Flowing Exhaust ports with a "pipe"....
02-21-2005, 12:07 PM
#41
I am in the middle of what both are saying.
First off there is NO REASON to flow anydamn thing with a straight pipe as NOBODY uses a straight header on their car.
If you can get a exhaust port to flow 250 (just for comparision) with no pipe, then install a pipe that is bent and sized the same as a header and have it flow anywhere in the same area your doing something good.
However lets say you designed your port to flow 250 w/o a pipe and when installing a pipe similar to a header it only flowed 210.
Now I would have to agree with Tony in saying why did you focus so much on the w/o the pipe numbers.
Most avarage buyers want the most horsepower they can get.
They base a good amount of their decision of flow data.
Most dumbasses look at the 600 lift number and decide by that alone. I wish all head porters used the same was of testing to get a actural fair comparision, but that will never happen.
If Tony designed his exhaust port to flow best in a "real world" enviroment then that would be the best was to design a head.
However if the pipe being used to flow his heads are not mimiced after a normal 1 3/4 or 1 7/8" headers then the actural design for "real world" if not true and is a waste.
Tony has done a 110% job at geting this right.
If he is using a pipe I would bet it's a pipe very similar to a header.
First off there is NO REASON to flow anydamn thing with a straight pipe as NOBODY uses a straight header on their car.
If you can get a exhaust port to flow 250 (just for comparision) with no pipe, then install a pipe that is bent and sized the same as a header and have it flow anywhere in the same area your doing something good.
However lets say you designed your port to flow 250 w/o a pipe and when installing a pipe similar to a header it only flowed 210.
Now I would have to agree with Tony in saying why did you focus so much on the w/o the pipe numbers.
Most avarage buyers want the most horsepower they can get.
They base a good amount of their decision of flow data.
Most dumbasses look at the 600 lift number and decide by that alone. I wish all head porters used the same was of testing to get a actural fair comparision, but that will never happen.
If Tony designed his exhaust port to flow best in a "real world" enviroment then that would be the best was to design a head.
However if the pipe being used to flow his heads are not mimiced after a normal 1 3/4 or 1 7/8" headers then the actural design for "real world" if not true and is a waste.
Tony has done a 110% job at geting this right.
If he is using a pipe I would bet it's a pipe very similar to a header.
02-21-2005, 12:16 PM
#42
Also the point Good Greg is making is very accurate about using a straight pipe. It does nothing for actural real life info and is just a helping tool to make "your" head's look better.
I would also have to believe that if Greg gets the flow numbers to 260 w/o a pipe when a straight pipe is installed they will flow to death, and I'm sure he will get the port nice enough to where it dosen't fall on it's face through a header.
I really hope he is kind enough to the LS1 world to sent the head back to AFR so Tony can throw it on his bench.
Acturally after the offer Tony made if this didn't happen I would lose some respect for what Greg says as it show's he wasn't sure enough about his product to have it tested elsewhere.
And to Tony if this does happen and he proves what he says, then this guy need to have a series of paycheck with his name on them.
I would also have to believe that if Greg gets the flow numbers to 260 w/o a pipe when a straight pipe is installed they will flow to death, and I'm sure he will get the port nice enough to where it dosen't fall on it's face through a header.
I really hope he is kind enough to the LS1 world to sent the head back to AFR so Tony can throw it on his bench.
Acturally after the offer Tony made if this didn't happen I would lose some respect for what Greg says as it show's he wasn't sure enough about his product to have it tested elsewhere.
And to Tony if this does happen and he proves what he says, then this guy need to have a series of paycheck with his name on them.
02-21-2005, 02:37 PM
#43
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Exhaust flow with a pipe is what is important, because under operating
conditions a header tube is attached.
Actually the exhaust port should be designed with a pipe similar to a header
tube that will be attached to.
As well as the intake side attached to a runner that it will likely be attached to.
Some of us will never agree on this.
conditions a header tube is attached.
Actually the exhaust port should be designed with a pipe similar to a header
tube that will be attached to.
As well as the intake side attached to a runner that it will likely be attached to.
Some of us will never agree on this.
02-21-2005, 02:46 PM
#44
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Originally Posted by JZ'sTA
I really hope he is kind enough to the LS1 world to sent the head back to AFR so Tony can throw it on his bench. Actually after the offer Tony made if this didn't happen I would lose some respect for what Greg says as it show's he wasn't sure enough about his product to have it tested elsewhere.
Ed
02-21-2005, 03:11 PM
#45
Originally Posted by Cstraub
Tony,
In speaking with Ron of Ron's Porting and Joe of HVH over the years both have said in passing comments, "you can tell a good valve job by how much the air flow is affected when you bolt a pipe to the exhaust port". I know both are very"elusive" when talking about angles and radius's on valve jobs. What is your opinion?
BTW,
Thanks for the retainers.
Chris
In speaking with Ron of Ron's Porting and Joe of HVH over the years both have said in passing comments, "you can tell a good valve job by how much the air flow is affected when you bolt a pipe to the exhaust port". I know both are very"elusive" when talking about angles and radius's on valve jobs. What is your opinion?
BTW,
Thanks for the retainers.
Chris
02-21-2005, 03:38 PM
#46
Tony, I'd be glad to do that, but the head doesn't belong to me, and I'm not at liberty to send it to another shop.
You don't have to believe my numbers if you don't want to. That's your choice if you decide I'm full of it. As far as I'm concerned they are accurate since I just checked my bench. The only props I look for are from customers, not peers. We have an old saying among head porter; "first liar doesn't stand a chance.....".
People have been flowing exhaust ports with pipes for decades. For the most part it is a discredited practice. For one thing, there are no standards for the dimension of the pipe. On the intake side a 3/4" radius or thereabouts is the accepted norm.
And I stand by that.
You don't have to believe my numbers if you don't want to. That's your choice if you decide I'm full of it. As far as I'm concerned they are accurate since I just checked my bench. The only props I look for are from customers, not peers. We have an old saying among head porter; "first liar doesn't stand a chance.....".
People have been flowing exhaust ports with pipes for decades. For the most part it is a discredited practice. For one thing, there are no standards for the dimension of the pipe. On the intake side a 3/4" radius or thereabouts is the accepted norm.
And I stand by that.
02-21-2005, 04:08 PM
#47
Granny,
They both have always said if you bolt a pipe on to the exhaust port and you pick up quite a bit of flow, then it is a poor valve job. The better the valve job the less the pipe will increase it. Larry Widmer also agrees with this if I remember correctly.
Chris
They both have always said if you bolt a pipe on to the exhaust port and you pick up quite a bit of flow, then it is a poor valve job. The better the valve job the less the pipe will increase it. Larry Widmer also agrees with this if I remember correctly.
Chris
02-21-2005, 04:47 PM
#48
Originally Posted by Greg Good
Tony, I'd be glad to do that, but the head doesn't belong to me, and I'm not at liberty to send it to another shop.
You don't have to believe my numbers if you don't want to. That's your choice if you decide I'm full of it. As far as I'm concerned they are accurate since I just checked my bench. The only props I look for are from customers, not peers. We have an old saying among head porter; "first liar doesn't stand a chance.....".
People have been flowing exhaust ports with pipes for decades. For the most part it is a discredited practice. For one thing, there are no standards for the dimension of the pipe. On the intake side a 3/4" radius or thereabouts is the accepted norm.
And I stand by that.
You don't have to believe my numbers if you don't want to. That's your choice if you decide I'm full of it. As far as I'm concerned they are accurate since I just checked my bench. The only props I look for are from customers, not peers. We have an old saying among head porter; "first liar doesn't stand a chance.....".
People have been flowing exhaust ports with pipes for decades. For the most part it is a discredited practice. For one thing, there are no standards for the dimension of the pipe. On the intake side a 3/4" radius or thereabouts is the accepted norm.
And I stand by that.
Don't be so defensive....I wasn't "attacking you" in my post and I'm not calling you a liar or trying to dicredit what you say in any way. I would LIKE to see a "bolt-on style head" (non C5R) flow 360 CFM and 280 on the exhaust using our flow equipment, fixturing, etc. Obviously the port would have to be extremely sizable to do so which might limit some of its applications but I would be psyched to see those numbers at ANY port volume. But my reality is that I have seen too many "claims" that never seem to pan out (which unfortunately is just the way it is) and there is nothing like seeing it firsthand to eliminate any questions or doubts.
I'm sure you can appreciate that, and regarding the whole pipe situation, my last response in this matter is that I feel a properly shaped pipe that mimics most conventional header designs is an extension of the port that will always be there, and I would rather design a port with it in place because it will have an effect on the dynamics and shape of the port I am trying so hard to optimize. It has NOTHING to do with "cheating" to try and show higher numbers or any other BS.
You don't feel that way obviously and that's cool....Its a free country and everyone is entitled to his or her opinion.
Hope we can still be on friendly terms despite our differences of opinion...
Tony M.
02-21-2005, 05:16 PM
#49
Of course we're on friendly terms. Reasonable people can differ. It's kinda funny, I thought you were the defensive one. 
The head I'm working is way too big for a stock cubic inch car, unless it's blown. It's for something along the lines of a max effort 427. It's more of a race head in that the intake flows smooth up to .800" lift. It just needs to flow a little more up high. Right now it doesn't gain much after .650" lift, it kinda levels out. It's like any other LS intake port. It has a tendency to get turbulent. The good news is that you guys made the head thick enough for a head porter to make what he wants out of it.
The head I'm working is way too big for a stock cubic inch car, unless it's blown. It's for something along the lines of a max effort 427. It's more of a race head in that the intake flows smooth up to .800" lift. It just needs to flow a little more up high. Right now it doesn't gain much after .650" lift, it kinda levels out. It's like any other LS intake port. It has a tendency to get turbulent. The good news is that you guys made the head thick enough for a head porter to make what he wants out of it.
Last edited by Greg Good; 02-21-2005 at 05:24 PM.
02-21-2005, 08:57 PM
#51
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Originally Posted by Tony Mamo @ AFR
Greg...
Don't be so defensive....I wasn't "attacking you" in my post and I'm not calling you a liar or trying to dicredit what you say in any way. I would LIKE to see a "bolt-on style head" (non C5R) flow 360 CFM and 280 on the exhaust using our flow equipment, fixturing, etc. Obviously the port would have to be extremely sizable to do so which might limit some of its applications but I would be psyched to see those numbers at ANY port volume. But my reality is that I have seen too many "claims" that never seem to pan out (which unfortunately is just the way it is) and there is nothing like seeing it firsthand to eliminate any questions or doubts.
I'm sure you can appreciate that, and regarding the whole pipe situation, my last response in this matter is that I feel a properly shaped pipe that mimics most conventional header designs is an extension of the port that will always be there, and I would rather design a port with it in place because it will have an effect on the dynamics and shape of the port I am trying so hard to optimize. It has NOTHING to do with "cheating" to try and show higher numbers or any other BS.
You don't feel that way obviously and that's cool....Its a free country and everyone is entitled to his or her opinion.
Hope we can still be on friendly terms despite our differences of opinion...
Tony M.
Don't be so defensive....I wasn't "attacking you" in my post and I'm not calling you a liar or trying to dicredit what you say in any way. I would LIKE to see a "bolt-on style head" (non C5R) flow 360 CFM and 280 on the exhaust using our flow equipment, fixturing, etc. Obviously the port would have to be extremely sizable to do so which might limit some of its applications but I would be psyched to see those numbers at ANY port volume. But my reality is that I have seen too many "claims" that never seem to pan out (which unfortunately is just the way it is) and there is nothing like seeing it firsthand to eliminate any questions or doubts.
I'm sure you can appreciate that, and regarding the whole pipe situation, my last response in this matter is that I feel a properly shaped pipe that mimics most conventional header designs is an extension of the port that will always be there, and I would rather design a port with it in place because it will have an effect on the dynamics and shape of the port I am trying so hard to optimize. It has NOTHING to do with "cheating" to try and show higher numbers or any other BS.
You don't feel that way obviously and that's cool....Its a free country and everyone is entitled to his or her opinion.
Hope we can still be on friendly terms despite our differences of opinion...
Tony M.
Greg has no reason to BS. I've personally seen some of his heads flow 360/280. The only secret is that there are no secrets.
02-21-2005, 10:37 PM
#52
Originally Posted by KingCrapBox
Tony, why does 360/280 seem so unbelievable? We've done MANY sets at the school that flow that much. Ask 'Tom The Roofer' how his heads did. We did his entire engine and he's been pretty satisfied with it.
Greg has no reason to BS. I've personally seen some of his heads flow 360/280. The only secret is that there are no secrets.
Greg has no reason to BS. I've personally seen some of his heads flow 360/280. The only secret is that there are no secrets.
OK....then you guys can send one to AFR that flows 360/280
Maybe the air in Texas likes going around curves better...I dont know.
Unless the head was paper thin with steeper than 45' seat angles I personally have a hard time swallowing that is possible considering the intake floor height and the angle of attack the incoming air has at the back of the valve etc. The architecture and layout of a factory LS head is good, but I don't think it's THAT good....those numbers are approaching C5R territory and would be impressive to see. In fact, a buddy of mine got a pair of ported C5R heads that went like 365 until they were re-worked and ended up somewhere around 380 if I recall.
Admittedly, I havent gone hog wild on ANY LS style heads as this was never part of the AFR gameplan...we were more concerned with designing a line of killer street/strip heads aimed at the general public running moderate camshaft profiles etc. and we focused our efforts on lift points around .600 and below trying to maintain small to moderate cross sectional areas as well to keep the airspeed high for better torque production.
Assuming I might be right in my assumption you guys are running 50 or 55 degree seats, that type of valvejob requires ALOT of cam lift to get thru the low and midlift flow numbers that are adversely effected by the steeper seat angle (total speculation on my part).
Anyway...SOMEONE send me one of these animals....I would love to see it.
Regards,
Tony
PS....For those who dont know I was born and raised in NY....not MO...it just seemed like the perfect adage to use
02-22-2005, 12:08 AM
#54
Tony wrote: Admittedly, I havent gone hog wild on ANY LS style heads as this was never part of the AFR gameplan...we were more concerned with designing a line of killer street/strip heads aimed at the general public running moderate camshaft profiles etc. and we focused our efforts on lift points around .600 and below trying to maintain small to moderate cross sectional areas as well to keep the airspeed high for better torque production.
That's fine and good. 99% of the market needs a small high velocity port with good mid lift flow. That's your bread and butter. That's what pays the bills. But some people are putting these heads on big cubic inch racing engines with high lift and need a better port. A guy with an .800" lift solid roller won't tolerate an intake port that backs up after .600" lift.
I read what you had to say in another thread defending an intake port that backs up. IIRC, you said something along the line that with deflection the valve never sees it's full lift. I gotta disagree with you there. Turning the engine over by hand will show you some deflection, especially with weak pushrods, but here we go again with tests that are made under non-running conditions. I have the opposite opinion. I have reason to believe that the valves on an LS1 actually see more lift than the cam is designed for.
I keep in close contact with a friend that runs a Spintron machine for a living. This fellow has forgotten more about valvetrains than I'll ever know. His specialty is Nextel Cup. He's voodoo good. He happened to call today and I brought up the subject of the LS1 with a hydraulic roller in it. I've had some Comp XER lobes cam doctored, and they have acceleration rates as high as a solid roller, but we can't use much spring on them due to the lifter. I've suspected for a while that the typical LS1 engine lofts the valve over the nose and potentially has a good bit more lift than it's designed to. The Nextel Cup valvetrains are set up to loft intentionally, but it's a controlled loft. NHRA Stockers also do this.
Anyway, factoring in steel valves, 5/16" pushrods, solid roller acceleration rates on the cam, insufficient spring pressure, he said there's no way the LS1 is not lofting the valves. How much it lofts is the question. I'm going to call my contact at Comp tomorrow to try to get some actual test results.
Loft is affected greatly by the strength of the pushrod. A smaller, lighter, and weaker pushrod will flex more on the opening side of the lobe. When the pushrod unloads it releases it's stored energy and screws up the harmonics. A stiffer pushrod, although heavier, will make the valve train much more stable. Loft should be had by using the right spring pressures.
I've smoothed out a lot of turbulent intake ports in the past. It's usually good for about 15-20 horsepower on a race engine. It's usually not a huge amount, but every little dab helps.
Now, hypothetically speaking, if a guy has a .650" lift hydraulic roller and it lofts .040", giving him .690", he needs an intake port that stays smooth to his max lift. Wouldn't you agree? Another thing we haven't figured into this turbulence thing is just how much air is actually moving through a port while it's running down the track. Harold Bettus of Superflow once told me that they had done in-cylinder tests that revealed up to 240 inches of pressure drop during the intake stroke. We obviously can't flow test that high, but one thing's for sure, if a port's turbulent on the flow bench @ 28 inches it's going to also be on the engine.
Don't be too hard on Ben (KingCrapbox). He's at a good school, and Casey Snyder, the head class instructor, is another one of those guys that's "voodoo good" at what he does. They have some awesome flowing stuff over there. We flow back and forth all the time and I see it. He's not pulling your leg.
That's fine and good. 99% of the market needs a small high velocity port with good mid lift flow. That's your bread and butter. That's what pays the bills. But some people are putting these heads on big cubic inch racing engines with high lift and need a better port. A guy with an .800" lift solid roller won't tolerate an intake port that backs up after .600" lift.
I read what you had to say in another thread defending an intake port that backs up. IIRC, you said something along the line that with deflection the valve never sees it's full lift. I gotta disagree with you there. Turning the engine over by hand will show you some deflection, especially with weak pushrods, but here we go again with tests that are made under non-running conditions. I have the opposite opinion. I have reason to believe that the valves on an LS1 actually see more lift than the cam is designed for.
I keep in close contact with a friend that runs a Spintron machine for a living. This fellow has forgotten more about valvetrains than I'll ever know. His specialty is Nextel Cup. He's voodoo good. He happened to call today and I brought up the subject of the LS1 with a hydraulic roller in it. I've had some Comp XER lobes cam doctored, and they have acceleration rates as high as a solid roller, but we can't use much spring on them due to the lifter. I've suspected for a while that the typical LS1 engine lofts the valve over the nose and potentially has a good bit more lift than it's designed to. The Nextel Cup valvetrains are set up to loft intentionally, but it's a controlled loft. NHRA Stockers also do this.
Anyway, factoring in steel valves, 5/16" pushrods, solid roller acceleration rates on the cam, insufficient spring pressure, he said there's no way the LS1 is not lofting the valves. How much it lofts is the question. I'm going to call my contact at Comp tomorrow to try to get some actual test results.
Loft is affected greatly by the strength of the pushrod. A smaller, lighter, and weaker pushrod will flex more on the opening side of the lobe. When the pushrod unloads it releases it's stored energy and screws up the harmonics. A stiffer pushrod, although heavier, will make the valve train much more stable. Loft should be had by using the right spring pressures.
I've smoothed out a lot of turbulent intake ports in the past. It's usually good for about 15-20 horsepower on a race engine. It's usually not a huge amount, but every little dab helps.
Now, hypothetically speaking, if a guy has a .650" lift hydraulic roller and it lofts .040", giving him .690", he needs an intake port that stays smooth to his max lift. Wouldn't you agree? Another thing we haven't figured into this turbulence thing is just how much air is actually moving through a port while it's running down the track. Harold Bettus of Superflow once told me that they had done in-cylinder tests that revealed up to 240 inches of pressure drop during the intake stroke. We obviously can't flow test that high, but one thing's for sure, if a port's turbulent on the flow bench @ 28 inches it's going to also be on the engine.
Don't be too hard on Ben (KingCrapbox). He's at a good school, and Casey Snyder, the head class instructor, is another one of those guys that's "voodoo good" at what he does. They have some awesome flowing stuff over there. We flow back and forth all the time and I see it. He's not pulling your leg.
02-22-2005, 12:50 AM
#55
This thread has gone rampant and of course were all having fun...I could argue in the fraction of a second your lifters are leaping off the cam lobe the port simply does not have time to go turbulent....meanwhile, all thru the entire lift curve both up and down, strong flow numbers thru moderate cross sections are packing the cylinder head with air....dont get me wrong...I would be nice if the port kept going at higher liftpoints, but my guess is the airspeed and low/midlift flow would suffer with that design and what I propose (or design) makes a killer cylinder head for the 99% crowd and in my opinion would still hold its own in a leaping .690 cam situation (due to the brief time it spends their....we both have agreed that an engine see pulses, not steady state air at some given lift point).
We...everyone...could bench race till the next millenium and one camp will see a particular topic one way and another will see it just the opposite. Who's theory does any given customer subscribe to??....Who knows, but I'm guessing thats who's cylinder heads they decide to buy or their buddy convinces them are "the best".
I started this thread to share my beliefs on a certain aspect of exhaust port design....mainly because it had been questioned in various threads. To be honest with you there isn't a doubt in my mind that my beliefs in that department are correct....Im sure you feel just as strongly about your beliefs....its as obvious as the way I feel about my own.
Lastly, in regards to the mega flowing LS heads I must quote a line from Jerry McGuire....great movie by the way....SHOW ME THE MONEY!
Can't wait to see what tomorrow brings...
(I love that avatar....couldn't resist)
Tony M.
We...everyone...could bench race till the next millenium and one camp will see a particular topic one way and another will see it just the opposite. Who's theory does any given customer subscribe to??....Who knows, but I'm guessing thats who's cylinder heads they decide to buy or their buddy convinces them are "the best".
I started this thread to share my beliefs on a certain aspect of exhaust port design....mainly because it had been questioned in various threads. To be honest with you there isn't a doubt in my mind that my beliefs in that department are correct....Im sure you feel just as strongly about your beliefs....its as obvious as the way I feel about my own.
Lastly, in regards to the mega flowing LS heads I must quote a line from Jerry McGuire....great movie by the way....SHOW ME THE MONEY!
Can't wait to see what tomorrow brings...
(I love that avatar....couldn't resist)
Tony M.
Last edited by Tony Mamo @ AFR; 02-22-2005 at 01:30 AM.
02-22-2005, 06:41 AM
#58
6600 rpm clutch dump of death Administrator
Well, the one thing I do know is that I don't know everything. But, I'm smart enough to ask folks smarter than me what they think. So, I did. Here is what they had to say... I asked the question of Larry Meaux of Meaux racing heads (he does heads for Futral), Darrin Morgan of Reher Morrison, OZrace (flowbench builder in Australia), and Bill Jones out of Utah.
maxracesoftware <--- Larry Meaux
Quote:
Some people feel its "cheating" when you flow an exhaust port with a "pipe".
then how do you look at flowing an Intake port with a Radius Entry ???
is that cheating also ?
Who would flow test a Cyl Head without a radius entry on the Intake Port ?
i will give you Flow numbers with and without the Pipe,
and Flow testing with a Pipe is not cheating !
the entire purpose of using a Radius Entry on the Intake Port
and using a Pipe with or without a radiused lip edge on the Exh Port
is=> to know what that Intake or Exhaust Ports is "ULTIMATELY"
capable of Flowing in CFM
knowing its maximum possible flow
gives you a "comparison" between what Flow losses are caused when you attach an Intake Manifold with or without a Carb, or Exhaust Header with or without Muffler.
also in many exhaust port designs, the exhaust port is still in the process of turning, and if you just dump out exh flow at that point, it will cause
turbulence on the FlowBench that never ocurrs in reality with the Header bolted on.
every Engine has at least some kind of exhaust pipe length attached to the exh port under real live engine operation
the goal of flowtesting is to measure Flow restriction that simulates as close as possible real live engine operation
flow testing with a Pipe attached is closer to live operation.
besides if you made some porting changes on an exh port without a Pipe,
it could definetly flow different or less flow when the Racer bolted on his Headers...you never want to Flow develope an exhaust port without knowing the effect the Header will have, especially if that port is still in the process of turning
so to satisfy the Racing Public, it would be a good idea to publish
Exhaust Flow Numbers with and without a Pipe attached
_________________
Meaux Racing Heads
MaxRace Software
ET_Analyst for DragRacers
www.maxracesoftware.com
ozrace
Quote:
Some people feel its "cheating" when you flow an exhaust port with a "pipe".
then how do look at flowing an Intake port with a Radius Entry ???
is that cheating also ?
Who would flow test a Cyl Head without a radius entry on the Intake Port ?
i will give you Flow numbers with and without the Pipe,
and Flow testing with a Pipe is not cheating !
the entire purpose of using a Radius Entry on the Intake Port
and using a Pipe with or without a radiused lip edge on the Exh Port
is=> to know what that Intake or Exhaust Ports is "ULTIMATELY"
capable of Flowing in CFM
knowing its maximum possible flow
gives you a "comparison" between what Flow losses are caused when you attach an Intake Manifold with or without a Carb, or Exhaust Header with or without Muffler.
also in many exhaust port designs, the exhaust port is still in the process of turning, and if you just dump out exh flow at that point, it will cause
turbulence on the FlowBench that never ocurrs in reality with the Header bolted on.
every Engine has at least some kind of exhaust pipe length attached to the exh port under real live engine operation
the goal of flowtesting is to measure Flow restriction that simulates as close as possible real live engine operation
flow testing with a Pipe attached is closer to live operation.
besides if you made some porting changes on an exh port without a Pipe,
it could definetly flow different or less flow when the Racer bolted on his Headers...you never want to Flow develope an exhaust port without knowing the effect the Header will have, especially if that port is still in the process of turning
so to satisfy the Racing Public, it would be a good idea to publish
Exhaust Flow Numbers with and without a Pipe attached
I completely agree. I have never tested without a pipe because to me it is illogical.
Why would you want to develop a port on the bench under conditions (no pipe) that it will never see on an engine ?
bill jones
-I normally never use an exhaust tube for two reasons:
-1 is I have flowtested everything from Ford flatheads to Studebakers to $10,000 a pop billet heads, and I most frequently flow test every port, so that means I'd have to have a library of not just tubes but 4 tube header stubs.
-Think about:
A- the cost if you had to BUY Ameduris tubes for more than 50 different types of heads.
B-you found out that Ameduri has the tube welded to the flange pointing a direction that you'd never use.
C-where you would store all these pieces and the problem you would have trying to find one specific tube assembly out of those 50 or more you have hanging on a wall somewhere.
2-When I started flowtesting in the late 1970's I went looking for published flownumbers to compare my new findings to.
-The majority of the available flownumbers were usually at 10", 12" or 25" do since I had a SF 300 flowbench which was the big bench of that era I decided to use 25" as tmy standard.
-AND---there were NO published results using either flowtubes and virtually no numbers with the induction systems installed.
-So to establish a decent data comparative base of flownumbers I chose to flow heads the easiest and quickest way.
-Think about:
-If you wanted to flow test every exhaust port with something close to optimum as far as the exhaust tube length and direction, what sort of time it takes to get that exhaust system figured out, and then to install it and remove it for every head.
-It all takes time, and that costs the little guy racer more money and what did that tube testing do for him on the track?
---------------------------------------
-And then if you decided that the little flare on the end of that pipe is worth another 2% of air so you flared every tube and the rest of the industry didn't, who's right or wrong?
----------------------------------------
-Most flow numbers I see that come from somewhere else, or the photos you see of about anybody doing flow testing, how many valves are in the head? ----Usually one pair of valves and one cylinder so that means they are cheating because they don't do all the cylinders and show you the good, the bad, and the ugly?
---------------------------------------
-Then if you find that for some odd reason you can port exhaust ports #3 &# 6 to ALWAYS flow really super and you just happen to always use those holes to show the customer your best work, and never show him the doggy ports that you just can't ever seem to get to flow decent at all, does that count anywhere in this conversation?
-------------------------------------
-When you put an induction system on the head and flow it, everything changes, the flow drops about 1% for each .100" valve lift, the swirl numbers do tricks that are amazing, the left hand ports flow totally different than the right hand ports particulaly on a single 4barrel open plenum cast intake manifold.
-But nobody publishes manifold flow results compared to a radius inlet so we are stuck with the easy to get numbers.
---------------------------------------
-I look at what I chase on airflow as the dollars per project are the limiting factor and most of the guys I deal with don't really care, they just want to see the car go faster and the cylinder head problems go away.
Darin Morgan
That's easy to answer. You do it BOTH ways! You have to do it both ways in my opinion in order to OPTIMIZE the a port properly. Sometimes the tube can cover up or minimize turbulence. You should have a smooth port with or without the pipe but it should smooth out even more with a pipe. I use both methods to evaluate what the port wants and needs. Doing it just one way gives you half the story although flowing without a tube is the normally excepted procedure.
_________________
Darin Morgan
R&D-Cylinder Head Dept.
Reher-Morrison Racing Engines
1120 Enterprise Place
Arlington Texas 76001
817-467-7171
FAX-468-3147
http://www.rehermorrison.com
maxracesoftware <--- Larry Meaux
Quote:
Some people feel its "cheating" when you flow an exhaust port with a "pipe".
then how do you look at flowing an Intake port with a Radius Entry ???
is that cheating also ?
Who would flow test a Cyl Head without a radius entry on the Intake Port ?
i will give you Flow numbers with and without the Pipe,
and Flow testing with a Pipe is not cheating !
the entire purpose of using a Radius Entry on the Intake Port
and using a Pipe with or without a radiused lip edge on the Exh Port
is=> to know what that Intake or Exhaust Ports is "ULTIMATELY"
capable of Flowing in CFM
knowing its maximum possible flow
gives you a "comparison" between what Flow losses are caused when you attach an Intake Manifold with or without a Carb, or Exhaust Header with or without Muffler.
also in many exhaust port designs, the exhaust port is still in the process of turning, and if you just dump out exh flow at that point, it will cause
turbulence on the FlowBench that never ocurrs in reality with the Header bolted on.
every Engine has at least some kind of exhaust pipe length attached to the exh port under real live engine operation
the goal of flowtesting is to measure Flow restriction that simulates as close as possible real live engine operation
flow testing with a Pipe attached is closer to live operation.
besides if you made some porting changes on an exh port without a Pipe,
it could definetly flow different or less flow when the Racer bolted on his Headers...you never want to Flow develope an exhaust port without knowing the effect the Header will have, especially if that port is still in the process of turning
so to satisfy the Racing Public, it would be a good idea to publish
Exhaust Flow Numbers with and without a Pipe attached
_________________
Meaux Racing Heads
MaxRace Software
ET_Analyst for DragRacers
www.maxracesoftware.com
ozrace
Quote:
Some people feel its "cheating" when you flow an exhaust port with a "pipe".
then how do look at flowing an Intake port with a Radius Entry ???
is that cheating also ?
Who would flow test a Cyl Head without a radius entry on the Intake Port ?
i will give you Flow numbers with and without the Pipe,
and Flow testing with a Pipe is not cheating !
the entire purpose of using a Radius Entry on the Intake Port
and using a Pipe with or without a radiused lip edge on the Exh Port
is=> to know what that Intake or Exhaust Ports is "ULTIMATELY"
capable of Flowing in CFM
knowing its maximum possible flow
gives you a "comparison" between what Flow losses are caused when you attach an Intake Manifold with or without a Carb, or Exhaust Header with or without Muffler.
also in many exhaust port designs, the exhaust port is still in the process of turning, and if you just dump out exh flow at that point, it will cause
turbulence on the FlowBench that never ocurrs in reality with the Header bolted on.
every Engine has at least some kind of exhaust pipe length attached to the exh port under real live engine operation
the goal of flowtesting is to measure Flow restriction that simulates as close as possible real live engine operation
flow testing with a Pipe attached is closer to live operation.
besides if you made some porting changes on an exh port without a Pipe,
it could definetly flow different or less flow when the Racer bolted on his Headers...you never want to Flow develope an exhaust port without knowing the effect the Header will have, especially if that port is still in the process of turning
so to satisfy the Racing Public, it would be a good idea to publish
Exhaust Flow Numbers with and without a Pipe attached
I completely agree. I have never tested without a pipe because to me it is illogical.
Why would you want to develop a port on the bench under conditions (no pipe) that it will never see on an engine ?
bill jones
-I normally never use an exhaust tube for two reasons:
-1 is I have flowtested everything from Ford flatheads to Studebakers to $10,000 a pop billet heads, and I most frequently flow test every port, so that means I'd have to have a library of not just tubes but 4 tube header stubs.
-Think about:
A- the cost if you had to BUY Ameduris tubes for more than 50 different types of heads.
B-you found out that Ameduri has the tube welded to the flange pointing a direction that you'd never use.
C-where you would store all these pieces and the problem you would have trying to find one specific tube assembly out of those 50 or more you have hanging on a wall somewhere.
2-When I started flowtesting in the late 1970's I went looking for published flownumbers to compare my new findings to.
-The majority of the available flownumbers were usually at 10", 12" or 25" do since I had a SF 300 flowbench which was the big bench of that era I decided to use 25" as tmy standard.
-AND---there were NO published results using either flowtubes and virtually no numbers with the induction systems installed.
-So to establish a decent data comparative base of flownumbers I chose to flow heads the easiest and quickest way.
-Think about:
-If you wanted to flow test every exhaust port with something close to optimum as far as the exhaust tube length and direction, what sort of time it takes to get that exhaust system figured out, and then to install it and remove it for every head.
-It all takes time, and that costs the little guy racer more money and what did that tube testing do for him on the track?
---------------------------------------
-And then if you decided that the little flare on the end of that pipe is worth another 2% of air so you flared every tube and the rest of the industry didn't, who's right or wrong?
----------------------------------------
-Most flow numbers I see that come from somewhere else, or the photos you see of about anybody doing flow testing, how many valves are in the head? ----Usually one pair of valves and one cylinder so that means they are cheating because they don't do all the cylinders and show you the good, the bad, and the ugly?
---------------------------------------
-Then if you find that for some odd reason you can port exhaust ports #3 &# 6 to ALWAYS flow really super and you just happen to always use those holes to show the customer your best work, and never show him the doggy ports that you just can't ever seem to get to flow decent at all, does that count anywhere in this conversation?
-------------------------------------
-When you put an induction system on the head and flow it, everything changes, the flow drops about 1% for each .100" valve lift, the swirl numbers do tricks that are amazing, the left hand ports flow totally different than the right hand ports particulaly on a single 4barrel open plenum cast intake manifold.
-But nobody publishes manifold flow results compared to a radius inlet so we are stuck with the easy to get numbers.
---------------------------------------
-I look at what I chase on airflow as the dollars per project are the limiting factor and most of the guys I deal with don't really care, they just want to see the car go faster and the cylinder head problems go away.
Darin Morgan
That's easy to answer. You do it BOTH ways! You have to do it both ways in my opinion in order to OPTIMIZE the a port properly. Sometimes the tube can cover up or minimize turbulence. You should have a smooth port with or without the pipe but it should smooth out even more with a pipe. I use both methods to evaluate what the port wants and needs. Doing it just one way gives you half the story although flowing without a tube is the normally excepted procedure.
_________________
Darin Morgan
R&D-Cylinder Head Dept.
Reher-Morrison Racing Engines
1120 Enterprise Place
Arlington Texas 76001
817-467-7171
FAX-468-3147
http://www.rehermorrison.com
02-22-2005, 06:41 AM
#59
6600 rpm clutch dump of death Administrator
BTW Greg, Don't get too bent with Tony. The fact is that several folks have sent him heads when swapping out to AFRs. All of them had "promised" flow numbers that so far have been WAY off. It natural to be skeptical if every set of heads that comes in falls well short of the "promised" flow numbers.
I don't think anyone here has any doubt about your abilities as a porter. The point here is that there are precious few stock castings that have been in the 340 range. One of the key deals has been as far as I am aware you are one of the few people to have those numbers ona regular basis. The other thing is there aren't a lot of your heads out there to compare performance figures to. So, even if you are one if not the best head porter in the LS market there are a lot of guyys trying to make your numbers that "fudge" the numbers a bit. This give the overall market a black eye. One of the things I've heard from numerous folks is that they were amazed that Tony's numbers on the AFRs were right on since most heads they check are usually way off the promised numbers.
BTW, for anyone who is interested. We recently had to have some heads touched up and repaired. I sent the heads to Greg for him to flow test and repair, and he did a fine job on the heads, and in the process picked the heads up a bit on the exhaust side (although I'm still waiting on my flow sheets to see exactly how much ). I'm from Houston, so I've been aware of Greg's work for many many years. Lots of folks around here know of Greg and his work.
Anyhow, I don't fault Tony for asking to have the ports verified at his shop or any other. In his shoes, I'd do the same. It like taking a "shop" car to an independant dyno. It removes anyone's ability to say XXX is rigged. Test from an independant third party give credence to any claim becuase there are always folks who no matter how good someone's rep is are going to be skeptical of in-house claims.
In my line of work I've always welcomes outside peer review, it give me some sense of job satisfaction when no one is any way shape or form can credibly question my work. But thats just me...
I don't think anyone here has any doubt about your abilities as a porter. The point here is that there are precious few stock castings that have been in the 340 range. One of the key deals has been as far as I am aware you are one of the few people to have those numbers ona regular basis. The other thing is there aren't a lot of your heads out there to compare performance figures to. So, even if you are one if not the best head porter in the LS market there are a lot of guyys trying to make your numbers that "fudge" the numbers a bit. This give the overall market a black eye. One of the things I've heard from numerous folks is that they were amazed that Tony's numbers on the AFRs were right on since most heads they check are usually way off the promised numbers.
BTW, for anyone who is interested. We recently had to have some heads touched up and repaired. I sent the heads to Greg for him to flow test and repair, and he did a fine job on the heads, and in the process picked the heads up a bit on the exhaust side (although I'm still waiting on my flow sheets to see exactly how much
). I'm from Houston, so I've been aware of Greg's work for many many years. Lots of folks around here know of Greg and his work.Anyhow, I don't fault Tony for asking to have the ports verified at his shop or any other. In his shoes, I'd do the same. It like taking a "shop" car to an independant dyno. It removes anyone's ability to say XXX is rigged. Test from an independant third party give credence to any claim becuase there are always folks who no matter how good someone's rep is are going to be skeptical of in-house claims.
In my line of work I've always welcomes outside peer review, it give me some sense of job satisfaction when no one is any way shape or form can credibly question my work. But thats just me...
02-22-2005, 01:49 PM
#60
TECH Junkie
Join Date: Aug 2002
Location: Fort Collins, CO
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Originally Posted by J-Rod
Well, the one thing I do know is that I don't know everything. But, I'm smart enough to ask folks smarter than me what they think. So, I did. Here is what they had to say... I asked the question of Larry Meaux of Meaux racing heads (he does heads for Futral), Darrin Morgan of Reher Morrison, OZrace (flowbench builder in Australia), and Bill Jones out of Utah.
That's a good board over there J-Rod. Lots of good information.