Mildly Modded 6.0L Intake Flow #'s
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Mildly Modded 6.0L Intake Flow #'s Just finished flowing a mildly modified 6.0L intake port. Here are the details:
* Swirl vane mostly removed
* Rocker boss bump smoothed but not removed
* Stock intake valve, no modification.
* Guide boss streamlined.
* Short side radius blended.
* Port cartridge roll smoothed with 50 grit.
* 4 angle valve job.
* 215 cc intake port volume, 5 cc total removed.
* Flowed with a 3.9" bore adapter at 28" H2O.
Lift Flow
.100 69
.200 139
.300 207
.400 247
.500 277
.600 295
This port has some potential! Matched with proper components, this head could make 550-570 FWHP. I am going to try some aftermarket valves with different backcuts and see what will happen.
Paul J.
* Swirl vane mostly removed
* Rocker boss bump smoothed but not removed
* Stock intake valve, no modification.
* Guide boss streamlined.
* Short side radius blended.
* Port cartridge roll smoothed with 50 grit.
* 4 angle valve job.
* 215 cc intake port volume, 5 cc total removed.
* Flowed with a 3.9" bore adapter at 28" H2O.
Lift Flow
.100 69
.200 139
.300 207
.400 247
.500 277
.600 295
This port has some potential! Matched with proper components, this head could make 550-570 FWHP. I am going to try some aftermarket valves with different backcuts and see what will happen.
Paul J.
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Mildly Modded 6.0L Intake Flow #'s Jason99TA: The 6.0L head seems to out flow the 5.7L head from about .300" lift on up. The short turn radius on the 6.0L head is quite a bit higher and wider, giving it a larger radius, thus reducing velocity and flow seperation. From .300" on down, I think both are on equal ground assuming valve sizes and seat design remain the same. All else being equal, the 6.0L head is 10-20 cfm better from .350" up. Stock port volumes are 200 cc and 210 cc for the 5.7L and 6.0L respectively.
Also, I noticed that between .400 and .500" lift, these heads develop a "tornado" swirl effect, significantly changing the test pressure and sound through the port. Even the 6.0L head with the swirl vane mostly removed did this at .500-.550" lift. Probably due to different cross sectional area on either side of the port creating a pressure difference, resulting in swirl. Very interesting though. The first time it happened, I thought something was wrong with my flowbench.
LS1derfull: Right now, I am concentrating on the Intake port design between 5.7L and 6.0L heads. I have done the exhaust runners on the 6.0L heads but have not finalized the seat design and port shape. When I finish them, I will post the flow #'s and port volume.
Paul J.
Also, I noticed that between .400 and .500" lift, these heads develop a "tornado" swirl effect, significantly changing the test pressure and sound through the port. Even the 6.0L head with the swirl vane mostly removed did this at .500-.550" lift. Probably due to different cross sectional area on either side of the port creating a pressure difference, resulting in swirl. Very interesting though. The first time it happened, I thought something was wrong with my flowbench.
LS1derfull: Right now, I am concentrating on the Intake port design between 5.7L and 6.0L heads. I have done the exhaust runners on the 6.0L heads but have not finalized the seat design and port shape. When I finish them, I will post the flow #'s and port volume.
Paul J.
I can shift faster than you.
iTrader: (21)
Joined: Nov 2001
Posts: 5,133
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From: Baton Rouge, LA
Re: Mildly Modded 6.0L Intake Flow #'s Very good info Paul! Thanks for posting. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Do you like the 6.0l/LS6 exhaust ports any better than the LS1s? I have heard of a few porters who actually totally change the shape of the port since they are not very fond of it (LS6). What is your take on that?
<small>[ May 15, 2002, 10:45 PM: Message edited by: Jason99T/A ]</small>
Do you like the 6.0l/LS6 exhaust ports any better than the LS1s? I have heard of a few porters who actually totally change the shape of the port since they are not very fond of it (LS6). What is your take on that?
<small>[ May 15, 2002, 10:45 PM: Message edited by: Jason99T/A ]</small>
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Mildly Modded 6.0L Intake Flow #'s Actually, I haven't done enough testing to be sure one way or another. The LS6 exhaust has a higher floor and a reduced volume over the LS1 port, which should increase velocity. More than likely, I will raise and widen the roof and concentrate most of my efforts in the seat area, 1/2" on either side of the valve. I think this is the area where there is significant flow to be gained. What works on the LS6 should work on the LS1, but sometimes the flowbench can suprise you.
Paul J.
<small>[ May 15, 2002, 10:58 PM: Message edited by: Paul J. ]</small>
Paul J.
<small>[ May 15, 2002, 10:58 PM: Message edited by: Paul J. ]</small>
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TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: Mildly Modded 6.0L Intake Flow #'s That is risky installing aftermarket valves, and not porting with flow bench.These heads are sensitive big time to valve shape and you could have poor flow condition, even with decent porting effort.
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Brett Foote Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Mildly Modded 6.0L Intake Flow #'s LS1derfull is correct. I have tried various backcuts on the stock intake valves with no improvement over stock. Also, the stock valve job is very good, flowing close to my special 4 angle valve job. GM engineers spent a lot of effort in optimizing the stock valve job, and it shows. Adding aftermarket valves without flowtesting the combo would be a crapshoot in my opinion. As far as the port dimensions, I believe they are 1" x 2.5" at the port entry. With minor port mods, grinding on this port entry shows no improvement, and will actually reduce velocity, hurting torque.
Many port modifications I though would kick *** fell flat on their face on the flowbench.
Paul J.
Many port modifications I though would kick *** fell flat on their face on the flowbench.
Paul J.
Re: Mildly Modded 6.0L Intake Flow #'s I just installed a set of "home ported" 6.0L heads.
I don't have a flow bench but, specs are
Ferrea 2.02/1.55 valves.
My intake ports cc'd to 214cc.
Chamber afer a 0.30 cut 63.5.
3 angle with seats completed blended to port.
Kind of wish I flowed them but after not driving my car for a month I was ready to get it going.
I performed mods to the port similar to what you describe. What is the with of your ports at the intake port entry, ie. did you take much of the runner walls?
Mine was about 1.1 inches wide.
So far I am kind of disappointed with the seat of the pants feel. I am going to the track tonight and probably dyno Sat.
Any suggestions on tuning? Hopefully I can find some power that would make me feel better for all my time and effort.
I'll post track and dyno results later.
I don't have a flow bench but, specs are
Ferrea 2.02/1.55 valves.
My intake ports cc'd to 214cc.
Chamber afer a 0.30 cut 63.5.
3 angle with seats completed blended to port.
Kind of wish I flowed them but after not driving my car for a month I was ready to get it going.
I performed mods to the port similar to what you describe. What is the with of your ports at the intake port entry, ie. did you take much of the runner walls?
Mine was about 1.1 inches wide.
So far I am kind of disappointed with the seat of the pants feel. I am going to the track tonight and probably dyno Sat.
Any suggestions on tuning? Hopefully I can find some power that would make me feel better for all my time and effort.
I'll post track and dyno results later.
Re: Mildly Modded 6.0L Intake Flow #'s Hey thanks for the negative feedback.
Here you go, guess this sucks too,
First time EVER drag racing,
street tires,
3700 lb race weight
115 mph best trap
12.66 best et.
Not sure of the weather conditions, but serveral turbo cars claimed they were down anywhere from 4-5 mph than there best traps.
Mac headers through Hooker cat back,
Stock MAF, Stock LS1 intake, T1 cam.
Here you go, guess this sucks too,
First time EVER drag racing,
street tires,
3700 lb race weight
115 mph best trap
12.66 best et.
Not sure of the weather conditions, but serveral turbo cars claimed they were down anywhere from 4-5 mph than there best traps.
Mac headers through Hooker cat back,
Stock MAF, Stock LS1 intake, T1 cam.
Re: Mildly Modded 6.0L Intake Flow #'s Yup, you should be running low 12s with your mods.. Better luck next time.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong>Hey thanks for the negative feedback.
First time EVER drag racing,
street tires,
3700 lb race weight
115 mph best trap
12.66 best et.
Mac headers through Hooker cat back,
Stock MAF, Stock LS1 intake, T1 cam.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong>Hey thanks for the negative feedback.
First time EVER drag racing,
street tires,
3700 lb race weight
115 mph best trap
12.66 best et.
Mac headers through Hooker cat back,
Stock MAF, Stock LS1 intake, T1 cam.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: Mildly Modded 6.0L Intake Flow #'s Negative feedback? I wish others offered me such important info cautions, as i gave you.I wasnt hoping for problem just trying to shed some light on possible cause of poor sotp feel.
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Mildly Modded 6.0L Intake Flow #'s Speed Demon: I did not intend to be negative, in fact I just tested the Ferrea valves you are using (2.02" #F6231 and 1.55" #F6232) unmodified against stock 2.00" and 1.55" valves in the above 6.0L head. Listed below are the gains (+) or losses (-) in CFM compared to the stock valves:
Intake:
Lift Flow
.100 -2
.200 -7
.300 -12
.400 -4
.500 -7
.600 -7
Exhaust
Lift Flow
.100 +1
.200 +3
.300 -2
.400 -2
.500 -3
.600 -2
The intake lost considerable flow compared to the stock valve. Some experimenting with different backcuts may improve the flow. The exhaust faired better in the lower range but lost from .300" on up. The exhaust port was cleaned up with a preliminary valve job and flowed 195 CFM @ .600" lift. The Ferrea valve has less of a tulip shape compared to the stock valve, which may have hurt the flow above .300" lift. Only time and testing will tell for sure.
Paul J.
Intake:
Lift Flow
.100 -2
.200 -7
.300 -12
.400 -4
.500 -7
.600 -7
Exhaust
Lift Flow
.100 +1
.200 +3
.300 -2
.400 -2
.500 -3
.600 -2
The intake lost considerable flow compared to the stock valve. Some experimenting with different backcuts may improve the flow. The exhaust faired better in the lower range but lost from .300" on up. The exhaust port was cleaned up with a preliminary valve job and flowed 195 CFM @ .600" lift. The Ferrea valve has less of a tulip shape compared to the stock valve, which may have hurt the flow above .300" lift. Only time and testing will tell for sure.
Paul J.
Re: Mildly Modded 6.0L Intake Flow #'s That's cool, Paul J. and LS1derfull,
It just sounded like what I have heard many times before. "You don't know what you are doing, don't mess with it, you'll be sorry."
I didn't expect to get anywhere close to what the tuner shops make, and I didn't want to spend $2500 for a set of ported heads.
What exactly do you mean by back cuts, valve or seat? This has been a learning experience for me too. I wish I had a flow bench and a machine shop to work with.
Paul J., did you open up the intake seat and rework the seat any to fit the Ferrea valves? Other than the 30,45,60 seat angles what did you use? The machine shop that set up my seats with the above angles and a 78 I believe and one more that angled down into the bowl, but they ground the ridge out of where the last to angles meet. So pretty much after the 60 angle the valve seat goes straight into the bowl. Follow me? I was unsure if this was the correct thing to do.
The car is faster, but no wow factor.
I need to dyno it.
It just sounded like what I have heard many times before. "You don't know what you are doing, don't mess with it, you'll be sorry."
I didn't expect to get anywhere close to what the tuner shops make, and I didn't want to spend $2500 for a set of ported heads.
What exactly do you mean by back cuts, valve or seat? This has been a learning experience for me too. I wish I had a flow bench and a machine shop to work with.
Paul J., did you open up the intake seat and rework the seat any to fit the Ferrea valves? Other than the 30,45,60 seat angles what did you use? The machine shop that set up my seats with the above angles and a 78 I believe and one more that angled down into the bowl, but they ground the ridge out of where the last to angles meet. So pretty much after the 60 angle the valve seat goes straight into the bowl. Follow me? I was unsure if this was the correct thing to do.
The car is faster, but no wow factor.
I need to dyno it.
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Mildly Modded 6.0L Intake Flow #'s Backcutting the valves is basically adding one or more angles to the valve between the 45 deg seat and the 10-15 deg angle at the back of the valve. A 30 deg would be a fairly common backcut angle. The size and diameter would be determined by flow testing.
For the Ferrea valves, the intake seat was enlarged to take advantage of the larger valve. Backcutting the valve seemed to work fairly well with the stock valve job up to .400" lift.
Paul J.
For the Ferrea valves, the intake seat was enlarged to take advantage of the larger valve. Backcutting the valve seemed to work fairly well with the stock valve job up to .400" lift.
Paul J.
