spring pressure - 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 01-27-2004, 08:59 AM
cadallac's Avatar
New Member
 
Join Date: Jan 2004
Location: tennessee
Age: 72
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
spring pressure

i need to know why you have to have so high a pressure on the springs of a roller cam it dosen't make any sence and i talked to a lot of racers but no one knows the answer only that yo have to

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-27-2004, 09:14 AM
camaroman7d's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Vacaville, California
Age: 47
Posts: 2,245
Wiki Edits: 0

Thanks: 3
Thanked 9 Times in 9 Posts
The ramps are so steep (how fast they get to maximum lift), this is their advantage. This requires higher spring pressures to control the lifter (so it doesn't jump off the cam). If you do not run high enough spring pressure it is damaging to the lifters, valves, valve seats.

Royce
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-27-2004, 09:24 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 37
Posts: 4,080
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
As well as controlling valve loft or float. Rollers wiegh in at a Ounces rather than Grams for a flat tappet hyd.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-27-2004, 10:40 AM
King of my Man-cave.
 
Last photo:
Join Date: Nov 2003
Location: Michigan
Age: 55
Posts: 2,899
Wiki Edits: 0

Thanks: 3
Thanked 15 Times in 12 Posts
To put the last two post together, the heaveier lifter is moving at increased velocities so the loads are heavier, hence the need for increased spring pressures to control valve bounce and lobe launching.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-27-2004, 01:10 PM
cadallac's Avatar
New Member
 
Join Date: Jan 2004
Location: tennessee
Age: 72
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
spring pressure

thanks fellows i can understand that now what is the lowest spring pressure for the roller cam
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-27-2004, 01:18 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 37
Posts: 4,080
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
Depends on the Intended RPM but for stock applications no less then 300 pounds over the nose.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-27-2004, 01:41 PM
cadallac's Avatar
New Member
 
Join Date: Jan 2004
Location: tennessee
Age: 72
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
spring pressure

time to tell you what i have. 71 chevy nova 355.>steel crank 12/1
pistons forged>555/578 crane cam> solid lifters>balanced', 462 heads ported and polished,202 intakes 160 exaust>holly dominator intake >holly 750 dp carb >all the goodys to go /with it powerglide trans brake 513 rear full spool 11 inch rinkel slicks and i want to go to a good roller it turns 710 in the 8th now got any sugestions??:
also it has a 5500 stall convertor

Last edited by cadallac; 01-27-2004 at 02:00 PM.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-27-2004, 03:04 PM
camaroman7d's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Vacaville, California
Age: 47
Posts: 2,245
Wiki Edits: 0

Thanks: 3
Thanked 9 Times in 9 Posts
Call your prefered cam company and give them the same details you just listed and they will set you up with a cam and springs.

Royce
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-27-2004, 03:18 PM
brainsboy's Avatar
brains
 
Last photo:
Join Date: Jan 2004
Location: tampa
Age: 42
Posts: 988
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You have to goto crane cams website, it will tell you what spring pressure to use.

Its hard to know what spring pressure a roller cams need because you cant go just by duration,lift,rpm.. You need to know technical things such as ramp speeds, ect,ect, things that you probably dont have the specs on. This is why a crane cam and competition cam although may have the exact same duration and lift listed but will be two totaly different cams. Comparing cams is very difficult with only the information they give to the consumer.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-27-2004, 03:23 PM
Member
 
Last photo:
Join Date: Oct 2003
Location: Tri-Cities, TN
Posts: 726
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Lobe profiles differ but you woul be safe with 220# on the seat and 550# open. You will need to change dist. gears to a bronze gear.

Chris
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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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



All times are GMT -6. The time now is 02:34 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.