I have a 97 Expedition with a blown head gasket. I have pulled the engine. What a PITA... I am a professional wrench but not on Fords. I want to increase the performance of this vehicle which I use primarily to tow a 22ft enclosed car trailer. It has the trailer towing package with the 5.4. I would consider any combination that would increase the performance shy of putting a supercharger on it. Has anyone done the later 5.4 PI into the early chassis. I am wondering what is involved in integrating it with the 97. I have a complete engine machine shop so rebuilding the engine is not an issue. Just looking for proven combinations. The engine needs more torque.
Head Gasket Blown on 5.4 What Performance Mods
- Thread starter tatios
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Installing "PI" heads and intake on an earlier non-PI motor should improve performance considerably (+40hp ?!). The difference in combustion chamber size between the 2 heads is enough to raise compression to about 10 to 1 (due to difference in pistons) Non PI heads have 51cc heads, PI have 42 cc heads. You do need to be aware of piston to valve clearance.
Never done this myself but from what I understand, this is a straight forward swap. A custom tune after would obviously give you the best results.
Im sure if you google it you will find info on the swap.
A good book on the 4.6 & 5.4 modular motors>>> http://www.amazon.com/gp/product/1932494804
Never done this myself but from what I understand, this is a straight forward swap. A custom tune after would obviously give you the best results.
Im sure if you google it you will find info on the swap.
A good book on the 4.6 & 5.4 modular motors>>> http://www.amazon.com/gp/product/1932494804
BakerEdition
EF Chaplain
Tom, I hate to sound stupid....But I have seen this before and wondered...what does PI stand for with cylinder heads?
Its just the label ford gave the new 2v heads. "Performance Improved".
BakerEdition
EF Chaplain
what years did they put them on?....Hey got a question regarding O-2 sensors..wanna replace mine all 4 of them...any recommendations...Motorcraft, etc...is there a difference between up and down stream? thank tom....
In the expys I believed they went to the pi heads in 1999. In 2003 they went to 3v heads. Have not replaced my O2's on the expy. Upstream is used by the ecu for tuning purposes. The downstream sensor are more or less there for checking if cats are working. If you were only going to do two do the front ones. I use bosch on my stang.
BakerEdition
EF Chaplain
meaning the ones up closest to the engine?
Correct.
tallsville
Full Access Members
tom they went to 3v in 05
PI in Early Expedition
I am hoping to find someone running the combination. I will have to do the calculations on the compression to see what the combination yields. The pistons sit in the hole which I normally don't like and if the combustion chambers are smaller on the PI then the pistons will probably need to be changed. I read that the PI heads and intake flow better out of the box than ported early heads... I am worried about compatibility with wiring harness, transmission, ecu, etc... This is not a vehicle I want to take apart a few times while figuring things out.
BTW I would not run any type of generic O2 sensors. On anything with 4 wires or more the generics will give you grief. Bosch works fine on my 97 but I used the specific units for the vehicle.
I am hoping to find someone running the combination. I will have to do the calculations on the compression to see what the combination yields. The pistons sit in the hole which I normally don't like and if the combustion chambers are smaller on the PI then the pistons will probably need to be changed. I read that the PI heads and intake flow better out of the box than ported early heads... I am worried about compatibility with wiring harness, transmission, ecu, etc... This is not a vehicle I want to take apart a few times while figuring things out.
BTW I would not run any type of generic O2 sensors. On anything with 4 wires or more the generics will give you grief. Bosch works fine on my 97 but I used the specific units for the vehicle.
BakerEdition
EF Chaplain
I found these on e-bay....would replace both fronts your opinion on these?
http://cgi.ebay.com/ebaymotors/BOSC...:Expedition&hash=item336b5709eb#ht_1428wt_931
http://cgi.ebay.com/ebaymotors/BOSC...:Expedition&hash=item336b5709eb#ht_1428wt_931
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It comes up incompatible with a 2000 ford expy when I type it in...Make sure you get ones specific to your model and year..
ops... mistake.. I stand corrected
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rburch
Full Access Members
This is a common swap. It is probably the best bang for your buck other than turbo or supercharger. common power gains from this swap are around 150hp with a set of cams.
There shouldnt be any problem with clearance. At least i havent heard of it. Never hurts to check though!.
And not only is the combustion chamber smaller the dish in the piston is smaller also!
There shouldnt be any problem with clearance. At least i havent heard of it. Never hurts to check though!.
And not only is the combustion chamber smaller the dish in the piston is smaller also!
Thermo
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tatios, I have pulled the heads off of my truck. It isn't a hard job, but plan on most of a weekend. The only trouble spot I had was getting the harmonic balance off (couldn't get my hands on a large enough 3 point puller). I pulled the heads and put them back on in about 16 hours of work (by myself). Get 2 guys knowing what they are doing, probably do it in a day.
Yes, the PI heads will fit on your truck. You need to replace pretty much everything above the heads too as the intake was slightly different. I would say to also port/polish the heads since you have them off. I did this on mine and it made a nice change. I didn't go with larger valves, I simply smoothed out the intake to allow the air to move more freely.
Yes, the PI heads will fit on your truck. You need to replace pretty much everything above the heads too as the intake was slightly different. I would say to also port/polish the heads since you have them off. I did this on mine and it made a nice change. I didn't go with larger valves, I simply smoothed out the intake to allow the air to move more freely.
Engine is already out
We pulled the engine this past weekend. My vehicle had very rusty exhaust studs and the EGR tube would not come out. I had signs of water in the oil so I didn't want to just throw a set of gaskets on and bolt it back together. Now that I made the leap to pull the engine I want to upgrade without spending a ton of money. The PI heads sound like they will add some torque and would be worth the effort to install if the engine bay harness and ECU can be reused. It annoys me that the truck can barely pull my trailer at 70 MPH in overdrive and only gets 7.5 mpg. I work on a lot of different cars and find this one of the most difficult vehicles to work on. It's not a matter of complexity but a issue with packaging and accessibility especially on a vehicle so large...
We pulled the engine this past weekend. My vehicle had very rusty exhaust studs and the EGR tube would not come out. I had signs of water in the oil so I didn't want to just throw a set of gaskets on and bolt it back together. Now that I made the leap to pull the engine I want to upgrade without spending a ton of money. The PI heads sound like they will add some torque and would be worth the effort to install if the engine bay harness and ECU can be reused. It annoys me that the truck can barely pull my trailer at 70 MPH in overdrive and only gets 7.5 mpg. I work on a lot of different cars and find this one of the most difficult vehicles to work on. It's not a matter of complexity but a issue with packaging and accessibility especially on a vehicle so large...
BakerEdition
EF Chaplain
Tatios. Boy I envy you...I paid someone to just put spark plugs in mine because of the tight quarters...I repeat my fathers words as a retired mechanic.."If those son of a ******* had to work on what they designed, they would make allot of changes" It all looks good on paper..GOOD LUCK my friend! 
My experience towing is that it always ran better and more effortless if I was able to keep speeds above 70 mph. Below 70 and the motor is out of its powerband and it would struggle with the extra weight on inclines (stock tires & 3.55 gears) Based on this if yours is primarily for towing I would consider swapping in a lower gear ratio. This would give you more torque at the wheels and get the motor in it powerband sooner. Just my opinion.
Whats your location?? I have set of PI heads, intake, etc...
Actually I have complete motor minus a few items.
Thermo
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tatios, with the engine out of the engine bay, things will be much easier to work on. Big thing to keep in mind is the head bolts are 1 time use only. You end up stretching them when they get installed. Also, pay attention to the colored links on the timing chains. You need to put them back just as you found them else you will potentially hurt the valves.
May want to also look into the "Gotts Mod". That will help free up some power too. Another thing to look into is long tube headers. They will also make a difference. A little pricy, but the power gains will match nicely with the PI heads.
May want to also look into the "Gotts Mod". That will help free up some power too. Another thing to look into is long tube headers. They will also make a difference. A little pricy, but the power gains will match nicely with the PI heads.
I'm in the Philly area. My vehicle has 3.73 with LSD and is 4wd so that is a bit of a pricey proposition to change ratios. Was the Expedition offered with 4.10? I can run without OD but then it is spinning more than 3500 rpm which is in the power band but the fuel mileage sucks. I have never gotten more than 12 mpg running empty without the trailer. The tires are about 5 percent larger than stock. I already have to do the head gaskets so why not upgrade?
Ed
Ed
One of the the reasons I pulled the motor was so I could use ARP head studs. I am not going to use factory stretch bolts. I see too many head gasket failures on engines that are run for long periods with heavy loads. I run 24hr endurance races and stretch head bolts are the Achilles heel of stock motors.
Headers are a PITA with all the salt on the roads here in the Northeast. They rust out fast. If anyone makes stainless headers they would be quite expensive and that is the only thing I would use. I appreciate the warning on setting up the cams. I am quite used to degreeing in cams, timing chains and belts. I will put multi key way adjustable gears on the crank to get the cam timing where I want it. I think I will advance the cams a few degrees with the long chains these motors have. It may help by lowering the power band and as the chains stretch with use the timing will come back to factory spec. A trick I have found that works well on old 12 cylinder Ferrari motors. I have to look up the "Gotts Mod" I have seen it mentioned several times in other posts.
Headers are a PITA with all the salt on the roads here in the Northeast. They rust out fast. If anyone makes stainless headers they would be quite expensive and that is the only thing I would use. I appreciate the warning on setting up the cams. I am quite used to degreeing in cams, timing chains and belts. I will put multi key way adjustable gears on the crank to get the cam timing where I want it. I think I will advance the cams a few degrees with the long chains these motors have. It may help by lowering the power band and as the chains stretch with use the timing will come back to factory spec. A trick I have found that works well on old 12 cylinder Ferrari motors. I have to look up the "Gotts Mod" I have seen it mentioned several times in other posts.
