Horsepower then and now - 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 09-01-2003, 06:56 PM
New Member
 
Join Date: Aug 2003
Location: Los Angeles
Posts: 13
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Horsepower then and now

Hello all,
I have a tech question regarding horsepower ratings.
In 68 the 350 motor was rated by GM at 295 horsepower. At some point in the 70's they redid the way they measure horsepower. I guess what I'm trying to figure out is:
a. What would that 295 h.p. be in todays numbers?
b. Why and when did they change the formula/ reading/ rating?
c. Why don't I know this already?

I'm sure a lot of you know this , so please bear with my seemingly stupid question.

Thanks

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-01-2003, 07:15 PM
New Member
 
Join Date: Aug 2003
Location: Greenville, Oh
Age: 60
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I've been told that a good estimate of the HP in today's measurement is to deduct 1/3. Using this system your engine would have about 200 hp.

Don't really know why it was changed, but one theory would be that it was caused by the insurance companies, due to how the manufactures misrepresented their muscle car hp. Just a theory.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-01-2003, 07:31 PM
Member
 
Last photo:
Join Date: Aug 2003
Location: Sault Ste Marie, On. Canada
Age: 29
Posts: 171
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
a: I've heard of using the 1/3 rule, but you used it the wrong way, so multiply 295 by 1.333 and it should be somewhere around 390

b: After the insurance rates started to climb, car manufactures changed the way they rate engines from peak horsepower to net horsepower. Using this method they made it look like the engines were making less power (and thus safer), when they really were just about equal (due to some restraints, they did make less peak horsepower as well)

c: because, until now, you never took the time to ask
__________________
1984 Pontiac Grand Prix
-350 4-bolt main
-Torker II Intake
-Holley 600 cfm 4-barrel
-Flowmaster Afterburner headers
-Turbo 350 Transmission
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-01-2003, 07:33 PM
mstngjoe's Avatar
Member
 
Last photo:
Join Date: Jan 2003
Location: Oregon
Age: 63
Posts: 593
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
This thread may answer a question or two:

http://hotrodders.com/showthread.php?s=&threadid=22047
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-01-2003, 08:10 PM
New Member
 
Join Date: Aug 2003
Location: Los Angeles
Posts: 13
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
horsepower....and my "Frankenmotor"

Wow...thanks guys for the quick reponses. I did a search in the archives. More info than I can even digest at this point.

Last edited by SteveW; 09-01-2003 at 08:43 PM.
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



All times are GMT -6. The time now is 06:57 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.