Extrude Honed head Sr20det higher flow capacity?

[GabeS14]

S14 SR20det,
I just called a local socal shop to get a quote on port and polishing and machining my SR head for oversized valves, and they told me about the Extrude hone option, now, I have heard about the benifits of extrude honing but never heard of doing it to the entire head instead of a regular port and polish. I was told it will create graiter flow capacity then a regular port/polish job. and for the power I am trying to reach(550-600) whp I could use every last bit of air flow.

Has anyone done this before?
Is the higher price worth it?
I was quoted $800 for machining the head for oversized valves, and extrude honing the entire head.

[Okinawandrifter87]

I cant remember where cause it was an old post but I know Steve Shadows knows about this cause he mentioned it somewhere before if thats any help to you =0/ sorry brotha

[GabeS14]

I cant remember where cause it was an old post but I know Steve Shadows knows about this cause he mentioned it somewhere before if thats any help to you =0/ sorry brotha

I remember learning about extrude hone through Codyace on the 2871r turbo thread, but he only did it to his oem exhaust manifold.I believe, he did say it did wonders

[K_style]

S14 SR20det,
I just called a local socal shop to get a quote on port and polishing and machining my SR head for oversized valves, and they told me about the Extrude hone option, now, I have heard about the benifits of extrude honing but never heard of doing it to the entire head instead of a regular port and polish. I was told it will create graiter flow capacity then a regular port/polish job. and for the power I am trying to reach(550-600) whp I could use every last bit of air flow.

Has anyone done this before?
Is the higher price worth it?
I was quoted $800 for machining the head for oversized valves, and extrude honing the entire head.


$800 sounds pretty good price..
I had quote for my stock SR20 exhaust manifold extrude honing job for $500 here in OR...

[Wake]

LOL how is it that I was just looking into this for my intake manifold. Weird.

Anyway gethoned.com wants $715 for a 4cyl head so your quote sounds pretty on target. However i dont have any personal experience with the benefits or drawbacks.

[let5l1de]

Extrude honing the entire head is a great way to increase flow. Most important, Extrude Honing equally increases the port sizes which is critical to proper airflow throughout the full rpm range. A nice touch in a few areas by hand before and after the EH process will put the finishing touches on the head.

Be sure to match both manifolds to the head. Otherwise, you will not see the full potential performance from your head.

As for pricing, get full details of work needed/offered and cost to determine who will earn this project. Check to see if these shops offer detailed Flow Bench info prior to and after the work has been done.

Keep us posted with numbers!

grp
~mario

[tt99ol]

I have heard about extrude honing your oil and coolant passages for better flow/cooling
heard it helps alot
should work great on the head as well and the finish is really nice for flow

[jr_ss]

I'd suggest coverting to the VVL head and calling it a day. You're going to dump all that money into a poorly designed head. Save it and bolt on the VVL setup. You can flow enough on a stock VVL to reach those numbers easily. Sure the initial investment may be more but it will have so much more potential.

[GabeS14]

Be sure to match both manifolds to the head. Otherwise, you will not see the full potential performance from your head.

As for pricing, get full details of work needed/offered and cost to determine who will earn this project. Check to see if these shops offer detailed Flow Bench info prior to and after the work has been done.
~mario

so your saying i need to have both manifolds and take them together with the head to get matched? I was planning on buying the exhasut mani as one of the last things lol..EFR twinscroll mani from full race is like 1600..haha

also I will def ask about the flow bench..does it show how much more the head flows after the job?

[let5l1de]

Depending on how much work is done to the ports on the head (both int. exh.), you will want to open or match both manifolds to the new size. This requires either trimming a gasket and or measuring the physical size of port and matching the manifolds to the new size. Too small or large of a manifold port may impede flow characteristics. This is typically done by a well trained hand or cnc process.

Full race twinscroll mani is great stuff but soooo expensive.

Yes, Flow Bench performance testing will show how well the individual ports of the head are performing.

[codyace]

I'm gonna do some digging for you know, I'm almost positive there was a before/after on EvoM and the owner loved it!

The nice thing about it, is that they'll also port match if you supply gaskets (they do not get ruined either).


I've sworn by their results on OEM exhaust manifolds forever now. Cheaper option than any decent tubular setup, and makes better torque/power than any bottom mount turbo manifold out there. Even in FWD land, getting GTiR manifolds extrude honed is the ticket (as is going external wastegate with both setups :D )

[codyace]

Some pics of it on my exhaust manifold:
http://www.codyace.com/albums/album188/ex8.sized.jpg

http://www.codyace.com/albums/album188/ex3.sized.jpg

http://www.codyace.com/albums/album188/ex5.sized.jpg

Don't mind the crack in the manifold, every single SR manifold seems to have one there.

[nieko]

That looks pretttyyyyy, haha. And how much did it run you for just the manifold?

[idahotuner]

wow cody i havent ever seen the pics of your manifold before, that looks nice.

[codyace]

That looks pretttyyyyy, haha. And how much did it run you for just the manifold?

At the point in time I got in on group buy so it was stupidly cheap. However they do have pricing at High Performance, High Output Racing - GetHoned (http://www.gethoned.com)

If you're prior/current military they give discounts as well.


wow cody i havent ever seen the pics of your manifold before, that looks nice.

For as long as I've been on here whoring them out, and for as long as we've talked on here that's surprising hahaha! How are things though, good? Everything turn around ok?

Off TOpic:
The ultimate combo then is to do this to it:
http://www.codyace.com/albums/album20/manifolds_06.sized.jpg

:D

[Razi]

Wow cody, that manifold looks brilliant.

[let5l1de]

That's a nice manifold Cody! I like the external option too. Do you have any dyno numbers with this manifold?

~m

[s13silvia123]

it is critical in some areas of the intake ports if it is extruded wrong. sometimes some motors have sharp turns right by the valves which can create a larger amount of HP especially in Honda S2000 motors. in turn that area is left alone without blending the area. when extruding and porting specific areas where the bowl is, if done incorrectly you'll lose a significant amount of power if not done right. your gains will be a lot less then the stock head itself and flows a lot less. you want to build velocity to have effective air flow as well as HP gains

[GabeS14]

Awesome info, I gues I am going to wait till I order the Exhaust manifold and all the head components, and take both intake and exhaust mani's together to get them port matched.
should I expect to get charged extra for the port matching?

and any shops you guys would recommend for this?

The shop I called is talking about sending my head out to the shops that will be doing the work, so I am assuming some of the money I am paying could be saved if I went directly to the guys doing the work.
my google searches failed for extrude honing shops lol

[codyace]

Wow cody, that manifold looks brilliant.

My buddy Jay at the local Fab shop has been making a few of these now for me, for other members here. Both the 38mm flange, and some of the V band MVS gate ones as well. If you want/interested in one, shoot me a PM and I'll get you his contact info.

That's a nice manifold Cody! I like the external option too. Do you have any dyno numbers with this manifold?

~m

I don't have any personal before/after as I did mine when I initially put the engine together. I know from personal experience on FWD setups, the extrude hone gains nearly 10-15 ft lbs through the midrange, a few rpm of spool, and about 15 peak hp gains...it's really neat stuff.

Here is my personal dyno though, (hate to shit up gabes thread) stock engine, JWT s3 cams, greddy intake manifold, 20 psi, JWT rom tune.
http://www.codyace.com/albums/Dynos/uncorrected.sized.jpg

[codyace]

it is critical in some areas of the intake ports if it is extruded wrong. sometimes some motors have sharp turns right by the valves which can create a larger amount of HP especially in Honda S2000 motors. in turn that area is left alone without blending the area. when extruding and porting specific areas where the bowl is, if done incorrectly you'll lose a significant amount of power if not done right. your gains will be a lot less then the stock head itself and flows a lot less. you want to build velocity to have effective air flow as well as HP gains

While I can't share knowledge on that level with the S2000 engines, I have always been under the assumption that you want headflow as smooth and direct as possible...with any sharp edges creating flow turbulance and effecting HP...I'm not a performance engine builder, nor engineer, so I could be wrong, but something tells me that extrude honeing a head could do nothing but good thigns, as it smooths the entire tract, without removing too much material.

Again much of what I know/read/experienced are from older engines...with newer/modern engines it's hard to know as many of them come darn near perfect from the factory, especially in regard to port design and valve angle etc etc. With that said, what works for SR20 may not even relate to F20 and vice versa...however it's all good stuff to know and learn from.

[homeslicej2]

I know that extrude honing the exhaust manifold and exhaust side of the head works wonders, but when you have headwork done, I thought you were to only port/polish portions of the intake side, to ensure the air/fuel mixture sees enough turbulence to promote proper mixing.

[PoorMans180SX]

jr_ss said it.

Forget the DET head, use a VE head and call it a day. Better flow, more power, and no need to worry about exploding rocker arms.

That being said, I have heard of decent gains in extrude honing from some of the Honda guys. It is recommended that you go through the intake ports again and make them less than mirror smooth though, I believe it helps the intake charge not build up a boundary layer. I'm no expert on fluid dynamics though.

[STR8E180]

there is a workshop here in Australia that does them as well
we dont normally do it to cylinder heads because u cant control the shape of the port
it will open up the whole port where as some times when porting u want to focus on areas of the port and not just the whole lot
lets say u wanted to leave one area alone and just focus on a different area

mostly use it for intake and exhaust manifolds but for cylinder head porting its not ideal if u want to shape the port into a new shape with out just opening up the whole lot

http://www.rlengines.com/images/extrude/extrude.jpg
as u can see from the picture it will be an uncontrolled port job
it will just open up and clean the ports and give it a bigger and smoother finish
if u wanted to change the shape of the port it wont be able to because u cant focus it into area's u want to work on

[Om1kron]

jr_ss said it.

Forget the DET head, use a VE head and call it a day. Better flow, more power, and no need to worry about exploding rocker arms.

That being said, I have heard of decent gains in extrude honing from some of the Honda guys. It is recommended that you go through the intake ports again and make them less than mirror smooth though, I believe it helps the intake charge not build up a boundary layer. I'm no expert on fluid dynamics though.

Running a VE head isn't cheap. Most people here aren't willing to spend the amount it would cost for a decent turbo setup for the numbers gabe wants on just a head, block off plates, custom manifolds, etc.

It's about 2-3 grand just to get a VE head operational on an SR block.

As far as the extrude honing goes, you want to leave some kind of material on the intake side of things so you're not burning unnecessary amounts of fuel

[PoorMans180SX]

Yeah but it looks like he'll be forking out the dough for an EFR turbo/manifold, so I don't think the cost aspect is that big for him.

Plus then you save the money from building/porting the head, and cams. Stock VE head is good for 8000rpm, and big cams stock.

[codyace]

Yeah but it looks like he'll be forking out the dough for an EFR turbo/manifold, so I don't think the cost aspect is that big for him.

Plus then you save the money from building/porting the head, and cams. Stock VE head is good for 8000rpm, and big cams stock.

As you point out, It's certainly not much more to go VE in regard to Gabes or any big power setup. Figure Big cams+valvetrain are going to be nearly 1000 dollars, factor in another 500-1000 for port/head work or extrude hone, and you're nearly at the cost of a VE head...again, at Gabes point it's not much more to just go straight to the best of the best.

[codyace]

As far as the extrude honing goes, you want to leave some kind of material on the intake side of things so you're not burning unnecessary amounts of fuel

Curious as to what you mean by this?

[Om1kron]

Curious as to what you mean by this?

I was trying to find the article I had read on this but basically smoothing the whole head down fuel just shoots through the cylinder instead of pooling up for the ignition sequence as originally designed to do so.

I don't remember all the technical mumbo jumbo I just know it's bad for the area of the head that receives fuel to be as smooth as a babys ass.

[s13silvia123]

While I can't share knowledge on that level with the S2000 engines, I have always been under the assumption that you want headflow as smooth and direct as possible...with any sharp edges creating flow turbulance and effecting HP...I'm not a performance engine builder, nor engineer, so I could be wrong, but something tells me that extrude honeing a head could do nothing but good thigns, as it smooths the entire tract, without removing too much material.

Again much of what I know/read/experienced are from older engines...with newer/modern engines it's hard to know as many of them come darn near perfect from the factory, especially in regard to port design and valve angle etc etc. With that said, what works for SR20 may not even relate to F20 and vice versa...however it's all good stuff to know and learn from.


youre right but when it comes to newer motors compare to older motors, the newer motors are almost perfect. all they need is to small amount of work and the head flows like wonders. on the other hand motorcycle motors are different, if you make the intake ports smaller, the motorcycle is faster when you are riding it. all motors are different but if you port and blend intake ports correctly. but what can i say when we can't compare these motors because they all flow differently.

lets educate each other and we can learn more about this.

[jr_ss]

I think what Om1kron is trying to describe is fuel atomization? I believe he is refering to, correct me if I'm wrong, the "roughness" that the intake tract has from the factory to add turbulence into the air, to mix/swirl the fuel/air mixture. I know on carburated cars it is bad to have smooth all the way into the motor. They rely on that "roughness" to get a good mix on the fuel/air. If the entire tract is smooth there's nothing to swirl or mix the fuel/air and it is bad. However, I believe that newer technology has "allowed" some room for smoothing of the intake tract based on the design and spray patterns of the injectors themselves. Hell pretty much all new intake manifolds are plastic and have no imperfections so to speak. With that said newer injectors tend to atomize the fuel very efficiently straight from the injector rather than relying on the intake "imperfections" to help mix the fuel/air.

If I'm way off base I understand, but this can be regarded as part of the discussion.

I still believe if he's going to go through with all this extrude hone, then a valve job, etc, etc, it's going to get up there in price fast. I think he'd be better off going with the VE head from the start. Hell the sheet metal intake manifold and all needed items for the swap besides head/solenoids/CAS from Mazworx is $2400. You can find a P11 head for under 1k and shouldn't have to touch it. Like I said, intial invest may slightly be more but well worth the benefit.

[Def]

A carb has the fuel going all the way through the intake manifold, an EFI port injected car injects the fuel at the entrance to the head so it doesn't matter too much like what the finish in the intake manifold is.

That said, a really smooth curved surface is not necessarily the best, as it can have more flow separation than one with a slight surface roughness that can trip the flow into the turbulent region. Example - a dimpled golf ball flies farther than a perfectly smooth one by breaking up the boundary layer and reducing flow separation on the trailing edge.

[codyace]

A carb has the fuel going all the way through the intake manifold, an EFI port injected car injects the fuel at the entrance to the head so it doesn't matter too much like what the finish in the intake manifold is.

That said, a really smooth curved surface is not necessarily the best, as it can have more flow separation than one with a slight surface roughness that can trip the flow into the turbulent region. Example - a dimpled golf ball flies farther than a perfectly smooth one by breaking up the boundary layer and reducing flow separation on the trailing edge.

For sure, I was just confused as to what Wayne was saying...for the most part, a modern engine wants it neary as smooth as possible. I know when looking at a direct injected head, it's very smooth as far as OE castings go.

[GabeS14]

As you point out, It's certainly not much more to go VE in regard to Gabes or any big power setup. Figure Big cams+valvetrain are going to be nearly 1000 dollars, factor in another 500-1000 for port/head work or extrude hone, and you're nearly at the cost of a VE head...again, at Gabes point it's not much more to just go straight to the best of the best.
This has been my dilema for a while now...

I dont have unlimited amounts of money to spend, I am trying to go with top quality while still counting every dollar,
and hoping to be able to achieve the 550/600 whp mark witht he EFR setup.

so at the end I realized I could save money going with port job+V mount instead of VE.

I already have the 275 JWT cams and springs which work with the factory rocker arms and It would be pretty hard to sell them right now.
so I feel like I am stuck with the big port option.

[GabeS14]

Been doing more and more thinking and I rechecked my expenses for both ways, and I decided to just go neo VVL head...lol

I might get it extrude honed anyways !
would eb awesome if I can sell my JWT c2 cams and springs to make up for some of the cash i spent on them..im selling them for dirt cheap..

[jr_ss]

Good deal... I'm in the transition now on mine.

[GabeS14]

It's just so hard to
Sell after market power parts even at super low prices. I almost feel like just going ls1

[jr_ss]

Just hold out, don't give them away...

[daryl337]

The theory of the golf ball dimple does not necessarily relate in the same way it was being referenced here. The golf ball dimple phenomena is a result of turbulance creating a low pressure around the ball, therefore decreasing the resistance as the ball travels through the air. The benefit is not so much an increased velocity of the air going around the ball (velocity of ball) as it is that it reduces the effects that drag have. The difference here being that our cylinder heads for all intents and purposes are stationary. We do not have an interest in creating a low pressure scenario on the intake side of the cylinders. (if anything, scavenging techniques employed in the S2000 motor heavily rely on having a higher pressure in the intake system than the combustion chamber.)

Our main goal is going to be intake velocity and flow. The question then is: Can roughness have an effect on the velocity?

I also want to note, increasing port sizes by too large of an amount also has a tendancy to decrease velocity of your intake charge.

In regards to fuel itemization, in theory you could use roughness to an advantage for fuel itemization, however in practice that would require you to know the proper placement of the "obstruction", as fluid dynamics has a tendancy to create the swirls in "pools" after an obstruction. Its hard to imagine with air, but a better example would be with water flow down a river. Think of an eddie in a river for example. Ideally, you would want that swirl to be placed into (or near) the combustion chamber as it will effectively draw more air in, as well as mix. It all sounds great in theory, but in practicality it is going to be very hard to do for one main reason:


Your engine does not stay at a constant speed. As the velocity of the air increases at a rate proportional to the rate your pistons are travelling, the velocity of the air going across the grain is going to affect the location of the swirl. The gains you will recieve are going to be at a very specific powerband. For this exact reason, F1 had variable trumpets(until banned) to increase/decrease intake port velocity at different powerbands.

In regards to porting then, many people have gone with a smooth intake port approach, as its easier to smooth everything out and have a constant even flow than it is to try to map out (or guess) where roughness is going to actually benefit you.



Atleast thats in my experience. There may be a better person to explain/counter my personal justification of extrude honing.



-edit- Since that entire post was pretty much not needed after finishing up reading the thread, I've decided to leave it and say congrats on making a wise decision with vvl. I should have done the same. The mechanical advantage alone is worth it

[srstan]

its so nice to read a thread where intelligent people are talking about something interesting....not just how someones car could be lower and how they need to do this and need to do that. keep it up guys.

[daryl337]

in regards to Omnikron's post about fuel build up, he's half correct.

On the lower side of the port (the shorter side), the air travels slower then the roof of the port.

The lower speed air, coupled with a smooth port will end up with a fuel deposit staying on the intake port instead of entering the combustion chamber. So if you want to port the intake side, you make the roofs smoother than the bottom, as turbulance could help keep the fuel suspended in the air, and not dribble in your intake

[s13silvia123]

its so nice to read a thread where intelligent people are talking about something interesting....not just how someones car could be lower and how they need to do this and need to do that. keep it up guys.

we just know our shit and ad been doing this for a long time. our knowledge is base on experience.


Gabe

if i where you, i'll keep the SR head and save the cash to build the VET head just as i am doing right now. i've been thinking about this for a long time just as some other older members here thought about it. i'll like to keep a spare motor just in case i blow a motor so i'll have something to run on so downtime is not an option. keeping an extra motor or two can have its advantages if your track your car often and have no downtime.

[jr_ss]

in regards to Omnikron's post about fuel build up, he's half correct.

On the lower side of the port (the shorter side), the air travels slower then the roof of the port.

The lower speed air, coupled with a smooth port will end up with a fuel deposit staying on the intake port instead of entering the combustion chamber. So if you want to port the intake side, you make the roofs smoother than the bottom, as turbulance could help keep the fuel suspended in the air, and not dribble in your intake

I don't see fuel collecting into the intake tract too much base on the injectors being located on the head flange and spray almost on to the back of the valves. Infact, I had no pooling of fuel in my extrude honed S14 SR intake. To be honest, I don't really see it pooling anywhere on the intake track. The head ports slope down into the combustion chamber and any pooling will most likely "flow" or "drip" into the combustion chamber. You may see some fuel dropping out of suspension on the lower side of the intake port due to the velocity of air being slower compared to the upper portion of the port, but I think this would help in swirling entering the combustion chamber. However, in a boosted application I dont really see a chance for fuel to pool at all, except perhaps under no/low loads where there is no boost, but like stated earlier, there's really no where for it to "pool".

I could see this happening if our intake ports had "ridges" and "valleys" before the valves, but they transition well and are ultimately free from these casting issues due to design. There are some heads (older V8's inline 6's) out there where the intake ports are so screwed and have ridges and valleys in them, which are usually removed when porting.

[codyace]

I don't see fuel collecting into the intake tract too much base on the injectors being located on the head flange and spray almost on to the back of the valves. Infact, I had no pooling of fuel in my extrude honed S14 SR intake. To be honest, I don't really see it pooling anywhere on the intake track. The head ports slope down into the combustion chamber and any pooling will most likely "flow" or "drip" into the combustion chamber. You may see some fuel dropping out of suspension on the lower side of the intake port due to the velocity of air being slower compared to the upper portion of the port, but I think this would help in swirling entering the combustion chamber. However, in a boosted application I dont really see a chance for fuel to pool at all, except perhaps under no/low loads where there is no boost, but like stated earlier, there's really no where for it to "pool".


Totally agree. There isn't much to the SR intake tract, it's a no nonsense straight shot into the back of the valves.

As before, (and as daryl pointed out) just keep it smooth and you'll be good (you being anyone interested in it).

[lagvoid21]

Gabe, any chance you'll extrude parts soon? I want to extrude my parts like Codyace and it looks like you only need 4 items for a 15% discount group buy.

[Def]

The theory of the golf ball dimple does not necessarily relate in the same way it was being referenced here. The golf ball dimple phenomena is a result of turbulance creating a low pressure around the ball, therefore decreasing the resistance as the ball travels through the air. The benefit is not so much an increased velocity of the air going around the ball (velocity of ball) as it is that it reduces the effects that drag have. The difference here being that our cylinder heads for all intents and purposes are stationary. We do not have an interest in creating a low pressure scenario on the intake side of the cylinders. (if anything, scavenging techniques employed in the S2000 motor heavily rely on having a higher pressure in the intake system than the combustion chamber.)

Our main goal is going to be intake velocity and flow. The question then is: Can roughness have an effect on the velocity?

I also want to note, increasing port sizes by too large of an amount also has a tendancy to decrease velocity of your intake charge.

In regards to fuel itemization, in theory you could use roughness to an advantage for fuel itemization, however in practice that would require you to know the proper placement of the "obstruction", as fluid dynamics has a tendancy to create the swirls in "pools" after an obstruction. Its hard to imagine with air, but a better example would be with water flow down a river. Think of an eddie in a river for example. Ideally, you would want that swirl to be placed into (or near) the combustion chamber as it will effectively draw more air in, as well as mix. It all sounds great in theory, but in practicality it is going to be very hard to do for one main reason:


Your engine does not stay at a constant speed. As the velocity of the air increases at a rate proportional to the rate your pistons are travelling, the velocity of the air going across the grain is going to affect the location of the swirl. The gains you will recieve are going to be at a very specific powerband. For this exact reason, F1 had variable trumpets(until banned) to increase/decrease intake port velocity at different powerbands.

In regards to porting then, many people have gone with a smooth intake port approach, as its easier to smooth everything out and have a constant even flow than it is to try to map out (or guess) where roughness is going to actually benefit you.



Atleast thats in my experience. There may be a better person to explain/counter my personal justification of extrude honing.



-edit- Since that entire post was pretty much not needed after finishing up reading the thread, I've decided to leave it and say congrats on making a wise decision with vvl. I should have done the same. The mechanical advantage alone is worth it


Your understanding of aerodynamics is.... rough.


A golf ball has dimples to trip the flow into the turbulent region. It doesn't not affect the velocity of the flow around it, and I never said it did. What this DOES do is reduce flow separation on the trailing edge, which is significant on a smooth sphere. This reduced flow separation translates into less drag force, hence the golf ball flies farther.

The concept of vortex generators on cars is the same principle.

It doesn't matter if an object is moving in a given inertial reference frame or the flow is moving, relative motion between the fluid and the object is all that matters. This is something you learn in the first 5 minutes of a Fluid Dynamics course (which I hope you haven't had... otherwise it looks like you failed it).


Turbulence and interrupting the boundary layer of a fluid have very little to do with its free stream/nominal tube flow velocity. No idea why you keep mentioning it.

[GabeS14]

we just know our shit and ad been doing this for a long time. our knowledge is base on experience.
Gabe
if i where you, i'll keep the SR head and save the cash to build the VET head just as i am doing right now. i've been thinking about this for a long time just as some other older members here thought about it. i'll like to keep a spare motor just in case i blow a motor so i'll have something to run on so downtime is not an option. keeping an extra motor or two can have its advantages if your track your car often and have no downtime.

You just made it all just seem so simpel haha, no idea why i never thought of that before.I will do just that!

[daryl337]

Your understanding of aerodynamics is.... rough.


A golf ball has dimples to trip the flow into the turbulent region. It doesn't not affect the velocity of the flow around it, and I never said it did. What this DOES do is reduce flow separation on the trailing edge, which is significant on a smooth sphere. This reduced flow separation translates into less drag force, hence the golf ball flies farther.

The concept of vortex generators on cars is the same principle.

It doesn't matter if an object is moving in a given inertial reference frame or the flow is moving, relative motion between the fluid and the object is all that matters. This is something you learn in the first 5 minutes of a Fluid Dynamics course (which I hope you haven't had... otherwise it looks like you failed it).


Turbulence and interrupting the boundary layer of a fluid have very little to do with its free stream/nominal tube flow velocity. No idea why you keep mentioning it.



I think you are arguing the same point that I am making. Perhaps I wasn't clear enough.

My understanding is not necessarily rough, but trying to convey my point in lamens terms is. I'm not arguing that dimples do not create a turbulance, and I should probably edit my post to reflect that its not a "pressure" difference, as much as a reduction in drag. My argument is that creating less drag on a trailing end of an object that is stationary will have little effect on the velocity of the air entering the chambers.


If the goal to porting an intake manifold is to maximize the engines ability to acquire as much air as possible while keeping the fuel atomized, then velocity of air entering chambers, as well as volume are going to be our goal, not reducing drag. That is why I commented on your golf ball example, because the introduction of dimples in aerodynamics is to reduce drag. If we want to increase air entering the chamber, reducing parasitic drag is not the main priority, increasing flow and velocity is.


If you feel my analysis is flawed, then please do explain. However, I fail to see how the effects of reducing drag is going to increase your engines power without talking about fuel itemization. In which case, you should probably read the rest of my post.

[codyace]

I suck at golf, what does Turbulence hafta do with that ? LOL

Oh VVL....why why why must you exist. I guess I have a winter project now.

[daryl337]

No, thats just a bad swing. ;)

[Def]

I think you are arguing the same point that I am making. Perhaps I wasn't clear enough.

My understanding is not necessarily rough, but trying to convey my point in lamens terms is. I'm not arguing that dimples do not create a turbulance, and I should probably edit my post to reflect that its not a "pressure" difference, as much as a reduction in drag. My argument is that creating less drag on a trailing end of an object that is stationary will have little effect on the velocity of the air entering the chambers.


If the goal to porting an intake manifold is to maximize the engines ability to acquire as much air as possible while keeping the fuel atomized, then velocity of air entering chambers, as well as volume are going to be our goal, not reducing drag. That is why I commented on your golf ball example, because the introduction of dimples in aerodynamics is to reduce drag. If we want to increase air entering the chamber, reducing parasitic drag is not the main priority, increasing flow and velocity is.


If you feel my analysis is flawed, then please do explain. However, I fail to see how the effects of reducing drag is going to increase your engines power without talking about fuel itemization. In which case, you should probably read the rest of my post.

Not trying to be an ass, but really, you don't seem like you've got a good grasp on this stuff if you're not understanding what I'm saying... or spelling turbulence correctly...

The golf ball experiences reduced drag due to LESS FLOW SEPARATION. The turbulent boundary layer keeps flow attached around geometry it would otherwise separate from. The same thing happens in an intake runner as it curves down to the valve seat. Less flow separation = more flow through the intake port.

Can't make it any simplier than that.

[PoorMans180SX]

Oh VVL....why why why must you exist. I guess I have a winter project now.

You won't :naughtyd:

[daryl337]

Not trying to be an ass, but really, you don't seem like you've got a good grasp on this stuff if you're not understanding what I'm saying... or spelling turbulence correctly...

The golf ball experiences reduced drag due to LESS FLOW SEPARATION. The turbulent boundary layer keeps flow attached around geometry it would otherwise separate from. The same thing happens in an intake runner as it curves down to the valve seat. Less flow separation = more flow through the intake port.

Can't make it any simplier than that.

My spelling was never my strong point. ;D

You are right, good thing I never majored in aerospace engineering. I understand how drag is created with flow separation, but I failed see where you were going with a reduction of drag as being a benefit. I concede that you are right. Were talking about inducing a laminar flow here right? Or am I once again missing the point altogether?

[omgRWDgoodness!]

Gabe, any chance you'll extrude parts soon? I want to extrude my parts like Codyace and it looks like you only need 4 items for a 15% discount group buy.

Not committing just yet, but I've been watching this thread and I would totally be in for extrude honing my exhaust manifold in the near future. Those pictures pretty much sold me, and it's better than getting some whack ass top-mount manifold that costs more than the turbo mounted on it and requires a custom downpipe/elbow setup.

[daryl337]

Well, the general consensus at this point in time is going to be that you do not want a perfectly smooth/mirror finish on the intake port.

In regards to porting at all, I have to ask (since I don't own a flow bench... and havent chopped up any heads in testing)... has there been any testing done to see where the actual restrictions in the intake ports are? Besides viewing the ports and seeing a highspot, have anyone actually tested sections of a port to see if we would even gain any benefit? As I recall, redtop motors had a high port design to begin with, so reshaping of the port is going to be fairly limited, since we are already dealing with a near optimal set up. My suspicion is going to be that the true restriction of flow is probably going to be the intake valve itself. Without oversizing the valves, I am not entirely convinced that you would benefit much from an intake port job on a redtop.


However, this is speculation... since I don't have any flow numbers to back such an assertion up.

[PoorMans180SX]

Yes, there have been flowbench analysis' done on the SR head. There are definitely gains to be made.

As far as porting technique, all it is is seeing the imperfections (rough patches, casting lines, lips around valves, etc) and taking them out, and maybe opening it up a little depending on the application. There is no way to actively "see" flow restrictions in real time.

Of course the main restriction is the valve itself, but bigger valves require opening up the port, which you may or may not want to do depending on what you plan on using the engine for.

[daryl337]

I'd be interested to see a port sectionalized breakdown of flow #'s of a stock SR head port.
Any idea where someone may have that type of data stored?

I know with LS1 engines, many hotrodders have already taken a standard LS head and have actually deconstructed the ports into sections and flowbenched them individually. Many found that within the first section, it would flow almost 2X as much as the valve itself would let past. Increasing the lift of the valves helped, but even when achieving dangerously high lift numbers, they found that the actual diameter of the valve was the restriction.


This type of analysis would greatly benefit the community as a whole, as it will give anyone who takes porting seriously an idea of restrictive "sections" of the port. I'd rather have true and accurate knowledge of restrictive sections than going balls to the wall with a grinder to smooth out everything.



I'm sure someone somewhere must have something.... but perhaps they arent the type of person to troll the zilvia boards.

[Jybfan04]

Yes, there have been flowbench analysis' done on the SR head. There are definitely gains to be made.

As far as porting technique, all it is is seeing the imperfections (rough patches, casting lines, lips around valves, etc) and taking them out, and maybe opening it up a little depending on the application. There is no way to actively "see" flow restrictions in real time.

Of course the main restriction is the valve itself, but bigger valves require opening up the port, which you may or may not want to do depending on what you plan on using the engine for.

what cons would there be for going with larger valves?

[jr_ss]

what cons would there be for going with larger valves?

One con is a heavier valve. For revving a small 4cyl like ours you need the revs to make a good amount of power. Heavier valves will inhibit that. If you want to rev to the moon you want your valve train to be as light as possible while still retaining strength. I haven't looked at the weights of stock valves versus aftermarket over sized ones though.

[codyace]

You won't :naughtyd:

You know me too well... If I am gonna dump 1500/2000 bucks into this, it's going to go towards a LS2 ;)

[codyace]

Not committing just yet, but I've been watching this thread and I would totally be in for extrude honing my exhaust manifold in the near future. Those pictures pretty much sold me, and it's better than getting some whack ass top-mount manifold that costs more than the turbo mounted on it and requires a custom downpipe/elbow setup.

It's all relative though; I'm the biggest fanboy of the extrude setup out there, but am also NOT a fan of big peak power 4 cylinder turbo cars...lag/crappy response etc etc drive me insane. So with that said, while it may be the 'best' setup IMO, but it's not the best for making big power.

If you're looking at making big power (500+) you will need to go top 35r/mount/tubular/custom downpipe etc etc...along with the countless other things required

If you're content with 400-425 whp and 325-350 ft lbs, then yes...it's the only way I'd fly...in the grand scheme of things my 2871r setup is probably the most capable 'street car' setup you could run with as it utilizes stock stuff and is easily replicated. Not only is it deadly quick on track, but it's also capable of 120+ trapspeeds, super mid to low 11's in a full weight s14. In a lighter hatch, and with experience, there is no reason someone couldn't click off a 11 flat/high 10 in a drag based setup (in fact guys have on here already so it's proven)


Yes, there have been flowbench analysis' done on the SR head. There are definitely gains to be made.
Without a doubt gains are possible, and to be had...but at the cost they are often not the best 'power per dollar' for street guys. (which you know obviously, but not everyone does)



One con is a heavier valve. For revving a small 4cyl like ours you need the revs to make a good amount of power. Heavier valves will inhibit that. If you want to rev to the moon you want your valve train to be as light as possible while still retaining strength. I haven't looked at the weights of stock valves versus aftermarket over sized ones though.

I'll be the first to say that I'd never spend any money on oversized valves this side of a race car.

[jr_ss]

I'll be the first to say that I'd never spend any money on oversized valves this side of a race car.

There's no reason too unless it's a drag or trailer queen specific setup. I think that larger valves will maybe gain 50 peak hp. There's no sense in it unless you're trying to extract every last pony out of it.

[codyace]

There's no reason too unless it's a drag or trailer queen specific setup. I think that larger valves will maybe gain 50 peak hp. There's no sense in it unless you're trying to extract every last pony out of it.

Ok, so I'm not alone.


I do get a kickout of the idiots who spend 1000 on valves/springs/headwork, and then put 2 dollar BC cams in them thogh haha.

[jr_ss]

Ok, so I'm not alone.


I do get a kickout of the idiots who spend 1000 on valves/springs/headwork, and then put 2 dollar BC cams in them thogh haha.

You'll never, ever see me with BCs in anything I run. Once I get my setup where I want it I'll be throwing Kelfords into it. JWT doesn't make cams for the VVL and I think that the Nismo cams for the SR16VE leave somethings to be desired.

[codyace]

You'll never, ever see me with BCs in anything I run. Once I get my setup where I want it I'll be throwing Kelfords into it. JWT doesn't make cams for the VVL and I think that the Nismo cams for the SR16VE leave somethings to be desired.

...JWT has been 'working' on VVL cams forever...nothing has ever come from them yet :( Shame as they could really make something nice their. I knwo the FWD power guys have used the Kelfords with good success.

[Def]

My spelling was never my strong point. ;D

You are right, good thing I never majored in aerospace engineering. I understand how drag is created with flow separation, but I failed see where you were going with a reduction of drag as being a benefit. I concede that you are right. Were talking about inducing a laminar flow here right? Or am I once again missing the point altogether?

You majored in AE? Yikes...

I'll say it again... I AM NOT TALKING ABOUT DRAG IN AN INTAKE PORT!!! I AM SAYING LESS FLOW SEPARATION DUE TO A TURBULENT BOUNDARY LAYER CAN GET YOU MORE MASS FLOW THAN A LAMINAIR BOUNDARY LAYER.

[jr_ss]

You majored in AE? Yikes...

I'll say it again... I AM NOT TALKING ABOUT DRAG IN AN INTAKE PORT!!! I AM SAYING LESS FLOW SEPARATION DUE TO A TURBULENT BOUNDARY LAYER CAN GET YOU MORE MASS FLOW THAN A LAMINAIR BOUNDARY LAYER.


Def, he said he never majored in AE...

[daryl337]

Def.

It looks like YOU may need to read the post again. Then perhaps, you may see I was following your train of thought.

Laminar flow, being the non-turbulent (IE less drag) flow which also happens to have a better and smoother flow... is better than a turbulent flow (IE more drag).

I was admitting that I was stuck thinking about drag, as that is how the golf ball had benefited. I then also conceded that you are right, in that having a laminar flow is going to be better than a turbulent flow.
Hence, you are right. Dick. ;D

[PoorMans180SX]

Def.

It looks like YOU may need to read the post again. Then perhaps, you may see I was following your train of thought.

Laminar flow, being the non-turbulent (IE less drag) flow which also happens to have a better and smoother flow... is better than a turbulent flow (IE more drag).

I was admitting that I was stuck thinking about drag, as that is how the golf ball had benefited. I then also conceded that you are right, in that having a laminar flow is going to be better than a turbulent flow.
Hence, you are right. Dick. ;D

You still don't get it.


what cons would there be for going with larger valves?


In order to see gains from bigger valves, you need to open up the valve throat and some of the port. Bigger ports lower the velocity of the intake charge, which will shift your powerband up a little; meaning less low-end torque and more top-end. Thus, this is more suited to an all-out track car.

[daryl337]

You still don't get it.




:(




Its a good discussion either way. :) Help me understand then, as im not one to have enrolled in many fluid dynamics courses.

I think im understanding where the communication breakdown is (and it comes down to me not being entirely familiar with fluid dynamics and terminology) and should probably edit my previous posts... but in order to help others on this im going to keep my faulty train of thought posted so they can see where I was wrong. A) It isnt laminar flow, it is still a turbulent flow. It is simply a turbulent flow that adheres closer to the object by a reduction of boundary layer. I think in my mind (which is hard to explain without a visual) I was essentially mislabeling this as causing the flow to become more laminar... since I was thinking of laminar flow as uniform.


Let me see if I can explain this with correct terminology.


Increasing a boundary layer separation reduces the potential flow as the air is displaced less. The displacement of air has a negative effect on the internal flow potential of an object unless given a fixed volume and pressure.


amirite? yay?

[PoorMans180SX]

It isnt laminar flow, it is still a turbulent flow. It is simply a turbulent flow that adheres closer to the object by a reduction of boundary layer.

Okay, there you go! :bigok:

[daryl337]

Yeah.

I had the concept, but having a poor vocabulary in relation to the discussion really put me off as looking like a jackass.



It was on par with saying "so that doodad hooks up with that doohickie and results in moar power"

[codyace]

It was on par with saying "so that doodad hooks up with that doohickie and results in moar power"

Hey! Whats wrong with that ;)

[Wake]

as long s it results in moar power who cares about the technical jargon.

its just words.

[daryl337]

Agreed.

Moar Power!!