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Pammy
| | Posted on Tuesday, May 09, 2006 - 02:17 pm: | 
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Anything is possible. It's not likely, but possible.
Wes probably knows more about head porting than most anyone in the business. But what makes him exceptional in that respect, is his knowledge that there is always something new to be discovered. He says that once he thinks he knows all there is to know, then it is time to quit. Knowing Wes, like I do, I don't think that time will come. He lives and breathes this stuff. |
Blake
| | Posted on Tuesday, May 09, 2006 - 02:34 pm: |
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Sean,
I think in a mass production scenario, you have a point. For specialized applications, I think flow and velocity characterization versus the range of lift is vital to obtain optimum results. Just guessing though. I just know that none of this stuff is intuitive at all for me.
Of primary consideration is that the flow in real world engine terms is nothing like steady-state.
It seems to me that the dyno is the only real-world shop tool that can verify head porting performance for the engine system it is intended for.
But I am sure that the experts, the folks who have successfully made a career of this very kind of highly technical performance R&D for so many years are able to discern quite a bit from flow and velocity characterizations along with their big hairy knowledge of cam characteristics, combustion chamber effects, and exhaust scavenging effects.
I'd sure like to learn more about the art and science of high performance head porting. Unfortunately much of what we would be interested in learning is likely highly proprietary information. General concepts are about all we'll ever likely learn from the most highly acclaimed experts. |
Rocketman
| | Posted on Tuesday, May 09, 2006 - 06:09 pm: |
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What cracks me up with head tuning is looking into the ports. You can look for a very long time into a Thunder Storm port for instance, and you can wonder there is only so much a tuner could do.
You can compare one tuners work with another, given both are at the top of their game, yet approach the ports in different ways, perhaps even ending up with similar results, but again I'm left wondering, there is only so much you can do.
So here's a question. Where does the rest come from when it seems all is said and done?
What a mystery.
My TVR heads are getting worked on by the top V6 Essex engine man in the business. As they are race heads running BIG stainless steel valves in cast iron guides, and there is little valve guide to see in the ports, I'm forced to go in the opposite direction. To gain reliability for long term road use phosphur-bronze guides are being fitted and no doubt they won't be as cut back as the cast iron race ones were. Still, I'm expecting to gain by hitting 200bhp or more, which is a massive increase from 137bhp stock, so a little guide issue isn't such an issue in this case. Especially when one considers the TVR weighs 900kg.
Good stuff this head tuning.
Rocket |
3boyz
| | Posted on Tuesday, May 09, 2006 - 11:53 pm: |
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Thanks Alex, These heads were flowed at Hals Speed shop and we stopped at .650. Although the T-storms' numbers stayed the same after .550 lift I did not see the flow sheet for the XB heads. I'm sticking with the T-storms for now as they are already set up for the 585 cams.
Thanks for the input everyone.
Rob |
Xldevil
| | Posted on Wednesday, May 10, 2006 - 01:34 am: |
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Thanks for the offer Alex, but last time they went to the States, the wrong ones were returned, and eventually, when the right heads were returned to me flowed, they cost a fortune in shipping alone lol!
Hey Rocket.
Alex,or M-Tek is german.So you ship inside EU,you'll have to pay no tax.
I can really recommend Alex,very reliable and fast,very good and durable results.
I'm riding his heads now for more than 10K Kilometers and I know at least two other guys how are totally satisfied with head porting done by M-Tek.
http://www.m-tek-motoren.de/
Regards,Ralph |
Alex
| | Posted on Wednesday, May 10, 2006 - 02:45 am: |
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Thank You very much Ralph,
a good word of a satisfied customer is the best reward and advertising that one can have for his work.
And yes, I´m over here in Germany. So Rocket if You really like to know here is my offer: You pay for transportation I measure for free. But only for You and only one time. You will get Your set of heads back.
Now some word to Your questions.
You wrote:
It would seem to me entirely possible that someone with a bit of wisdom in such head matters could port a head without the use of a flow bench and gain fantastic results over and over again. Am I right in thinking so, or has the black art moved on so much, technology needs to be in place to keep ahead of the game?
You need to see that the flow bench has two major tasks. First it is a development tool. You use it to find out the influence of changes (port shape, seat angles/radius, valve size, valve shape.....)on flow behavior. Second You use it as a quality check tool to see if Your porting work always results in the same flow numbers. Some people believe that the flow bench is a machine to do port work. But that´s not true. Port work is done either by hand (with hand grinders, flap wheels and so on) or with a CNC mill. The flow bench is "only" a measuring device.
So to get back to Your question: You need a flow bench to find out what head design (i.e. port design, seat design, valve design, combustion chamber design...) works. You have to back up the results by dyno results. If You found a good design You reproduce this with other heads (heads of the same kind; a Thunderstorm design might not work with an XB head) and use the flow bench to check if the flow numbers are always the same (they won´t be exactly the same but they will be within a certain range. This is Your quality check.). Then You have a head design that will always work as long as the flow numbers are in the "quality check" range. You call it "Stage 1" and You are ready to sell it to customers. During the years You may slightly change the design to make it even better.
I designed my Thunderstorm Stage 1 head concept some years ago with small changes over the years. Today I could port a Thunderstorm Stage 1 set without the use of a flow bench and it would work. But it would miss the quality check step. Without a flow bench I wouldn´t have been able to find the design (and I wouldn´t be able to find new designs). Which brings me to Your second question:
"So here's a question. Where does the rest come from when it seems all is said and done?"
The port is only a part of the game. The seat design and combustion chamber design plays an important role, too. Without a flow bench one can never find the real secrets. I´ve tested some heads that have been done by people without flow bench. These heads were ported to "what the eye and mind" believes to be good. Unfortunately air doesn´t care too much about that. Sometimes a sharp edge can be better than a smooth radius, sometimes a valve guide sticking in the port is better for flow than removing it. Who knows? Ask the flow bench. It will answer Your questions.
Best regards
Alex |
Rocketman
| | Posted on Wednesday, May 10, 2006 - 02:55 pm: |
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Thanks Ralph, I must be bloody daft not realizing Alex is ice cold in Germany.
Alex, that's a fabulous and generous offer, but if those heads need to come off anytime soon, it will be after riding season. Taking heads off leads to further problems also. Imagine this......
"Rocket, I've measured your heads for free and Dick did a good job, but..........But technology has moved along since 1999 and I can guarantee you 110rwhp using your N9's and the 42mm flat slide. Interested?"
I'm trying to stop getting involved in modifying my Buell. It's become a bad habit, and it eats away at my piggy bank.
I'm seriously thinking about the Brutale, but business commitments keep conspiring against me. I don't know if the 910 is for me not having ridden one, but reading the tests it's not possible to choose between that or the 750. The 750 might just stack up nicely, especially as they're found reasonably priced for used ones with hardly any miles on them. If I wait a little longer, I'm thinking the £5000 Brutale is just around the corner. Saves selling the Buell to finance buying one. I'd like very much never to part with the Buell. I know I'll regret it if I do, but I really need another Streetfighting two wheeled tool. Once I have one (Brutale) my attitude will changed for the better towards the Buell. One thing I can say for certain is I won't mind the downtime with the Buell if I'm modifying her in some way. That and the Buell can become even more of a focus for my attention. The Brutale can take the strain lol.
Keep your offer on hold. Maybe when I get the chance I'll pop across and say hello. Thanks again.
Rocket |
Alex
| | Posted on Thursday, May 11, 2006 - 02:21 am: |
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Rocket,
Your setup should already have 110 rwhp. Although I wouldn´t choose the N9 cams.
You´re welcome.
Alex |
Rocketman
| | Posted on Thursday, May 11, 2006 - 04:17 am: |
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Yes Alex, it should have somewhere for certain between 100 to 110rwhp. Probably closer to 110, but it was only ever on the dyno back in 1999, where after a mere 5 pulls it hit 100.5rwhp.
Since I put the big Buell back together last year, I've been intending to find a good dyno local enough to me. I think Matt from Trojan might have pointed me in the right direction, so will get there soon.
Why are you not in favour of N9's? What would you have used given my set-up, and why?
Thanks,
Rocket |
Alex
| | Posted on Thursday, May 11, 2006 - 06:53 am: |
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Rocket,
N9s have pretty much overlap together with pretty much TDC lift. There is not too much space in the Thunderstorm heads even with stock size valves. So one would have to sink the valves deep into the seats especially when using bigger valves. Not good for low and mid range flow.
I love to go with less radical cams, less compression and more flow. If I made the specs from our drag race engine public I´m sure there would be a lot people telling me that it wouldn´t be enough for a drag race engine (we use much less overlap for the 97" displacement than Your N9s do). Still it is the fastest engine in its class 
Another example are XB cams. They are pretty "conservative" when looking at the specs. Still You can easily make above 100 rwhp using them with stock displacement, stock compression and a good set of heads with even stock valves. My philosophy is "Go with flow" (yes I know, velocity is important, too).
I can´t really tell You what cams I would use with Your setup as I don´t really know it. But I`m pretty sure that I would take a different way.
Best regards
Alex |
Steveshakeshaft
| | Posted on Thursday, May 11, 2006 - 07:11 am: |
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I think the new SE575's look a good cam set myself. |
Pammy
| | Posted on Thursday, May 11, 2006 - 08:44 am: |
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Here is a decent set of cams: 590 lift, 240 degrees intake duration, 248 degrees exhaust duration, 40 degrees of overlap. TDC lift .166 and .192 |
Jimidan
| | Posted on Thursday, May 11, 2006 - 12:35 pm: |
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Pammy sez:
"Here is a decent set of cams: 590 lift, 240 degrees intake duration, 248 degrees exhaust duration, 40 degrees of overlap. TDC lift .166 and .192"
Whose cams would those be? Without looking up the specs they sound a little bit like the W8S cams I bought from Bob Wood several years ago. I do remember that they were 590 lift and in the mid 240's duration. Pulled like a tractor too.
jimidan |
Jimidan
| | Posted on Thursday, May 11, 2006 - 02:07 pm: |
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To my tiny brain, this head tuning stuff has always seemed about 1 part science, 9 parts voodoo. I wish it were more intuitive to me too. I admit that I have donated large sums of money at the alters of these "witch doctors", as has many of you. I guess I can see similarities and a few differences when comparing different porting guru's handiwork with my naked eye and crude measuring implements, which to the true pro practitioner must seem about as sophisticated as using a shovel and rake. But I was a true believer.
I started doing track days several years ago, taking my street bikes out there and risking the big hit. Thank God I have never wrecked on of my Buells out there. However, I low-sided my Super Hawk in the wet grass in an exercise on the benefits of target fixation, and after paying for a lot of overpriced plastic, decided that if I was going to continue to succumb to the pangs of this addiction, that I needed to "invest" in a true race bike.
Irregardless of the folly of my logical disconnect whereby an investment of this sort makes any freakin' sense, I purchased an S1 Lighting Series racebike. I spent around $7K on having an engine built that I thought would be appropriate for the track.
Somehow, after a while (and several piston scuffs and a cam lobe flaking incident) I came to the realization that I still was spending way too much money on track day entertainment...so I bought a Honda F4 racebike for a fraction of what I had in one of my Buell engines. Since I had been raised in the Buell School of Modification, I immediately started looking into what I could do to this Honda engine to make it faster, disregarding that I had bought it to "save" money.
The Honda already had an Erion race cam and jet kit, and full header/muffler on it. I was told by the owner that other than that, the engine was bone stock. Bone stock sounded to me like the broth in which meat, fish, bones, or vegetables are simmered...and not something I would want my race bike to be, so I set about to change it.
Being from the Buell School of Modification, I had learned early on that one of the best and most cost efficient things you can do to your motor is head work. I put out the inquiries on the web for who was doing the best race-prep engine work on these IL4's, and the name Dan Kyle kept coming up. Since I had spent $1800 on a set of Buell STD heads to compare to, I figured how much could some head work on a Honda be, if I already had the head?
So, I called up Mr. Kyle (who does build a bunch of the successful AMA/CCS/WERA privateer's motors) and talked to him about doing some work on my head. What he told me was shocking...a regular paradigm shift. The heads on my Honda F4 were already about as good as they can be, and that he could port them a little but that it would probably not be worth it, unless I was going to all-out race it. He said to just plane off about .0015" from the head since I was going to use 103 race gas, and that would be it.  Huh?
The question that has been in my head since (maybe I need to get MY head ported), if Honda can make their production heads with ports and combustion chambers that are about as good as they can be, even with a race cam setup, then why can't HD? I have to admit, that when looking at the stock port and combustion chamber casting on the Honda, that they are really smooth.
How come there is so much to be gained over the stock casting on the Harley? Is this just another example of the Harley tax (taxation without representation has never been very popular )? The HD/Buell engineers are not stupid, and they could shape the ports and combustion chambers any way they wanted to...so why did they do it so badly that we need to spend $1600 on getting a head job?
jimidan |
Panic
| | Posted on Thursday, May 11, 2006 - 02:15 pm: |
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I'd explain, again, but then you're still not listening.
A flow bench has a single purpose: to make an A-B comparison pre and post mod on the same head, same day, same pressure, blah. Otherwise, it's as exact and scientific as conducting a boxing match by saying "A beat B, and B beat C, therefore A will beat C".
An engine builder who tells you that increased flow on the bench makes more power every time began his career when you walked in the room.
Flows 100"? A drinking straw flows 100" if the engine is small enough.
By the way: 100" H2O is only 3.6 psi vacuum or 7.4" Hg.
The reason they give you that handy chart is to avoid the obvious and embarrassing question "do I need to buy another bench if I can't pull enough vacuum on an engine?".
The answer is "only if you want the test to show anything useful." |
Pammy
| | Posted on Thursday, May 11, 2006 - 02:21 pm: |
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These are not Bob Woods. Andrews makes Bob's cams. These are not Andrews. These would be some Edelbrock cams that I have around here. |
Pammy
| | Posted on Thursday, May 11, 2006 - 02:36 pm: |
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"An engine builder who tells you that increased flow on the bench makes more power every time began his career when you walked in the room."
Which is why I said everything is relative.
I don't think anyone can tell you(truthfully) how much vacuum a live engine experiences, through all ranges anyway. There are some darn good guesses, but that's all they are. Educated they may be, but guesses, none the less. |
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