PI head swap

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Mar 8, 2007 | 12:08 PM

#31

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by BURNSTOUGHFORD

So basically a PI cam swap is the route to go. It will be off of a pick up so it will be the right torque curve.

The cams in PI engines,car and truck are idetical.
Both are .510" lift intake and .530" lift exhaust,and almost the same duration specs as the NPI cams which are .466" lift intake and exhaust. I've got the duration specs at home-I measured 4-5 sets of them awhile back when I was doing some investigation into cams for my TBird. I swapped a set of PI cams into my F150,and it made a noticeable differnce in torque even with 180K miles on the old beast. I'm at 205K now,and it still runs like a top with plenty of oomph to pull my 30ft travel trailer.
JL

Mar 8, 2007 | 12:38 PM

#32

BURNSTOUGHFORD

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From: Iowa

How much work is it to swap cams on these bad boys. Never done one on these modular motors.

Mar 8, 2007 | 12:40 PM

#33

BURNSTOUGHFORD

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From: Iowa

also your sig says built 4r70w. what did you do to it to beef it up... I just swaped one in and was told by a trusted mechanic that the shift kits in these newer trannys dont make much differnce.. Not like it did back in the day with the turbo 350 and turbo 400 trannys and what not.

Mar 8, 2007 | 12:46 PM

#34

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by BURNSTOUGHFORD

How much work is it to swap cams on these bad boys. Never done one on these modular motors.

To do it properly,you have to pull the cam covers and timing cover off,along with the PS pump,and the alternator to get to it all easier.
Takes me about 4 hours,but i've done it a few times on different vehicles..for a first-timer-I'd say 10-12 hours to be safe.
JL

Mar 8, 2007 | 12:52 PM

#35

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by BURNSTOUGHFORD

"shift kits" in the 4R70W's will ruin them quick. Aftermarket manufacturers of "shift kits" haven't got a clue as to how these transmissions function,and their guesswork has ruined many good 4R70W's.
The truck VB is a piece...of junk. if you want a good shifting 4R70W,you really need to get a '99-up car VB and change it out,along with a few mods to the seperator plate,and simply removing a few springs and replacing others with alternate OEM pieces. You can build a helluva tough 4R70W that'll handle 450-600 hp with OEM parts.
JL

Mar 8, 2007 | 01:14 PM

#36

xtrford

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Quote:

Originally Posted by Johnny Langton

Swapping a PI intake onto a NPI truck is honestly not worth hardly anything. The PI truck intake is almost identical in port cross section to it's NPI counterpart. The cams do give a nice torque gain,but minimal on the HP because of the intake choices. Trucks are severely knock contrained,so a compression bump that PI heads would yeild on a NPI shortblock would be counterproductive-you'd have to seriously retard the ignition timing to get it run without pinging-even with premium fuel. Porting modular heads isn't about making the ports larger,and getting more flow-there's alot of specific things that needs to be done to get flow without hurting velocity.
JL

Is that why my truck likes to slightly ping even when I'm running 94 octane fuel? Although I am running a tuner it did it before wether running 87 octane or higher. Another question for you is do these motors (5.4l with PI's) get alot of carbon build-up causing higher compression which in turn causes pinging?

Mar 8, 2007 | 01:34 PM

#37

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by xtrford

I'd say yes,that's why they tend to ping even when stock.The intake manifolds do such a good job of packing the cylinders full of air at low rpm that they unfortunately make a ping-sensitive enviroment. I was stunned at how little ignition timing these trucks can tolerate without pinging compared to the cars,and it's mostly due to the intake.
I have seen some 5.4L truck heads with alot of carbon buildup on the backside of the intake valves,but not as much as one would think in the combustion chamber on the same truck. My original 4.6L out of my Tbird at 215K miles had very little buildup on the piston crowns,and also minimal on the valves,but I always ran good quality fuel,and none of that bargain basement stuff you see at big grocery and chain stores.
JL

Mar 8, 2007 | 02:12 PM

#38

BURNSTOUGHFORD

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From: Iowa

so are you saying that the tranny performance gaines that i have gotten from my tuner aren't really helping me out much. I know the thing shifts alot harder. I droped one tranny at 150000. I lost a bearing and it got pumped threw the whole thing.. other than that the tranny was amazing looking on the inside as far as wear. So put a tranny in that had 120,000 on it and looked like new...with no worrys.

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Mar 8, 2007 | 08:27 PM

#39

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by BURNSTOUGHFORD

Maybe,maybe not. There's alot more to a good shift that how hard it is. For max power to the wheels(driveline efficiency) you have to have enough EPC pressure to complete the shift without slippage of the clutch,but not too much or the pump will waste power from inefficiency. Same goes for TCC lockup. My original trans failed the #8 bearing at around 195K miles.I rebuilt a low-mileage '01 4R70W adding some clutch frictions and slight mods, and it's been in there for the last 10k miles with no issues at all, and I forsee it lasting many, many more thousands of miles.
JL

Apr 11, 2008 | 02:52 PM

#40

bbender85

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From: Middleville, MI

sorry for bringing this thread back from the dead, but i found some surprising information that throws all the homework i've done out the window, and want to verify what i'm hearing:

for my non-PI, '99 F-250 i want:

-PI cams
-stick with my NPI heads
-PI intake from a car? or a truck? which?

i was ready to pick up a set of complete used PI heads, but this may change after finding this.

Apr 11, 2008 | 02:58 PM

#41

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by bbender85

In all honesty-the PI intakes on the truck engines aren't much better than their NPI counterparts. On the cars-it's a huge difference. I'm the first one in the country that I know to have done that swap,and then many have followed since then. I picked up about 20rwhp peak and a few ft-lbs torque,but the big difference was around 40rwhp and 35 ft-lbs at 6000 rpms. You can try it,but don't expect alot from the truck intake-nothing like I found when we were experimenting with the PI intakes on out NPI 4.6L's. The PI cams will make a big difference in torque and a small difference in power-I picked up 13rwhp/18 ft-lbs on my 4.6L when i did this years and years ago.
JL

Apr 11, 2008 | 03:06 PM

#42

bbender85

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From: Middleville, MI

thanks for responding..

what about running a car PI intake then? i remember reading about making torque at different rpms... my truck is used for a daily driver, i dont pull anything, and want some top end power for clawing up the dunes. i think you said the truck curve was fairly flat 2500-3500, the car peaking at 4000... value-wise, how much higher was the car's peak tq vs the truck? or is the car intake a bad idea.

also... would 4.6 SOHC Ford take out PI camshafts work? These were taken out of a set of new Ford Racing PI (Romeo) heads.

i really appreciate it!!

Apr 11, 2008 | 03:18 PM

#43

Johnny Langton

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From: SE Texas

Quote:

Originally Posted by bbender85

You can use the car intake,but there are alot of little things that would drive you nuts getting tit on and functioning properly. Fuel rails are different,and the Mustangs with PI heads use returnless fuel,so those rails won't work,and have the fuel inlets on the passenger side-the trucks are on the driver's side if I remember right. The air tube will be exiting on the passenger side unless you can round up a Crown Vic or Explorer upper inlet elbow-they exit forward toward the driver's side. The car intake will be softer down low in the RPM range-it's made for a much lighter car-that choice would be yours as to the difficulty and the loss of bottom-end torque.
You can use the take-out cams from a set of Romeo PI's-the cams are all identical as for specs on all of the PI modulars-if yours is a windsor,it'll just have pressed-on sprockets and the Romeos will be bolted on-just leave the cam gears on the take-out cams and use them like that-there's no physical difference in the two other than the retention method for the sprockets.
JL

Apr 11, 2008 | 03:24 PM

#44

bbender85

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From: Middleville, MI

alright, cams only it is then. not looking to build this motor by any means, just already done the intake system, exhaust, and tuner, and want to go one more step to get this heavy thing moving. thanks again.