valve shrouding

[Matra et Alpine]

Read this article here It explains in clear detail why porting heads is almost always bad and why increasing velocity is almost always good...

as said right at the start.
He's talking bike engines.
TINY ports compared to cars. Tiny heads compared to cars.
Short stroke engines.
Also much of his stuff is on old bikes and his comparisons are difficult give how much bike intakes are restricted DELIBERATELY by the manufacturer.

I meant ANOTHER engineers analysis.

Trying to sperate out his myth from truth is difficult .... especially coz he deliverately misquotes things.

But one he incluides ...... ) Do you not wonder why he puts this in the smallest text possible ? Hinding something from the gullible )
(Actually, a few creative thinking tuners in Europe do already know about this. They're not anxious to reveal this info, because their success on the racetrack is somewhat dependent on it remaining a secret.)

So do a lot of car tuning "experts" ... David Vizard being one I quoteed and recognised as a god on Ford adn BL engines

I suspect you've fallen in to the trap he deliberately sets. That is that nobody else tunes ports properly. It's a great tag for his business. It ignores that good tuners have been doign it for decades --- just not crowing about it Valve size, angle and lift are all used mainly to achieve what he is saygin by his approach of jsut porting ( is my interpretation of it ). Doing JUST what he says isn't goign to be a big win for many reasons.

[hightower99]

as said right at the start.
He's talking bike engines.
TINY ports compared to cars. Tiny heads compared to cars.
Short stroke engines.
Also much of his stuff is on old bikes and his comparisons are difficult give how much bike intakes are restricted DELIBERATELY by the manufacturer.

I meant ANOTHER engineers analysis.

Trying to sperate out his myth from truth is difficult .... especially coz he deliverately misquotes things.

But one he incluides ...... ) Do you not wonder why he puts this in the smallest text possible ? Hinding something from the gullible )
(Actually, a few creative thinking tuners in Europe do already know about this. They're not anxious to reveal this info, because their success on the racetrack is somewhat dependent on it remaining a secret.)

So do a lot of car tuning "experts" ... David Vizard being one I quoteed and recognised as a god on Ford adn BL engines

I suspect you've fallen in to the trap he deliberately sets. That is that nobody else tunes ports properly. It's a great tag for his business. It ignores that good tuners have been doign it for decades --- just not crowing about it Valve size, angle and lift are all used mainly to achieve what he is saygin by his approach of jsut porting ( is my interpretation of it ). Doing JUST what he says isn't goign to be a big win for many reasons.

the fact that motoman uses this technique on bike engines is of no consequence at all. The size of the port relative to another on another vehicle doesn't matter either! so what if he is working on smaller ports? the smaller ports are attached to smaller engines. Bikes are actually known for having rather large port size to capacity versus the port size to capacity ratio on cars! He has performed this on many new bikes too but you skip over that part I guess. And what is this about his comparisons being difficult he compares the same engine before and after porting it! He doesn't misquote things at all you can't give me one example of it!

(Actually, a few creative thinking tuners in Europe do already know about this. They're not anxious to reveal this info, because their success on the racetrack is somewhat dependent on it remaining a secret.)I know exactly why he put this on his website in small text! He put it small because he is running a theme through the whole website and that is that this is something that other people will not like to hear and don't believe to be true (he points out that it isn't just him who uses this technique!) He doesn't set any traps he is doing his best to make everything honest. He doesn't say that nobody tunes ports properly he says that many many many people have the wrong ideas and are spreding them around to no good. By the way Motoman has been doing this for decades too...! If you look at what he plans on writing about in his powernews letter valve angle jobs are on the list aswell. The porting technique is a seperate thing, you cannot achieve similar results without doing it. Tuning valve size, lift, and angle will help but in other ways!

Matra et Alpine why don't you go out and buy some cheap 250cc 4 stroke and follow his technique... If that doesn't prove it to you nothing will and you are a lost cause, a closed mind...

[Cyco]

hightower, if this small valve idea worked as well as you claim why don't the most high performance NA engines (F1 and MotoGP) use this? It's not like they dont have the budget to test it, yet they keep using very large valves and polished ports.

[Matra et Alpine]

the fact that motoman uses this technique on bike engines is of no consequence at all. The size of the port relative to another on another vehicle doesn't matter either! so what if he is working on smaller ports? the smaller ports are attached to smaller engines. Bikes are actually known for having rather large port size to capacity versus the port size to capacity ratio on cars!

Bikes are known for having exceptionally SHORT ports.
That was the point I was making.
Length is VERY important if thinking about flow

He has performed this on many new bikes too but you skip over that part I guess. And what is this about his comparisons being difficult he compares the same engine before and after porting it! He doesn't misquote things at all you can't give me one example of it!

Comparing it with other alternatives, ht.
At least the likes of Vizard explored and shared all the options they tried and the plus and negatives.
Actually scanning the rest of his site I couldn't' find anything newer than 2001 and most of his port stuff comes from an early 90s designed head.
Hardly a recommendation for doing ANYTHING to a new head/engine
NOWHERE does he say he has done it to cars that I can find.
That would be like saying because a speedboat hull is faster then the next cruise ship should be designed like that

I know exactly why he put this on his website in small text!

You KNOW ?
You have asked and confirmed from him that "fact" ? or is it like the other "facts" you cite ???

He doesn't set any traps he is doing his best to make everything honest.

He cites a flow manufacturer as if the whole industry says it.
THAT is a trap for the dumbest readers who won't investigate or question !

Tuning valve size, lift, and angle will help but in other ways!

AND they interact, which is all I keep pointing out to you !!!!

Matra et Alpine why don't you go out and buy some cheap 250cc 4 stroke and follow his technique... If that doesn't prove it to you nothing will and you are a lost cause, a closed mind...

Because when I was your age I was shaping and rallying Minis with '295 heads which we ported, revalved and reshaped combustion chambers on> Taking experiences from as wide sources as possible. Trying different things each time. Some involved managing flow by NOT opening out the ports in some places ( which is what's at the basis of his "build up" technique ). Guessing I've personally done about a dozen '295 heads. no two were the same. Ford X-flows I've done about 4 or 5. Rather than taking ANOTHER motorbike engine and testing it I contend I've done some of what he suggests ( or did you NOT read what he says in his small print -- I'm in Europe ). It's why I have WARNED not to follow your stupid comment to someone that epoxy won't cause harm. Vibration nd wrong epoxy choice and a lump will be ingested. I noticed you never dared to put your hand up to pay for a new engine if it happened. Your instructions are the biggest issue. You lack the experience and knowledge to be aware of the risks.
Dependant no the head there are many other things which will provide equal gains. IN cars I can only think of one manifold where there were stall eddies in the plenum. These are best solved by fabricating a new plenum then sticking epoxy in. Reducing filter resistances is BY FAR the best way to increase flow rates and again a better choice than sticking epoxy in.

Sorry, ht, but I think you've got a half-baked idea and only see it in isolation.
Taking the big picture then it's not as clear-cut as you or Motoman implies. It IS something he's using to make his name with but I noticed one race engine he was touting was stripped and the ports were declared STANDARD. So there was one case ON HIS OWN SITE where the fast bike he tuned better than anyone else's DID NOT have the port mod you are over-selling.

Doign it to a 250cc bike engine won't translate to a car engine for the reason I already told you they were different.

how many car and bike engines have you actually worked on and then driven/ridden to get teh REAL results from ?

[hightower99]

hightower, if this small valve idea worked as well as you claim why don't the most high performance NA engines (F1 and MotoGP) use this? It's not like they dont have the budget to test it, yet they keep using very large valves and polished ports.

F1 and MotoGP use similar ideologies but they don't use epoxy. In F1 they have ports that have zero dead volume in them and are tuned for the highest optimum flow (that is why they have the big valves... which is good) and in MotoGP they have roughly the same thing (they can't increase the bore and shorten the stroke as much as F1 can) and if you look at some of the ports from both series you will notice that... they are not polished the have what looks like a cylinder hatchmarking on them.

Bikes are known for having exceptionally SHORT ports.
That was the point I was making.
Length is VERY important if thinking about flow

Yes and this is a technique for getting rid of dead volume in ports... (there is much more dead volume in car ports then in bike ports)

Comparing it with other alternatives, ht.
At least the likes of Vizard explored and shared all the options they tried and the plus and negatives.
Actually scanning the rest of his site I couldn't' find anything newer than 2001 and most of his port stuff comes from an early 90s designed head.
Hardly a recommendation for doing ANYTHING to a new head/engine
NOWHERE does he say he has done it to cars that I can find.
That would be like saying because a speedboat hull is faster then the next cruise ship should be designed like that

His point is that the many amatuer porters out there (many of them are actually name brands) don't have the right idea and that the way he learned to work ports works better. (You have no proof to the contrary) He talked about performing this port tuning on a 2003 GSXR1000 and this technique is being used as we speak on current racing motorcycles in several racing series. I never said that MotoMan used this on cars I said that when you learn the theory behind it you can apply that to cars (taking into account the differances)

You KNOW ?
You have asked and confirmed from him that "fact" ? or is it like the other "facts" you cite ???

I haven't asked him but I pointed out that you where showing it out of context and making it sound like something it isn't. You have an affinity for misunderstanding things.

He cites a flow manufacturer as if the whole industry says it.
THAT is a trap for the dumbest readers who won't investigate or question !

No he doesn't he quotes what is in the manual and says exactly where it came from. He doesn't hide anything. He is trying to point out that going to your nearest porting shop will not get you the results that you are led to believe are possible.

AND they interact, which is all I keep pointing out to you !!!!

You said that tuning valve size and lift and angle will get the same results through the same effects... I am saying they do not. I said nothing about the fact that they are an added helper. I know they interact and if you know what you are doing you can get all this to work together!

It's why I have WARNED not to follow your stupid comment to someone that epoxy won't cause harm. Vibration nd wrong epoxy choice and a lump will be ingested.

Sorry let me revise my statement: There is no harm if you use epoxy responsibly and if you have a head with half a brain on your shoulders... If you follow the instruction on the box for mixing the epoxy it should be fine. And if you remember to let it cure completely before strapping the head back on your engine and starting it then it should be fine. Epoxy is not the most dangerous thing in the world.. of course shite happens and sometimes you are unlucky but that has nothing to do with the technique!

Doign it to a 250cc bike engine won't translate to a car engine for the reason I already told you they were different.

I told you to do it to a 250cc because it is cheap and something that if it goes wrong won't hurt your wallet. If it doesn't work then you have proved that to yourself and thats fine but untill then you have no way of knowing...

[Cyco]

hightower; How can super large valves and restricting port size be considered the same idiology?

[Matra et Alpine]

Sorry let me revise my statement: There is no harm if you use epoxy responsibly and if you have a head with half a brain on your shoulders... If you follow the instruction on the box for mixing the epoxy it should be fine. And if you remember to let it cure completely before strapping the head back on your engine and starting it then it should be fine. Epoxy is not the most dangerous thing in the world.. of course shite happens and sometimes you are unlucky but that has nothing to do with the technique!

I'm not bothering writing even MORE comments pointing out the abuse of truth in the rest of it.

I am instead goign to ONLY concentrate on the above part as it is most critical.

Engines are subject to vibration.
Epoxy bond can be broken by flex and vibration.
Without PROPER analysis and the introduction of pnning and uindercutting then the epoxy may break free in part or whole. You don't get detailed onstructions on those issues on any instructions.

YOU ARE REPEATING A VERY DANGEROUS OPTION and AGAIN your belittling the risks.

UCPers DO NOT DO this unless you are VERY knowledgable on the specific materials you are bonding too, their vibration adn expansion/contraction coefficients and match it to teh epoxy you intend to use.

I told you to do it to a 250cc because it is cheap and something that if it goes wrong won't hurt your wallet. If it doesn't work then you have proved that to yourself and thats fine but untill then you have no way of knowing...

I have, DID YOU MISS or deliberately IGNORE that point I highlighted that Motoman knew Europe was already doing this. RIGHT AT THE START I told you that modern engines don't have large dead spaces in intakes anymore. I cited you engines from the 60s that didnt' have it either.

Sorry, ht, you are either lying to yourself by ignoring it or lying to us.

When YOU get the experience rather than citiing web sites then PM me and I'll take you off my ignore list ( if only it still existed -- WOUTER !!! ).

"Filling dead spaces" is also a LOT different from narrowing the port to increase speed. So you are switchign benefits to suit the issue at the minute. Make your mind up I know what it's doing and how it benefits. It's not as simple as you make out ( and was first pointed to you at the start ).
See you when you get more real world experience.

[hightower99]

hightower; How can super large valves and restricting port size be considered the same idiology?

it isn't just restricted port size... When a team competeing in F1 makes a motor they now that you can't have any dead space in the ports (the volume of the port for any given mm can not be larger than the previous mm) Motoman realised that you can actually run lower volume ports without losing flow. (this is what can be done to almost all engines... even now) many tuners working in racing have found this out way before he did. This is the dead space I have been talking about (sometimes it isn't visible) most motors can run lower volume ports without losing flow and almost all engines should have a smaller choke point closer to the valve. So the ideaology is large valves mixed with properly sized and correct volume ports.

I'm not bothering writing even MORE comments pointing out the abuse of truth in the rest of it.

I am instead goign to ONLY concentrate on the above part as it is most critical.

Engines are subject to vibration.
Epoxy bond can be broken by flex and vibration.
Without PROPER analysis and the introduction of pnning and uindercutting then the epoxy may break free in part or whole. You don't get detailed onstructions on those issues on any instructions.

YOU ARE REPEATING A VERY DANGEROUS OPTION and AGAIN your belittling the risks.

UCPers DO NOT DO this unless you are VERY knowledgable on the specific materials you are bonding too, their vibration adn expansion/contraction coefficients and match it to teh epoxy you intend to use.

These risks are true and that is why I told you to test them on a cheap motor that you could afford to lose. I am not asking Paul or anyone else to actually use only epoxy and drive around with only that in the intake(Even though this has been proven to be safe). I suggest that anyone willing to try to get a high grade temp and vibration resistant epoxy and use that to find the best shape (this should not take many tries) then when you are happy with the results you remove the epoxy and use welds to take the place of them. I am not belittleing that risks I am suggesting that they shouldn't scare anyone away from doing this.

I have, DID YOU MISS or deliberately IGNORE that point I highlighted that Motoman knew Europe was already doing this. RIGHT AT THE START I told you that modern engines don't have large dead spaces in intakes anymore. I cited you engines from the 60s that didnt' have it either.

Motoman pointed out that only a few in europe knew about this and were using it properly! Modern engines don't have large dead spaces? then they do have small ones? anyways almost all engines can run lower volume ports without losing flow this is the dead space it may not be a physical increase in volume that has to be plugged. The engine you cited would still benefit from this system anyways! also this technique makes for a smaller choke point which is closer to the valve this will help almost all engines aswell (especially cars cause there choke points are notoriously far from the valves.)

"Filling dead spaces" is also a LOT different from narrowing the port to increase speed. So you are switchign benefits to suit the issue at the minute. Make your mind up I know what it's doing and how it benefits. It's not as simple as you make out ( and was first pointed to you at the start ).
See you when you get more real world experience.

He isn't just narrowing the port to gain speed he is making it lower volume untill it starts effecting flow. This is the "dead" space I am talking about. The end result is normally more narrow ports. The technique also helps out in other ways. (making it harder for fresh charge to be pushed out of the cylinder)

[Matra et Alpine]

ht, you're making vast assumption about engine intakes that demonstrate how little you actually know about cars.
You keep repeating his info on bikes - which I've already said doesn't translate - and applying it to cars.
You take an engien cited ans say it can be improved. AND YET you dont' knwo how close to optimal the port is ? Youahve fallen into the trap he set fo rthe gullible that nobody else knows how to port PROPERLY. Go take the time to get a Vizard book and read it. You'll learn a LOT more than from one web site !!!!
Until then, STOP making BS comments about finding the right epoxy for materisl and vibrations. THAT takes an engeering degree in materials to get right. Anything else is russian roulette. Thankfully the comments made here make that so obvious everyeon else now sees it as common sense and aren't likely to take your dangerous advice first given -- remember you added NO CAVEATS. ------ bad advice

[Cyco]

the dead space I have been talking about (sometimes it isn't visible) most motors can run lower volume ports without losing flow and almost all engines should have a smaller choke point closer to the valve. So the ideaology is large valves mixed with properly sized and correct volume ports.

So this contradicts your earlier statments that restricting in inlet diameter will give signifigent increase in hp? I don't see ANY racing engine with a choke point introduced (near the valve or otherwise), can you please show me some example of modern racing engines (not converted road engines) that do this?

if you look at some of the ports from both series you will notice that... they are not polished the have what looks like a cylinder hatchmarking on them

Can you please post pics of this? The pics I have soon don't agree with your assertions.

STOP making BS comments about finding the right epoxy for materisl and vibrations. THAT takes an engeering degree in materials to get right

I studdied what was almost this and there is NO way I'm putting epoxy anywhere it can possibly do the damage that failure if this would cause. The proximity to the combustion chamber that hightower 99 is reccomending for some of this filling will lead to heat levels that will exceed most epoxies thermal trasition to a glassy state which would then allow it to "run" into the engine, the combustion properties would not be benificial.

IF you where to try this I would be machining a metal part and inserting it into the area with perhaps a BMI resin to secure it.

[hightower99]

here is a picture of an epoxy ported engine done right. and here is what was writen under the picture: "Pro Race Only Epoxy Filled Intake Port. Port retains the Pro "D" shape and is made smaller, flow remains near the same (over 130CFM at 10 inches of water) but the velocity goes to the moon! You then adjust camshaft timing to take advantage of this ram tuning by spreading the lobe centers apart more. 113-116 degrees! These engines get over 100% volumetric efficiency. The flat port floor gives the port short side radius more area and it thinks it is as long as the long side. Flow and velocity go straight up."

Here Is a link to a picture showing the intake trumpets on a old F1 car. Notice that the rims are polished but the inside is oddly kept rough?!?! These guys knew what they were doing.

Here is the 2002 ferrari F1 engine unfortunately you cant see that far into the ports because they put paper in them but you can see that the carbon fiber lip is smooth and the metal underneth is rough...

So this contradicts your earlier statments that restricting in inlet diameter will give signifigent increase in hp? I don't see ANY racing engine with a choke point introduced (near the valve or otherwise), can you please show me some example of modern racing engines (not converted road engines) that do this?

I never said anything about restricting the intake diameter (as that implies a loss of flow) I said gaining velocity by getting rid of dead space leads to HP gains! And I hope you just misunderstood what choke point is. The choke point in an intake is where the cross section has the smallest area. all engines have a choke point in the intake!

I studdied what was almost this and there is NO way I'm putting epoxy anywhere it can possibly do the damage that failure if this would cause. The proximity to the combustion chamber that hightower 99 is reccomending for some of this filling will lead to heat levels that will exceed most epoxies thermal trasition to a glassy state which would then allow it to "run" into the engine, the combustion properties would not be benificial.

IF you where to try this I would be machining a metal part and inserting it into the area with perhaps a BMI resin to secure it.

First people are driving around right now on motorcycles that have epoxy ported intakes (and some have epoxy ported exausts too) and none of them have suffered catastophic failure! next If you are paranoid you can follow what I said: Take the head off take it too a flow bench center. Start adding epoxy (there is no heat or vibration involved in a flow bench test) keep adding epoxy untill the flow rate goes down. Form the epoxy and mark where it is and how it is shaped then remove it. then you can follow your own good suggestion of using a machined piece (can be hard to make) and BMI resin to hold it or use weld material to take the place. strap the head back on and run it on the dyno and see what you got!

and just to make Matra happy If Paul goes ahead and trys this I will be happy to pay for a new motor if it gets destroyed due to epoxy being ingested (Note: offer not valid if all precautions where not heeded)

[Cyco]

it will tell you how to make your ports smaller

Port retains the Pro "D" shape and is made smaller

I never said anything about restricting the intake diameter

Please explain how several pieces of advice to make the port smaller is different to restricting its diameter?

The 1st trumpet pic looks dirty, rather than rough, and the Ferrari engine pic is to low res to really tell, remembering that shop peening for fatigue life may take precedence over polishing for flow. The latest F1 enging regs with fixxed CoG hight mean that weight saving at high points is no longer as important so the inside of the current engine would be the real test - but I cant see either of us having access to that in the next couple of years.

You are obviously not very familair with epoxies, a couple of years at Uni studying material science will only teach you the basics of areas such as these. My personal interests in cycling, motor sport and high performance aircraft is the reason I have studdied the area further and consider myself in a position to make a fair and educated comment. Those who support epoxying engine parts without a reasonable level of education in the field (like in most areas of life) are dangerous to both themselves and others.

[hightower99]

Please explain how several pieces of advice to make the port smaller is different to restricting its diameter?

Restricting the port diameter implies negative effects also it implies a negative effect on the flow. I may have said "make the ports smaller" but for all the quotes you posted, none of them are in full context. The ports being smaller is not the point, the point is that all the dead space is gone and the ports volume is smaller... Without lowering flow!

I am certainly not an expert when it comes to epoxy but I certainly have experianced that epoxy can be quite resistant and resiliant.

[Matra et Alpine]

I am certainly not an expert when it comes to epoxy but I certainly have experianced that epoxy can be quite resistant and resiliant.

and you STILL offered to fix anyones engine that gets screwed with epoxy ingestion

epoxy bonding is a MAJOR SCIENCE and the industrial epoxies that get used in vibration and corrosive atmospheres are NOT the kind of stuff you get in a local DIY store ( the one used on our conrete floor could only be mixed and applied while wearing full Breathing Apparatus because of it's toxicity - but it worked 100% !!! )

[hightower99]

Well I know that there are quite a few people driving around with epoxy in their ports so I am not worried...

Epoxies for this application:
J-B Weld
Loctite Metal Set
Bondo Automotive Body Filler

I believe the J-B Weld to be the best of them (as that is what I used)