Alright. I posted this few days ago in another section, but it was a little OT. So I figured I would post a new thread. Based on my current budget, I could afford to do one of two things:
-Install a stroker kit with 11:1 comp into an '04 P71, with a set of Hitech StgII cams and LT's
-Install a 5.4 into the aforementioned P71, with an HPS intake. A set of cams could also be possible, depending on what the swap ends up costing. I'd like to get the HP/TQ figures for those setups, so I can do a comparison. Any help is appreciated .

 

DUH! 5.4l all the way.

I've got an old '95 P71 That I put a t45 5spd in. I've been building a very stock 5.4l for it and now since the HPS intake is done it would be alot easier. Most problem with installing in a Panther would have been the wiper motor box, when using the stock 4.6l intake and adapters, but now HPS has solved this problem

 

I know a 5.4 would be more unique, but it would also be more of a PITA for me. I was just looking to get a comparison, so I can see if the 4.6 with goodies would keep up with a stock 5.4.

 

5.4 FOR SURE NO CONTEST!!!
my friend had an old '95 P71 That he had a t45 5spd in. he has been building a pretty stock 5.4l for it. HPS will solve the problem. Hope this helps, let me know.

 

More displacement=more power. Plain and simple. If you run 2V heads on the 5.4 and 4V heads on the stroker, than yes, the stroker wins but you still won't match the low end grunt of the 5.4.

 

That's why I asked for a numerical comparison. I want to SEE how much of a difference there is.

 

That's why you should do a 5.4L 4v engine swap.

I know it's a bit outside of the OP's price range but still. If you're going through the trouble of an engine swap you might as well do it right or at least that's how I'm justifying it to myself.

 

Yes... I GET IT. 5.4's are great. But that was not my question. I just want some numbers. If you guys are going to keep going on about the 5.4, then forget I mentioned it. Just give me the numbers for the stroker that I mentioned in the OP.

 

Sorry but a high compression 2v 4.6 with cams and longtubes is gonna make more power and be faster then a 2v 5.4 with just exhaust and bolt on's or even cams. I say go for the high compression 2v 4.6 and spray it. It will also be lighter and not need a big *** hood.

 

I severely doubt a 4.6 w/ the same mods as the 5.4 will be faster. It's like saying a 302 is faster than a 351. They may make the same power but it's all about that torque curve that only the 5.4 can deliver.

 

The point is I could afford more mods for the 4.6, because that engine is already in the car. Not to mention the fact that I can't even get LT's for the 5.4. Like I said before, just disregard the 5.4. Now I just want someone to give me the numbers for the 4.6 w/ 5.0 stroker kit, 11:1 comp, Hitech stage II's, and a set of LT's.

 

hmmm all of that work only to stick with un-ported heads...why only do 75% the extra cost wont be that high to the 4 grand on the motor build. why get a cookie cutter grind? get something that will be spec'd for your motor build, **** it costs the same.

i havent seen a lot of hi-tech numbers out there but a stock long block 2 valve has the stage 2's and the dyno numbers were impressive at 300 hp and 306 torque...the guy even took his car to a 12.1 or 12.0 pass in the quarter without a power adder! I can see the stroker getting some more torque but it will not make up for what the 331 can do if it had the same build. dont know if you even tried to look but you can find old 5.4's for a couple hundred bucks...

i dont think you are even really trying

oh and yes i added nothing useful nor answered your questions...doubt anyone will address them either.

 

If it were $4k, then it would be too much. $700 for the budget stroker kit, $900 for the 03+ Vic LT's, and $650 or so + springs for the cams. Kooks says that you have to buy their $600 center assembly when you buy their LT's, but I'm sure I could have a shop fab up something for a lot less. And yes, I did look into the used 5.4 route. It would most likely be too much of a PITA for me to do, plus there are no LT's available for a 5.4 swapped Vic. I would have to get a shop to make a set for me, and god knows how much that would cost. A simple 5.4 swap with an HPS intake would cost about the same as the mods above, if I buy an engine in decent shape. But the 5.4 would lack the high-comp ratio, cams, and LT's, which is why I originally posted this question in the first place. And yes, I would consider having my heads ported in the future.

 

budget and motor build do not fit in a sentence...i havent experienced it but i know i will soon 12#'s of boost now with 17* of timing instead of 12* a detonated motor is in my future. i just hope i could be stateside when it happens 800 in shipping could go towards something else.

 

You really think a stock 5.4 with just some bolt on's and maybe cams is gonna be faster then the same car with a high compression 2v 4.6 with cams and full bolt on's with long tubes? Come on.

 

Oh, I see now. You are keeping the comp ratio lower for the 5.4 and denying it long tubes. Well, that isn't very fair but the 5.4 will still win in the torque department. Remember, the stock 5.4 makes 350 ft*lb at 2500 rpm. Imagine w/ a set of cams and a HPS intake can do. No matter what's thrown on the 4.6, I doubt it'll match the torque of the 5.4 (and torque is what wins the day on the street/strip).

 

Of course. If I went through with the swap, I wouldn't have money available afterwards to modify the 5.4. And I wouldn't be "denying it" longtubes. They just aren't available for 5.4 swapped Vics. And getting a custom set made is out of the question, especially if it's going to cost anywhere near what r3d paid (over $5k.)

 

I wouldn't be surprised if Mustang headers fit. However, I wouldn't worry too much about lts. Remember, a Panther is heavy, it needs the torque that only the 5.4 can deliver. The power may be better w/ a 4.6 but it means nothing since the torque is lacking.

 

Perhaps. This wasn't meant to be a definitive "end all" post. I haven't quite made up my mind yet. Hell.. If the economy keeps getting worse, I won't be able to do either of these setups. The thing is, this post was always about numbers. I just wanted to do a numerical comparison between the two setups. Yes.. I know the 4.6 may not make as much TQ. But a 5.4 would be more of a PITA for me. Plus it's kind of hard to hide a complete engine w/stand in the garage, if you know what I mean..

 

I can tell you I would not waste my time with the 5.4 swap in it. But I think money is better spent else where then on that. Just my opinion.

 

I should just send a message to r3d. He seems to be pretty good about calculating hp/tq figures.

 

he built a calculator from his own R&D

 

through the slushbox tranny and pulling the ginormous mass of a p71 the 5.4 is a better choice regardless of power figures on paper. I can sit at desktop dyno for hours pumping out theoretical combos but you can figure that without longtubes on the 5.4 you'll be corking the peak HP number but making oodles of power where you need it which is from idle to 5000rpm and with the stroked 4.6 you'll be getting much of the same at a SIGNIFICANTLY higher cost except that the peak power number will be higher (longtubes) and it'll probably make less power from idle to 3000rpm than the 5.4 but then come on strong, necessitating higher ratio rear end gears to make up for the power band shift.

I'd rather not keep you guys fixated on dyno numbers but force you to look at the application for the power plant as much as the actual power it makes. Better decisions are made that way.

Cliff's notes: the stroked 4.6 will make best power at mid to higher RPM's, the 5.4 will make best power at low to mid rpm. A 5.0L modular stroker is vastly more expensive to do than a stock bottom-end 5.4 transplant.

 

so theoretical numbers for giggles, all I'm doing is taking my DD file and playing with the cam selection, exhaust type and the displacement. I'm leaving intake and head flow and compression alone. BTW.. these are brake numbers not rear wheel:

5.4/10.5:1/stg2 head/xe270cam/shorties/intake: 337@5500/398@3500
5.0/10.5:1/stg2 head/xe270cam/shorties/PI-intake: 334@5500/363@4000

5.4 as above with longtubes: 385@5500/423@4000
5.0 as above with longtubes: 379@6000/393@4500

What you're seeing is a 500rpm difference in where the power comes on. Heavy cars need it early, light cars can take it a little later.

 

FWIW, my current car makes a little over 300hp @ 6200rpm, and 295ft lbs from 3000-4000 rpm. And my current car weighs 4200lbs, which is a little heavier than a P71. I'm used to that powerband. I don't mind having the TQ a little higher up, because most of my "runs" are done at highway speeds (not 0-60.) I suppose RAR is a factor as well, but I don't know the specs for the car I'm buying. I've seen a few different ratios, depending on what package the car is given. I'll have to check the code once I've bought it. BTW, I noticed that you left the comp ratio of the 5.0 at 10.5:1. I was actually planning on doing between 11:1 and 11.5:1. Would that change those figures for the 5.0 much?

 

the change would be marginal but 11:1 is as far as you should consider.

 

Yeah.. Most of the available kits don't go above 11:1 anyways. And I wouldn't be able to do it right away, but how much of a difference would I see with a "decent" head port? I'd be freeing up exhaust flow with the LT's, so it would only make sense to help it breathe a little better as well.

 

I made 650/725(or 750 cant remember now) and had under $300 in my entire 5.4 setup. Im not sure how you think your going to get away cheaper going with a stroker. There is machine work,, etc.
Get a stock 5.4 with flat tops and spray the **** out of it. You make it out to be some huge budget buster, it doesnt HAVE to be.

 

Perhaps.

 

single is correct. A 100 shot of giggle and a stock 5.4 makes for a helluva ride down the strip.