pressure recovery of the port.

Image

You could always produce a port this way, maybe with a divergent section and a convergent section, however, the valve is fixed. Additionally, how much power would you have to produce to overcome the weight disadvantage and potential efficiency losses? How much is there to gain considering the use of multiple gear transmissions?

A quick search of patents shows many different ways of attempts to vary the port area. It's not a new idea by any means.
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Re: Is Port Energy validation just around the corner?????

Post by swampbuggy » Sat Sep 23, 2017 9:53 pm

Ok Bob. I went to the shop and got the paper I wrote Darin's statements on. QUOTE, There is no air speed, wave amplitude or special harmonic tuning below 6500 rpm's. And engines induction is almost un-tunable until it hits 6500 rpm's. At 6500-6800 rpm you can build wave propagation and inertia in the system to attain higher V.E.'s, below that forget it. The entire scope and design of the induction system changes when your building engines below 6500rpm. Low rpm engines don't obey the same rules. If you try and build them the same way you do a high rpm engine you will be leaving a lot of power on the table. Thanks, Mark

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Re: Is Port Energy validation just around the corner?????

Post by hoffman900 » Sat Sep 23, 2017 10:01 pm

swampbuggy wrote:Ok Bob. I went to the shop and got the paper I wrote Darin's statements on. QUOTE, There is no air speed, wave amplitude or special harmonic tuning below 6500 rpm's. And engines induction is almost un-tunable until it hits 6500 rpm's. At 6500-6800 rpm you can build wave propagation and inertia in the system to attain higher V.E.'s, below that forget it. The entire scope and design of the induction system changes when your building engines below 6500rpm. Low rpm engines don't obey the same rules. If you try and build them the same way you do a high rpm engine you will be leaving a lot of power on the table. Thanks, Mark

I found the thread. I kind of agree and kind of disagree. There are examples that support my disagreement.

Further in that thread, I found this:
ou only have to look to the EM challenge to learn what makes power from 2500 to 6500rpm. The recipe is simple but the application is highly critical and complex.

(1) Low seat timing HIGH overlap flow in conjunction with valve speed out the ying yang. (Thats a technical term LOL) High valve speed lets you keep the valve on the seat longer yet expose more curtain area at max piston speed. Our engine as well as other have 240 degrees at .050 and .880 lift at the valve using a 2:1 or even 2.1:1 rocker arm. Valve speed is key but if you have an endurance engine valve speed is the enemy of longevity.
(2) Just enough CSA to make power at 6000rpm but absolutely no more than that. You must rely on overlap to move air through the engine at low rpm and this makes the exhaust system hyper critical. Think about it. The exhaust side is the only portion of the system with any usable energy to move air with.
(3) Wave tune on the engine dyno through trial and error and throw most of your equations out the window. So little air speed exists in the 2500-4000rpm range that there is no wave action to speak of. the waves that do exist are of so little amplitude that no usable energy exists to raise density at valve opening. Do a wave simulation on your Performance trends Engine Analyzer software and watch how little air speed and consequently how little wave amplitude exists below 4000rpm. Even is you try and build air speed you get almost nothing in return. This is why there is a direct correlation between engine speed, piston speed and VE! Without engine speed you CAN NOT build high VE. Its impossible.

I am not saying you cant wave tune an engine at 2500rpm or 3000 or 4000rpm. I am saying that to make power over the whole 4000 range you need the recipe stated above.

I talk at least an hour on this topic in my Advanced induction class. Its really impossible to do anything more than hit the high points on a message board.
This is more like it.
-Bob

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Re: Is Port Energy validation just around the corner?????

Post by swampbuggy » Sat Sep 23, 2017 10:06 pm

Thanks Bob i really appreciate your input, Mark.

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Re: Is Port Energy validation just around the corner?????

Post by turbo2256b » Sat Sep 23, 2017 10:06 pm

Their was another engine 4 stroke 4 banger were i DESIGNED it with reed valves like a 2 stroke. Which in some ways be like the jet engine idea. Dont remember any real improvements except maybe reversion.

Some of the best results were the split port heads like the 3.8. We didthem for just about every pushrod ford engine and easily out performed the ohc FORD engines

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Re: Is Port Energy validation just around the corner?????

Post by David Vizard » Sat Sep 23, 2017 10:19 pm

Bob,
Who wrote the following:-



You only have to look to the EM challenge to learn what makes power from 2500 to 6500rpm. The recipe is simple but the application is highly critical and complex.

(1) Low seat timing HIGH overlap flow in conjunction with valve speed out the ying yang. (Thats a technical term LOL) High valve speed lets you keep the valve on the seat longer yet expose more curtain area at max piston speed. Our engine as well as other have 240 degrees at .050 and .880 lift at the valve using a 2:1 or even 2.1:1 rocker arm. Valve speed is key but if you have an endurance engine valve speed is the enemy of longevity.
(2) Just enough CSA to make power at 6000rpm but absolutely no more than that. You must rely on overlap to move air through the engine at low rpm and this makes the exhaust system hyper critical. Think about it. The exhaust side is the only portion of the system with any usable energy to move air with.
(3) Wave tune on the engine dyno through trial and error and throw most of your equations out the window. So little air speed exists in the 2500-4000rpm range that there is no wave action to speak of. the waves that do exist are of so little amplitude that no usable energy exists to raise density at valve opening. Do a wave simulation on your Performance trends Engine Analyzer software and watch how little air speed and consequently how little wave amplitude exists below 4000rpm. Even is you try and build air speed you get almost nothing in return. This is why there is a direct correlation between engine speed, piston speed and VE! Without engine speed you CAN NOT build high VE. Its impossible.

I am not saying you cant wave tune an engine at 2500rpm or 3000 or 4000rpm. I am saying that to make power over the whole 4000 range you need the recipe stated above.

I talk at least an hour on this topic in my Advanced induction class. Its really impossible to do anything more than hit the high points on a message board.


Thanks
DV
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Re: Is Port Energy validation just around the corner?????

Post by hoffman900 » Sat Sep 23, 2017 10:26 pm

David Vizard wrote:Bob,
Who wrote the following:-



You only have to look to the EM challenge to learn what makes power from 2500 to 6500rpm. The recipe is simple but the application is highly critical and complex.

(1) Low seat timing HIGH overlap flow in conjunction with valve speed out the ying yang. (Thats a technical term LOL) High valve speed lets you keep the valve on the seat longer yet expose more curtain area at max piston speed. Our engine as well as other have 240 degrees at .050 and .880 lift at the valve using a 2:1 or even 2.1:1 rocker arm. Valve speed is key but if you have an endurance engine valve speed is the enemy of longevity.
(2) Just enough CSA to make power at 6000rpm but absolutely no more than that. You must rely on overlap to move air through the engine at low rpm and this makes the exhaust system hyper critical. Think about it. The exhaust side is the only portion of the system with any usable energy to move air with.
(3) Wave tune on the engine dyno through trial and error and throw most of your equations out the window. So little air speed exists in the 2500-4000rpm range that there is no wave action to speak of. the waves that do exist are of so little amplitude that no usable energy exists to raise density at valve opening. Do a wave simulation on your Performance trends Engine Analyzer software and watch how little air speed and consequently how little wave amplitude exists below 4000rpm. Even is you try and build air speed you get almost nothing in return. This is why there is a direct correlation between engine speed, piston speed and VE! Without engine speed you CAN NOT build high VE. Its impossible.

I am not saying you cant wave tune an engine at 2500rpm or 3000 or 4000rpm. I am saying that to make power over the whole 4000 range you need the recipe stated above.

I talk at least an hour on this topic in my Advanced induction class. Its really impossible to do anything more than hit the high points on a message board.


Thanks
DV
Darin Morgan. It does clarify his original statement.
-Bob

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Re: Is Port Energy validation just around the corner?????

Post by Joe-71 » Sat Sep 23, 2017 10:58 pm

I came to this website late, but have been reading as much as I can absorb in one sitting nearly every night. I have been following David V's advice for nearly 30 of my 45+ years of porting, and I can verify that velocity is key to making more torque and horsepower. I have had several engines built over the years that exceed 120% VE with sheetmetal intakes and well ported cast intakes that reach 118% VE. We have tested many combinations of intakes including dual plane, single plane, tunnel rams, sheetmetal intakes trying to find the best intakes for EMC engine entries, and if I can keep the intakes at around 120% airflow of the intake port, then torque averages increase, and horsepower does not fall off in the higher rpm ranges. Many times we have seen small ports produce great torque, but go flat the last few hundred rpms with horsepower not climbing, and just the opposite with larger ports being down on torque, but horsepower keeps increasing in the upper rpm range. I have the unique advantage of having supported several engines with intakes and heads at EMC over the last several years,(one winner) and that has opened my eyes to what works, and what is "just bench racing" information. Back in the '87-89 time frame, several of my heads and intakes were featured in Super Ford Magazine, Muscle Mustangs, Mustang Monthly with dyno tests to prove these tried and true concepts. Having just finished another pair of 289 heads for a Super Stock engine, it will be interesting to see how David proves his points. Joe-71

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Re: Is Port Energy validation just around the corner?????

Post by MadBill » Sun Sep 24, 2017 12:13 am

Darrin is of course rightly and highly respected in the racing engine world, but I have to disagree with his statement "So little air speed exists in the 2500-4000 rpm range that there is no wave action to speak of."
Any number of production engines take advantage of intake wave tuning to pick up mid range torque. For example Chev TPI engines of the late eighties/early nineties used very long runners tuned for, AIR, ~2800 RPM. They were effective enough to produce a substantial torque bump and even required a several degree dip in the WOT spark table to stave off detonation.
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Re: Is Port Energy validation just around the corner?????

Post by maxracesoftware » Sun Sep 24, 2017 1:33 am

MadBill wrote:Darrin is of course rightly and highly respected in the racing engine world, but I have to disagree with his statement "So little air speed exists in the 2500-4000 rpm range that there is no wave action to speak of."
Any number of production engines take advantage of intake wave tuning to pick up mid range torque. For example Chev TPI engines of the late eighties/early nineties used very long runners tuned for, AIR, ~2800 RPM. They were effective enough to produce a substantial torque bump and even required a several degree dip in the WOT spark table to stave off detonation.
Do a wave simulation on your Performance trends Engine Analyzer software and watch how little air speed and consequently how little wave amplitude exists below 4000rpm.
Bill , i agree with you 100.0 % percent ! or a million percent if there was such a thing :)

i have a lot of Dyno tests from 2500 RPM upwards and a few at 2000 RPM upwards
that prove there is a tremendous amount of TQ and HP gains from Wave tuning, especially in the 2000 to 4500 RPm Range !

so i guess you might as well throw away Phillip H Smith's book "Scientific Design of Intake and Exhaust Systems" ( Smith and Morrison )
of which most of the Data was from 1000 RPM to 5000 RPM with Morrison Pressure Indicator

i'm guessing all those NHRA Stockers and SuperStockers , especially the Hemi SS in the 60's 70's with Torque Converters ,
with those extra long Header Collectors were all wrong ???

The Street Class RPM range in 2012 was 2500-6500
http://www.maxracesoftwares.com/forum/v ... f=12&t=231

these Chrysler engineers don't seem to know what they are doing either ??
likewise an Edelbrock Dual-Plane Air-Gap manifold should not work either ???

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Last edited by maxracesoftware on Sun Sep 24, 2017 1:40 am, edited 1 time in total.
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Re: Is Port Energy validation just around the corner?????

Post by SchmidtMotorWorks » Sun Sep 24, 2017 1:40 am

Chrysler has a system that effectively changes both duct cross-section and length with a valve that opens about 25%.

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The concept and quantities involved are only a mystery to anyone that doesn't bother to learn from a 1D simulation.
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Re: Is Port Energy validation just around the corner?????

Post by hoffman900 » Sun Sep 24, 2017 2:28 am

MadBill wrote:Darrin is of course rightly and highly respected in the racing engine world, but I have to disagree with his statement "So little air speed exists in the 2500-4000 rpm range that there is no wave action to speak of."
Any number of production engines take advantage of intake wave tuning to pick up mid range torque. For example Chev TPI engines of the late eighties/early nineties used very long runners tuned for, AIR, ~2800 RPM. They were effective enough to produce a substantial torque bump and even required a several degree dip in the WOT spark table to stave off detonation.
I think his second post further on provides clarification. I disagree with the original post, but it is undoubtably weaker at lower RPMs. He makes that clarification in that post I dug out of that thread.

However, one needs to forget RPMs and think piston velocity as that is what really drives the whole thing NOT the air crashing into the back of the intake valve. You correctly pointed this out at least a decade ago here - if the air is doing that, then you're closing the valve way too early. Measured pressure graphs and 1D simulation clearly show what is happening. The Chrysler engineers knew what was happening. The whole crashing into back of the valve thing was in a Superflow manual - since they sold a lot of those, that idea has become quite pervasive.
Last edited by hoffman900 on Sun Sep 24, 2017 2:38 am, edited 2 times in total.
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Re: Is Port Energy validation just around the corner?????

Post by digger » Sun Sep 24, 2017 2:32 am

I think the benefit of long intake runners below 2500 is significantly less than above 2500rpm so in a way I agree with Darin that low rpm youre up against it probably in part due to the practicalities of fitting longer runners. Perhaps a smaller runner diameter may help with producing higher amplitudes at low rpm

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Re: Is Port Energy validation just around the corner?????

Post by joe 90 » Sun Sep 24, 2017 4:12 am

If you take a close look at some of the technology from Honda (VTEC), Mitsubishi (MIVEC)and Nissan (SR20VE) you'll see that as well as using switchable cam profiles, they use switchable runners and they achieve a flat torque curve from 2000 to 8000 RPM , peak HP is at peak RPM and the VE gets close to 140%.
It's been around for over 20 years.

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