PONTIAC ZONE TECH FORUMS
 

Go Back   PONTIAC ZONE TECH FORUMS >
Engine Tech
> High Port Head
User Name
Password

High Port Head High Port owners can give there opinions along with their track results

sponser links

Reply
 
Thread Tools
Old 03-12-11, 04:27PM   #61
Stan Weiss
Registered User
 
Join Date: Oct 2010
Location: Philadelphia PA
Posts: 782
Default

Quote:
Originally Posted by EC View Post
Quote:
Originally Posted by Dragncar
Wait until someone goes with cfmc CNC Tiger 450 cfm heads on a 572, then they might make 1000+.
That would be interesting, although I think you are crazy to run a 4.75 stroke crank in a standard deck height block but that is just me.
How about some build a 518 (4.355" bore, 4.35" stroke, 2.3" intake valve) with around 490 cfm @ 1" plus lift and then make 1075 HP @ around 8000 rpm.

Stan
Stan Weiss is offline   Reply With Quote
Old 03-12-11, 05:43PM   #62
Dragncar
Registered User
 
Join Date: Aug 2005
Location: Mcinleyville CA
Posts: 647
Default

Stan, what I put out there is a serous real world bolt on combo. They make the stuff. I do not know of any 490cfm Tigers and do not think a +1" lift cam has ever been used on a Pontiac.
Now about Wide Ports on a 4.155 bore.
Gach, you ever hear of such a thing.
Dragncar is offline   Reply With Quote
Old 03-12-11, 06:39PM   #63
Dragncar
Registered User
 
Join Date: Aug 2005
Location: Mcinleyville CA
Posts: 647
Default

EC, someone has Tigers that go more than Langers 480 heads or is that Langer he is talking about.
Now, back to the 4.155 bore and Wide Ports. Anyone know of a combo.
Dragncar is offline   Reply With Quote
Old 03-14-11, 06:19PM   #64
Aaron
 
Posts: n/a
Default

EC,

I bet you can make more power than that. A 400 I built years ago running 1995 vintage E-heads made 620 on pump gas with a .620" lift cam. I bet you can make over 700 hp without killing yourself. I agree with your post on all accounts.

Good luck with the build,

Aaron

Quote:
Originally Posted by EC View Post
By the way I plan on next winter starting a 400 build (3.75 stroke) that will be a true street engine (drive it from coast to coast) and make close to 650hp. The plan right now is to run the best head (either HP or the new Victor heads) and intake combo that I can get, put a somewhat mild cam in it with good lift and see what it will do. Those heads I expect will flow over 350cfm with a 2.150 valve with no problem.
Again flow means nothing (will almost nothing) it is the size of the port that matters (cross sectional area not port cc), since the HP head has raised runners it will flow more than an e-head given both ports are sized the same. That is the advantage of the raised runner, it gives the air/fuel a straight path to the valve.
  Reply With Quote
Old 03-14-11, 09:42PM   #65
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,603
Default

Surely port cc means some thing, it has to increase at some point.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 03-14-11, 10:09PM   #66
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,603
Default

I get it. So all those CV ports really come from the require CSA for a given combo like what a 428 ci motor would need. I was wondering why he was posting those ports in runner cc.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 03-15-11, 01:15AM   #67
Aaron
 
Posts: n/a
Default

Now we're making progress Gach. An NA wants enough CSA to get about .5 mach at max power speed for best performance in the intake port. A boosted engine wants more area than an NA. The reason is your trading off port restriction (area) vs. capturing the dynamic pressure head of the intake air with a higher velocity port (smaller area). The dynamic head is a considerable factor on NA engine because it is a decent percentage of the pumping work required to move air in and out. On a boosted engine the pumping work is larger and the dynamic head of the intake air is a much small percentage of the total. The best trade off on efficiency with boosted engine then drives you to a larger CSA and lower velocities. The indicated work on a boosted engine is much higher than an NA as well which makes the pumping work a smaller percentage of the indicated work as compared to an NA. Make sense?

Have a look at the Dynomation 5 users manual. It contains a details to help better explain the trade offs above. The manual is worth looking at, even if you don't have the software. Dynomation isn't quite as good as WAVE or GTPower, but it's very good for what it costs.


Quote:
Originally Posted by Gach View Post
I get it. So all those CV ports really come from the require CSA for a given combo like what a 428 ci motor would need. I was wondering why he was posting those ports in runner cc.
  Reply With Quote
Old 03-15-11, 01:28AM   #68
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,603
Default

Dose anyone know the formula for calculating air speed.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 03-15-11, 02:26AM   #69
Stan Weiss
Registered User
 
Join Date: Oct 2010
Location: Philadelphia PA
Posts: 782
Default

These are from a Post by Larry Meaux on another forum

FPS = ( CFM / CSA ) * 2.4

CFM = FPS * CSA / 2.4

CSA = ( CFM / FPS ) * 2.4

Stan
Stan Weiss is offline   Reply With Quote
Old 03-15-11, 02:27AM   #70
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,603
Default

Velocity Formula

1. ( CSA - "Radii" .16*) = " Final CSA "
*
2. ( Final CSA* /divide by/ 144 ) = " Sq. Feet Area "
*
3. ( Max CFM /divide by/ Sq. Feet Area ) = " FPM "
*
4. ( FPM /divide by/ 60 ) = " FPS "
*
*
............. note, most people will use the entry dimensions as the CSA for point of reference ...........
*
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 03-15-11, 02:30AM   #71
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,603
Default

What's the velocity. On 3.4 CSA
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 03-15-11, 02:40AM   #72
Stan Weiss
Registered User
 
Join Date: Oct 2010
Location: Philadelphia PA
Posts: 782
Default

350.3 fps is normally max @ 28 inches of water

What is the CFM?

Equation (cfm / 3.4) * 2.4
Value
of cfm fps
300.0000 211.76
325.0000 229.41
350.0000 247.06
375.0000 264.71
400.0000 282.35
425.0000 300
450.0000 317.65
475.0000 335.29

Stan
Stan Weiss is offline   Reply With Quote
Old 03-15-11, 03:13AM   #73
Stan Weiss
Registered User
 
Join Date: Oct 2010
Location: Philadelphia PA
Posts: 782
Default

First you do understand that you are talking average air speed in this calculation.

If we are measuring air speed in the below port at the locations marked by the "O". The air speed will be different. one of the things that the port is trying to do is keep the differences between the higher and lower air speed s as close as possible.

Stan

Code:
___________
|    O    |
|         |
|         |
|O   O   O|
|         |
|         |
|    O    |
-----------
Stan Weiss is offline   Reply With Quote
Old 03-15-11, 09:17AM   #74
Aaron
 
Posts: n/a
Default

On a running engine it depends on the engine displacement and peak rpm. For example if you're running a 434 CID at 7000 rpm, the peak velocity would be ~502 ft/sec or .43 Mach at 85 deg F. At the same conditions for a 500 CID, the velocity would be ~578 ft/sec or .51 mach.


Quote:
Originally Posted by Gach View Post
What's the velocity. On 3.4 CSA
  Reply With Quote
Old 03-15-11, 01:57PM   #75
Stan Weiss
Registered User
 
Join Date: Oct 2010
Location: Philadelphia PA
Posts: 782
Default

Hi Aaron,
Are you Aaron S Q with whom I have exchanged e-mail over the years?
Stan
Stan Weiss is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
670 Heads, 67cc, pocket ported, fresh; 1.52 PRW roller rockers Josh69 Parts & Cars For Sale & Wanted 3 08-04-10 04:44PM
rockers t-bar Engine Tech Discussion - Street or Strip 5 06-08-08 01:55PM
No oil at rockers PnchoPwr Engine Tech Discussion - Street or Strip 1 04-18-07 02:19PM


All times are GMT -3. The time now is 09:34AM.

Featured Ads
Ken's Speed & Machine
Mayhem Turbocharging

Carter Cryogenics.  What can we freeze for you?

Pacific Performance Racing

Central Virginia Machine Service.  Home of the Injun Engine!

All Pontiac Engine Kits

Larry's Auto Machine.  Full serivce auto, marine machine shop, domestic and foreign.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
2001 - 2007 PontiacZone.com
Page generated in 0.12933 seconds with 43 queries