What do you think of these flow numbers
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Joined: Aug 2002
Posts: 1,509
From: Red Oak Texas
Re: What do you think of these flow numbers
Phil,
I know that you have "MUCH SKILL" on LT1's and if you had any low and mid lift #'s close to the #'s on the above flow sheet?
Maybe the SF 1020 spits out #'s at 40" instead of the 28" #'s that we are all used to.
Lloyd Elliott
NightTrain66
I know that you have "MUCH SKILL" on LT1's and if you had any low and mid lift #'s close to the #'s on the above flow sheet?
Maybe the SF 1020 spits out #'s at 40" instead of the 28" #'s that we are all used to.
Lloyd Elliott
NightTrain66
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Joined: Nov 1999
Posts: 487
From: East Petersburg, Pa, USA
Re: What do you think of these flow numbers
Originally Posted by kevmor99
This should be good 
By the way, you can subscribe at the top by clicking 'thread tools'...
By the way, you can subscribe at the top by clicking 'thread tools'...
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Re: What do you think of these flow numbers
I'm a special projects manager where I work. I do all the hiring and firing. When I hire a person, I look at their education and more to the point of this discussion... their references.
Fantastical claims are common but they don't mean much to me without sources to verify them. If you have worked with such and such race team or whatever... just name the race team and maybe give us a source we can contact about the work. Hey, we're HIRING you to do the work, so I don't think that's too much to ask. Guys like Bob Dumont over at BPE... he'll give you all kinds of references you can check out. Not to mention, he lists many of them (some record holders) on his website. Other companies like FastTimes Motorworks do their own porting in house. You need only look at their track record to see that they know a little about strong engines and cylinder heads. Porting for big name race teams? List em. I think every person hiring another's services has the right to that.
-Mindgame
Fantastical claims are common but they don't mean much to me without sources to verify them. If you have worked with such and such race team or whatever... just name the race team and maybe give us a source we can contact about the work. Hey, we're HIRING you to do the work, so I don't think that's too much to ask. Guys like Bob Dumont over at BPE... he'll give you all kinds of references you can check out. Not to mention, he lists many of them (some record holders) on his website. Other companies like FastTimes Motorworks do their own porting in house. You need only look at their track record to see that they know a little about strong engines and cylinder heads. Porting for big name race teams? List em. I think every person hiring another's services has the right to that.
-Mindgame
Re: What do you think of these flow numbers
Registered User
Joined: Jan 1999
Posts: 989
From: Baton Rouge, la
Re: What do you think of these flow numbers
Hey, lets have a lt1 head tuner shootout at one of the f-body races. Lets say limit it to 360 cubes on a gm head casting(lt1/lt4).
And where did he go. I really would like to see an answer to mindgames question.
And where did he go. I really would like to see an answer to mindgames question.
Registered User
Joined: Aug 2002
Posts: 1,509
From: Red Oak Texas
310 cfm LT1 heads
I was sent a link to this post just like Phil and that is what struck my interest. I was not ripping anyone, I would just hate for someone esle to get ripped off or if these things are flowing ANYWHERE close to the #'s provided at 28", I am wanting a set my self so I can see how the hell they are doing it. I have no doubt that they will perform well and make good power by looking at them but the flow #'s provided seem VERY high as mentioned. Most people would be happy with the performance of them even if they end up flowing 60 cfm less than posted.
I am learning stuff all of the time so I am not gonna say anything is impossible. The peak #'s that he posted about were very high but I could care less. The #'s I was really concentrating on where the .050 to .450 lift #'s and wandering HOW is that much air coming from that size valve in an LT1 port.
I get "ecstatic" when I find 1 CFM at .050 to .300 lift. It is tough to get air at these lifts since the air is traveling through such a small opening. If he does have a magic recipe and can get another 20 to 30 cfm over the #'s an, I will GLADLY pay $1500 for a set of them to learn how. As I mentioned, I would want a 3rd party bench to "confirm" the #'s before I spend my $$$.
The best advice that I can give anyone would be to NOT buy ANY cylinder heads (mine ore any one elses) based on a flowsheet since these #'s will vary depending on the flow bench used, test procedures, etc, etc, and can EASILY be manipulated, inflated or lied about. In this industry where a flow sheet is what sells the heads, you can see why it happens so often. Even if 2 sets of heads flow the exact same at all lift points on the same bench, they can perform differently due to ALOT of vartiables.
If you ignore flow sheets and just look at HP/track time results from other similar set ups using their heads. When comparing HP #'s, make sure and consider what cam was used, TB, injector size, header type, exhaust type, quality of tuning and time spent tuning, etc, etc. When considering track times, consider weight, traction, gearing, elevation of track, etc. along with everything mentioned above as well.
Lloyd Elliott
NightTrain66
I am learning stuff all of the time so I am not gonna say anything is impossible. The peak #'s that he posted about were very high but I could care less. The #'s I was really concentrating on where the .050 to .450 lift #'s and wandering HOW is that much air coming from that size valve in an LT1 port.
I get "ecstatic" when I find 1 CFM at .050 to .300 lift. It is tough to get air at these lifts since the air is traveling through such a small opening. If he does have a magic recipe and can get another 20 to 30 cfm over the #'s an, I will GLADLY pay $1500 for a set of them to learn how. As I mentioned, I would want a 3rd party bench to "confirm" the #'s before I spend my $$$.
The best advice that I can give anyone would be to NOT buy ANY cylinder heads (mine ore any one elses) based on a flowsheet since these #'s will vary depending on the flow bench used, test procedures, etc, etc, and can EASILY be manipulated, inflated or lied about. In this industry where a flow sheet is what sells the heads, you can see why it happens so often. Even if 2 sets of heads flow the exact same at all lift points on the same bench, they can perform differently due to ALOT of vartiables.
If you ignore flow sheets and just look at HP/track time results from other similar set ups using their heads. When comparing HP #'s, make sure and consider what cam was used, TB, injector size, header type, exhaust type, quality of tuning and time spent tuning, etc, etc. When considering track times, consider weight, traction, gearing, elevation of track, etc. along with everything mentioned above as well.
Lloyd Elliott
NightTrain66
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Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
Re: 310 cfm LT1 heads
Lloyd makes some good points, as I would expect with him knowing a lot more about cylinder heads than I do. But I go out on a limb and say 310cfm from an LT1 casting is "impossible" at 28" unl;ess the data or test conditions are somehow manipulated in some way. There just isn't enough material to get the port big enough to flow that much. Now, maybe with a huge amount of welding, IOW adding material and basically reworking the whole casting you might see those kind of flow numbers, so I guess it is "possible" in that sense. But unless the heads cost $4,000+ that wouldn't be what you would be getting in a set of "310cfm heads" because it would cost that much to completely rework a set.
As far as the limitations of the flow bench, yes and no to what Lloyd said. There sure is a lot more to head performance than flow numbers. But if they are so unimportant why be "ecstatic" to find 1cfm? For a given type of head, generally speaking, the higher flowing heads will make more hp. If you are talking about two completely different heads, with different chamber and runner designs it's much less straightforward. Using track times to compare heads has so many vaiables that it's pointless unless the times are based on identical setups or better yet, represent a swap of heads on the same car. The ideal method is dyno testing, where the heads are working as part of the whole system but variables can be controlled. Most of us don't have the luxury of that kind of testing, which is where flow numbers play into the picture again.
Rich
As far as the limitations of the flow bench, yes and no to what Lloyd said. There sure is a lot more to head performance than flow numbers. But if they are so unimportant why be "ecstatic" to find 1cfm? For a given type of head, generally speaking, the higher flowing heads will make more hp. If you are talking about two completely different heads, with different chamber and runner designs it's much less straightforward. Using track times to compare heads has so many vaiables that it's pointless unless the times are based on identical setups or better yet, represent a swap of heads on the same car. The ideal method is dyno testing, where the heads are working as part of the whole system but variables can be controlled. Most of us don't have the luxury of that kind of testing, which is where flow numbers play into the picture again.
Rich
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Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Re: 310 cfm LT1 heads
How large can an LT1 port go anyways? 
If they can go as large as 215cc, then ~310cfm should be possible. That's a little less than the 1.45cfm per cc that some highly developed 23º heads make.
They still won't make as much power as a head with similar flow and higher port entries but it would have the flow capabilities to keep up with high rev engines.
As far as the other thread is concerned, I think all the nonsense claims will stop when people wake up and demand that ALL these guys claiming to do work for "professional race teams" list their sources and provide contact information.
Just say NO to overblown resumés.
And if you're not concerned with achievements and the costs that come with that kind of experience, find the guy who will do the best work for the money you have to spend.
As far as the limitations of the flow bench, yes and no to what Lloyd said. There sure is a lot more to head performance than flow numbers. But if they are so unimportant why be "ecstatic" to find 1cfm?
If I could find another cfm from filling in one area of a port I guess that'd be exciting to me. Could be a good indication that you're making steps in the right direction right?
-Mindgame
If they can go as large as 215cc, then ~310cfm should be possible. That's a little less than the 1.45cfm per cc that some highly developed 23º heads make.
They still won't make as much power as a head with similar flow and higher port entries but it would have the flow capabilities to keep up with high rev engines.
As far as the other thread is concerned, I think all the nonsense claims will stop when people wake up and demand that ALL these guys claiming to do work for "professional race teams" list their sources and provide contact information.
Just say NO to overblown resumés.
And if you're not concerned with achievements and the costs that come with that kind of experience, find the guy who will do the best work for the money you have to spend.
Originally Posted by rskrause
As far as the limitations of the flow bench, yes and no to what Lloyd said. There sure is a lot more to head performance than flow numbers. But if they are so unimportant why be "ecstatic" to find 1cfm?
-Mindgame
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Joined: Aug 2002
Posts: 1,509
From: Red Oak Texas
Re: 310 cfm LT1 heads
oops, I meant this to be posted on the on going thread instaed of starting a new one. That is what I get for typing and talking on the phone at the same time.
Rich,
I understand what you are saying buy my "CFM on a flow sheet not mattering" coment was made as more as advise for people looking to buy heads since the flow sheet can be easily produced regardless of the heads ever being put on a flow bench.
The other part about the two heads flowing the same but making the engine respond differently would have to do with velocity in several places of the port (the seat being most important IMO), cross sectional area, reversion, etc,
The flow bench is a good TOOL used for a porter to help find what he is looking for and compare different things that he wants to compare but I did not want people to think that a higher flowing head ALWAYS makes more power because this is not true. Especially if you are comparing the flow #'s that are supplied with the heads from different benches.
I agree with everything that Rich said, I just wanted to clear up what I said a lil better and the reason it was said.
The more you learn about cylinder head porting, the more you realize there is to learn. As long as you are always learning, I guess you are going in the right direction.
Lloyd Elliott
NightTrain66
Rich,
I understand what you are saying buy my "CFM on a flow sheet not mattering" coment was made as more as advise for people looking to buy heads since the flow sheet can be easily produced regardless of the heads ever being put on a flow bench.
The other part about the two heads flowing the same but making the engine respond differently would have to do with velocity in several places of the port (the seat being most important IMO), cross sectional area, reversion, etc,
The flow bench is a good TOOL used for a porter to help find what he is looking for and compare different things that he wants to compare but I did not want people to think that a higher flowing head ALWAYS makes more power because this is not true. Especially if you are comparing the flow #'s that are supplied with the heads from different benches.
I agree with everything that Rich said, I just wanted to clear up what I said a lil better and the reason it was said.
The more you learn about cylinder head porting, the more you realize there is to learn. As long as you are always learning, I guess you are going in the right direction.
Lloyd Elliott
NightTrain66
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Re: What do you think of these flow numbers
Just for the record, the gauntlet was thrown down to ALL porters claiming to do "race team work".
And I like the shootout idea, it'd definitely push guys to develop. One thing about that though... porters who don't build engines have had problems with that over the years, due to the lack of control. They port a head for "So & So Racing", who has another shop build the engine and the car doesn't perform all that well. Could be chassis related, could be a lot of things, but the porter's banner is stuck on the side of the car. May or may not be a good barometer of their work. That's why porters like to work real closely with engine builders... either that or they work for the engine builder (FastTimes example).
As it stands, I think your best bet is to go up to your track hero and ask them who ported their heads. Word of mouth has always been a big part of the highly competitive, but close-knit, drag racing scene. Makes the sport that much more fun.
"best" LT-1 head porter = small block chevy head porter
Lots of company there.
-Mindgame
And I like the shootout idea, it'd definitely push guys to develop. One thing about that though... porters who don't build engines have had problems with that over the years, due to the lack of control. They port a head for "So & So Racing", who has another shop build the engine and the car doesn't perform all that well. Could be chassis related, could be a lot of things, but the porter's banner is stuck on the side of the car. May or may not be a good barometer of their work. That's why porters like to work real closely with engine builders... either that or they work for the engine builder (FastTimes example).
As it stands, I think your best bet is to go up to your track hero and ask them who ported their heads. Word of mouth has always been a big part of the highly competitive, but close-knit, drag racing scene. Makes the sport that much more fun.
"best" LT-1 head porter = small block chevy head porter
Lots of company there.
-Mindgame
Registered User
Joined: Mar 2002
Posts: 4,827
From: Waynesboro, PA
Re: What do you think of these flow numbers
Originally Posted by Mindgame
As it stands, I think your best bet is to go up to your track hero and ask them who ported their heads. Word of mouth has always been a big part of the highly competitive, but close-knit, drag racing scene. Makes the sport that much more fun.