In the other 434 thread it was recommended by the mod, allthrottlenobottle, that we start a cyl head thread.

It was seconded by Deakins, and verified by Cuisenart Vette.

So as I said there, let's not talk about it let's do it.

As you know it is my position that there is a lot of mis information being thrown around here. All I ask is an honest review of the theory submitted without mentioning brand names or models. If you think there's a particular attribute that is important, tell us what that is and WHY it's important. If that is too much work, then don't bother.

I will start with what I think is gross misinformation as a part of discussion, which I get to do as the thread starter, and we can go from there. Hence, my following manifesto, would make the unibomber jealous.

I have done a ton of research, put in a ton of time, and I hope my work serves someone, anyone, some insight. I am putting my thoughts out there for review, and opening my self to the associated abuse. That's OK. Just if you respond, please have thoughtful, insightful answers.

My ultimate goal here is just to separate the fact from the bull****, the marketing from the truth, and the hype from reality. That's it. Take nothing personal, and no personal attacks.

 

As a result of recent events here, I have studied the subject in quite some depth, for quite some time. I did not rely on marketing brochures or manufacturer’s claims. I have spent the last month talking to Engineers, FOUR of them. One of which is a close friend who has 7 Engineering degrees from Steven’s Institute here in Jersey. Oh, did I mention he even carries a Masters in Engineering? But wtf does he know? Happens to be he’s an avid racer and engine builder. Not a professional builder, but he puts his own engines together. He is one of the few people who ever finished all seven disciplines of engineering in the history of Stevens, not a stupid man for sure.

Two engineers are forum members who have offered their expertise on fluid dynamics and have verified this information independently of each other. The first has 25 years of fluid dynamics experience working as an engineer designing shocks. The second, is an aeronautical engineer and engine builder. The last is an engineer who’s job it is to design heads, who is not a forum member. Also, I sat with two engine builders who both have a long history and great reputation. A fairly robust set of expertise if I must say so myself.

Although I am no technical expert, being smarter than your average bar stool I have learned the following. I have had each of them review this information for accuracy before posting, and they have blessed it as completely accurate.

First of all, I anticipate you're going to hear a lot of noise about this and that. Typically you're going to hear about flow numbers and port size. You are going to be told that the ideal head is the one with the biggest flow and the smallest port. Like all urban legends, there is some truth to that but also like urban legends, has little basis in fact. Port size and flow are not the “be all to end all” in head selection.


I find value in engineering. I find little value in people going through a catalog and picking out the coolest most expensive parts in the consumer realm, screwing them together and calling themselves experts. I look to racing as the arbiter of quality, process, and results. BILLIONS of dollars a year is spent on R&D in racing circles so it's a good place to reference, even for a street build...An example I like to use is kinda like a guy bragging about his Sony receiver to a guy who has a wall full of tube McIntoch equipment. Two different worlds and two different levels of equipment, but doesn't mean you can't learn from the higher end, when building the lower end.

Bottom line I have put considerable time, effort, and energy into developing this information for the forums benefit, and I would appreciate it if it is read and digested and people don’t start spouting off about flow numbers. I hope that we all can learn something from my research and the great amount of time I spent. I will recite just the facts as the experts have presented them. I challenge ANYONE to find fault with the facts I will present going forward. I recommend you call someone, if you have trouble with the big words and intangible concepts.

But I digress, so let's cut through the crap I expect you're going to hear, please note my posts to follow.

 

1. It's all about flow....true and false...

Looking at cylinder head flow on a flow bench represents simply how restrictive the intake tract is, that’s it, period. In other words, are you breathing through a straw or a garden hose… Unfortunately for everyone that develops engine combinations; air isn’t simply sucked through the intake tract as a constant stream. Elements such as intake valve closing, pressure bleeding through the ever so slightly opened intake valve cause what is commonly referred to as reversion. When was the last time you ever heard that mentioned here? This is important because it demonstrates that the one dimensional view of a dry flow bench does not take into consideration true operational environments.

The “reversion” is a pulse of pressure that is part of the longitudinal wave (look it up) traveling back up the intake track. You see it push back through the carburetor when the timing of the event, actually the tuning of the intake tract, is off and the pulse is passing too far up the intake tract. Who hasn’t seen fuel spouting out of the intake once or twice? What do you think that does to engine performance? Common sense dictates that this is not a good situation, so port design matched to intake design is of consummate importance, above and beyond flow numbers.

Another important aspect is that air cannot compress at any velocity we will find inside an intake tract so it must speed up or slow down with changes in cross sectional area. (again look it up) This represents the biggest shortcoming of the DRY flow bench. The bench does not measure velocity, nor does it attempt to predict or model any of the increases or decreases encountered throughout the intake tract and how they are affecting flow. This means that all too often an intake tract is ineffective at controlling intake velocities throughout the entire operating range for the particular engine, throughout the entire intake tract (both are a big issue). In other words, FLOW NUMBERS DON’T TELL THE WHOLE STORY ON A ANY FLOW BENCH! Now, air DOES compress above .3 mach, but not enough to mathematically effect the outcome of many equations to effect VE. I looked this up in a textbook. Point is although true you CAN compress air and change density, however, insignificant based on the speeds air travels through an engine, it's statistically insignificant. The generally accepted max velocity in an engine is about mach .62, at this velocity the effects of compressibility are insignificant. This does not mean that compressibility effects can not be included, but are typically admitted as negligible.

This also leads to problems when working with the wet flow development. The concept of wet flow makes sense to most people; fuel is atomized into the intake tract and needs to stay evenly distributed all the way into the combustion chamber. Many experienced designers have found the all too common problem associated with converting a design from gasoline to alcohol. Since we have different mixtures associated with the fuels the density and overall saturation changes as well. So gas burns differently than alcohol, and you have to have ore of one than the other in and of itself is not really earth shattering, HOWEVER, this serves to demonstrate that it’s about DESIGN not just flow. Another example where flow numbers don’t matter. With the wet flow bench one can at least attempt to identify and monitor problematic areas of the intake tract (designers whish there were even more robust methods)

An even bigger problem is once airflow becomes a problem upstream the entire tract is not designed in an effort to correct this, it simply stays somewhat messed up and depending on how the rest of the tract is design can potentially get worse as it flows, in other words, it’s a mess. The quality of the airflow is important, not only the quantity. What this results in is that irregular airflow causes problems with the mixture and subsequently, causes problems with the proper air/fuel mixture getting into the cylinder. now get a crayon and write this down.. If you talk to people who design on wet flow benches, they will tell you that yes, their dry flow numbers on paper are not as good as some other manufactures. HOWEVER, it is their position that they can suck more fuel into the cylinder more cleanly and efficiently based on their designs (the resulting changes to promote better flow characteristics on the wet bench will often lower flow numbers on the dry bench slightly, negating the port size/CFM flow argument TOTALLY). They will also tell you that dry flow numbers are utter bull**** and have no indication of the actual performance of a head outside of the one metric that a dry bench measures. That is their position, and it makes total sense.

Take a time out, go get a drink, and come back for the rest. It is far easier to parrot marketing crap than to think deeply as to what goes into the development of a head and those aspects which embody making power. I know this can be tiresome and trying, but I did the work dammit, and you’re going to read it.

 

2. Smaller port size, the better for same flow

Looking above we see that there is a great deal of effort put into not only how much air could be pulled through the port, but mostly, how it will get through the port, that’s what is really important, getting air into the engine during actual operation effectively and efficiently, it’s not all about VOLUME, it’s about QUALITY. You must always remember that a flow bench is only measuring how easily air can be pulled into the cylinder, not how much fuel is in that stream or the QUALITY of the flow when operation is actually taking place. This means that when comparing cylinder head sizes the most important aspect as the SHAPE of the port and how that shape relates when viewing flow all the way to the combustion chamber. Airflow must be controlled, and hence the shape and measurements of the port are far more important that just looking at flow versus runner size. In other words DRY FLOW BENCHES ARE USELESS IN HEAD DESIGN AND FLOW VS. RUNNER SIZE IS A MYTH.

Again; a flow bench does not measure how much air will be pulled through the port during operation or the quality of delivery of that air, it measures the most simple of measurements, how easily it can be pulled though in a vacuum. Which tells you nothing about head performance.

When looking to design a port design a big consideration is to see what the airflow demands will be; they also must look to what type and how much fuel will be induced into the mix, what RPM the engine will be operating at and lastly, must look past the port into the combustion chamber and into the intake manifold. Again, a head with lower flow bench numbers which produces better charge delivery (through cleaner airflow and physics) and does so throughout the operating range of the engine, is a better, more efficient head that creates more power. Despite the mantra we hear here about efficiency being measured by some made up formula of port size vs. flow numbers, that is not the case in true engineering, or the laws of physics. It is simplistic marketing hype for the simpleton masses.

Significant hp can be gained or lost by port design regardless of the airflow number changes. GASP! A cutting edge cylinder head not only has low restriction and a proper shape for tuning purposes it also has to control velocity along with cutting back on irregular flow (turbulence). Now, a combustion chamber can promote flow or hinder it, it can also promote proper filling and flame travel (often trade offs); how a cylinder is filled is as important as how much of it is filled; all of the above have to balanced throughout the design process as there is no end all be all design that contains the best of every aspect. Flame travel, ever hear flame travel mentioned here? I didn’t think so. No one here wants to think real hard about stuff, it’s easier to spew meaningless numbers.

Another very complicated aspect of how the engine makes its power, valve and spark plug placement and combustion chamber shape have to consider this as well as how much air it can pass! To sum up, without the benefit of a wet flow bench, you would never be certain as to how the design works (and even the wet flow bench leaves something to be desired amongst designers but hey it’s a step in the right direction that measures additional variables). Now, that’s not to say you can’t get lucky by coping someone else’s design, or through trial and error like many speed shops, however, there is no science behind guessing on a dry flow bench (just what worked well in the past…). It’s brute force vs. elegant design.

 

3. Exhaust flow has real meaning.

This is one that every professional I talk outright laughs at; the idea that a cylinder head has to flow a ton on the exhaust side to make good power. When I ask this question I usually get a response like “a 900hp race engine has an exhaust port that flows 250cfm, so why would you feel that a street engine needs one to support 500-600hp?”. Does sound ridiculous on the face of it doesn’t it?

Think about this in terms of airflow demand just as we would the intake side. Again, the shape and tuning of the exhaust is what pulls the last bit of exhaust out and first bit of intake charge in, not the flow number. In other words, in the absence of real design work being done, go for brute force, or big numbers. This is not a design, this is a guess. Think of a siphon, if you’re simply letting water run out of a hose, vs, a siphon sucking it through, that’s what port design and wet flow (on the intake side) will do for you and that is why exhaust flow numbers are meaningless. That is why we put X pipes in our cars. Isn’t it? If you don’t subscribe to the above, I will expect we should all be pulling out our X pipes tomorrow..

Therefore, a few engine builders have expressed that they do not feel that restriction in the exhaust port is anything to really look at, the flow bench number, and it has no value. To them it’s all about tuning that tract to do the above. Many will cite how unimportant cylinder head flow numbers become when a supercharger is added to the intake side as some of the reasoning they feel that exhaust port flow numbers are not the hot ticket. So essentially, this exhaust flow thing you’re going to hear is utter nonsense perpetuated by the ignorant, ill informed and uneducated.

 

I have also learned other things about engine design and they are also important, as they relate to head design. There are aspects of engine design such as:

A modern camshaft like one produced by CompCams will utilize a very aggressive lobe design. The idea here is simple, cylinder heads used in racing classes often have to sacrifice low lift airflow (.100-.300) in order to get the very high flow at high lift numbers. They have found that through camshaft design that they can generate more hp through a pretty simple concept. Now many will talk until they’re blue in the face that a good head has superior low and mid lift numbers and that is not entirely correct. SURPRISE!!!

If for example, you are going to use a 1.7 rocker to achieve .675 lift (with today’s valve springs and valve train parts is not a big deal for a dual purpose engine) and you are utilizing a new CompCams solid roller you are wasting your time focusing on lift numbers and here’s why. The aggressive lobe was designed to get the valve quickly (very, very quickly actually) into the .400 lift and higher range. You also sped the process up a bit by using a higher ratio rocker. The end result here is simple, you have a package that is designed to get the valve open quick, and stay open for as long as possible (when the valve spends most of it’s measurable time at high lift, it’s best to get your flow there). You also (since you read the above) have a well tuned exhaust tract that is aiding in the initial cylinder filling… In other words, IT’S ABOUT THE COMBINATION!!!


Other considerations in head design which are far more important than just air flow.

 

1. Flame travel
2. Valve position in the chamber....
3. Gas vs. Alcohol

As I have learned these things listed above can have a drastic effect on performance. The only way to measure those designs and the effectiveness of such would be to engineer heavily with computational fluid dynamics, modeling, and then demonstrate R&D on the wet flow bench (right now that’s all people can do; everyone I talk with whishes they had something even better…). Dry flow benches tell you NOTHING when it comes to engineering and design other than how much restriction a tract imposes on airflow.

Major manufacturers such as Edlebrock, Dart and Brodix use some form of wet flow technology to refine their intake and combustion chambers to best perform in the operational environment which they were designed to work in. This is key to validating what the numbers say during the design process; it’s not used to rate the effectiveness of said cylinder head (because even it doesn’t simulate operational characteristics), but to analyze and improve upon the theories being utilized. Another example where design is more important than raw numbers.

Dry flow benches can be an ok tool to measure the changes of porting by hand porters, but have little value in research and development in head design. For the guy with a grinder in his hand they are currently the only method of measuring anything about his changes that he can afford to own/operate.

For the engineer who wants to design the perfect transition into the combustion chamber to promote a different method of filling the cylinder, they have no value. You can't R&D on a dry bench effectively since this type of measurement leaves so much out of the picture. It really does sound like playing chess in the dark doesn’t it; we all know how well that would work… Personally, I would stick to the companies that have taken the next step and gone into wet flow development. They have found (often through being at the panicle of racing technology) that standing still will put you in last; this is why they are pushing forward in the development of better modeling the testing equipment (and that is filtering down to the consumer level).

 

Funniest line I ever heard about flow dry numbers:“We may as well judge the quality of a head by how much it weighs.”

I would spend my time looking at companies who have made the investment in engineering, research, and development which is shown by utilizing a wet flow bench.
What we see today is people building bigger and bigger motors in custom builds… the old generic build 350 is giving way to 400+ cubes, 500+ cubes for the big blocks is common place now making all these aspects crucial and they need to be taken into consideration. With so many different cylinder heads with different features and sizes the what’s what and how for must be addressed or the combination will be lacking.

So with that said, I would like to sum up that anyone can hack a port of any size to flow any number, that does not mean it is the best designed head for a given application. I want to get this small port big number urban legend off the table once and for all, and I hope it’s been useful for everyone. You’re welcome. Again, I challenge ANYONE to prove the science wrong. Well, anyone of any credentials or credibility.

And we're off. For the record, I do not claim to be a technical expert. I am using this forum to attract technical experts so I can learn, and we all can learn. I am simply repeating information as I have been given it and trying to present it in a layman's perspective.

 

What I want to know about is the texture of the port walls. Seems there has been some sophistry about the texture keeping air/fuel in suspension. But then I have read that this is not the case.

 

i brought up that whole point of quality over quantity and tony basically told me what is more important than flow, like i was an idiot. which is funny cause that is what i was told from the people at advanced induction. what do they know..

 

(Big sigh......)

Quality and quantity is what makes big power...

The quality part mainly aimed at the EFFICIENCY of the particular cylinder head or port design which promotes high air speed in addition to volume (peak flow). Exactly what all the AFR Eliminator products offer the end user. They have huge area under the curve (strong low and midlift flow numbers in addition to their industry leading peak flow) and manage to do all of this thru port volumes significantly smaller than what's ever been seen in the past, including our former product line which was arguably top dog before the redesign of the Eliminator product.

In fact I will soon be posting results that make an interesting comparison of a heavily ported stock LT4 head ("Stg III") versus our 195 cc "comp" ported head that is approximately the same price, 45 cc's smaller, yet handily outflows the MUCH larger ported stocker at any usable liftpoint below .650 (essentially any cam most of you would consider). Now if I were to compare the same head to one of our larger race head offerings which would be a much fairer comparison (our 227 head for example), the comparison of the two looks even more ridiculous (looking at the even larger disparity in the flow numbers), and the AFR port is still substantially smaller.

The key to a powerful street (or street/strip head) is one that provides the most average airflow (strongest curve from the crack of the valve to your engines peak usable lift point) and does so thru a modest cross section which promotes higher velocity to pack the cylinder even more than similar airflow would thru a larger (lazier) port design. Negative aspects of reversion is improved or eliminated with a high speed port design, power is improved, and fuel economy is increased as well. The engine is that much more efficient and you will see higher VE numbers and stronger BMEP numbers when you hit the dyno....

JSUP....when are you going to get as serious and scientific as you try to portray yourself and actually get to the dyno. Perhaps you might learn a little something about your own combination that might add or subtract from your own crusade.

Just to read some of the stuff on this board pains me lately, but I bite my tongue and I calm myself down simply knowing that recently enough individuals (on this board) have purchased our product and when all the BS clears from these threads that will ALL likely be locked, I am confident that irrefutable facts will show that the AFR's will perform better than anything else on the market....period. The continued and future results from both the dyno's and the tracks will set most of you free. Some are so stubborn and stuck in the mud trying to justify the decisions they have already made nothing will matter, but those reading these threads with an open mind and a quest to really learn something will have all the ammunition and facts to make a wise purchase decision in the months ahead (those that question theory and simply want to see the end results and proof in the pudding).

JSUP, I also don't care how long your posts are becoming or how many rocket scientists and PHD's you continue to quote....few people here are more familiar or passionate about EXACTLY WHAT WE ARE DISCUSSING than myself. At the risk of stating the obvious....I head up the AFR R&D depratment and I have more real world dyno experience than most....not to mention literally thousands of hours on the flowbench some of which include very creative cylinder head testing and evaluation (utilizing intake manifolds, headers, and other ways to simulate real world conditions). I know my competition extremely well (we have paid retail prices to obtain our competitors products at times) and I have flowtested and dynoed most of their products....need I go on. It's ridiculous I even need to remind you of this....its like me getting into an argument with someone in a field I just dabble in versus something they have devoted their entire life mastering....I wouldn't be very opinionated and would do alot more listening than talking.

Lastly, I have also conveyed the many other attributes the AFR heads bring to the table (some of which augments their efficient port designs and power generating abilities even more) and spent hours doing so....Im not going to rehash all of this again.

See this thread in case you missed it (in the event your just tuning in)

http://forums.corvetteforum.com/show...429&highlight=

BTW, I went thru the same negative BS when we launched our Gen III product four years ago (the first aftermarket Gen III product to hit the market). I was pained by the negativity and stuck in the mud thinking I was confronted with but knowing clearly how good our product truly was I bit my tongue and bided my time. A year later so many people were pushing the AFR's and all their inherent benefits I didn't have to....the same situation will play out here as well....I promise you that.

Honestly, besides a few solid technical threads I foresee starting in the near future I will spend less time here as I would rather spend my time in an environment that welcomes new ideas and new technology from a company that has proven itself and has stood the test of time. The negative BS is really getting old here and I have done my best to lead the horse to water as they say. What will speak much louder than my voice (because it appears to be so obviously tainted/biased) is the voices of our customers and my guess is in the next 3-6 months you guys are going to see quite of few hard running AFR headed combo's that set the bar higher both at the chassis dyno and at the track than has been seen before in similar combinations....and then I can spend even less time here as the product (and our very satisfied customers) will ultimately have spoken for itself.

Amen to that....



-Tony

PS....If I have time this weekend I may try and put that post together comparing the ported stocker to the AFR numbers. Same bench, same fixtures....directly comparable real world results.

 

Is anyone gonna actually read all that?

Why not just start a thread saying "Why I think I'm smarter than Rick and Tony"?

 

See here's the problem; if you don't want to read it, please don't post. What's being attempted here is simple; Jsup is trying to get as deep as possible into the subject at hand (and it's not whose product to buy, it's what are the things that should be looked at and how they should be quantified when the time comes to select a cylinder head). This thread was started in an attempt to stimulate the flow of knowledge and I applaud anyone who steps in and posts their thoughts or ideas. I expect anything that I post to get scrutinized and put through the wringer. I do not ask anyone to take my word for it; I strongly urge you to verify everything that I post (if it’s wrong, correct me, I will do the same for everyone else). Tony I would like to say thanks for taking time out of your day to respond to what was written.

Now as I watched this thread I was really hoping a person of your magnitude would come in and start debating facts. There is a lot of information up there, some I feel is right on and some I feel either needs to be expanded upon or changed completely. What I didn't want to see was the situation we now have; your post not only didn't directly dispute any of the factual information posted (or better yet expand upon it), but also brought the brand names back into the subject.

If you noticed there was no application stated, no recommendation made, simply a collection of ideas irrespective of brand or type of usage (I happen to believe that the principles that govern how engines make hp extend throughout all areas of the performance sector, not simply for racing or street strip ECT). I urge people to read this thread and do so in the right context. This is not about what product to buy; it's some ideas about how the products work. If at any time you are typing the name of a manufacturer in a response, you are responding to the wrong thread.

Now, there was a question about cylinder wall texture posted; this is from experience an old wise tale (that on a very high level does have some truth, but not for the as stated reasons). The reason I feel that way is this; when looking at airflow you will observe what is called the boundary layer. Think of it as a little bit of air that does not flow with the free stream (although it does flow, just a reduced velocity); it somewhat bridges the gap between the surface and the airflow (just as a bearing essentially floats on the layer of oil). Now if you have a rapid increase in cross sectional area (like too severe of a hump coming off of the pushrod pinch) you may develop flow separation that leads to turbulence. If the surface of the port is rough the boundary layer will be turbulent; this will help the airflow to stay laminar (smooth and regular) and reduce the amount of flow separation. Many of us feel that massive velocity fluctuations and irregular airflow contribute heavily to problems with fuel distribution. So, if the port is properly shaped, there will be no negative affect (and also no positive affect either) to having the walls polished to a fine finish. If the port has a problem it will help to band aid it slightly (if the problem is bad enough you will not avoid flow separation) but not completely.

 

"Is anyone gonna actually read all that?"

Yes, I have read Tony's thread.

 

 

Deakins,

Had this post been started by anyone else I would have responded much differently, but the reality is that anyone here with an IQ in the triple digits likely sees the agenda at hand....and the fact your sought of trying to cover for him as you have done in numerous threads before.

The reality here is the OP is really not interested in finding the answers to his questions, only to continiue to be in the limelight with continued drama on this board and also find a way to justify the decision he has already made concerning his combination.

Do all of you realize that JSUP has averaged 24 posts a day for the last four years....this includes Xmas, Thanksgiving, and every major Holiday. If he was away from a computer for 24 hours that would mean he would need to post 48 times the next day just to maintain that average. I cant picture posting 24 times in one day never mind maintaining that pace for almost 1500 in a row....call me crazy I guess but someone who posts that many times a day likely craves attention.

Also, I have already invested a tremendous amount of time and energy just posting in that single thread I posted a link to above....never mind the many others I have also chimed in on....and I have clearly laid out theory and the many attributes of what is involved in building and designing a world class cylinder head. I tried to be informative as possible and explain things in such a way that you didnt have to be an expert engine builder to understand the theory. I suggest you re-read that thread in the event you may have quickly skipped over it. In fact I stated numerous times the shape is far more important than size and I believe I also touched on how surface finish is not especially important either (as you correctly advised concerning the boundary layer of air along the port walls etc.). Honestly I have posted so much Im not sure if I hit that or not but believe in one of my posts that I may have touched on it.

Yes I could have been alot more gracious in my former reply but honestly its like beating a dead horse already....

I welcome ANY of you that want to speak to me personally (who may have a question related to our product or a particular application) to contact me directly. I would enjoy the opportunity to speak one on one with any of you and I assure you the phone call will be a worthwhile one. PM me if thats easier as Im pretty good at getting back to most people within a reasonable amount of time.

As I said I will still be here and I know for a fact that I have a few very technical posts planned for the future to share with all of you (one very soon), but I can't be involved with all the bickering and semi-hidden agenda's that seem to be so prevalent on this particular board. Plus I find myself constantly rehashing theory and topics I have thoroughly touched on before....that doesnt do you guys much good nor is it a wise investment of my time either.

Regards,
Tony
(661)257-8124 Ext. 109

 

So Jsup....all that means is......I should buy AFR heads and be done with it?


Tony, you've posted some doozies on here too. You know good and darn well that a home porting job is just as good as your top of the line cylinder head. LMAO.

Both you guys should probably hire publishers for these heavily worded posts. lol.

 

All kidding aside. I respect what both of you gentlemen (Tony and Jsup), have to say.

Jsup is entitled to his opinion and has obviously done a lot of research on the subject. He might be a little obsessed with the subject, but he certainly has to right to call people out on the carpet. This is a free society, right?

I must say that as a result of Jsup's posts and all of the replies and reactions to it, I learned a hell of a lot more about cylinders heads.

 

Yes... intellectual people that like to learn will read, analyze and counter research it. I am guessing you are not one of them.

Or they don't/can't do anything else for the time being. Thanks to both of you for the info and the research i get to do tonight. It is much appreciated.

 

All jsup is trying to do here is create a honest dialogue with solid information and a open discussion about the dynamics of head flow and what constitutes that, ( save the this guy is better then that guy crap). I applaud his efforts and look forward to the discussion.