roller rockers on vortec heads - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-02-2012, 03:40 PM
Registered User
 
Join Date: Jul 2012
Posts: 43
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
roller rockers on vortec heads

Hey guys ? For you I was wondering if I have to run speical rockers on vortecs and if you could give some part numberd would be appreciated

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-02-2012, 04:40 PM
Registered User
 
Last photo:
Join Date: Jan 2011
Location: Hopewell, Va
Age: 62
Posts: 1,234
Wiki Edits: 0

Thanks: 0
Thanked 125 Times in 120 Posts
roller rockers on vortec heads

The self aligning rockers are used with the center bolt valve covers. If using the old style valve covers use full roller rockers, guide plates, and hardened pushrods.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-02-2012, 05:39 PM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,259
Wiki Edits: 0

Thanks: 0
Thanked 110 Times in 101 Posts
I used Scorpion SCP 1073BL full roller rocker arms.
They are 1.5:1 ratio, narrow body, self aligning, no guide plates. I used ARP 134-7301 3/8"-24 screw in rocker studs. My Comp Cams beehive valve springs were set up at 1.750" at 144 lb. closed and 330 lb.open at .500" valve lift.

Comp Cams 1015-16 (1.5:1) full roller rockers have the same specifications.

Full roller rocker arms are only necessary if your valve springs have pressure approaching 350 lb. open or you risk burning up rocker pivot balls.

If you need new rocker arms anyway, and have valve springs with less than 330 lb. open pressure, Comp Cams roller tip rockers will fit Vortec heads with center bolt valve covers. Comp Cams 1417-16, 1.52:1 ratio or Comp Cams 1418-16, 1.6:1 ratio. They should be used with less than 325 lb. open pressure.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-02-2012, 06:25 PM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 632
Wiki Edits: 0

Thanks: 0
Thanked 33 Times in 31 Posts
smith9300,
You didn't say what pn Vortecs you've got, or exactly what rpm you plan on turning, roller or flat tappet cam, or how much you want to spend?
I'm guessing that you have stock springs, and studs(3/8" w/no guide plates), and center bolt valve covers?
If I'm not mistaken, you have a stock bottom end on a 400 sbc, or at least you did on a previous post. If it has stock rods w/stock bolts I wouldn't turn it over 5500rpm IMO. If you have stock pistons you'll probally have problems with too much compression,
Stock heads had around 76cc combustion chambers. Vortecs have around 64cc if I'm not mistaken. Installing vortecs would raise the compression ratio at least one full point if not more. If the stock engine had 8.75:1 CR w/76cc heads, it would increase to at least 9.75:1 with vortecs and detonate on pump gas if everything else remained stock IMO. I know for a fact that no 400 sbc came stock with vortec heads.
If I'm not mistaken you said you had a Comp XE256 cam in mind on a previous post. The early closing intake valve would cause the dynamic compression to be around 8.5:1, too much for iron, or aluminum, heads on pump gas IMO. I'm guessing 0.25" in the hole, stock bore, and an 18cc dish volume. May be more like 12cc (someone that knows better is welcome to chime in) which would make things even worse.
You really need to reconsider your use of stock pistons if thats what they are?
If you have stock springs you don't want to run a roller cam(not enough pressure to controll roller lifters). If the heads don't have the stock valve guides machined for more than stock valve lift, you don't need 1.6:1 roller rockers, and are limited to about 0.450" valve lift.( I'm guessing thats why you picked the 256 cam?)
In my opinion with that small of a cam you don't need roller rockers. Stock type guided rockers would be fine.IMO
Others have tried to tell you about the excesive compression. You really need to see that they are trying to help you from blowing up your 1st engine, before you can even get it broke-in, or at least read up on it for yourself. Here is an excelent article IMO on dynamic compression, and a compression calculator you can download that can help you make an informed decision.
Dynamic CR
FWIW
ssmonty
stock type rockers summit pn NAL-12495490
I know others will disagree on the roller tip w/ball type fulcrum, but
I've had good results with these style of Comp rockers for over 15 years. Summit pn CCA-RP1417-16, but like I said the stock type would work fine.
I can't say what full roller rocker would work with centerbolt valve covers, sorry.FWIW.
Edit: I took so long to type I see that others have beat me to it. I started about 2 hours ago.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-03-2012, 06:33 AM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,259
Wiki Edits: 0

Thanks: 0
Thanked 110 Times in 101 Posts
The first thing you should do is replace the stock pressed-in rocker studs with ARP 134-7301 rocker studs, no matter what valve springs or rocker arms you use. They are preferred even with stock equipment.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




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

Posting Rules
You may post new threads
You may 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Roller Rockers to use with Vortec heads??? GUITAR1989 Engine 5 06-02-2011 06:24 PM
Crane Steel Roller Rockers with Aluminum Heads? rac43 Engine 5 12-18-2010 09:58 AM
Vortec Heads/Roller Rockers Sinister Engine 7 04-28-2009 09:47 AM
Roller rockers on centerbolt heads? staleg Engine 9 10-24-2006 08:14 PM
Vortec - roller rockers? dev Engine 2 09-20-2004 06:05 AM


All times are GMT -6. The time now is 01:45 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.