Go Back  Offshoreonly.com > Technical > General Q & A
maching vortec heads >

maching vortec heads

Notices

maching vortec heads

Thread Tools
 
Old 12-30-2010 | 05:38 PM
  #11  
JimV's Avatar
Registered
20 Year Member
 
Joined: Nov 2000
Posts: 709
Likes: 2
From: Grand Rapids Mi. U.S.
Default

Originally Posted by innerrage
its a 350ho vortec with msd ignition 8.5 wires 8m blue ignition box holley 650 edlebrock performer rpm intake and revolution marine 4inch aluminum wet exchaust with a gaffrig air cleaner the motors only has about 15hours on it and i got a set of ss full roller rockers for it to put on
Sorry, I thought you were talking big block. The small block heads are very workable as well. I'm working on a set right now. You may want to use a 1.6 rocker on the intake side.
JimV is offline  
Reply
Old 01-11-2011 | 10:55 AM
  #12  
JimV's Avatar
Registered
20 Year Member
 
Joined: Nov 2000
Posts: 709
Likes: 2
From: Grand Rapids Mi. U.S.
Default

Here are some flow numbers from a stock head:

Lift....................CFM....................... CFM
Intake EX

.2......................127.....................10 1
.3......................185.....................13 8
.4......................222.....................14 9
.5......................216.....................15 5
.55....................215.....................157

The intake port peaks at .4 and looses air after that point.
The exhaust poops out at about the same lift. Meaning there is an 11 cfm increase between .3 and .4lift and a 6 cfm increase between .4 and .5.

After some port work with the same valve:


Lift..............CFM...............CFM
Intake Exhaust

.2...............126.................111
.3...............191.................152
.4...............236.................178
.5...............242.................184
.55.............246.................186
.6...............248.................187

If I were to go to a 2.02 I would expect a gain on the intake at .4 and higher but would need extensive bowl and short turn work. Not a bad gain for stock valves. An added gain would be to increase cam lift to .550 to take advantage of the extra airflow at higher lifts.
Attached Thumbnails maching vortec heads-vortec-heads-002.jpg   maching vortec heads-vortec-heads-001.jpg  

Last edited by JimV; 01-11-2011 at 11:00 AM.
JimV is offline  
Reply
Old 02-12-2011 | 09:06 AM
  #13  
Thread Starter
Registered
 
Joined: Jul 2009
Posts: 1,659
Likes: 0
From: ct/fl
Default

thanks i wish you were closer
innerrage is offline  
Reply

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.