in case u ever wondered what the s/c cobras rwhp stock..

Yhank you and Merry Christmas to everyone here to. Good debate. I am saying take a 351w BLOCK and and LS1 BLOCK N.A. all minus the puter and same supporting mods and the 351 will produce more power because it has more cubic inches. Now can anyone prove that statement wrong? 5spd? Does tat make sense? Thanks,

So my point is that the ls1 is not special or magical, it is simply a well put together combination from the FACTory.

Can we prove it wrong? Can you prove it correct? And the problem here ain't quite as simple as you make it out. Martyd asked a question earlier in the thread.

" With a $4000 budget which would make more power an LS1 or a 351w? ."

Well lets look at that question from a practical stand point. I have a 94 Mustang GT and a 98 LS1 camaro sitting in the garage right now, which two of these cars is gonna make the most power on 4 grand. Well the problem with the mustang is I don't have a 351W. Which means unless your fortunate enough to have a 351 engine fresh out of the machine shop sitting in your garage your gonna need to go buy one. More then likely your gonna need to send it out to a machine shop. By the time you get through buying the rotating assembly, HCI, new headers and new tune your way beyond 4 grand. So in this scenario the LS1 wins.

The camaro needs this, and a tune.

Trick Flow 515 HP GenX Top-End Engine Kits for GM LS1

So lets go to scenario 2. Lets say the mustang just happens to have a 351W sitting in it ready to go. You show me one N/A top end kit that will match the same power as the one I just showed you for the LS1.
 
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I would take a 347 over a 351.

515 HP is nothing when talking about HP at the engine. A 347 can easily do it.

If you are not going to keep the playing field even, as far as cubic inches, then do not compare anymore greenlantern.

A ton of my questions have not been answered, without quotes from some articles.
 
Not to mention its going to be a little tough to find 351W for comparison sake, since most owners once they have them apart opt for a stroker set up when replacing the stock cast/hyperutectic pistons. Its just so inexpensive and easy, you'd be a fool not to? Why pay for a stock rebuild when a forged rotating assembly capable of another 100 horsepower and like amounts of torque is only a few hundred dollars more? :shrug:
 
I would take a 347 over a 351.

515 HP is nothing when talking about HP at the engine. A 347 can easily do it.

If you are not going to keep the playing field even, as far as cubic inches, then do not compare anymore greenlantern.

A ton of my questions have not been answered, without quotes from some articles.


If you choose a 347 over a 351 thats your business, I could care less. 515 HP is nothing, really? A 347 can easily do it? OK wheres your proof? What combo? What 347 have you seen that made 515hp NA, surely you of all people have some sort of dyno sheet or link to back that argument up. All Im saying is show me. The argument here was made that there is nothing so efficient about an LS1 that a SBF windsor can't match with bolt on parts. I disagree, my argument is not that a SBF can't match a stock LS1, my argument is that mod for mod a more efficent better designed LS1 will beat a SBF. So weather your talking about a 347 or 351 show me one that can match the same amout of power NA is all Im saying. And what are you talking about not keeping the playing field even I didn't bring up the 351, pokageek and martyd did. Besides according to you the LS1 is just another pushrod engine surely your not suggesting it has any type of advantage?
 
Maybe I'm missing something but :shrug:

515 motor hp

A 15% drive line loss

Does that not pan out to around 515 x .85 = 438 rwhp

That is a pretty mild NA 347 as I see it

*** EDIT ***

Well I was off by only 100 rwhp :eek: :bang:

Somehow ... I was originally thinking 338 rwhp

Just chalk this post up to me having a ... Senior Moment :rlaugh:

Grady
 
Not to mention its going to be a little tough to find 351W for comparison sake, since most owners once they have them apart opt for a stroker set up when replacing the stock cast/hyperutectic pistons. Its just so inexpensive and easy, you'd be a fool not to? Why pay for a stock rebuild when a forged rotating assembly capable of another 100 horsepower and like amounts of torque is only a few hundred dollars more? :shrug:

I agree with that but again I didn't bring up the 351. A 347 is a much better comparison in this debate and will make more power than a stock LS1, not a modded one. And for the record a 347 goes well beyond a few bolt on parts.
 
I dont really like arguing on here or any were so Im not trying either just saying what I think.


The Ls1 is a great engine. GM did their homework and a great job at it. Makes good power has a 6 speed for the added gas efficientcy and the top end pull in 5th. It is not quiet. Im surrounded with nothing but LS1 owners. All my friends my brothers and I can say they are not quiet. I do believe they had a good sound proof buddy though so that the noise doesnt come in as much but when you pop the hood its just as loud as a Mustang motor I guess. But honestly I think you cant compare apples to apples when it comes to the LS1 and Mustang debates. Ford didnt mass produce 351 in stangs like the LS1's. Ford went modular and stayed their. Ford owners get mad when you compare a 2001 or any older Mustangs cuz and GM owners get mad when you compare a 03-04 Cobra since it is Supercharged but yet it came stock and SVT also did their homework to have a mora powerful car than the LS1 and they did with less cubic inches but decided to add a supercharger.

I guess all Im saying is you cant compare apples to apples since there is to much to take into account and especially that from 1998-2002 the LS1 ruled until it was stopped in production and SVT came out with the 03-04 Cobra after it had to nothing to compare to a new car of the same year.

I think the best way to compare them would be to give a person 15k dollars or something and start from nothing and use that money to buy the car and the mods.
 
Maybe I'm missing something but :shrug:

515 motor hp

A 15% drive line loss

Does that not pan out to around 515 x .85 = 438 rwhp

That is a pretty mild NA 347 as I see it

*** EDIT ***

Well I was off by only 100 rwhp :eek: :bang:

Somehow ... I was originally thinking 338 rwhp

Just chalk this post up to me having a ... Senior Moment :rlaugh:

Grady
You're thinking SAE Flywheel vs. Rear Wheel Horspower in your comparison. But in reality, the 515hp rating is taken on an engine dyno, without accessories or complete exhaust components. This is very similar to the way engines were rated in the 60's.

I'm quite certain that SAE Flywheel rating from the factory take accessories and exhaust systems into account when the numbers are published. From there, add drive train loss to that figure as it would be should it be measured on a chassis dyno and you'll see that 515hp figure drop like a stone.

It'll still be an impressive engine package, but not so much when you factor in accessories, exhaust systems and drive train loss.
 
You're thinking SAE Flywheel vs. Rear Wheel Horspower in your comparison. But in reality, the 515hp rating is taken on an engine dyno, without accessories or complete exhaust components. This is very similar to the way engines were rated in the 60's.

I'm quite certain that SAE Flywheel rating from the factory take accessories and exhaust systems into account when the numbers are published. From there, add drive train loss to that figure as it would be should it be measured on a chassis dyno and you'll see that 515hp figure drop like a stone.

It'll still be an impressive engine package, but not so much when you factor in accessories, exhaust systems and drive train loss.

No doubt your gonna have drivetrain loss, what engine won't? And I think its fair to assume that if your gonna go as far as doing a HCI swap you've already addressed the restrictive factory exhaust. This is usually one of the first mods made. Factor in drivetrain loss, you should still be pushing in the neighborhood of 440rwhp. And you didn't have to pull the motor to stroke it, impressive indeed.
 
Factor in drivetrain loss, you should still be pushing in the neighborhood of 440rwhp. And you didn't have to pull the motor to stroke it, impressive indeed.

Impressive for sure....but no where hear unatainable for a 347 stroker, or a 351W either.

The point is, that engine dyno numbers always sound impressive on paper, but they don't always translate to as impressive of a figure in real world applications.
 
You're thinking SAE Flywheel vs. Rear Wheel Horspower in your comparison. But in reality, the 515hp rating is taken on an engine dyno, without accessories or complete exhaust components. This is very similar to the way engines were rated in the 60's.
I'm quite certain that SAE Flywheel rating from the factory take accessories and exhaust systems into account when the numbers are published. From there, add drive train loss to that figure as it would be should it be measured on a chassis dyno and you'll see that 515hp figure drop like a stone.

It'll still be an impressive engine package, but not so much when you factor in accessories, exhaust systems and drive train loss.

Exactly!

Drivetrain + Accessory loss often can eat up 30%, no joke.

Now, re-do the math.

Think about this:

My H/C/I 302 on a stock shortblock had tons of torque, and was in the 290-300 RWHP range. You would not tell me or any of my friends that it was not daily driveable (and I am picky!), or that it did not have torque. It was done by 6,000 RPM.

That HP range is what a 346 CI (200 cc/longer runner head), with an mean cross section on the intake of 2.7X". I beat ls1's consistently, trapping 4-5 MPH more often, weighing in at a bit over 3,400 lbs.

So how "efficient" is that 346, if a daily driveable stock shortblock 302 can match it. The ONLY noticeable difference in torque between it and the ls1 was the idle sound coming from the 302. Face it, an ls1 is as weak as a TFS-1, GT-40 heads, GT-40 intake 347, sitting at 290-300 RWHP.

I still want to here why the ls1 is a better engine?

By the way, there are several 400-450 RWHP 347's running around. Just search around on here, the corral, etc.

FordMuscle Webmagazine: Feature Cars - Yellow Fever - 1994 Mustang GT 10 Sec Street Car

I would choose a 347 over a 351, for rotating weight purposes. There is a 20-30 lb difference in, internal rotating weight. That is SIGNIFICANT.

I apologize to everyone for not having the time to really get detailed, as I could blow the debate wide open. Oh well. :)
 
Ok compare the materials used, compare the weights both solid weight and rotating mass. The ability to take 80% of a LS1 apart with 1 tool. Siamese bores, block casting is better/offers more durability, improved oiling. Compared to gen 1 and 2 GM V8's of the same displacement it had a smaller bore and bigger stroke to aid in tq being produced. Raised camshaft to clear 4+ inch stroke cranks. Deep skirted bottom end allows for cross bolted mains, separate valley plate cover used to improve block structure. The blocks are stronger and also lighter or right at the same weight as a 302 or even a big bad 347. But the LS series can be built up to well over 427 cubic inches. It is a small block with big block abilities in power, torque, and displacement.
 
Ok compare the materials used, compare the weights both solid weight and rotating mass. The ability to take 80% of a LS1 apart with 1 tool. Siamese bores, block casting is better/offers more durability, improved oiling. Compared to gen 1 and 2 GM V8's of the same displacement it had a smaller bore and bigger stroke to aid in tq being produced. Raised camshaft to clear 4+ inch stroke cranks. Deep skirted bottom end allows for cross bolted mains, separate valley plate cover used to improve block structure. The blocks are stronger and also lighter or right at the same weight as a 302 or even a big bad 347. But the LS series can be built up to well over 427 cubic inches. It is a small block with big block abilities in power, torque, and displacement.

That right there shows me that you got this out of some magazine article.

Also, the longer stroke was not just for the said, torque. A small bore helps with emissions and a better burn. Reminds me of the 4.6L, which is even better in that department.

I love the comparison between a '90's model block to a 60's model block, and the 60's model base competes with the LsX. :nice:

A 4.6L is even more efficient than an Ls engine.
 
Exactly!

Drivetrain + Accessory loss often can eat up 30%, no joke.

Now, re-do the math.

Think about this:

My H/C/I 302 on a stock shortblock had tons of torque, and was in the 290-300 RWHP range. You would not tell me or any of my friends that it was not daily driveable (and I am picky!), or that it did not have torque. It was done by 6,000 RPM.

That HP range is what a 346 CI (200 cc/longer runner head), with an mean cross section on the intake of 2.7X". I beat ls1's consistently, trapping 4-5 MPH more often, weighing in at a bit over 3,400 lbs.

So how "efficient" is that 346, if a daily driveable stock shortblock 302 can match it. The ONLY noticeable difference in torque between it and the ls1 was the idle sound coming from the 302. Face it, an ls1 is as weak as a TFS-1, GT-40 heads, GT-40 intake 347, sitting at 290-300 RWHP.

I still want to here why the ls1 is a better engine?

By the way, there are several 400-450 RWHP 347's running around. Just search around on here, the corral, etc.

FordMuscle Webmagazine: Feature Cars - Yellow Fever - 1994 Mustang GT 10 Sec Street Car

I would choose a 347 over a 351, for rotating weight purposes. There is a 20-30 lb difference in, internal rotating weight. That is SIGNIFICANT.

I apologize to everyone for not having the time to really get detailed, as I could blow the debate wide open. Oh well. :)

Let me get this right, I show you a top end kit that will put out 515hp on a stock LS1 shortblock and your defense is "drivetrain + accessory loss will eat 30% of that power? Well I don't know what you have on your motor but if its eating 30% of you engine power you have a problem. 15% to 20% is the norm.

And as far as your HCI 302 matching a stock 346. That is here say at best. Lets look at what we know, a stock LS1 is a mid 13 second car. The right HCI swap on a fox mustang should put it into the 13's so you get no pat on the back from me partner. Bottom line you had to change the top end of your car to run with a stock one. I would'nt climb that high horse just yet.

Mild bolt ons on a LS1 puts it into the 12's NA that is a fact, now what? Remember what I said, mod for mod? Change the top half of that LS1 and you have no choice but build a stoker. And I have yet seen one that will match the same amount of power NA.

Look I ain't gonna agree with you and you obviously ain't gonna agree with me so we agree to disagree. You build what you like and I'll build what I like. I enjoyed the debate as always.
 
Let me get this right, I show you a top end kit that will put out 515hp on a stock LS1 shortblock and your defense is "drivetrain + accessory loss will eat 30% of that power? Well I don't know what you have on your motor but if its eating 30% of you engine power you have a problem. 15% to 20% is the norm.

I must not have explained my post above properly. The 515hp figure was taken on an engine dyno. Engine dyno's don't take into account parasitic loss, or drag from accesories (alternator, water pump, power steering, polution, A/C, idlers, etc), nor are the engines run with full exhaust set ups (mufflers right off the manifold only, if not open headers alone).

So with real world figures, you not only have to worry about a 15-20% drivetrain loss you would have to contend with by going from an SAE Net, to a rear wheel horsepower figure, but you've also got to accept another 5-15% loss that the accesories and exhaust system eat up.

Like I said.....most of the time engine packages look great on paper, but don't translate as well once the horsepower hits the pavement. That 515hp rating might lose 100+hp by the time it makes its way to the back wheels.

Understand? :shrug: