Well,
I certainly don't need to add much to that!!! Good job.

 

Thanks man I was just looking back through the thread and you actually had some decent ill let you know when I start a build thread

 

Hell I had no idea the pistons were designed differently between the non pi and pi motors, I am just an owner of an 87 ttop stang with the good old push rod 302, glad I purchased a 99 X like my buddy told me too.

 

No wonder he called himself gonemad, he is mad for he didnt even get what I was saying. I will be the winner here and not post on this thread anymore. Im not the one bragging about anything

 

No need to go to the "corral", lol. I've done the PI cam swap, PI head swap, aftermarket cam swap, intake manifold swap, injectors, maf, custom tuning, etc. Granted I did none of this on my F150, it was on my 97 4.6 Cougar, but none the less, I can give you some real world experience.

To start, I use this online-calculator to calculate static compression ratios:
RSR Static Compression Ratio Calculator

using these specs:

• Bore= 3.552"
• Stroke= 4.165"
• HeadGasket= 0.036"
• Deck Height= 0.112"
• Piston dish= 10.49cc
• Combustion chamber= 50cc

you end up with the stock 9:1 static CR for stock 5.4 NPI motor. Drop the combustion chamber to 42cc from the PI head, and you end up with 9.8:1. So almost (or should I say only) 10:1, but no where near 11:1. Now on passenger cars, like mustangs, Tbirds/Cougars, crown-vics, etc, due to the differences in deck height (0.012 vs 0.112) and stroke (3.543 vs 4.165), the CR does indeed go up higher; but even then its 10.54:1, so still not 11:1 unless you shave the heads a significant amount.

So for the most part, the stock timing tables are conservative enough and the resulting CR is low enough that a PI head swap doesn't necessitate the need for premium fuel; the exceptions being normal carbon buildup in the combustion chambers, or perhaps some timing table changes in the different calibrations that get released over the years. This is why some people have good luck running 87 octane, but others end up needing mid-grade or premium to curb the pinging after a PI head swap. Either way, the compression bump is worth it IMO, as it is the basis for a high-powered modular motor; they love compression.

As far as getting over 300 BHP naturally aspirated out of a 2V 5.4, you can forget about it if you plan to keep the stock intake manifold. The runners are skinny and very l o n g, because that is what allows the torque to build up earliet to get these heavy vehicles up and moving--and thats the exact opposite of what you need for upper-RPM power; ideally you want FAT and SHORT runners. The stock intake just doesn't lend itself to shifting the powerband up high, like the way the PI intake allows on the passenger cars. More compression will bring up both the torque & HP curves at all points, but once you try to shift the powerband up higher, you just see a very disappointing plateau at higher RPMs where the manifold is choking for air and holding everything back, no matter what cams or exhaust you have. You'd need something like this:

ModularHeadShop 5.4 2V intake page


or like mine (but for a 5.4 truck which are available):



either way, you're looking at top-dollar stuff to make lots of N/A power of a 5.4 2V motor.

 

See now that's an itelligent answer now the truck will wear a full exhaust and I will dyno tune to see what see what we end up with. Im figuring with the PI swap I can put the motor around 270-275 fwhp a full exhaust (+10-15hp) and a tune I can get real close to 300 fwhp not rwhp. So let's say I out down 240 at the tire and 300 tq that to me would be impressive on this motor and def not out of reach. Great info though thanks a ton. Wish you had answered first. As far as the pushrod motor you got ...I can help ya on that had a fox for 15 years and went from stock (14.80s) to now 9.50s on only 150 shot with another 300 on board for when its dialed in. Thanks again and ill PM ya if I have some detailed questions along the way

 

300 at the crank with stock unported heads is still kinda high without larger cams. But if you're gonna go ahead with a PI head/cam swap, I highly suggest you go with some ported heads from Modularheadshop - MHS . I'm getting their Stage III ported PIs, but their Stage I ported PIs are just over $1k and flow a hell of a lot better than stock (~ 195cm at stock valve lift). A good tune will likely give around 10HP, and exhaust--well that I'm not sure of, but lets be conservative and say 5HP, so we don't sound like ricers, lol. An electric fan and water pump will also go a long way to bump up the usable power.

 

look at those prudy aftermarket intake manifolds, too bad BOTH WILL COST LOW END TORQUE

 

Absolutely. With N/A performance, one must pick their poison, especially when starting out with such a crappy intake manifold that is not geared towards high-rpm hp production.

Luckily the laws of physics tell us that torque is not conserved, this it can be manipulated in ways hp cannot. If there is 10,000 ft-lbs at the wheels, external measurements cannot determine how much of that is due to engine torque, stall multiplication, or gearing.

What this spells out for people looking for N/A performance, is that hp production should take precedence, because torque at the wheels (which is what really matters), can be increased/decreased, most commonly through shorter gears. You can dial in pretty much any reasonable amount of torque after the engine produces what it can with available gearing. This is not possible with HP--whatcha got is whatcha got. Therefore for N/A performance, the HP should be built up, and any missing torque can be added back in via gearing, or maybe even a better converter with a greater K factor (multiplier).