Porting FIRST Intake -- Progress Thread w/ pics
Thread Starter
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
Porting FIRST Intake -- Progress Thread w/ pics
I've begun porting my FIRST intake for my 383 build. I will be gasket matching the base to a FelPro 1205 and opening up the base and runners such that the passage tapers from the inlet at the plenum to the minimum area at the intake manifold exit.
Here are some pictures of the intake parts before porting and my initial (very) rough-in of the first runner. As the pictures show, I've got a fair amount of material to remove, but these things have plenty of meat for porting. To give an idea of the size, the wooden ***** shown in the porting pictures are 1.75" in diameter. A stock TPI base and runners have a diameter of 1.47". The goal is to get the runners sized to pass a 1.875" ball through the runner all the way into the manifold where the shape transitions to a rectangle. I'm at about 1.86" now -- I'm sneaking up on it so I don't break through.
I'll post more progress pics as I go. Enjoy.
Here are some pictures of the intake parts before porting and my initial (very) rough-in of the first runner. As the pictures show, I've got a fair amount of material to remove, but these things have plenty of meat for porting. To give an idea of the size, the wooden ***** shown in the porting pictures are 1.75" in diameter. A stock TPI base and runners have a diameter of 1.47". The goal is to get the runners sized to pass a 1.875" ball through the runner all the way into the manifold where the shape transitions to a rectangle. I'm at about 1.86" now -- I'm sneaking up on it so I don't break through.
I'll post more progress pics as I go. Enjoy.
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
That will help quite a bit. I flowed #1 port on my First intake manifold and it flowed at 301cfm right out of the box. As you can see port one is probably the worst as it narrows by the thermostat area. Port 8 would be the next worst because it narrows for the distributor clearance. The others were not bad at all and just needed some cleanup.
I spent quite a bit of time on those two ports getting a good taper from the runner inlet to the head outlet. I ported my intake manifold inlet openings to just over 1.850". At the outlet to the head I was looking for just over 2.2 square inches. So mine is still less than a Felpro 1205 intake manifold gasket.
Down the road you might want to consider siamesing the runners part way to raise your rpm horsepower level. I think you will have plenty of torque.
Very good job you are doing and thank you for posting the pictures.
I spent quite a bit of time on those two ports getting a good taper from the runner inlet to the head outlet. I ported my intake manifold inlet openings to just over 1.850". At the outlet to the head I was looking for just over 2.2 square inches. So mine is still less than a Felpro 1205 intake manifold gasket.
Down the road you might want to consider siamesing the runners part way to raise your rpm horsepower level. I think you will have plenty of torque.
Very good job you are doing and thank you for posting the pictures.
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
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Thanks Todd,
I actually revisited this option this week. I was curious if it was matched to a 1204 out of the box. I guess so. That's a little suprising considering how bit the tubes are -- but I guess giant tube sizing won't hurt stockers. And, having 1205 ports would hurt a stocker.
Still, they could consider a 1205 version...
Also, it looks like the ball is close to going thru the mid-section of the tube. Is the middle bigger than the ends? IOW, is most of the grinding out toward the end of the tubes?
With your simulator, can you predict the difference between this option and an aftermarket TPI base + ASM runners on my 350 with 180 heads?
I was guessing the torque would be similar with 10-15 more hp up top.
Thanks for the pics!
Gregg
Oh yeah...
Assuming that's a FelPro 1205 in the pics, could you post (or PM me) a pic of the 1205 gasket sitting on the AFR 195's? I'm interested in seeing that matchup.
I actually revisited this option this week. I was curious if it was matched to a 1204 out of the box. I guess so. That's a little suprising considering how bit the tubes are -- but I guess giant tube sizing won't hurt stockers. And, having 1205 ports would hurt a stocker.
Still, they could consider a 1205 version...
Also, it looks like the ball is close to going thru the mid-section of the tube. Is the middle bigger than the ends? IOW, is most of the grinding out toward the end of the tubes?
With your simulator, can you predict the difference between this option and an aftermarket TPI base + ASM runners on my 350 with 180 heads?
I was guessing the torque would be similar with 10-15 more hp up top.
Thanks for the pics!
Gregg
Oh yeah...
Assuming that's a FelPro 1205 in the pics, could you post (or PM me) a pic of the 1205 gasket sitting on the AFR 195's? I'm interested in seeing that matchup.
Last edited by GREGGPENN; Nov 26, 2008 at 01:27 AM.
Drifting
Joined: Jan 2001
Posts: 1,408
Likes: 13
From: Dayton, Ohio
Sorry to be the one to have to say it, but YOU'RE WRONG. I've seen it.
Compared to a stock TPI, these tubes are big enough for small dogs to run through. BTW Frenchy, I like the red Vette in your avatar. Any chance of emailing me some pics?
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
That will help quite a bit. I flowed #1 port on my First intake manifold and it flowed at 301cfm right out of the box. As you can see port one is probably the worst as it narrows by the thermostat area. Port 8 would be the next worst because it narrows for the distributor clearance. The others were not bad at all and just needed some cleanup.
I spent quite a bit of time on those two ports getting a good taper from the runner inlet to the head outlet. I ported my intake manifold inlet openings to just over 1.850". At the outlet to the head I was looking for just over 2.2 square inches. So mine is still less than a Felpro 1205 intake manifold gasket.
Down the road you might want to consider siamesing the runners part way to raise your rpm horsepower level. I think you will have plenty of torque.
Very good job you are doing and thank you for posting the pictures.
I spent quite a bit of time on those two ports getting a good taper from the runner inlet to the head outlet. I ported my intake manifold inlet openings to just over 1.850". At the outlet to the head I was looking for just over 2.2 square inches. So mine is still less than a Felpro 1205 intake manifold gasket.
Down the road you might want to consider siamesing the runners part way to raise your rpm horsepower level. I think you will have plenty of torque.
Very good job you are doing and thank you for posting the pictures.
If they flowed 301cfm, I would of left them alone. Educate me plz.
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Drifting
Joined: Aug 2006
Posts: 1,279
Likes: 0
From: Delray beach FL
Porting this intake will most probably slown down the venturi effect that could affect the combustion process with those heads and result in less perfs.......
Thread Starter
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
Thread Starter
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
The reasons why I'm opening it up have to do with the flow dynamics of the air as it moves through the passage and the geometry of the passage itself. IOW, I'm trying to improve the efficiency of the flow by optimizing the shape of the port.
As received, there are places in the intake where the cross sectional area (CSA) of the port is less than the minimum CSA of my heads. This is undesirable from a flow perspective. I am sizing the runner and base such that the minimum CSA of the intake tract is right at the valve bowl. Also, I am opening up the runners as large as possible and tapering them from top to bottom so that I get a gradual reduction in CSA all the way from the plenum to the head. This makes the passage act like a funnel such that the air gradually accelerates to its maximum velocity at the entry to the head.
The length of the passage remains unchanged, so the resonance RPM will remain as it currently is, but the shape of the passage will offer much less restriction to flow, especially at higher RPM when it's important to quickly accelerate big gulps of air through the port.
Hope this helps.
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
Right, with everything hooked up the flow will be less than 301cfm. With everything hooked up to the heads the flow will be even less through the heads. So you want to optimize things up stream.
Sounds like you have a good handle on the flow and wave science part of it.
If you do decide to siamese later on do it to the runners and start at the plenum end of things. Just for reference the LS1 total runner length including the heads is around 13.5 inches. That seems to be a good compromised length for both torque and horsepower.
Sounds like you have a good handle on the flow and wave science part of it.
If you do decide to siamese later on do it to the runners and start at the plenum end of things. Just for reference the LS1 total runner length including the heads is around 13.5 inches. That seems to be a good compromised length for both torque and horsepower.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
He's talking about the base itself. The flow numbers with the runners and plenum attached will be something less than that.
The reasons why I'm opening it up have to do with the flow dynamics of the air as it moves through the passage and the geometry of the passage itself. IOW, I'm trying to improve the efficiency of the flow by optimizing the shape of the port.
As received, there are places in the intake where the cross sectional area (CSA) of the port is less than the minimum CSA of my heads. This is undesirable from a flow perspective. I am sizing the runner and base such that the minimum CSA of the intake tract is right at the valve bowl. Also, I am opening up the runners as large as possible and tapering them from top to bottom so that I get a gradual reduction in CSA all the way from the plenum to the head. This makes the passage act like a funnel such that the air gradually accelerates to its maximum velocity at the entry to the head.
The length of the passage remains unchanged, so the resonance RPM will remain as it currently is, but the shape of the passage will offer much less restriction to flow, especially at higher RPM when it's important to quickly accelerate big gulps of air through the port.
Hope this helps.
The reasons why I'm opening it up have to do with the flow dynamics of the air as it moves through the passage and the geometry of the passage itself. IOW, I'm trying to improve the efficiency of the flow by optimizing the shape of the port.
As received, there are places in the intake where the cross sectional area (CSA) of the port is less than the minimum CSA of my heads. This is undesirable from a flow perspective. I am sizing the runner and base such that the minimum CSA of the intake tract is right at the valve bowl. Also, I am opening up the runners as large as possible and tapering them from top to bottom so that I get a gradual reduction in CSA all the way from the plenum to the head. This makes the passage act like a funnel such that the air gradually accelerates to its maximum velocity at the entry to the head.
The length of the passage remains unchanged, so the resonance RPM will remain as it currently is, but the shape of the passage will offer much less restriction to flow, especially at higher RPM when it's important to quickly accelerate big gulps of air through the port.
Hope this helps.
Drifting
Joined: Jan 2001
Posts: 1,408
Likes: 13
From: Dayton, Ohio
I was over at Todd's last Sunday. If you've never seen a 1st intake, let
me tell you, they're huge. As I was talking to Todd about it, he showed
me his AFR heads. I saw them as delivered a while back, but now after he's done some cleanup on them, they're awsome! He does some really nice work. Like most castings, the 1st could be smoother inside the air passages. Todd's work REALLY cleans all that up. By removing/smoothing the casting boogers and opening the tubes up to a more uniform cross section, his work will eliminate a good bit of undesired turbulence in the flow path. I wish I had his patience. Even more, I wish my wife had his wife's patience
me tell you, they're huge. As I was talking to Todd about it, he showed
me his AFR heads. I saw them as delivered a while back, but now after he's done some cleanup on them, they're awsome! He does some really nice work. Like most castings, the 1st could be smoother inside the air passages. Todd's work REALLY cleans all that up. By removing/smoothing the casting boogers and opening the tubes up to a more uniform cross section, his work will eliminate a good bit of undesired turbulence in the flow path. I wish I had his patience. Even more, I wish my wife had his wife's patience
Last edited by Yguy; Nov 27, 2008 at 01:01 PM. Reason: Happy Thanksgiving !!!!!!!!!!!