Yes.
Keep in mind that most of the power increase from swapping to PI heads is from the higher compression ratio and different cam. For the blown guys, the rise in compression ratio isn't a good thing.

Porting the NPI heads means you don't have to replace a bunch of other stuff.
The intake on the 5.4 is the biggest bottleneck.

Renegade seems to do the best P&P for the NPI heads, but they are pricey and it may take a while. Steen Racing is just as good IMHO will P&P your NPI heads for $750.
http://www.steenracing.com/products.htm

 

So as i sit here at work i keep reading and reading taht thunderbird post. And i got to this at the bottom of page 3.

11-03-2003, 06:35 AM
SCT Guy
Authorized Advertiser Join Date: Sep 2003
Location: Inside my head
Posts: 1,196


I guess it's time to jump in here.

First, all the above cars were tuned by me, and all of these people are friends of mine.

I don't think anyone on this thread is trying to convince you to take off your PI heads and put on non-PI heads. In fact, Kris stated that he thinks the gain is very small between the two.

Here is what I think the point is;
If you have a pre 99 motor and want to put heads on it, a ported NPI head, with a good intake (which I don't know that it exists other than an SVO and that's a lot of money) is equal to a ported PI head. This is very important for blower guys since they DON'T want the increase in the compression ratio. Our friends in CA can only get 91 octane gas, what do they do?

Now, if you are considering a head swap today, I think the answer is still PI, since there is no resolution for the intake problem. It is assumed that the power falls off in JL's car from the intake. This is speculation, but most likely the cast because if you look at his graphs no matter what his combo was, power flattened out at the same point with each setup. The cams were different, the heads were different, the headers were added, the intake is probably the only thing that was common for all those runs.

I think once Fox Lake's intake is available, and installed on motors like JL's, the power will respond very, very well and it's power will be right up there with PI motors.

The point is, PI heads are NOT the Holy Grail for mod motors. Just because Ford did it doesn't mean it's better. They got rid of the 5.0L by saying it was a dirty engine that could NEVER be made to meet emissions. Well, 5 years later guess, what? The 5.0L Explorer was meeting emissions standards that the engine design guys said that it could NEVER meet. They were wrong, it happens. Will they go back, not a chance. A great test would be to make some adapters to put a PI intake on JL's car and see what happens. That would be a great comparison, but I don't know if it's possible.

I think flowing the heads with the intake is a great idea and I'll look into getting this done over the next few months.
.................................................. ......................................

......Well from that i would say that the best option for me is go with the pi head and intake. What do you guys think after reading that.

 

How is an increase in compression ratio a bad thing.. answer... IT'S NOT!! For a n/a motor compresion is your freind. The non PI heads may flow great ported, but for a budget hp build you won't find better gains than swaping to PI heads. For properly ported head of any kind your looking at some serious bucks. Most won't go for that.

 

You may be right. But how boring would it be if, as a group, we all responded by chanting "GO PI" - in unison of course?

 

if your that worried about it, just get a built long block. I have just the stock pi heads with come cams 102500 and the power is amazing. You have to run 93 octane, but the difference between filling your tank with 93 vs 87 is only $5 with todays prices...

 

I take it that you have the 4.6l and looking at your numbers and mod's you have the truck i have been trying to unleash from mine. I would like to find that little bit of hidden power from her. I have many times thought about doing a 5.4 swap just to get there quick but i am looking at both of the ways to get power. Wither building myine up or swaping it out and i watn to see both sides of the fence. How much do you have into yours? This buiild is something i have been planning on doing for a while and i will get the chance in about 6 months. So i want to figure out what i want to do and start collecting parts and such.

 

Hey Built54 - I didn't know you had the 4six in that thing

So what's up with your user name ? Wishful thinking

 

No I Have the 5.4

 

Well in the head swap I have right over $2000, heads, cams, intake, tuning, injectors, fuel pump, and gaskets. But this isnt enough, that is why this is soon going in.

Mahle pistons, eagle rods, forged crank, custom grind cams, ported blower, 8lb lower, 2.75 upper, ported heads....

 

 

WOW I think that JBREW said it best. I want that thing. I just can make up my mind mind about either the 5.4 or the 4.6 work-up. Im looking to you greawt guys for a little wisdom. Im looking for something that will hold the hills of Montana a little better and also tow some trailers.

Im mad. i just got off the phone with edge and i have to send my evo back to them and to return my truck back to stock. I have only had the thing like a week and i put it back on stock and its a differnt truck. I hate it now.

what do you guys think about the swap. Im leaning towards the 5.4 due to the fact that it has a ton more low end power and it will cost me a bit more to do it right but i think i will like it more.

Get TP to do teh tune for it so i can run my 4.6 coils and stuff and not mess with changing harnesses.

What do you guys say????????

 

Holey Cow Joey - where have you been hidding that ?? -That's the first I seen of it . How long have you had it ? Yu couldn't have had it that long - imposible to keep a lid on something like that for long - Damn , it's even dressed nice. 54 lb injectors ?

Very Nice , Very neat , I very jealouse


Awesome Mann

 

If it were me and I had a 4.6 - Yeah , I would find a 5.4L for it. But if there was nothing wrong with the 4six - I wouldn't swap it out. - not yet..

I would put the 5.4 for on a stand and take my time building it so when comes time , you'll really have something there..

 

Holy Chit That looks very nice It even matches the color of the truck.When is this going in?The next question is how long will your stock tranny hold up with that motor
twintips you might as well start with the 5.4 since you want it for towing

 

Well late august I Hope to be putting it in. I dont know how long the tranny will hold up, but I will find out. Its going to have a billet tripple disk 2000 stall, and it already has a shift kit.