I have a '98 f-150 W code (Romeo) 4.6. What I need to know is what engine can I drop in? The 4.6 give me enough power, and the truck was just a daily driver 'til the engine gave up.

I am finding many '99 W code engines at decent prices, $1200 or less. $1200 is about the max I want to spend. Will a Crown Vic romeo engine drop in short of the throttle body?? Will a newer COP engine work if I use the 4 tower setup and the electronics from my current engine? How much more of a pain would swapping a 5.4 be if I use all the current electronics? Will the electronics run a 5.4 with out causing other problems?

I need an engine pretty bad. Been driving my Miata the last 3 months and with winter coming I gotta get my truck fixed. Miata is way too squirrely in the wet can't imagine what is like in the snow and Ice.

Any help in locating an engine is very welcome. And if anyone is near Miami OK and has experience in this motor swap I could use the help. I am pretty mechanically inclined, but the electronics is the scary part for me. I have an A-frame and can get a cherry picker, and I have chain falls for the a-frame. I swapped and engine 15 years ago, but it was a 302 in a 74 F-100. So, it isn't like I am flying blind, but I do realize this is a much different engine.

Thanks and forgive if this is a repeat, but search came up with a ton of unrelated subjects.

 

yes your 4.6 computer will run a 5.4 but only after a custom tune, since you do not have a PI (power Improved) engine I wuld suggest a '99 or newer motor, the PI Truck intake manifolds can be found on ebay and stuff for pretty cheap. YOu can ru your current coil&wire setup on evena 5.4, just may have to lengthen some of the wiring harness

so basicly a '99 or newer 2 valve (sohc) 4.6 or 5.4 will bolt into your truck, If you pick up a 5.4 engine you will need to ensure you get a 5.4 torque converter in order to keep your transmission within it's limits.

as far as electronics goe, get a used Xcal, gryphoon or diablo and have a reputable tuner email you a custom tune if you swap to a 5.4, I would suggest one for a 4.6 as well for optimum fuel mileage and performance

 

If you stick with a 4.6 you can swap any 1997-99 4.6 truck engine be it Romeo or Windsor and they will just plug and play. Again staying with the 4.6 you can swap a 2000 - 2004 Heritage 4.6 which has COP Ignition and transfer your Engine Harness and Coil Pack components. Personally I would stay away from car engines as they have smaller rods. Here are some notes on a 4.6 to 5.4 swap.

Notes for 4.6 to 5.4 swap Revised 25 June 2008

Exhaust: The collectors on the exhaust manifolds are set at different angles and locations. The 4.6 exhaust will not bolt up to 5.4 manifold. You will need to have a muffler shop modify your 4.6 exhaust to match up.

Ignition: All 5.4 engines use Cop ignition. . 2000 and later 4.6 use COP ignition. 1997-99 4.6 engines use coil packs. It is easier to wire your 5.4 using the harness from the 4.6 and the 4.6 ignition coil packs if applicable. If you use the 4.6 Coil pack ignition you will have to fab a bracket for the driver side coil pack.

Engine harness: The IAC harness must be relocated to the rear of the throttle body elbow. The oil sender wire on the 4.6 may be too short so measure or test fit the harness to see if it must be extended. All 97-00 4.6 engines use some sort of intake manifold runner control valve. Remove it from the 4.6 and plug it into the 4.6 harness and bolt it to the engine some where out of the way. Note you can get a tune to remove its function and eliminate it all together. All 97-98 4.6 engines use an engine coolant temp sensor. Some use 2. None of the 99+ 5.4s use any. You will have to tap the intake manifold crossover pipe to fit the sensor. Some 4.6 engines (97-8) have two sensors.

Transmissions: the 4.6 and 5.4 have the same bellhousing bolt pattern. That means that all the transmissions will bolt up. All the 5.4 engines have 8 bolt crankshafts. Some 4.6 engines (ROMEO ENGINE) have 6 bolt cranks. You will need the flex plate from the 5.4.
Manual transmissions: If you don’t have an 8 bolt flywheel a flywheel from a 1997-8 4.6 Windsor engine will work. As it has 8 bolts it will bolt right up to the 5.4 crank. Remove the flex plate spacer and install a pilot bearing from a 4.6.

Torque Converters.
4R70W
ENGINE Stall Speed Multiplication
4.2 1978-2330 2.3:1
4.6 2105-2505 2.3:1
5.4 1830-2190 1.9:1

4R100
All ?????? 2.2:1
If you swap a 5.4 into a 4.6 engine bay and use the 4.6 converter you will multiply the 5.4's torque at a higher rate and at a higher stall speed which will put the torque at the transmission input shaft close to the limit if not over the limit of the 4R70W. The 99+ 5.4 produces 350 ft/lbs of torque. 90% of that is available at 2000 rpm. The stall speed of the 4.6 is above the 2000 rpm range so more than 90% is available. 350 ft/lbs x 2.3(4.6 multiplier) x 90% is 724.5 ft/lbs.

Tuning: It is best to have a custom tune done to accommodate the extra displacement of the 5.4.
You should be able to use the 4.6 MAF as any competent tuner can adjust for it. It is always best to discuss this with your tuner.

Knock Sensor:
The 97-98 99 4.6 uses a 2 wire knock sensor. The 97-98 5.4 has 3 wires of which one is a ground. Both have a Yellow /red wire to pin 57 on PCM.
1997-98-99-2000-01 Yellow/red to 57 on PCM 4.6 Same for 5.4.
97-98 Pin 91 feeds power for 4.6 and other components. Same for 5.4
1999- 2000-01 Pin 32 for power. Same fore 5.4
2002+ Cannot confirm.



Accessories: Some engines have 8 rib serpentine belts and some have 6. Be sure to check so that your accessories have the correct pulley.

Misc: Both engines use the same engine mounts and their location on the block are also the same so your old ones will fit. Unbolt and place aside the AC and PS. You need to remove the intake manifold for the engine to come out. Yes there are 3 bolts on the starter.


Regards

Jean Marc Chartier

 

tarajerame & JMC Thanks for the info. I will be staying 4.6 as that is a ton of stuff to switch to to go with a 5.4. Since I am planning to use the Coil pack plugs and wires from my current engine I won't be quite as picky as I was in the beginning. The reason for using the coil packs from current engine it I have the MSD Coils and Denso Iridium Plugs with 10mm silicone wires. It is the Troyer ignition upgrade kit. And it was installed back in December of '07.

All that said now all I need is the right motor at the right price. I still have about 3-4 weeks until I get all the cash i need, but should I find the right motor I may have to skimp and some things to go ahead and purchase it.

Thanks again, and I'll let everyone know how the transfer goes.

ps. I plan to keep the old motor and rebuild it for a back up. There is a rod clunking around in it now. So, I may do a 5.0 stroker kit on it. I realize i'll need custom tune when the time comes to reinstall it, but at least I'll know going in now.

 

Put a 5.4 in it Scotty,,,don't let JMC scar you with all that info.

Phil

 

#1 you can use your current ignition system on any of the engines, the PI (power improved) engines have more power and better fuel mileage


#2 it'll be cheaper for a 5.4 swap

 

The only big hassle is the exhaust. You can cut the pre-cats out and use flex pipe to align the 5.4 manifolds/headers to the 4.6 exhaust system. That is how mine was first set up then later on I had a muffler shop weld in some pipes. When cutting the pipe in front of the second cats you need to leave enough pipe to allow the flex pipe to slip on and hold a clamp. My set up has always passed Canadian emissions so far but I cannot be sure it will meet your US standards. I purposely do not include that part in my notes because of the emissions issue.

Regards

Jean Marc Chartier

 

The exhaust on my truck needs rebuilt anyway, so that isn't the problem. I just want it to go quickly and smoothly. And with all the swapping of parts I just foresee too many chances for extra problems, not to mention the chance at a money pit.

We'll see what comes my way over the next month or so, and then I'll evaluate at that time. Just trying to get my ducks in a row before jumping into this.

 

Here is the low down. Due to unforeseen problems with Miata, I am getting a loan to pay to have the work done.

I am hoping salvage yard will still have the 56,000 mile engine I called about Thursday. Should get loan Tuesday or Wednesday. $1300 for motor and $700 for install. Not too bad.

Figured I wold let you all know.

Thanks again for the help it is much appreciated.

I do have one question. What is the best, yet cheap, header for the 4.6? BBK for $300 at Jegs seems best so far.