JagV12 is going to teach us Gross vs. Net HP

Quote from the other thread

frenchyd said:

Stampie (FS) said:

In reply to frenchyd :

Offered in ‘71 only was the LS6 454 cu in (7.4 L) big-block featuring aluminum heads and delivering 425 hp 

What year Jaguar V12 came stock with 486hp?

Do you know the difference between Gross/Advertized and Net horsepower?  

Since Frenchy thinks I'm a DA and don't know the difference between Gross/Net I'll let him carry on his rant here.  BTW the LS6 was 325 net.  The same year the Jag was 282 I assume net.  So back to my question.  What year Jag V12 had 386 NET hp?

Here's the quote that started it all.

frenchyd said:

In reply to TheV8Kid :

From the bottom the engine looks like a top fuel with 4 extra cylinders.  
Stock it's very powerful for the time. Stone stock it made 61 more horsepower than a Chevy 454 ( with American pollution specs it still made 32 more HP than the 454 )    

In reply to Stampie (FS) :

Do you really believe that it made 325 SAE net installed horsepower?  Or might that be net dyno horsepower?   
  I wasn't there. We're you?  
But with the better aluminum heads. It might be as powerful as a V12.    Maybe even a fudge more. 
Except I really doubt you can find a decent one of those today for a few hundred dollars.    
      

WEll, according to the internets the most powerful stock Jag V12 from Jag was 333hp/365tq as advertised in 1993. There were TWR variants that were punched out to 7.4L that made 750hp but thats not a stock Jag V12.

So the answer is: None.

EDIT: I guess you could find like a truck motor or something. The TBI 454 from like 1990 made 230-255hp but 385-405 tq. 1990 V12 would have been 285hp/319tq.. That's 55.... so we're getting close. 

In reply to frenchyd :

You still haven't answered my question.  What year Jag V12 made 61 more horsepower than a LS6 454?  Now I'll answer your question.  No I do not believe it made 325 installed HP.  That engine was widely known to be underrated for insurance/factory racing purposes.  I believe it made a lot more than 325.  Are you going to answer my questions or keep repeating your Jag V12 myths?

I know this is a tangent, but there was a V12 Jag that had 425hp in it.

But 1) it didn't carry a Jag badge on it, and 2) the V12 was very much not from Jaguar.

The car was a derivative of the XJS platform- and was closer to it than the Jag that came out at the same time.

The engine was made of parts from one of the most common cars being sold in the US at the time.  Later versions were above 460hp, IIRC.

Yea, that has nothing to do with this debate, though.

Haha!

I was just about to start a thread titled "Stampie and Frenchy's Argument Page... Big Block Chevy vs Jag V12"

Thank you for pulling it off of the Studebaker page. 
 

carry on...

In reply to Stampie (FS) :

How many of those were made?  Pretty limited production wasn't it?  So I guess  the TWR and Lister versions should count shouldn't they?   Especially the TWR since that was a factory approved deal. 
   But more to the point. The rest of the world got 291 horsepower until 1980 when it went up to 299 horsepower.    
     

I'm sorry I used to work on planes so my hearing isn't too good.  What year did you say made 61 more HP than the LS6?

In reply to frenchyd :

I mean, if you're going to include race engines, there were 1500+hp big blocks. Do you really want to go down that path?

This is such a weird rivalry.

Stampie. 
Chevrolet built a good value car. So much so I've bought 20 new ones in my lifetime.  ( never bought a new Jag ) 

     I tried racing a Chevy V8 in my Corvette. But they don't last. Very few of the street versions have forged crank shafts. Those that do aren't hardened.  Chevy's could be modified  to make  a lot of power at elevated RPM and stock rods aren't up to living at elevated RPM.  Rocker arms and valve springs also need to be upgraded. Plus push rods. As does the camshaft ( just like Jaguar) 

My preference for a Jaguar  has everything to do  with racing and nothing about practical day to day driving on the street. 
Can we at least agree about that?  

In reply to frenchyd :

Are you suggesting that the Jag V12 is more successful than the Chevy V8 in racing?

Considering the eras, it took quite a while for a Jag V12 to win anything- if I get my timing right, the Group 44 XJS was one of the first ones, right?  Well after the domination of the GM engines in CanAm (up until the P flat 12).  And the numerous wins in Trans Am.  And weren't Lolas very much powered by a Chevy?   Realistically, the GT40 could have easily been powered by a GM motor had it not been for Ford spending the money.  

And lets not pretend that NASCAR didn't exist.

There's no issue if you prefer the Jag motor, just like I prefer Alfas.  Nothing wrong with that.

To pretend that they are better, though....  Can't see that one.

In reply to frenchyd :

Funny that the elder Nelson in the other thread has stated in the past that the big block Chevy was his preferred racing engine for years.  Look I don't mind that you like Jag V12s.  I used to like them before having to listen to your propaganda all the time.  What I mind is you misstating facts to prove your point.  I also mind how you talk all your crap about being better than Chevy engines but don't back it up.  Over the years I've made all kinds of offers for a fair race, dyno pull, or whatever else will make you put up or shut up.  I've even offered to pick your Jag up north and transport it to the Challenge paying for the transportation and the fee to enter.  Come on man I understand you're butt hurt about all the stupid rednecks that swap in a Chevy rather than deal with the best engine ever made by mankind but do you have to go on and on about it?  Hell I'm not even a big block Chevy fan boy, I actually like the Cadillac big blocks better but you don't hear me bitching everytime someone swaps a Chevy into an old Cadillac do you?

Mr_Asa said:

This is such a weird rivalry.

Many get tired of the constant posting of incorrect and/or unrelated information. 

Stampie (FS) said:

I'm sorry I used to work on planes so my hearing isn't too good.  What year did you say made 61 more HP than the LS6?

I'll let you pick the year. From 1975- 1992 the Jaguar made 291 Net DIN horsepower  to the Chevy 454 which made 230 Net SAE horsepower.  In 1980 Jaguar made 299 Net DIN horsepower. 
wait I minute and I'll get you the correction factor.   The only one I found after reading 12 pages is 3.2%.  DIN is higher by 3.2%    I remember a smaller number but can't recall exactly what it is. 
I did read about how strict  the DIN number compared to how flexible the SAE number is. But that's not what the argument is or should be about.   
 

In reply to Stampie (FS) :

I agree completely with everything you have said.  It's tough to stomach facts that are a moving target.
 

But with all due respect, it takes 2 to argue, and some of us don't care any more. 

This debate has gotten exhausting, and it makes no difference who is right. Neither of you has brought a fast car based on either the Jag or the BBC. 
 

Thank you again for pulling it out of the Atlas thread. I really did appreciate that. 

...and just to make BOTH of you happy, I'm currently building a street rod cruiser. It has a BBC, and a Jag IRS. 

In reply to frenchyd :

Again you aren't answering my question.  You are purposefully choosing years that you know didn't make as much power for the Chevy.  Tell you what let's make a chart for 1971 the first year of the Jag V12.  Jag had 16 years of techical advancement over Chevy at that time.

Engine                   HP                Weight

Chevy LT1 350      275                575

Chevy LS6 454     325                 675

Jag V12                 282                680

So you barely beat a SBC but weigh 105lbs more?  You weigh 5lbs more but make 43hp less than a BBC.  71 is the fairest year to compare as you yourself have constantly pointed out the nonemissions power levels of the Jag.  If you want to get all special I'll start quoting Callaway 5.7 power levels from the 80s.  You could order them from the dealer so they count right?

Hotlinked for OUR pleasure. 

frenchyd said:

My preference for a Jaguar  has everything to do  with racing and nothing about practical day to day driving on the street. 

IF that was the way you presented yourself, no one would mind. But it’s not. 

Fight, fight, fight, fight!

What in the berkeley did I just walk in on? 
 

It's like that co-abusive couple who fights in public and makes everyone else uncomfortable then starts furiously making out and makes everyone else even more uncomfortable.