Porting Porn

Bob,
Why not send an email directly to NPS and ask for pricing? With the strong U.S. dollar, parts from Europe are relatively cheaper for us in the U.S. than they were a couple of years ago. I am thinking $1400/1500 should buy you a whole lot more in Europe than in the States. When I was looking for a ported head a few years ago, NPS was at the top of my list, BUT the Euro was very strong compared to the U.S.$, so I spent my money in the states.

I asked here because they have stepped up to do the real flow bench work and dyno testing and can build a top rate product.

What about the CR heads? Do/can they flow more air than the PD heads?

2.0cr head flows ~9% in ~7% exh more at 8mm lift than 2.0 BKD (16v PD).

2.0cr compared to 8v PD flows ~30% more at 2mm and 4mm, 20% more at 6mm and ~17% more at 8mm lifts on intake side.
Exhaust flows also ~30% more up to 4mm on CR head, but is about even at 10mm lift
this probably does not fit in to originators topic, but I could try to take some pics of BKD and CR heads =)

Nice numbers Marko. A CR head might come to you in a while if you have time for it.

/Theo

Good work
Could You give some pic of you work and a break down of some costs.
I do know what it takes to do this kind of work.
I headed up my fathers MANN Engineering flow bench and dyno department from late 70s to late 80s

MarkoP said:

2.0cr head flows ~9% in ~7% exh more at 8mm lift than 2.0 BKD (16v PD).

2.0cr compared to 8v PD flows ~30% more at 2mm and 4mm, 20% more at 6mm and ~17% more at 8mm lifts on intake side.
Exhaust flows also ~30% more up to 4mm on CR head, but is about even at 10mm lift
this probably does not fit in to originators topic, but I could try to take some pics of BKD and CR heads =)

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This is supposed to be: "I'll show you mine, you show me yours." It is not for commercial use to promote any vendor's product(s). If you are going to advertise, do it on the proper forum.

When the commercial interests have posted pictures, they are evasive and don't show anything of value to promote the purpose of this topic. We are talking port design. As far as I can see, the commercial interests are not contributing much within the purpose of this thead.

Port shape is what this is all about. There are some obvious things that are necessary to improve porting design and much of this is purely logical. After all, when a cylinder head is so 'commercial' in it's approach, with a bottlenecks in the exhaust runners and restrictions in the swirl chamber is so obvious, common sense dictates improvements.

The word 'phenomenon' indicates that the solution is not understood or does not follow conventional wisdom. The reality is there is a solution, but it is not presented. I listened as well as watched that video, Marko. There are some very strange sucking noises going on. I think the correction is apparent.

Also, there is not 'perfect' solution, but only compromises. Valve guides are too short, intake porting has potential for cracking, mis-match to exhaust can be as much a 1/4" off, bolt holes are intruding best flow angles, water jackets are too close...and all of these require modifying designs to balance pure flow against cylinder head design insufficiency.

All in all, we have no complaints from customers with the improvements we have made. As a matter of fact, most complaints come from competitors who haven't even seen or applied our work. We are okay with that.

We have worked with another well-known porter, Matt Whitbead. When examining each other's work, we found that what each of us, individually, found improvements which are very identifiable in each other's work. There are bottlenecks and rakish inside turns. Do the obvious and improvements are there.

The biggest issue... we find so many builders are wanting design extremes, then want to see if we can 'keep up'. Questions like, "What does your cam dyno?", "Can you make the engine produce 300hp?", "How much larger a valve can I install?"... When the design purpose of the engine is fuel efficiency and longevity. All of these requests are outside the intended design parameters of the engine. Our goal was to improve the engine within it's limitations. That does not dyno well.

But when you get enough practice and find over your historic builds that engines show improved fuel economy AND improved hp, we feel that is the right path. We are trying to optimize, not maximize, the purpose of the engine. We are working toward different goals. We do not require 12mm lift to create performance, as that is detrimental to the cam/ cam follower life-expectancy. The same is true for excessively increasing boost pressure, valve size, piston size, injectors, valve springs, etc, all of those 'improvements' increase strain and reduce engine life.

Our main focus is not to create race cars, but to optimize the engine for a very street-able vehicle with long life expectancy. As it turns out, that is the goal of the largest segment of TDI owners. We hope to provide that segment with designs for a sustainable engine that will get reasonable performance gains while maintaining longevity.

Like the shiny runners gentlemen. If anyone can post up some bew heads from different angles and/or real gains in hp numbers as direct result of said massaging, that would probably finish me off.
Next to nothing comes up for these engines that I have searched.
Pics are worth a thousand words. We've got a lot of words on the last few pages so I think we're all due for some pics. Great work I've seen so far but if anyone has some dirty pics of port matching with a mirror on block, I'm up for that too. I would be that guy who would try that if it would net me 5hp so...

The pic really mean nothing . For the whole post only a few people have run a flow bench for over 5 years. I mean some one that has sat down and grind then test over and over. Than to the dyno and than to the track.
That is not to say you can do some basic porting and follow known guild lines for flow improvement or just copy someones flowed head and get close.

Franko6 said:

This is supposed to be: "I'll show you mine, you show me yours." It is not for commercial use to promote any vendor's product(s). If you are going to advertise, do it on the proper forum.
<snip>
Also, there is not 'perfect' solution, but only compromises.
<snip>
... When the design purpose of the engine is fuel efficiency and longevity. All of these requests are outside the intended design parameters of the engine. Our goal was to improve the engine within it's limitations. That does not dyno well.
But when you get enough practice and find over your historic builds that engines show improved fuel economy AND improved hp, we feel that is the right path. We are trying to optimize, not maximize, the purpose of the engine. We are working toward different goals.
<snip>
Our main focus is not to create race cars, but to optimize the engine for a very street-able vehicle with long life expectancy.
<snip>

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I like your thinking, frank06. To distill your thoughts further yet
- Improvements within design limitations.
- Improved fuel economy AND improved hp.
- Optimize, not maximize
- Optimize the engine for a very street-able vehicle with long life expectancy.

What's not to like?
Love your pics, drop dead gorgeous. I know the extra polish was for pictures. Continue marching. You're definitely on the correct path.
frank

Bob, You are losing credibility by saying a picture means nothing. And I will be very clear that if I don't get 2CFM compared to a job that costs me twice as much, big freakin' deal....

Do you know, Bob, a good friend of ours recently got a cylinder head from a well-known manufacturer just South of us in Arkansas for Chevy's, which he is big into building, and although the head showed CFM claimed numbers, they were nowhere close. My friend took what was supposed to be 'the best' and made it better than what was claimed. Sure, they used a flow bench. Sure, they are racing competitively to win races. We are not going to even attempt that. We aren't interested in all-out-max. Because, quite honestly, it costs to create and costs over and over again as you rebuild and rebuild again for an engine that will not stay together.

I am looking for this head we got into the shop where the mismatch on the port is so outrageous, it cannot be ignored. Even if we are not requested to do so, we will alter the port, just to make some sense of it. So, I will ask this question... if the port had a 1/4" shoulder INSIDE the port that was a mismatch, would a porting company ignore it? Of course not. Then why, for Heaven's sake, would they ignore the mismatch at the end of this short exhaust runner? That makes no sense.

Wait a minute... it's three times as much...

We have no fear showing our workmanship. If what Bob says it true, what is there to lose?

If your not careful, you could..... LOSE YOUR HEAD!

Sorry. I didn't even know what you guys are talking about. Just thrilled to be home from work. Was hoping to find more head pics tho...

This is a serious question.
I plan to vnt17 bew blah blah. If I'm into the engine for a timing belt, turbo, cam check at the same time. Is it worth it from your perspective to pull the head and just port match and reinstall with arp studs. I mean,realistically, it has a turbo to feed it air and it's no revver so ? However I don't like the idea of the flow hitting a 1/4" wall, obviously that's a problem.

First thing, the BEW has a KP-39 Borg, which amounts to a vnt 17.

The porting issue I am speaking of is not a 'wall' but instead a transition point. The runner ends into the exhaust manifold. If the transition is matched, there is less of a incidence of turbulence at the entrance of the manifold. The question is, does it matter. Some believe it is better to get the air flow correct out the runners and make no issue of the exhaust manifold. I think it does make incremental differences.

In your situation, Bmali98, I do not think you need to understand what you have before you can figure out where you are going. The ARP head studs are something you need if your purpose is to go large...more than 2x hp. Otherwise, I think it's a big waste of money.

We have seen quite a number of the BEW turbos go for over 350,000km, so I would not be in too much of a hurry on that Are you intending a larger build? A stock turbo and injectors will take you at least 30% without changing anything except the tune.

The cam is an issue that we have designed not only the cam with .020" taller lift, but reusable cam and rocker bolts, modified cam bearings for additional oiling to the lifters and improved oil flow to the bearings themselves. We are probably going to get sets of sputtered cam bearings shortly. We really like the sputtered bearings for improved bearing life.

The business with port matching is something we feel is not without merit. It cannot be strictly a runner issue, as no sooner than the exhaust hits the manifold, there is a turbulence issue. We do not agree with alternative arguments.

Would I remove a cylinder head strictly to do a port match? No. The most logical improvements are: 1.) Cam align bore correction 2.) Improved cam profile for true hydraulic application 4.) Cam bearing mod for additional bearing and cam follower oiling 4.) If increased power is your motivation, removal of intake port dividers and slow-speed port butterfly plate 5.) Full Port, not just port match

ARP studs we reserve for engine builds at or above 2x hp. Truthfully, we do not recommend excessive builds for the PD motor, due to cylinder head cracking between the injector hole and the intake seat.

Frank, what would the symptoms be of a PD head that has cracked between the injector hole and intake seat?

Frank06. I am just going to do the turbo then. I'm planning to get to 160-170 hp with the stock injectors but Malone told me the kp39 will boost creep before I can use what the injectors can offer. Like your porting is with durability in mind so are my upgrades. The wall I was referring to is the transition between head and exhaust/intake also but if Its not realistically worth the gains(if any) I will leave it alone. I have a stage 1 tune Now. I plan to retune after the turbo with the torque limited around 240 and up the hp for the automatic Trans. Hp is what I'm 100% after within reason. I'm on the cheap.

Thanks for the advise and nice work on the ports.

bmali98, we are off topic. I will respond by PM to Bmali98. But I will say overall, durability is important and porting, in itself, is not a durability issue at all. It allows potential for performance.

Oldpoopie, is closer to the point and purpose of this thread that we find power restrictions with the PD heads due to cracking. The particular point with the PD heads has been brought up earlier.

There is a crack that commonly occurs between the injector bore and intake seat. The crack can progress up the injector hole and we have seen it cause 1.) A blow out under the intake seat and 2.) the crack extends up the injector bore all the way to the injector seat.

This is something that VW obviously knows about and has provided a 'bandaid' approach to resolving by placing a thickening in the wall of the intake port directly along the line of the injector bore. The intent is to forestall the crack from advancing.

We have received cylinder heads that were cracked in this manner that the customer's request was to port and build for horsepower. We recommended not to use a cylinder head that was already cracked. Although VW knows of the issue, they do not seem to agree that it is a major problem and allow for it. We think it is a lesser issue if the engine remains stock.

Not a porting question but still a cylinder head modification question. What could one do if they are fortunate to have a crack free casting? I have a well seasoned head sitting on my work bench that appears to be completely crack free and I ponder if it would be wise to add a chamfer to the injector bore and the glow plug bore. Everyone knows that sharp edges are more prone to stress cracking so adding a small chamfer might help in preventing this common cracking issue.

More on topic, I don't see where anyone is suggesting ignorance to a grossly mismatched port to manifold transition. The thing is, it's elementary in concept and is not worth much of anything by itself. Please, let's start talking about the real port shape improvements and let's also stop ignoring the valve seat design and valve shapes. Btw, pictures really don't offer much. Now if someone were willing to cut open a proven port design and point out where changes were made compared to a stock port, side by side; that would actually show us something.

Good point newlite
More on topic, I don't see where anyone is suggesting ignorance to a grossly mismatched port to manifold transition. The thing is, it's elementary in concept and is not worth much of anything by itself. Please, let's start talking about the real port shape improvements and let's also stop ignoring the valve seat design and valve shapes. Btw, pictures really don't offer much. Now if someone were willing to cut open a proven port design and point out where changes were made compared to a stock port, side by side; that would actually show us something.
There is a lot of talk here from some that have never touched or run a flow bench for many years and use a dyno to back up their claims . Its like I think it will work and it is shiny right.


It all comes down to shapes and angles and size and endless hours of work.
As one of the few here that has 10 years of flow bench and Dyno R/D and runs a real TDI powered Road Racer I help when I can.

I believe that I list most of the contributing factors in post 97. It is not all about porting.

Conversation is good. The design of a stock head has several obvious points to improve. We aren't particularly interested in creating a full race head, so if we don't happen to shave 1/2 second off lap times, it's ok.

Rather than destroying a cylinder head, there is a post back several pages that shows latex castings, which are certainly practical. Matt Whitbread did cut up a cylinder head and drew an obvious path of metal that needed to be removed to correct a bottleneck. I will look for that. You see, we can talk all the testing equipment to tweak to perfection, but some of this is as obvious as the nose on your face.

Newlite, as to your question, we are in agreement that removing sharp edges reduce the risk of fractures. That is one of the things we are required to modify at the bottom of the intake swirl, as the sharp angle is a place where cracking occurs.

We have several valve shapes which are improvements. The exhaust actually has a taller tulip and the intake is very flat. Just looking, I am going to guess that Bob has stock intake valves? I believe there is a honda valve that comes close to our needs, but it is a single-keeper seat. Not sure I like that.

volvo has good tulip head exh valve.. intake is tulip too but can be turned flatter for more flow and less weight

Lots of talk, lots of pictures, lots of discussion

Who's going to stop talking and put some data behind it like Alex22 did 5 years ago? It's not complete, but far more than anything I've seen from anyone else.

http://forums.tdiclub.com/showthread.php?t=307098

Competitors and those who never bought from us complain against us. People who own actually bought from us have very few complaints.

Most hobbyist builders are interested the price of the product and to some point, would like to do some of it themselves instead of breaking the bank. Most people don't have the cash to lay out for the "professional" port work. However, some things are so obvious, it's hard to deny benefit from certain alterations. That being said, there are some well-known members and builders who think porting is a complete waste of time. I disagree with them, and I believe that porting has great potential for improvements.

Some of the things we do with porting, we believe are plainly obvious. As analogy, if we were to make a brick more aerodynamic, we would not stand it on end flat face forward. Turn is sideways, and instantly, you have reduced it's drag by about 1/2 . Lay it flat and it's about 1/2 again. If you improve the internal corner radii and bottlenecks and take the humps out of the bowl beneath the valve seat, it's going to be an improvement. If we were to design a 'perfect head', maybe it would look more like an Offenhauser or Cosworth.

But in our real world, everything is a compromise. Just as we have compromised for maximum CFM by increasing the valve guide length. It is an interruption in air flow, but increases the life expectancy of the guide and increases heat transfer. We compromise the intake swirl chamber at the top inner corner, reducing the 100 degree sharp angle to a radius that reduces potential for cracking into the water jacket. This causes a reduction in swirl chamber effect, but it's a reasonable trade-off for viability. You see, maximum CFM and durability are not necessarily partners in cylinder head work. But the big trade-off we want is improved reliability. It's not just a big CFM number.

I have always said and will continue to say... If my interests were to make maximum performance and 'stupid' high power, then get your dyno out. Maximizing and optimizing are two different purposes. We aren't risking a million-dollar car coming in 2nd place. You can't dyno fuel economy. You can't dyno longevity.

If you have something to add, beside challenges, bring it on. Something like what Rub87 is helpful. I personally, would like to see the valve Rub87 speaks of.

The valve tulip changes are an incremental improvement, although a perfect tulip shape could make dramatic flow event changes, even if will add some weight. Valve diameter adds flow improvement, but even polishing the tulip of the stock valve will see small gains in flow. The following picture is something we have been doing for years with our valves on every cylinder head we work on, whether reused, as in this picture or if we are 'fixing' new valves. Sometimes the little things make differences. If you look at any high-end performance valves, they have a very smooth and polished slope going up to the valve stem. Here is a 'before and after' picture of the exhaust valve 'stock' and polished. The larger valve to the far right is a Ferrea valve that has a slightly higher tulip, but we think not tall enough.


I have seen some of your work, FTB. I suggest you post your results here, if you think it's all about numbers.

Why the 4" exhaust?

I very much understand the difference between maximizing and optimizing. Both should be supported by data is all I'm saying. There are lots of discussion about transitions, port angles, where to remove material, etc but nothing to support that it's better or worse (for what particular goal?) other than "it looks good". These things are absolutely quantifiable.

Show us what you're optimized for and how much better it is than stock or maximized. Yes, I'm challenging you and the "complaint group" to demonstrate some quantifiable benefits after 113 posts of discussion.

I've posted all the porting work I've done on the forum here starting on post 131 - it's my own work on my own car. I don't have the foggiest idea if it's better or worse, I don't have the equipment to prove or disprove any benefits of the porting work I've done. If I did, I'd share it. Frank - you're the one with something to sell here, not me nor most of your "complaint group". Even taking the $$ component out of it - what's better or worse (for optimization since that's your goal) and how do we know?

There isn't a single benefit of a 4" exhaust on a TDI other than to say that I was able to do it. It's heavier, more expensive and likely has zero advantage over a 3.0" or even 2.5" for most any single turbo TDI build that's driven on the streets. There might be some benefit for a 1.8T that's pushing 700+HP, but that's getting even more off topic.

You make a good point Fix until broke
we need some one that has up to date flow numbers and dyno numbers to jump in .
But it takes time and money as we can see in your build.
There where some good books on the subject many years back I have asked my brother if he could dig them up. I have nothing here to sell or the time to grind up one for show and tell. But I do have some junk ones I will try to cut up one and post some pic and those that are grinding can shows us where we should fix and not touch.

Woah - Frank, you made some VERY significant changes to post 113 after my most recent post (114). That's not cool .

You keep repeating the fact that you're not trying to maximize (something?), like you're trying to rationalize what you're doing? Just document and quantify what you're trying to optimize. What is "better"?

I don't think I have any more to add (even with all your changes/edits).

Really guys? Why does it seem like every time one of these technical discussions gets started it turns into a pissing match. Look, here is the easy way to stop all the fussing and fighting: you all get together in the same room, drop trou, and see who has the biggest junk, that way the pissing matches will stop for good. I joined this site because there was a lot of helpful information being presented by a lot of helpful members with experiences I didn't know if I would ever have. Please don't turn this site into another b!tchfest like some of the others are. If you are right then good, if you are wrong and man enough to admit it also good, but I really don't care if the flow difference at 0.050 is 0.000001 CFM more (or less) than yours has. Please be objective and not obnoxious, okay men? Thank you.

Nevada_TDI said:

Really guys? Why does it seem like every time one of these technical discussions gets started it turns into a pissing match. Look, here is the easy way to stop all the fussing and fighting: you all get together in the same room, drop trou, and see who has the biggest junk, that way the pissing matches will stop for good. I joined this site because there was a lot of helpful information being presented by a lot of helpful members with experiences I didn't know if I would ever have. Please don't turn this site into another b!tchfest like some of the others are. If you are right then good, if you are wrong and man enough to admit it also good, but I really don't care if the flow difference at 0.050 is 0.000001 CFM more (or less) than yours has. Please be objective and not obnoxious, okay men? Thank you.

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Nevada_TDI - we'll get this out of the way right off the bat since it seems to be what you're interested in. I have the smallest junk - There, now that we're done with that, can we get back to a discussion of cylinder head porting?

Google said:

Objective
1.(of a person or their judgment) not influenced by personal feelings or opinions in considering and representing facts.
"historians try to be objective and impartial"

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My personal feelings and opinions are that there aren't many/any facts represented here to consider. MarkoP's post 94 has some data in it. If this is just a photo gallery of who's got the shiniest hole and/or a veiled advertisement for Frank, then maybe it should be moved to the vendor section and I'll go crawl back in my corner.

Frank didn't seem to like it when someone else who happens to be a competitor posted porting pictures in this thread...

Franko6 said:

This is supposed to be: "I'll show you mine, you show me yours." It is not for commercial use to promote any vendor's product(s). If you are going to advertise, do it on the proper forum.

When the commercial interests have posted pictures, they are evasive and don't show anything of value to promote the purpose of this topic. We are talking port design. As far as I can see, the commercial interests are not contributing much within the purpose of this thead.

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I'll offer up a proposal if anyone is interested. I have access to a flowbench and a dyno. My TDI Ranger is also very quick/easy to swap the timing belt and head. Perhaps we could do a real world comparison of stock vs ported head measuring both airflow and associated power gains?

greengeeker said:

I'll offer up a proposal if anyone is interested. I have access to a flowbench and a dyno. My TDI Ranger is also very quick/easy to swap the timing belt and head. Perhaps we could do a real world comparison of stock vs ported head measuring both airflow and associated power gains?

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If you were closer, I'd bring my ALH head over. It's off right now and I'm about to have it ported.