[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/bbcode.php on line 483: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4752: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3887)
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4754: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3887)
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4755: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3887)
[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4756: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions.php:3887)
Tractorsport Flowbench Forum Archive • View topic - Port shapes

Port shapes

Have an interesting technique, tool or just anything related to porting? Post it here . . . please no bashing anyone for the model of engine they are working, we're here to share ideas . . .

Postby evilgenius » Sun Sep 30, 2007 11:38 pm

I build Harley engines and on the twin cam heads there are a lot of different ideas about port shape. they all have a D shape on the intake and some guys are dividing the D on the intake and the exhaust port narrows at the exit. the engine is EPA so i think they do this to keep the head temp high. the after market heads from Harley have a D shape in the exhaust too but it still seems very restrictive I think that some of that might be to create reversion to preheat the chamber. But it seems to me this would be better accomplished with a good 2 into 1 exhaust. dose anyone have any thoughts? ??? ???
evilgenius
 
Posts: 2
Joined: Tue Jul 17, 2007 5:56 pm

Postby gofaster » Tue Oct 02, 2007 11:18 pm

The D exhaust serves to raise the floor, broaden the short turn radius, and act as an anti reversion dam.
Jim
gofaster
 
Posts: 237
Joined: Fri Jul 01, 2005 6:39 pm
Location: Indiana

Postby evilgenius » Wed Oct 03, 2007 1:33 am

I understand how it would broaden the short turn radius but how dose the D shape act as anti reversion dam? and in the Harley head don't you want some reversion?
evilgenius
 
Posts: 2
Joined: Tue Jul 17, 2007 5:56 pm

Postby gofaster » Fri Oct 05, 2007 12:34 am

The D faces a round exhaust pipe, making a ledge. No, you never want reversion!
Jim
gofaster
 
Posts: 237
Joined: Fri Jul 01, 2005 6:39 pm
Location: Indiana

Postby msj442 » Wed May 20, 2009 11:32 pm

the d shape is most common on an aftermarket head where the short side is raised along with the center side of the cylinder floor being higher than the opposing side. if you look at a good flowing exhaust port it is tilted whenever possible. the roof is raised on the center side also along with the floor.

jmo, max
msj442
 
Posts: 331
Joined: Wed Feb 20, 2008 10:58 pm


Return to Porting techniques?

Who is online

Users browsing this forum: No registered users and 5 guests