Collapsible boundary layer

[mpgmike]

I finally found a test that can quantify a claim I've been making about creating a collapsible boundary layer through port texturing. I realize that by posting this here I'm opening myself up to be questioned and challenged by the best in the industry and I humbly submit myself to such scrutiny.

The article can be found at:

http://powrehaus.com/2007/04/27/collaps ... r/#more-40

Comments welcome.

Mike

[Unkl Ian]

Would have been nice if he included a base line test
of a stock head at all three depressions.

Are the conversion factors he has used correct ?

[Stan Weiss]

For 10 to 28 I get 1.67332005
For 28 to 34 I get 1.10194633
so rounded he is correct

[shawn]

I don't know anything about the claims as I haven't seen any data for the use of "lynz". I do know that the methodology used to support the claims is wrong. All that i see being displayed is a head that flow different at different depression vs. what a correction from one depression to the next says. There isn't numbers shown with a "control" product that is unmodified, or the same cylinder tested unmodified first then later with the addition of the "lynz".
One of the reason's I just built a new bench was to be able to flow heads at higher depression's than my current sf-600 was capable of, just for those reasons. Ports don't flow the same at different depression. I would try testing again using a control head and see what your results are.
shawn

[Joe Mendelis]

Not to offend, but just to be honest; if port texture made a difference it would make a difference in power or fuel requirements, which it doesn't do either of.

[mpgmike]

I once did a VW VR-6 with only a 20 pitch Lynz. No other changes. Power was up significantly. So much that the owner grenaded 3rd gear on the maiden voyage out. I don't have dyno data, but I'm convinced that the Powre Lynz add power by better vaporizing the fuel. I haven't figured out a way to test that theory, but believe I found a way to test the variable boundary layer theory.

I have to move this up coming week. It will be awhile before I can get back to testing, but I concede that a base test without the Lynz, then add the Lynz and test again needs to be done.

Mike

[FordManVT]

This is pretty similar to leaving the CNC steps in the head, which some people have shown to be an improvement in certain cases.

While not having a unmodified head puts his experiment in the can, I still think this modification is viable.

[mpgmike]

My intent for posting these results is to spark interest from people that have better access to equipment (like a flow bench as I have to run heads up to the machine shop to have them flowed). I am proposing that texturing the intake ports creates benefits, and have some data to support that claim. The chosen vehicle is screw threads. Dana44 from another forum uses the scallops caused by a chattering carbide bit as his vehicle and claims very positive results.

If other head porters were to take this subject seriously enough to devise their own tests, and perhaps their own frorm of texturing, this whole "port texturing" theory could be refined into very predictable data. Sharing this info puts into the hands of customers better products, regardless of whom the porter is. As a head porter, I'm sharing this info with hopes of getting back testing data from other head porters so that my own process can be improved.

If this is as significant as I think, then it should be shared. It is a tuning tool and not a means to an end (my thoughts on the Somender Grooves as well). So what I'm doing is giving away one of my trade secrets in hopes that the process can be refined by the hands and minds of others and we all can benefit.

Mike

[larrycavan]

Hi Mike,

I have reason to cast any doubt on your success from texturing the port finish with those tools. However, please keep in mind that the test method is somewhat flawed. I won't go as far as to say it's false. Here's what I get from reading the test results.

1. Flow comparisons at different test pressures, especially widely spaced pressures can lead you on a wild goose chase.

2. Without a standard flow mechanism to use as a comparator, there really is no standard to compare the calibration of the flowbench at different test pressures.

3. Had they at least flowed the heads stock at both test pressures and then flowed them in modified form at both test pressures, there would be something to draw a better conclusion / assumption from.

To gain really useful data from the effect of finishing ports like that requires both flowbench and dyno or track data. The dyno or track results would show if there is in fact a power increase. The flowbench could be used to help explain why.

On my own flowbench, I routinely get slightly larger numbers when I convert from 10 to 28 than what I get at the actual 28" test pressure. Conversly, I also get slightly larger numbers when I convert from 28 to 10 than I get when conducting the test at an actual 10". The closer I flow to 28 and convert up from that value, the closer it is to the actual value obtained at 28".

My bench is calibrated at 28" but I also have a quick check plate that was tested on a SF110 at 10". That quick test plate always shows me within 1 - 1.5 CFM of it's test rated CFM number.

If there is gain in power from that port texturing, I would suspect it would show up in the form a tendancy for the carburetion to need leaning out. I would think lower BSFC vaues on the Dyno would support the claim of better fuel atomization as well.

JMO
Larry C

My intent for posting these results is to spark interest from people that have better access to equipment (like a flow bench as I have to run heads up to the machine shop to have them flowed). I am proposing that texturing the intake ports creates benefits, and have some data to support that claim. The chosen vehicle is screw threads. Dana44 from another forum uses the scallops caused by a chattering carbide bit as his vehicle and claims very positive results.

If other head porters were to take this subject seriously enough to devise their own tests, and perhaps their own frorm of texturing, this whole "port texturing" theory could be refined into very predictable data. Sharing this info puts into the hands of customers better products, regardless of whom the porter is. As a head porter, I'm sharing this info with hopes of getting back testing data from other head porters so that my own process can be improved.

If this is as significant as I think, then it should be shared. It is a tuning tool and not a means to an end (my thoughts on the Somender Grooves as well). So what I'm doing is giving away one of my trade secrets in hopes that the process can be refined by the hands and minds of others and we all can benefit.

Mike

[larrycavan]

If you look at the K&N test process in this thread http://speedtalk.com/forum/viewtopic.php?t=6303&sid=388a0bbbbdac9a50cc7bdd91163056c9 and convert the numbers up from 10" to 25 and then 50, you'll see a trend very similar to the test results of this thread's origin.

[Troy Patterson]

I have experimented extensively with texture on and off since the early eighties. The difficulty in obtaining "qualified results" is in the fact that when one item or component is changed, to accurately evaluate it's effect, many other items must also be change to "zero" the " engine's system" back out. Without doing so, subsequent tests are of an "engine system" having multiple changes for comparison, making it very difficult to effectively or accurately relate it back to the base line test.

To add greater difficulty to this, when experiementing with issues of fuel, fuel curve, droplet size, vaporization rates, precise air & fuel management / measurement relative to power production at varying throttle positions and loads, it is a subject few people really grasp and hard to quantify.

Smokey said something to the effect that a properly designed and sized poprt / engine combination does not need bandages. To some degree this is true however, anything we do is a compromise in some regard, so it is about finding the best compromise and that may include textures.

I would encourage further experimentation. I haven't heard of this material or treatment, MPG would you post some pictures please?

Troy Patterson TMPCarbs.net TMP Carbs

[automotive breath]

... I haven't heard of this material or treatment, MPG would you post some pictures please?

Troy,
Mike is in the process of moving his residence and shop, I don't know
if he is able to get his computer up. I don't want to speak for him, I
haven’t tried this but I have been following this for some time now.
What he explained to me was he puts threads inside the ports, when
fuel falls out of suspension the grooves collect the liquid , it is vaporized
from the heat of the intake and returned into the flow.

Here's some pictures he sent some time back, he is further along with
his tools and methods.

[larrycavan]

Troy,
Mike is in the process of moving his residence and shop, I don't know
if he is able to get his computer up. I don't want to speak for him, I
haven’t tried this but I have been following this for some time now.
What he explained to me was he puts threads inside the ports, when
fuel falls out of suspension the grooves collect the liquid , it is vaporized
from the heat of the intake and returned into the flow.

I've looked at that for a couple of months now and there are some things that bother me about the concept of fuel collecting in the grooves and then vaporizing back into the airstream to be burned.

If the fuel fall out of suspension then at what point, how many strokes later is it ingested as a vapor?

This simply isn't a once and done deal. Would it not be continuous? Fuel falling out of suspension indicates a problem in the port velocity, shape, csa.....something is wrong somewhere. It would mean that it continuously falls out of suspension and is vaporized at some later point in time. I highly doubt it falls out, collects on the rough texture, vaporizes and is ingested as vapor on the same intake stroke.

How exactly is the cycle working. Intake opens, fuel arrives in the port but doesn't make it past the valve, instead it collects somewhere in the grooves, heats up from contact with the hot port surface, vaporizes and waits for an opportunity to pick up where it left off when it fell out of suspension....the continues over and over and over every time the intake valve opens and the port conditions are such that fuel falls out of suspension.

Seemingly there is perfect timing for the vaporized fuel to be replaced with more undelivered liquid fuel.

Just seems to me if you need that level of roughness inside the port then you should really be looking into resolving the problem that is causing the fuel to fall out of suspension.

I would think the cure is either correct the port or look upstream for better atomization.

I won't say there hasn't been positive results from the technique because I just dont' know one way or the other. What I'm saying is it looks like a band aid approach to curing the real problem.


JMO

Larry C





Here's some pictures he sent some time back, he is further along with
his tools and methods.




[/quote]

[automotive breath]

Larry, I believe Mike is involved mostly with street performance where
power and economy are the goals, the engines see a lot of throttling.

[Troy Patterson]

The thing is, regardless of the level of development of the engine, it use and how highly the fuel droplets are atomized, there will always be some percentage of liquid (fuel) in the intake track. Some engines it will be more than others.

Liquid (fuel) in the intake track doesn't necessarily indicate poorly designed ports, manifold or even a lack of adequate atomization at the carburetor - it's more complex than that.

To really evaluate whether or not a port texture is appropriate of not, requires taking into consideration the percentage of light ends in the fuel used for testing, the degree of atomization by the carburetor's boosters and air speed through the carburetor to name a few items.

Unless, a inertia dyno is being used, I'd recommend in car at track testing for this sort of thing. Even then, incremental gains may be less than the margin of error or repeatability from one pass to the next.

Some people are more sensitive to their cars and engines than others. I happen to be extremely sensitive to subtle changes made, and after many years of experimentation and testing, I've developed some ability to read the subtlist signs from exhaust note to the sound of the carburetor and relate that back to the rate of acceleration, throttle position, etc.

If it works for a given application, it's good, but you may find with a different carburetor, it is less effective, or not effective at all, or perhaps more effective.

I would not say it is limited to only street applications, it is or can be equally effective in some race applications. There really is more going on inside the intake track than we yet understand.

For further examples of surface texturing, look to what some have done with motorcycle intake ports - in the past. I don't know if anyone is still doing it.

Troy Patterson TMPCarbs.net TMP Carbs