RPM, spray angle, bowl design

bigger Port volume or better port flow in a diesel has little to do with throttle response. First show me the throttle on a diesel. A better cylinder head is better period. Trying to confuse characteristics of a diesel with that of a gas motor will not work.

In a gas motor the lope or sluggish throttle response is from the air having to go from no movement to movement when the Throttle is open cause’s fuel to come out of suspension. . A diesel has no throttle or fuel in suspension.


Now to the cause of a engine feeling sluggish when a good cylinder head or cam is installed is that boost number, drop as the restriction to air entering the motor drop. More air is going in to the motor, but the reference for the injection system to put fuel in the motor is down. Be it mechanical, or CR the injection system only see boost present.
If you put Zacks head on a total stock motor, it will perform better period, but you must tuned to take advantage of the reduction in restriction of the intake track.

if it has less boost , or restriction , it will call for less fuel

This is not an area where there is any ambiguity , it’s just basic fact.
 
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Hamilton Cams said:
Yes I do think port volume is to blame for poor low rpm performance with daily drivers.
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Exactly, the low port velocity is being affected, what greg is saying sounds good on paper and works once the turbo starts making boost and makes it faster with more power. But for the guys street driving with less than 10psi cruising around 90% of the time at low rpm.

Sad thing is Greg thinks he knows something more than the owners of their truck that are seeing it first hand.
 
Hamilton Cams said:
The biggest problem I have seen with our heads in daily driver applications, is not necessarily lack of swirl, but intake port volume that is a bit large for low rpm response.

Stock heads, on my bench have about 3800rpm swirl at .550". The Hamilton head, with some intake seat angles is as much as 3500 rpm at the same lift and slightly less with others. At high rpm they make great power! Under 2200 RPM they will make less power than a stock head, not due to swirl, but loss of port velocity. I have seen stock heads that had less swirl than our head, but yet had small ports that were better on bottom end.

As far as the people that have had issues with our head, in most cases they were using lower than OE compression. The first order of heads was not exactly like the model we used for port developement. On the next order that issue will be fixed with a smaller intake with a better shape.

Joe, your statement on un-shrouding and swirl sounds bogus. He was geting close to 10 before with a set of weston's injectors , and I cut him a deal on the head and to see if it would help in his application. No good deed goes unpunished, right? Working with somebody in testing and getting thrown under the bus will really slow down testing and developement!
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Well I applaud the fact that your actually set up to test intake induced swirl!

LOL I have a feeling Greg has absolutely no concept of that.

Now on the valve un-shrouding....I've noted over and over in SAE literature that sinking the valves into the head increases the swirl produced at low lift. When you think about it, when you shape flow after the valve your promoting it's direction. Inherantly when you shape the port for increased flow swirl is reduced....(Not necessarily bad in a high rpm performance application).

Swirl and port velocity go hand in hand so in that sence I agree with your statment on port volume being detrimental at low RPM and this aligns with research I've read. Only my reference would be to port velocity. The chicken or egg as it would be.

Your in a particular position having heads out there and feedback attained from builds across the spectrum.


COMP461 said:
bigger Port volume or better port flow in a diesel has little to do with throttle response. First show me the throttle on a diesel. A better cylinder head is better period. Trying to confuse characteristics of a diesel with that of a gas motor will not work.

In a gas motor the lope or sluggish throttle response is from the air having to go from no movement to movement when the Throttle is open cause’s fuel to come out of suspension. . A diesel has no throttle or fuel in suspension.


Now to the cause of a engine feeling sluggish when a good cylinder head or cam is installed is that boost number, drop as the restriction to air entering the motor drop. More air is going in to the motor, but the reference for the injection system to put fuel in the motor is down. Be it mechanical, or CR the injection system only see boost present.
If you put Zacks head on a total stock motor, it will perform better period, but you must tuned to take advantage of the reduction in restriction of the intake track.

if it has less boost , or restriction , it will call for less fuel

This is not an area where there is any ambiguity , it’s just basic fact.
Click to expand...


Are you insane?

No amount of porting in the world is going to drop boost below aneroid engagement in a mechanical!

Even the electronics will go into full fuel on much less than full boost!

LOL old Smarty tunes would full fuel off zero boost.

Google up the effect of swirl on combustion and exhaust emissions in heavy duty diesel engines and see if you can wrap that peanut around some of it.

LOL what's even more funny is intake induced swirl is a magnitude of MORE importance in a diesel engine! Diesels having a optimum of 2-4 time greater than their gaser counterparts.
 
yeah zach did a bunch of stuff to try to get swirl back up. I have a feeling the low end would have been a lot worse without all that.
Wish I had the supercharger on there before I did the head. Would have made for some real interesting results I bet.
 
Joe, with all due respect SAE papers are usually written within a narrow scope of intended end uses. Most of the stuff I have read is small variations on production designs or not full-tilt application of new technology but new technology with an emphasis on how to apply it to production vehicles.

What we are trying to do, in most instances, exceeds the limits or is outside of the scope of research. A few of the things that they do not cover is that there are trade-offs with swirl, flow, port volume and cam design. Is swirl, max flow, velocity or low lift flow more important? In my experience, port velocity and good low to mid lift flow trump swirl. Excessive swirl can create restrictions to airflow which can kill power band, cam design can kill power. In other words there are more ways to screw up than do it right.

Heads that flow over 220 or so on the intake usually result in a small loss of low rpm power. Further porting will further exaggerate the issue. A smaller cam that has less lift and duration can help low rpm power with one of these heads, but will kill the higher rpm power.

I believe that at higher rpm, swirl is less of a concern. In this instance mass flow trumps swirl in a MAJOR way. Higher flow will allow the injected fuel to meet more oxygen in a given time than lower flow with much higher swirl. When fuel economy is the primary goal and rpm is lower, you will only have a given amount of air available, swirl will allow the oxygen to meet the fuel faster and give a more efficient burn. I think discussions like this are allowing more people to realize possibilities. I have said all along, bolting a performance or ported head on any vehicle is not a "silver bullet" for fixing issues with injectors, timing, cam, incorrect turbos, head up rear etc.... Most people do not know that they have issues with their tuning.
 
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WTF are you talking about? Some engineer wrote it down, that makes it law. LOL
 
I thought velocity is what makes turbulence, tumble or swirl stronger inside the cylinder
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Lets clear this up for everyone, VELOCITY is SPEED, VORTICIES/VORTEXES are turbulence produced when SEPERATION OF AIR TAKES PLACE FROM THE PORT WALLS/FLOOR/ROOF BOTH SSR & LSR, VALVE SEAT&THROAT, VALVE HEAD as well as the guide area.

COMP, if you have an engine that is suddenly loaded gas or diesel, you WANT a port adequately sized to be able to recover easily to keep going. I believe air speeds are of higher important along with rotating weight especially in the realm of creating good throttle response.Technically we should be saying pounds of air into the cylinder but the only way we get that either is if the air charge is flowing properly both in least frictional loss and port routing.

I have said all along, bolting a performance or ported head on any vehicle is not a "silver bullet" for fixing issues with injectors, timing, cam, incorrect turbos etc
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IMO, as long as people engineer the drafting table designs, these flat runner layouts will not go far too fast. I believe port position is holding diesel intake & exhaust flows back from opimization as far as one part of the higher rpms picture. I see you are keeping Clay Smith's legend going, love it!

Swirl is induced naturally with two valve heads not matter what. 24 valve engines will produce tumble from the valve unless the port is designed to promote swirl coming out of the valve bowl. As our squish action, piston movment toward and away from TDC, the bowl should create both swirl and tumble at some point. As you have stated, swirl slows flow down when coming out of the head into our chamber, reason is its a long distance to travel, entailing a longer cam lobe duration may help the engine out.
 
9724VF350 said:
WTF are you talking about? Some engineer wrote it down, that makes it law. LOL
Click to expand...

Wow what original thought! If that's all you have to add might as well just STFU.

Hamilton Cams said:
Joe, with all due respect SAE papers are usually written within a narrow scope of intended end uses. Most of the stuff I have read is small variations on production designs or not full-tilt application of new technology but new technology with an emphasis on how to apply it to production vehicles.

What we are trying to do, in most instances, exceeds the limits or is outside of the scope of research. A few of the things that they do not cover is that there are trade-offs with swirl, flow, port volume and cam design. Is swirl, max flow, velocity or low lift flow more important? In my experience, port velocity and good low to mid lift flow trump swirl. Excessive swirl can create restrictions to airflow which can kill power band, cam design can kill power. In other words there are more ways to screw up than do it right.

Heads that flow over 220 or so on the intake usually result in a small loss of low rpm power. Further porting will further exaggerate the issue. A smaller cam that has less lift and duration can help low rpm power with one of these heads, but will kill the higher rpm power.

I believe that at higher rpm, swirl is less of a concern. In this instance mass flow trumps swirl in a MAJOR way. Higher flow will allow the injected fuel to meet more oxygen in a given time than lower flow with much higher swirl. When fuel economy is the primary goal and rpm is lower, you will only have a given amount of air available, swirl will allow the oxygen to meet the fuel faster and give a more efficient burn. I think discussions like this are allowing more people to realize possibilities. I have said all along, bolting a performance or ported head on any vehicle is not a "silver bullet" for fixing issues with injectors, timing, cam, incorrect turbos, head up rear etc.... Most people do not know that they have issues with their tuning.
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We're seeing eye to eye on everything there. AND the fact there are more ways to screw up that make it better.

Don't agree on SAE and two other organizations I read not publishing broad new ideas.

Your right they're not pushing the limits so to speak, that does not change general principles in flow dynamics and results of modifications and data gleaned from them.


Look at the Mazda skyavtiv diesel.

14:1 compression along with a major weight reduction AND fuel economy increase that rev's to 5K from factory. Meeting EURO 6 with NO fricking after treatment.

This engine is also being offered in a race form at 400HP or better on 2.2L.

Could that be done with mechanical injection, likely not. Sure makes you think though.
 
Joesixpack said:
If that's all you have to add might as well just STFU.
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Maybe pay attention a bit more there mr. almighty, I gave a example of a cylinder head that goes against everything that you swear by and it works, with a freaking Roosa Master and 2600psi nozzle.

It appears to have been placed in the "huh. wtf?" category.
 
Zach, in Kawi600's case, do you think that twins with say a 58mm turbo with a diverter valve over a larger turbo would help, what injectors would you recomend, how could he go about raising compression, and what results would you expect, any other recomendations for street use
 
COMP461 said:
bigger Port volume or better port flow in a diesel has little to do with throttle response. First show me the throttle on a diesel. A better cylinder head is better period. Trying to confuse characteristics of a diesel with that of a gas motor will not work.

In a gas motor the lope or sluggish throttle response is from the air having to go from no movement to movement when the Throttle is open cause’s fuel to come out of suspension. . A diesel has no throttle or fuel in suspension.


Now to the cause of a engine feeling sluggish when a good cylinder head or cam is installed is that boost number, drop as the restriction to air entering the motor drop. More air is going in to the motor, but the reference for the injection system to put fuel in the motor is down. Be it mechanical, or CR the injection system only see boost present.
If you put Zacks head on a total stock motor, it will perform better period, but you must tuned to take advantage of the reduction in restriction of the intake track.

if it has less boost , or restriction , it will call for less fuel

This is not an area where there is any ambiguity , it’s just basic fact.
Click to expand...

Are you fricken serious?? And people actually assume automatically that you're credible...

It is blatantly obvious that significantly larger ports of a competition head must drop air velocity which 9/10 times will decrease low end power.
 
That is not the case in diesel engine where the heads at best are tiny
Ok explain why more air equals less power, the diesel has no throttle the need for any velocity to overcome the opening of the throttle is not necessary. The diesel moves air in relation to engine speed and density of the intake charge air. This comes from the best out there including Greg at ZZ who spends more time on diesel cylinder head design then anyone, and Chris Franks who designs 500 inch real Pro Stock and designs for Profiler.
I’m not a head porter, but I have spent a good deal of time on flow bench.
More air equals more power smother transition and cooler EGT’s
As to a aneroid not caring about boost , or a MAP sensor not caring , if you reduce the restriction in the intake track and boost drops but your moving more air lbs. of air in to the motor, the computer of the aneroid if not tuned to this will think the motor has less boost , meaning less fuel.
 
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Charger said:
Zach, in Kawi600's case, do you think that twins with say a 58mm turbo with a diverter valve over a larger turbo would help, what injectors would you recomend, how could he go about raising compression, and what results would you expect, any other recomendations for street use
Click to expand...

Im looking at carl's supercharger setup, unless someone can think of a cheaper / easier way to get a cool 650hp with turbos while also having air to burn off the haze on the low end. Truck is a dog off the line.

Ive also thought about the idea of using a bypass to get around a small turbo in a twins or triples set. I guess Id want a pretty small turbo to be pushing some air even at idle speeds.
Wonder what that triple HX35 setup is like?
 
kawi600 said:
Im looking at carl's supercharger setup, unless someone can think of a cheaper / easier way to get a cool 650hp with turbos while also having air to burn off the haze on the low end. Truck is a dog off the line.

Ive also thought about the idea of using a bypass to get around a small turbo in a twins or triples set. I guess Id want a pretty small turbo to be pushing some air even at idle speeds.
Wonder what that triple HX35 setup is like?
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Carl built a triple he351 setup that was sweet.
 
you can also in a 650 hp truck make it spool quicker and cleaner with better fuel mileage raising compression
 
no real easy way to raise compression.. Id have to swap pistons to the industrial ones =(
 
deck the piston .030 and the block ,030 is worth about a point and a half in a CR in a 12 valve depends on the piston, is about a point.
most of the thoughtfull 2.6 engines out there are knocking on the door of 20 to 1.
 
COMP461 said:
deck the piston .030 and the block ,030 is worth about a point and a half in a CR in a 12 valve depends on the piston, is about a point.
most of the thoughtfull 2.6 engines out there are knocking on the door of 20 to 1.
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Most of the 2.6 engines won't tell you what compression their running. The winners in COTPC that I have insight to are most definitely NOT 20:1. I'd argue COTPC are some of the top trucks in the country.
 
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