Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:
View Poll Results: Get rid of CNC track lines on the intake runners?
Yes
21
23.08%
No
70
76.92%
Voters: 91. You may not vote on this poll

CNC track lines on intake runner

Thread Tools
 
Search this Thread
 
Old 03-13-2006, 06:37 PM
  #21  
TECH Junkie
iTrader: (3)
 
cantdrv65's Avatar
 
Join Date: Nov 2001
Location: TEXASS
Posts: 3,202
Likes: 0
Received 0 Likes on 0 Posts

Post

Originally Posted by Xtnct00WS6
If the design of the intake port wasn't changed, which it wasn't, it's safe to assume that I increased flow. I'll post pics as soon as I can get access to a digital camera.

There are inherent flaws from CNC machines that hand porting can take away. There seemed to be a ridge from where the CNC machine couldn't go any further from one direction that I was able to take down and make it smooth. I've seen this in many different pics from different companies. It's hard to see, but you can feel it when you run your finger over it. That itself convinved me why I should touch up the intake. I have plenty of time until I'm going to be installing these, so I decided to go the extra mile.

I'm not staying with the 224 cam for forever, so maybe one day my efforts will pay off

No disrespect here, I appreciate all the posts. Many of you have much much more experience than I do.
I had a small ridge in my cnc heads when I put them on and i didnt think about changing the port in the least. Believe it or not by making the port "look" better you could have actually lost performance. Thats all Im saying, a very strong possibilty exists, thats why Id have the heads flowed again before I put them on.
Old 03-13-2006, 07:04 PM
  #22  
TECH Enthusiast
iTrader: (21)
 
LETHL_SS's Avatar
 
Join Date: Oct 2005
Location: New Bern, NC
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default

Not sure if this helps but here are some pics of mine...

Chamber



Exhaust

Old 03-13-2006, 08:09 PM
  #23  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by LETHL_SS
Not sure if this helps but here are some pics of mine...
Those look nice! Wonderful numbers too! I remember PMing you about your setup. Glad to see some pics too. Any pics of the intake runner? Those were handfinished I take it?
Old 03-13-2006, 08:17 PM
  #24  
TECH Enthusiast
iTrader: (21)
 
LETHL_SS's Avatar
 
Join Date: Oct 2005
Location: New Bern, NC
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Xtnct00WS6
Any pics of the intake runner? Those were handfinished I take it?
I'll see if I can track some down.... for some reason they arent where they are suppose to be. They are handfinished as well.
Old 03-13-2006, 08:27 PM
  #25  
TECH Fanatic
iTrader: (3)
 
Ryan02SS's Avatar
 
Join Date: May 2003
Location: Lake Anna, VA/ Fairmont, WV
Posts: 1,795
Likes: 0
Received 0 Likes on 0 Posts
Default

Lethl, Those are Rapid heads right? I saw a set of Mikey's heads and they do look very good and always seem to perform. Just look at the ET's they have produced.
Old 03-13-2006, 08:34 PM
  #26  
TECH Enthusiast
iTrader: (21)
 
LETHL_SS's Avatar
 
Join Date: Oct 2005
Location: New Bern, NC
Posts: 726
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Ryan02SS
Lethl, Those are Rapid heads right? I saw a set of Mikey's heads and they do look very good and always seem to perform. Just look at the ET's they have produced.

Yes, these are Mikey's creation!
Old 03-13-2006, 09:19 PM
  #27  
TECH Resident
iTrader: (2)
 
CTSmechanic's Avatar
 
Join Date: Nov 2004
Location: Denver NC
Posts: 860
Likes: 0
Received 1 Like on 1 Post
Default

So if you do this are you just going to let all the grindings and grit hang out in the head or are you gunna dissassemble the heads?
Old 03-14-2006, 09:37 AM
  #28  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by CTSmechanic
So if you do this are you just going to let all the grindings and grit hang out in the head or are you gunna dissassemble the heads?
If your asking if I'm gonna get them cleaned up, then the answer is yes. Absolutely. I don't want that stuff floating around.
Old 04-13-2006, 09:21 PM
  #29  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Well I had some extra time so I took some pics of the final result if anyone wants to see:


Chamber

Intake

Chamber

Exhaust

Chamber...again

Last edited by Xtnct00WS6; 04-13-2006 at 09:42 PM.
Old 04-14-2006, 07:44 AM
  #30  
TECH Senior Member
iTrader: (4)
 
GuitsBoy's Avatar
 
Join Date: Apr 2003
Location: Long Island, NY
Posts: 6,249
Received 3 Likes on 3 Posts

Default

Beautious...
Old 04-14-2006, 03:49 PM
  #31  
777
TECH Senior Member
iTrader: (21)
 
777's Avatar
 
Join Date: Jun 2004
Location: Jacksonville, FL
Posts: 6,697
Likes: 0
Received 1 Like on 1 Post

Default

You doing this to try and get every little bit out could be reverse and you taking a little bit out. I wouldn't mess with what's proven. JMO They didn't just throw these up and port them. There was research done.
Old 04-14-2006, 04:05 PM
  #32  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by 777
You doing this to try and get every little bit out could be reverse and you taking a little bit out. I wouldn't mess with what's proven. JMO They didn't just throw these up and port them. There was research done.
That's why I didn't change the design of the ports. I was able to take out obvious ridges that were the result of the cnc machine. Ridges != better airflow. I'm probably going to get them flowed to see what exactly happened. I don't know how accurate the results will be because of the change in flow bench and possibly the procedure.
Old 04-14-2006, 06:20 PM
  #33  
TECH Resident
iTrader: (2)
 
CTSmechanic's Avatar
 
Join Date: Nov 2004
Location: Denver NC
Posts: 860
Likes: 0
Received 1 Like on 1 Post
Default

So why did you run a poll if you went ahead and did it anyways? More airflow dosent always mean more power..Our heads for our race motors are upwards of 15 grand and they dont seem to worry about the cutting tool marks to much... But there your heads and they do look clean..
Old 04-16-2006, 09:39 PM
  #34  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by CTSmechanic
So why did you run a poll if you went ahead and did it anyways? More airflow dosent always mean more power..Our heads for our race motors are upwards of 15 grand and they dont seem to worry about the cutting tool marks to much... But there your heads and they do look clean..
At first I wasn't going to handfinish the intake based on the overall results here, but then I didn't hear a good enough reason not to. The best reason I basically heard was "you could screw them up". Since I had already gotten good results for the exhaust, I was pretty confident that I could do good work to the intake.

Was it worth my time? Yes, because I enjoy that sorta stuff and they're better than they were before. Would it be worth someone elses time? Probably not.

I've been told that handfinishing will result anywhere from 1 to 2 percent gain in airflow. Doesn't sound like much but with my heads that'll range from 3-6 cfm. I'll take that! I also had a lot of time from when I'd be able to put the heads on. The blending of the valve guide could have used some work too. That was reason enough for me.

Besides, they look better
Old 04-17-2006, 04:40 PM
  #35  
On The Tree
 
Dart331Stroker's Avatar
 
Join Date: Sep 2005
Location: Suburbs of Detroit
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
Default CNC Lines

You should always leave the lines, rougher ports atomize fuel better, smoother ports will allow fuel to puddle and seperate from the air. We finish our heads in the runners to a very rough finish. The exhaust and chamber wont hurt to finish with about a 80 grit hard roll. We have done alot of testing with this exact question in mind, and when you wet flow the heads, the rougher port works much better, moves more fuel, doesnt have puddling, or seperation, when we dyno the motor it makes more power, and the car goes faster..

Just some free tech information!!!

John
Dart
Old 04-17-2006, 04:51 PM
  #36  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by Dart331Stroker
You should always leave the lines, rougher ports atomize fuel better, smoother ports will allow fuel to puddle and seperate from the air. We finish our heads in the runners to a very rough finish. The exhaust and chamber wont hurt to finish with about a 80 grit hard roll. We have done alot of testing with this exact question in mind, and when you wet flow the heads, the rougher port works much better, moves more fuel, doesnt have puddling, or seperation, when we dyno the motor it makes more power, and the car goes faster..

Just some free tech information!!!

John
Dart
Wow! What kind of test scenario was it? Was that with an LSX type engine? I was under the impression that with fuel injected engines that fuel atomization wasn't an issue.

Last edited by Xtnct00WS6; 04-17-2006 at 07:08 PM.
Old 04-17-2006, 07:42 PM
  #37  
TECH Senior Member
iTrader: (4)
 
GuitsBoy's Avatar
 
Join Date: Apr 2003
Location: Long Island, NY
Posts: 6,249
Received 3 Likes on 3 Posts

Default

Originally Posted by Xtnct00WS6
Wow! What kind of test scenario was it? Was that with an LSX type engine? I was under the impression that with fuel injected engines that fuel atomization wasn't an issue.
To the best of my knowledge, you are correct. The fuel is squirted right onto the back of the hot intake valve which boils off the fuel into vapor. If you had a carbed setup, then yes, the roughness would help mix the fuel.
Old 04-17-2006, 09:05 PM
  #38  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Originally Posted by GuitsBoy
To the best of my knowledge, you are correct. The fuel is squirted right onto the back of the hot intake valve which boils off the fuel into vapor. If you had a carbed setup, then yes, the roughness would help mix the fuel.
I went and looked at my head and it looks like you're absolutely right. Most, if not all of the fuel will be squirted to the top of the intake valve basically bypassing most/all of the intake port. In a test environment (or non EFI engine) where liquod would be flowing everywhere, I could see ridges or cnc marks being beneficial for the reasons stated above.

In a real life scenario there would be no use to the ridges from the cnc machine because the fuel had little to no contact to the part of the head that originally had cnc marks. It's not like the fuel is flowing all through the head like it would be in wet flow test. The area near the base of the valve seat hardly had any cnc marks to begin with and that is about the only spot where fuel will have contact to the intake port.

I'd love to see some back to back comparisons on this.

Last edited by Xtnct00WS6; 04-17-2006 at 09:29 PM.
Old 04-18-2006, 11:57 AM
  #39  
On The Tree
 
Dart331Stroker's Avatar
 
Join Date: Sep 2005
Location: Suburbs of Detroit
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
Default Test

Fuel doesnt flow through the head? How do you figure, does it dissapear after it comes out of the injector or carb?

FUEL INJECTION: What is the first word there, FUEL, yes its injected further downstream from from the throttle body, but it isnt like a down nozzle on a sprint car. So fuel is still entering the port, how do you think we test on a wet bench? Just like an injected car, the fuel is added to the air stream just prior to it entering the intake port, so yes it makes a difference.

We have tested this, and we have worked with fuel injection, we know it still makes difference. But if you dont want to believe thats cool, do it your way. Just giving away more free information, that people once again want to dispute.

John
Dart
Old 04-18-2006, 01:09 PM
  #40  
TECH Fanatic
Thread Starter
iTrader: (8)
 
Xtnct00WS6's Avatar
 
Join Date: Jan 2005
Location: Sterling VA
Posts: 1,429
Likes: 0
Received 2 Likes on 2 Posts

Default

Wouldn't you agree though that the majority of the fuel doesn't touch the port wall? Our injectors are pointed directly at the top of the intake valve. I agree that a rough surface could be benificial to the parts where the fuel hits the port, but that part (below the valve seat) is pretty smooth in the first place. I did a little bit of research and come to find out that a fuel injector is "designed" to atomize the fuel. http://auto.howstuffworks.com/fuel-injection3.htm "The injectors are mounted in the intake manifold so that they spray fuel directly at the intake valves." As long as the fuel injector is doing it's job, then the majority of the intake port could have the cnc marks taken out with no adverse effects...right?

By the way I appreciate all the advice and the "free information"

Could you elaborate on the test scenario though John? I'm just curious.


Quick Reply: CNC track lines on intake runner



All times are GMT -5. The time now is 10:34 PM.