Hi Flea,

The only difference in cylinder heads between 4.6's & 5.4's are the number of bolts for the cam covers, basically, otherwise all the modular heads are pretty much interchangeable on any of the blocks.

So yes, you can use 4.6 modular cams from the GT's to any of the aftermarket units, in a 5.4 motor. You just pick the grind that is most applicable, and for any increase in lift you also need a matching valvespring package, of course, as the truck cams are much "weaker" than the '99 & up Mustang GT cams or any of the aftermarket cams.

And no, you can't run just any camshafts without being tuned for it, there are different lobe centers, duration, overlap, etc., and we'll need the specs from the cam card when we do the tuning.

 

Thanks, Mike! I'm going to try to secure a set of those cams/springs this summer, and if I can, I'll do the swap. I'm sure I'll be talking to you come June, as my modding season begins!

Thanks again
-Flea

 

Hey Mike,


He did make mention of the blocks as well. I forgot to mention that. I would still like the forged crank myself. Which I will have with my built up block....Just seems like a lot of changing that wasn't ever mentioned from Ford.....

 

Hi ECM,

Ok, understood, & thanks for mentioning that. I'd give just about anything to see the R&D on that. And the next time I get my hands on a 2003 Harley, you can bet I'll bribe the owner to let us drop the pan & take a look at his crank (ok, no wisecracks! ).

If you happen to hear of any accurate method via external observation, I.E., numbers, casting or part numbers, build date numbers/codes, etc. as a means to identify supercharged 5.4's with a cast crankshaft, by all means please do pass it along.

We provide fully prepped forged steel cranks in our built 5.4 motors of course, & can provide everything from blower to oil pan ready to bolt in. With a prepped Ford steel crank, along with the appropriate pistons & rods, any of the 99-02 blocks can take 900 HP 1/4 mile racing.

With the newer block, we'll finally have a platform that can be built to get into the 1200-1500 HP ranges & perhaps even beyond. Of course, to exceed 900 HP, it needs a $2500 crank for openers, along with a standalone engine mgmt system, and, and, and...............

Thanks for your post,

 

1200-1500 hp range? hmmmmm, i wonder if you can street drive it

 

Mike,


I have spent enough already quit teasing me!

 

Hi Grin,

Sure, you can build a 1200-1500 HP motor (and more) that is "streetable."

You're talking either a 3.3 twin screw blower or twin turbo's, and you'd have to feed it something other than just pump premium, it would have to run some something like 100-110 octane race gas in it (or even better for another 20% power boost, alcohol), but it certainly can be done.

These days, with the engine mgmt. systems that are available and all the advances made in metallurgy, the raw parts, assembly, etc., it's possible to build streetable motors with insane amounts of horsepower.

These days, power levels are really just a question of money, like many things.

 

Hi ECM,

Hey, don't feel bad, even I can't afford to do all the things we're capable of doing for my personal Lightning, we *all* have budgets!!

 

more like we *all* have credit limits

 

Hi Grin,

So true!

 

I happened across this post just today and see that this old question of PI heads in a stock pre-PI motor is hot and heavy. I am one who went out and bought some PI heads from a 2001 Mustang GT and they are just sitting in my garage waiting for something to do. I also have a New Windsor 4.6 short block that I thought I was going to have to change the Pistons in to be able to run the PI heads given the higher compression ratio.
Am I correct in what I am reading here - that is not necessarily the case with a good Superchip tune?
I do however have a couple of questions (of course).
I was going to scrap the GT cams for some F150 cams but are the GT cams a better choice?
What intake manifold should I get? One from a mustang GT or from an f150? (I was actually kicking around putting a Mustang Bullet manifold on).
Will the motor have to run higher RPM’s to get the increased power out of it? I have 410 gears so I am not worried about producing low end power, I’m just concerned the stock crank, pistons and rods (all not forged) in the 4.6 can’t support much more then 5500 RPM.

I’ll just add, this is why I LOVE THIS SITE…

 

Hi WLF,

You can bolt on those PI heads to the non-PI block, but the compression will go up significantly, in many cases to 10:5 - 10.75:1. And with good tuning, that can work on good pump premium, no problem.

The issue of the lack of dish in the earlier non-PI motor pistons (actually, valve to piston clearance) is one that has come up, in fact JMC was talking about that quite a bit recently, as he is going to be doing the PI upgrade, too.

In talking with Dave Crower (of Crower Cams) about this, he sees no problem running .550 lift or so with the non-dished pistons, and perhaps as much as .600 lift, as long as the **lobe centers are kept wide**, 114 degrees. I caught up with him by phone last weekend and went over this in some detail with regard to several of his modular motor cam profiles.

The bottom line is, don't scrap those GT cams if they are from 1999 & up, as they will have more lift than these truck cams do, (.534/.505)! I'd run the GT cams & springs since you apparently already have them. And yes, the Bullet intake is the preferable intake to use in terms of peak horsepower, and since you have the 4.10's, you're not too concerned about low-end torque.

The 4.6 motor is "square" (the bore & stroke are virtually the same), so it can actually take some rpms. JMC has had us set his rev limiters to 6500 rpm on his last 2 manual-tranny trucks, which he's used for years, and so far (knock on wood) he's never managed to wound the motors. He's blown clutches, rear ends, etc., but never either of those 4.6 motors, to my surprise.

I'd say a practical maximum would be about 5800 rpm or so in terms of the upshift points on the stock motor, with a 6000-6100 rpm rev limiter setting. The stock pistons are good for about 450 hp. They will take heat, but won't take vastly elevated *pressure*, so figure 450 hp is it, either normally aspirated or supercharged, for the stock pistons. The stock rods & crank can take a little bit more perhaps, but figure 450 hp is it for the stock short block, basically.

One important thing to keep in mind is that just bolting on unported PI heads with GT cams isn't going to do a lot for power, you really need to port those heads & enlarge the valves to get the *real* power gains that are possible. When the 4.6 motor went "PI" in the F-150, it also got the COP ignition too, and all of that resulted in only an 11 hp gain with the truck cams, the rating went from 220 hp to 231 hp stock.

Now with a pair of .600 lift cams & matching springs dropped into a set of unported PI heads in the supercharged Lightning, the gain is anywhere from 12-18 hp.

Do the port job on those PI heads, install the larger Ferrea stainless valves & using those GT cams, you can get really nice power gains.

 

The 4.6 is a square engine; 90.2 mm bore x 90.0 mm stroke. These engines can rev quite high without undue strain. My revlimiter is set at 6500 rpm. It doesn't make any power at 6500 but it allows me to climb dunes without having to shift. I have the PI heads in the basement now awaiting the $$ to get them prepped.

JMC

 

can someone explain why square engines allow for more and safer revs?

 

Oh Boy! Oh Boy! .600 lift! Oh Boy! Oh Boy!

Crower cam #62803 Stage 3- Street/strip profile. Emphasis on top end power. Spring required. Lobe Center 114 adv duration 270 / 266 duration @ .050 224 / 220 lift w/1.8 .601 / .590 rpm range 1200 - 6500+

Made my first $1.00 donation in the MOD JAR.

JMC