Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

Real horsepower rating?

Thread Tools
 
Search this Thread
 
Old 01-29-2010, 05:24 PM
  #1  
Junior Member
Thread Starter
 
91formulaNY's Avatar
 
Join Date: Mar 2007
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Real horsepower rating?

We all know that car companies under estimate an engines " real/true" horspower ratings due to insurance reasons.. My question is, does anyone have an idea of the "true" horsepower rating of 350 tpi engine(L98) out of an 89 formula?
Old 01-29-2010, 05:52 PM
  #2  
Moderator

iTrader: (14)
 
five7kid's Avatar
 
Join Date: Mar 2000
Location: Littleton, CO USA
Posts: 43,169
Likes: 0
Received 36 Likes on 34 Posts
Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Actually, the current "net" ratings are much more accurate than what the factories said in the 60's.

Single cat L98 230 HP, dual cat L98 240 HP.

Now, if you want a "gross" flywheel HP number, take it to an engine dyno, use an electric water pump, long tube headers, and let 'er wail. You'll probably come up with something like 275-285 HP.
Old 01-29-2010, 06:25 PM
  #3  
Supreme Member

iTrader: (58)
 
Drew's Avatar
 
Join Date: Jul 1999
Location: Salina, KS
Posts: 20,309
Received 1,054 Likes on 749 Posts
Re: Real horsepower rating?

If you run the actual performance figures for these cars through the various calculators the factory ratings are pretty close.
Old 01-29-2010, 08:09 PM
  #4  
Junior Member
 
red30011's Avatar
 
Join Date: May 2009
Posts: 60
Likes: 0
Received 0 Likes on 0 Posts
Re: Real horsepower rating?

Dumb question but I need ask so I will know,lol. L98 motors are just 350s from around the 80s and 90s right? Before the 80s or so did they had a different name? I ask because I have a mid 70s 350 block and didn't know what that motor might be called or if it was also a L98?

Don't mean to hijack the thread but seemed like a good place to jump in...
Old 01-29-2010, 08:12 PM
  #5  
Moderator

 
Apeiron's Avatar
 
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes on 8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: Real horsepower rating?

No, an L98 is a 350 with TPI. They didn't exist before 1985, or after 1992.
Old 01-29-2010, 08:15 PM
  #6  
Moderator
TGO - 10 Year Member
 
AlkyIROC's Avatar
 
Join Date: Jul 1999
Location: 51°N 114°W, 3500'
Posts: 17,167
Likes: 0
Received 136 Likes on 114 Posts
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: Real horsepower rating?

There are a lot of 350 engines produced by GM. There are many variations of them with compression ratio, cam grind, induction systems. All of these get a specific engine code. The late 80's 350 TPI engine was classified as an L98. A mid 70's 350 usually had a L82 or L48 engine code and there were many others. The 1970 Corvette 350 got an LT1 engine code.
Old 01-29-2010, 08:21 PM
  #7  
Junior Member
 
red30011's Avatar
 
Join Date: May 2009
Posts: 60
Likes: 0
Received 0 Likes on 0 Posts
Re: Real horsepower rating?

ah, ok. I understand how the engine codes work now. I'll take a peak at my block again sometime and figure out what mine was. Thanks for explaining
Old 01-29-2010, 08:25 PM
  #8  
Moderator

 
Apeiron's Avatar
 
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes on 8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: Real horsepower rating?

That's also why it doesn't matter what an engine used to be, or what platform it was installed in, or how much power it used to make. As soon as you pull it out and take away some of it's factory-installed equipment it stops being what it was and becomes just another 350, or whatever.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Pac J
Tech / General Engine
3
05-17-2020 10:44 AM
mattcanty
Firebirds for Sale
4
10-12-2015 11:08 AM
LT1Formula
Engine/Drivetrain/Suspension Parts for Sale
7
10-08-2015 08:34 PM
oil pan 4
Fabrication
2
10-06-2015 11:56 AM
racereese
Tech / General Engine
14
10-03-2015 03:46 PM



Quick Reply: Real horsepower rating?



All times are GMT -5. The time now is 10:29 PM.