Ok, so I have read a ton of information about swapping heads, or swapping motors from a 4.6 to a 5.4. I called Karkraft.com yesterday and was told the 5.4 motors they have on their web site will not fit in my 98 F150 Xcab 4X4.

My problem is I had the heads pulled back when I had 66k on the truck for an antifreeze leak. Ford had the truck for 27 days and eventually milled the heads and put new gaskets in. This was 3 years ago. I now have 118k miles and the right head is leaking massive amounts of oil. 1qt every 500 miles or so.

I have about $4k to invest in fixing the problem. I would really like to swap for a 5.4, but need some help in finding one that fits the 1998. Would also need some help identifying what other components I'd need to make the swap. I have no problem doing the work.

Other options I would consider would be to just swap the heads for some performance ones and not touch the bottom end. I am guessing the problem with my 4.6 is the heads and not the block, but don't know for sure. If I only swap the heads, I would also look into supercharging as I found one on: http://www.superchargeronline.com/superchargers.asp
Powerdyne for $2,500.

Guess what I really need is some references where to purchase the parts I need and any help in the best way to proceed. ANY advise would be great.

Thanks,
Steve

 

Since no one has replied to my post, I have an additional question. What would happen if I just install a set of 4.6 PI heads and don't change out the pistons? Would the higher compression ratio cause any problems for me. The only other mod I would do is add headers as I have read supercharging with only the PI heads is bad due to the high compression.

If I go with PI heads, can anyone recommend somewhere to purchase?

Thanks for any help.

 

What reason did they say it would not fit?
The 5.4 fits in any 97+ F-150 engine bay.

You might want to tell them its a F-150 not a 140.

JMC

 

Steve,

I just called them. They are just a few miles across the border from me. The 5.4 will fit in your truck. Bonus, it has the complete wire harness to the firewall. All you will need is the motor mounts and PCM. Check my post in the other thread for the flywheel problems. If you don't want to spring for a PCM convert it to coil packs. This would be the easiest and cheapest.

 

Your truck should have sparkplug wires, the 5.4's have coil on plug. Individual coils on each spark plug. In order to run the coil on plug you would need the pcm for the 5.4, or you could use your pcm and run the two coils with the wires on the 5.4. In which case you would probably need to get a chip for it as the timing and fuel curves would be different. Also the cat converters would have to be modified as the 5.4 is wider and taller than the 4.6. The motor mounts are the same for both engines. Depending on whether your 4.6 is a windsor or romeo, it should be a windsor as most '98's came with windsors, the flywheel should be the same.
If you put the PI heads on your engine, you will also need the intake manifold as the ports are different there also.

 

i like the way you are think about making the most out of a bad situation.
might want to consider getting a bid from one of the professional head porter on exchanging you heads for the same year model that have been ported with a new valve job (most inexpensive way) plus you have no reson to keep your existing heads. with that milege i might consider new timing chains. no reason that if the motor has had good maitenace that the short block should not see 200,000 miles.
i might consider mustang cams but after market billet cams are $400 to $600 (more for custom profiles) plus new gears (2) at around 70 a peice.

below is the spec for the ford performance heads (for a mustang and i dont know how different it is for a truck.

4.6L GT Cylinder Heads
4.6L GT Cylinder Head (each)
$850.00

Direct replacement heads add 35HP instantly and up to 70HP with Ford Racing's intake manifold!

Direct replacement for stock 96-98 4.6L heads.
Will fit 99 when used with Ford Racing Intake Manifold.
Accepts production or SVO intake and exhaust manifolds
46.83mm intake valve diameters
(improves airflow 27% over stock)
35.88mm exhaust valve diameters
(improves airflow 44% over stock)
320-T6 aluminum casting
Perfect for Hi-lift cams, larger springs and
custom porting & polishing

 

This is great info.

One thing that you need to do if you redo the heads is to check the block carefully. It may be the cause of the leaks. For the amount of money you want to spend you may just get an exchange engine with 36K warranty too.

Good luck and keep us posted.

Mike

 

The only problem with running Mustang cams is that the profile is set for a lighter car, less low end torque. Low end torque is what a truck needs. True, you will probably gain a couple of hp on the top end, but you will sacrifice bottom end. In my book this is not the way to go. Spend the extra bucks and get some custom cams that are ground for a truck. More on the bottom end for get up and go. Just my :2cents

 

i dont know how much higher in the rpm the mustang makes its power, but the cam are only half of that, the trucks intake manifold with its long runners is responsible for some of the low end, so changing the heads and cams while retaining the stock intake is probably going to split the differance.
i think mustang cams because they would be a lot more affordable than aftermarket cams and the cam gears that can be from $550 to $750 (gears and cams). they might make them but i have not seen anyone develop cams for improved lowend (truck) application. a custom grind would be at least another $100 with no guarantee of a cam that peforms like you want.
if you did the heads with the mustang cams and the low end sufffered, there is alway the option of 4.10's. it is just my opion but the stock intake manifold is never going to allow you to make big numbers high in the rpm without a power adder. it is difficult to make big changes in power out put with out moving the rpm levels (the new 3v 5.4 makes more hp and tq but the peak output is higher in the rpms).
most aftermarket parts make the "10 hp gain" in the 4000 to 5000 range.

the big problem with all this is that we just wont know until someone does it. i havent seen any build ups involving the changes we are taling about on a truck. cosidering the cost of cams, heads, custom tune, and everything else that goes with it, it is not an attractive option to most. until you see dyno runs showing before and after, its all bench racing, which is about all the racing most of us have time and money for.

 

First off, I fat fingered when I typed F140.... I was typing with a broken finger. When I talked to karkraft I don't think I had a tech on the phone, and was not sure I was getting good info. from them.

Thanks JMC for making the call to karkraft. I appreciate that...
I feel a little more informed now. I plan on pulling the motor this weekend and will start making some hard core decisions once I have it out.

Thanks svt_sc_f150 and BROTHERDAVE for the other information on the heads and coil packs. This helps a lot!!!

What advantage would there be to swithcing the PCM versus changing to coil packs?

Once again, thanks for the great info. and I will let you all know what I do and how it's going.

Steve

 

Getting a 5.4 PCM will have all the correct calibrations. Switching to Coil packs will require a custom chip to recalibrate the PCM from a 4.6 to a 5.4. There is also the MAF. The one on your present engine is calibrated for 4.6L displacement. The 5.4 will require a different MAF.

JMC

 

JMC, i dont doubt you, but i have not heard of a maf being calibrated for a specific cubic inch, the only calibaration i have ever heard of was for a injector size and the both engines use the same one.

 

The early 4.6's, '97,'98, and early '99's had two coil packs with spark plug wires. All of the 5.4's had coil on plug. The pcm's are different due to the ignition system. The 5.4's have different hardware to trigger the coils on the plugs. Thus if you want to run a 5.4 with the 2 coils and plug wires, then you can stick with the 4.6 pcm. The maf does not have to be changed as both engines have the same maf and the same throttle body size. I cannot gurantee that the pcm will be able to adjust for the extra cubic inches, but it should. You would have to dyno it and see how the a/f ratio is. But theoreticaly, it should just swap in with just a modification to the exhaust.

 

When I shortened the sample tube on my MAF I tried neal's MAF on my truck and it set a code. At the time both of us were using stock injectors. Also The part numbers on the MAFs were different.

But hold that thought. I will check my notes and get back. Better safe than sorry.


JMC

 

I think I have narrowed the decision down to two options.


1. Go with the 5.4 from Karkraft as it is a new motor with a warranty. I have located a flywheel (8) bolt as mine is a Romeo (6) bolt for $35. I'm checking to see if I can get a PCM from the same salvage yard as the flywheel and as well the motor mounts.

2. Found a 2001 F-150 wrecked with a 4.6 and only 11K miles. I can pick up the long block for $1,250. This would already have the PI heads so would gain power from that. Would also leave me money to purchase headers and a chip. Could even consider supercharging with that low mileage. Powerdyne has a supercharger kit for $2,500.

My only other option is looking for a rebuilt 4.6, but I am a little leary of that as I would not know the condition of the heads, block and gaskets used, so could end up with a leaker again.

If I go with the 5.4 from Karkraft, I will try to order by the end of this week. I need to get this project going as the weather here in Iowa is turning cold.

Thanks for all the help and let me know what you all think of my options above.

Steve