Max N/A power from Gen 3
- Thread starter Wastelands Warrior
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Wastelands Warrior
Full Access Member
I once owned a 79 Trans Am that had a 455 Oldsmobile swapped in, a T400, and some 2.41s. That car had tons of low end torque and would top end like no tomorrow without breaking a sweat. Very fun ride.
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NukeGM/Ford
Active Member
1200+, when could you every get the boost above 1/2 throttle with those stock looking tires
:rock::rock::rock::rock::rock::rock::rock:
seethrough
Member
Ronnie, here is the last head I wet flowed here in the shop. What do you think of it? Is it good? Bad? Why?
Thanks!
I am curious. It says it is a wet flow test so I am assuming wherever the red dye is marks the low airflow areas. Is what we are seeing good or bad and how does it all relate to cfm versus air quality? Are wet flow tests ever run with valves installed and set at max lift range to see how airflow is impacted by them? Do wet test results correlate to dry flow bench testing? Inquiring minds want to know.
That is a popular LSx head as it comes from the maker. The wet flow is horrible. You can't see it in the pic but that port has a curved wing in the valve pocket. They put it there to reduce swirl, but in the process they cause air/fuel separation.
What you see is the head disassembled. It was tested in a normal flow test with the valves in. A mist of ink was sprayed into the port at maximum lift. The port converted it into liquid and did a poor job of distributing it around the head of the valve. The ink trails you see on the short side radius weren't even being allowed into the chamber.
I'll straighten out the wet flow problems, and also get a cfm gain in the process. You don't have to give up cfm to improve mixture quality on a wedge head.
ETA: A wedge intake port will swirl much harder on a running engine than on a flow bench. We wet flow on a flow bench to make sure we're in the ballpark, then study the carbon patterns in the chamber after it's run. Without swirl the air/fuel ratio will vary across the chamber. The intake will be the leanest, and the exhaust side the richest. We induce swirl to stir the mixture better and get a more complete burn. I'm a big fan of swirl. You would not want a wedge head that did not have it. You can adjust the intensity of it, and the geometry of it to get it the way you want it.
What you see is the head disassembled. It was tested in a normal flow test with the valves in. A mist of ink was sprayed into the port at maximum lift. The port converted it into liquid and did a poor job of distributing it around the head of the valve. The ink trails you see on the short side radius weren't even being allowed into the chamber.
I'll straighten out the wet flow problems, and also get a cfm gain in the process. You don't have to give up cfm to improve mixture quality on a wedge head.
ETA: A wedge intake port will swirl much harder on a running engine than on a flow bench. We wet flow on a flow bench to make sure we're in the ballpark, then study the carbon patterns in the chamber after it's run. Without swirl the air/fuel ratio will vary across the chamber. The intake will be the leanest, and the exhaust side the richest. We induce swirl to stir the mixture better and get a more complete burn. I'm a big fan of swirl. You would not want a wedge head that did not have it. You can adjust the intensity of it, and the geometry of it to get it the way you want it.
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Very interesting, thanks! So, assuming good swirl, can you have too much CFM for an application?
Good morning Greg:
It would appear you completely missed the irony in my post about your “Ignore List” as, for someone supposedly being ignored (me), my comments about cylinder heads and Intake Porting (especially regarding port-stall and a drop off in power) seemed to really set you off.
I couldn’t care less about being on or off of one of your lists.
I am simply passing along what I’ve learned (in forum form) for someone interested in this field to benefit from (or not), based on what I've learned over the past 47 years.
I’m sure you have lots of experience with building a wide variety of high-performance engines, from a wide variety of manufacturers, as do I.
When we spoke on the phone, I remember you making a comment that high-flow numbers sold cylinder heads, and I understand that from a sales point of view. (B.T.W. I'm assuming you are flowing at 28" when your flow numbers are reported).
I find your recent comments about flow theory contradictory to what you have stated in the past, however. Especially regarding flow quality vs. flow quantity.
I've found that most customers are not interested in the theory behind the science and simply want results.
As for selling a few sets of Strikers, I found it rewarding and the power/performance produced exceeded my expectations (and my customers'), every single time.
They were/are a great aftermarket head.
We are unlikely to ever meet face to face. I am not interested in being “your friend”, nor "your enemy”.
You deliver results and so do I when I'm involved in a build.
Continued Prosperity.
Ronnie
It would appear you completely missed the irony in my post about your “Ignore List” as, for someone supposedly being ignored (me), my comments about cylinder heads and Intake Porting (especially regarding port-stall and a drop off in power) seemed to really set you off.
I couldn’t care less about being on or off of one of your lists.
I am simply passing along what I’ve learned (in forum form) for someone interested in this field to benefit from (or not), based on what I've learned over the past 47 years.
I’m sure you have lots of experience with building a wide variety of high-performance engines, from a wide variety of manufacturers, as do I.
When we spoke on the phone, I remember you making a comment that high-flow numbers sold cylinder heads, and I understand that from a sales point of view. (B.T.W. I'm assuming you are flowing at 28" when your flow numbers are reported).
I find your recent comments about flow theory contradictory to what you have stated in the past, however. Especially regarding flow quality vs. flow quantity.
I've found that most customers are not interested in the theory behind the science and simply want results.
As for selling a few sets of Strikers, I found it rewarding and the power/performance produced exceeded my expectations (and my customers'), every single time.
They were/are a great aftermarket head.
We are unlikely to ever meet face to face. I am not interested in being “your friend”, nor "your enemy”.
You deliver results and so do I when I'm involved in a build.
Continued Prosperity.
Ronnie
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Nope. There is no such thing as too much airflow. You can have too much cross section though.
ETA: A good A to B example is NHRA Pro Stock Motorcycle. The 4 valve engines in the past ran cams with 10 degrees less duration than their 2 valve counterparts. The 4 valve heads flow better, and fill a cylinder quicker.
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Wastelands Warrior
Full Access Member
Thanks again gentlemen for taking the time to post up such interesting info.
I think I understand. You can have an incorrect amount of volume (this includes ports that are too large), or poor velocity (either from poor shape, too much volume, etc), and end up with not enough airflow. In other words, a correctly sized/shaped port will always yield more airflow, correct?
seethrough
Member
Thanks for the info Greg. Since you are allowing us to pick your brain I am going to take seconds. I understand the affects that creating a swirl have but is texturing or dimpling the chamber surface affective in these engines? I had heard that it aids in atomization but the last time I saw anything on it (20+ years ago) it was all based on carbureted motors. Thanks again for participating in a thread with some tangible info.
There are two schools of thought on it with smart people on both sides. I have tried every finish, but went back to a 60 grit finish. I've been carbide rough to 600 grit smooth.
My take...is that the guys picking up power with a really rough surface (or dimpled) have wet flow problems. I like to fix it a different way, with different airflow patterns.
But on a good running engine with good wet flow and good BSAC (brake specific air consumption) numbers (lot of power per cubic foot of air), We haven't seen any power going from 40 grit to 600 grit on the same day/dyno.
seethrough
Member
Greg, [rub on the lantern] for my third wish I would like to know what makes the Gen IV heads flow so much better than the earlier stock heads. Is it a raised intake runner? Bigger chambers? Better chamber shape?
I have seen the flow numbers on Trainman's set that you ported, I have had a set ported, and I have seen earlier heads' ported numbers and there seems to be a dramatic increase. What makes them have such a significant flow increase.
I have seen the flow numbers on Trainman's set that you ported, I have had a set ported, and I have seen earlier heads' ported numbers and there seems to be a dramatic increase. What makes them have such a significant flow increase.
Thicker port walls. Improved valve location in the chamber. Improved valve guide distance (so we can install a much larger valve).
I really like the semi-oval intake ports over the rectangular ports, but we can't have everything.
this is the only thing that i took out of your post.
thank you for using this statement correctly
anyways - carry on.
side note: i need a passenger head and am considering a H/C build in lieu of a stock head replacement and FI alternative.
true story...
this is the only thing that i took out of your post.
thank you for using this statement correctly
anyways - carry on.
side note: i need a passenger head and am considering a H/C build in lieu of a stock head replacement and FI alternative.
true story...
Nobody cares, also a true story.
Why can't we? Is there a limitation in the OEM V10 architecture that prevents the manufacturer from using a semi-oval port?
Grammar nazi.this is the only thing that i took out of your post.
thank you for using this statement correctly
anyways - carry on.
Nobody cares, also a true story.
Quoted just because I can.
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