cams - 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 06-09-2010, 06:14 PM
Registered User
 
Join Date: May 2010
Location: sacramento
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
cams

hello,
im pretty sure this is a dumb question but when im looking at cams for my engine and it says basic rpm range of like 2500 - 6000 or something like that, does this mean that my car will sit there and idle at 2500rpms?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-09-2010, 06:23 PM
eloc431962's Avatar
Evil Wicked Mean And Nasty
 
Last wiki edit: Pilot bearing and bushings
Last journal entry: roof repair
Last photo:
Join Date: Nov 2008
Location: back in the garage.
Posts: 13,762
Wiki Edits: 37

Thanks: 50
Thanked 28 Times in 24 Posts
No such thing as a dumb question, And no it don't mean it will have to idle at 2500 rpm. Those # s are the power range of the cam is from 2500 to 6000 rpm.JMO


Cole
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-09-2010, 07:01 PM
Registered User
 
Last photo:
Join Date: Feb 2004
Location: puerto rico
Posts: 242
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i`m guessing that it all depends on how far the RPM drops when u shift gears? like a close ratio trans drips only 500 rpm, like that of a muncie. OR like a c4 that drops alost 1000 at 800
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-09-2010, 09:36 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,564
Wiki Edits: 326

Thanks: 698
Thanked 878 Times in 746 Posts
Any camshaft you bolt into the motor will have an effective operating range of about 3500 rpm's. It will not be effective and make good power from idle to redline, but only in the range outlined. Let's say you wanted the cam to make power right off idle, then you might choose a cam that makes power from 1000 to 4500. At 4500, the motor would be running out of breath and you'd have to change gears to drop the rpm's down under 4500 for the motor to pull again in the taller gear.

Now, on the flip side, let's say that you are like most other young persons who thinks more cam makes more horsepower, regardless of static compression ratio or any other consideration. Most everything on and in the motor is stock, but you decide that a cam that makes power from 4000 to 7500 will be the hot ticket. You bolt it into the motor and now can't understand why the motor will not pull the hat off your head under 4000. Let's say you installed this cam and then installed a 4000 stall converter so that the motor would rev up past the range where it makes little or no power. This might be going in the right direction, but you still have stock heads on the motor, so it will run out of breath at 5000 or 5500 and you still have built a turd. You now only have a power range of 4000 to 5500, a 1500 rpm window of operation.

Once you understand that all the parts of a motor must be coordinated together to make power through a pre-determined range, then you will be a good amateur engine builder.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-10-2010, 12:00 AM
Registered User
 
Join Date: May 2010
Location: sacramento
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
you know techinspecter1,
i think i have learned more from you in your responses on my posts then just about anything.

thanks a lot
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-10-2010, 02:56 AM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,564
Wiki Edits: 326

Thanks: 698
Thanked 878 Times in 746 Posts
You're welcome. Many people have taught me, I'm just giving some of it back to fellows like you.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 06-10-2010, 08:55 AM
my87Z's Avatar
Veteran/Firefighter-EMT-I CRT
 
Join Date: Mar 2009
Location: maryland
Age: 30
Posts: 1,685
Wiki Edits: 0

Thanks: 6
Thanked 11 Times in 11 Posts
the advertised operating range for sbc cams is also rated for the 350 not all sbc, and the rule is the more cubic inches it has the cam it will eat up. so say the operating range of the cam is 2500-5500 for a 350, that same cam in a 383 will have an operating range more like 2200-5200, and for a 400 it will have and operating range of 2000-5000, but in a 327 it will have and operating range of 2800-5800. do you understand this. so it when picking a cam you also have to pick one that will be right for you specfic motor and the intended driving it will be used for.
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
confused about camshafts (FSB) pstrbrc Engine 9 11-30-2008 08:02 PM
Comp Cams hydraulic roller vs. solid flat tappet comparison Mad Maggot Engine 23 02-13-2005 10:29 AM
Solid cams vs Hydraulic cams, preference or power? killerformula Engine 17 02-03-2005 09:42 AM
Know of any good cams? TurboS10 Engine 19 12-20-2004 01:46 PM
Truth about, emmisions and cam's stereodud Engine 16 11-18-2002 03:25 PM


All times are GMT -6. The time now is 10:21 AM.


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.