4.6 to 5.4 Navigator Swap Mark Viii

[95Vert383AOD]

So im putting a 5.4 32v Navi motor in a 98 Mark viii. I know theres guys out there that have put the Mark viii 32v motors in mustangs. So i figured i could get some help.

The Question is about the electrical connections....

They are both Intech motors so valve covers 8 coil packs etc are the same. But under the intake it seems the 4.6 has 2 knock sensors where the 5.4 has one. Not sure if this matters or if that can just be turned off all together with a tune.

Also 4.6 32v motors have a secondary intake port per cyl. the 5.4 doesn't have this. Can that function be turned off in computer at the time of tuning too? Ive read that the secondaries open up at 3000+ RPM

Thanks for any info guys.
And if anyone knows of any issues i may run into that i haven't addressed please let me know.

Chris

 

[wmburns]

I may be jumping into a post that is way over my head. But are you sure that one of the knock sensors isn't a cylinder head temperature sensor (CHT)?

I thought the knock sensors are in the valley and the CHT sensors are screewed into boss holes in the head.

 

[patman0911]

If the Mark VIII motor has two knock sensors (I don't know for sure one way or the other) then there may be a boss that can be tapped for the second sensor on the 5.4 block.

You should be able to disable the IMRCs in the tune.

What are you planning to do for an intake manifold and/or hood? A 4.6L is already a tight fit under a MN12 hood The last time I looked, the state of the art was getting an Australian Boss 290 intake and modifying it and it barely clears a Mustang hood with the motor lowered in the chassis. The other option is a custom upper for the Navi lower.

I don't know of any Navi swaps in an MN12 but I haven't been paying attention for a while either - surely someone's done one. They've certainly been put in Mustangs so do some searching here and on some other of the Mustang boards and you should find some good info. Have you looked at http://forums.tccoa.com/? Great T-bird/Cougar/Mark info there - us Mustang guys could learn quite a bit from those guys.

 

[95Vert383AOD]

wmburns~

These are bolted into what would be the oil valley area on a pushrod motor. Both sensors look the same and have wires connected together that go to 1 plug on the harness. Its not on the head but on the block.


patman0911~

Can the sensor just be disabled in the computer? Also there seems to be a decent amount of room under the lincoln hood. Sullivan makes an intake...and if i have to ill add a cowl to the car. Sullivan says their intake only raises the motors height about 1" over stock height. it uses the cobra double opening on top of what looks like a spyder style intake. Either way if it doesn't fit ill cut the hood.

The 5.4 intech and the 4.6 32v are very similiar....i wont even have to modify the coils packs because the mark already has a coil on plug setup with identical valve covers. The coil actually sits in the valve cover and is hidden by a plate.

I just want to be able to fire this thing up and be able to get it to a shop to be tuned.

 

[tank_567]

wmburns~

These are bolted into what would be the oil valley area on a pushrod motor. Both sensors look the same and have wires connected together that go to 1 plug on the harness. Its not on the head but on the block.


patman0911~

Can the sensor just be disabled in the computer? Also there seems to be a decent amount of room under the lincoln hood. Sullivan makes an intake...and if i have to ill add a cowl to the car. Sullivan says their intake only raises the motors height about 1" over stock height. it uses the cobra double opening on top of what looks like a spyder style intake. Either way if it doesn't fit ill cut the hood.

The 5.4 intech and the 4.6 32v are very similiar....i wont even have to modify the coils packs because the mark already has a coil on plug setup with identical valve covers. The coil actually sits in the valve cover and is hidden by a plate.

I just want to be able to fire this thing up and be able to get it to a shop to be tuned.

The mark 8 has b-heads and the 5.4 has c-heads. The intakes will not work, you also going to have to get a tune on there for all of that to work.

 

[patman0911]

There's a possibility that the sensors are wired together. I don't think the computer cares where the sensor is that hears knocking, just that it does hear knocking and then it infers which cylinder it is from which one just had a spark event. However, without wmburn's wiring diagrams to pore over, I'm just speculating. You should be able to disable them in the tune, or you may find that you can use just one of them. It makes sense to use a knock sensor if the computer gives you that option - or you may find that you can't get reliable results since it's calibrated for a different block with different resonances and noise characteristics. I'm afraid I'm not going to be much help beyond that.

The Mark VIII computer is probably close enough to drive to the tuner as long as you avoid high RPMs and full throttle - resist the urges.

 

[95Vert383AOD]

tank_567

I'm using the C heads. so im all set there.

patman0911

I think youre right about the knock sensors not caring. Each sensor has 2 wires on it....but at the plug where it connects to the rest of the harness theres only 3 wires. Suggesting a signal wire from each sensor and a common ground. Also the 5.4 has 3 holes in the valley....1 where the 5.4 orignally had the knock sensor (in the middle) and one on each side closer to the cyl. close to the locations of 2 on the 4.6...so maybe i can use the 2 sensor setup on the 5.4 after all.

BTW how does the knock sensor work....it didn't seem like there was much to it.

Excuse my ignorance im used to pushrod engines that don't seem to have these lol

 

[patman0911]

It's deceptively simple. It's just a microphone which listens for loud transient noises in a certain frequency band where knocking is typically found. It then compares the signal to some threshold level and if it's above that level then the computer assumes knocking is taking place and, if it pulls timing globally then it starts pulling timing from all cylinders or, if it only pulls from the affected cylinders, it looks to see what the last cylinder to was that fired and pulls timing from that cylinder. I'm not sure which method the MK VIII use.

 

[95Vert383AOD]

It's deceptively simple. It's just a microphone which listens for loud transient noises in a certain frequency band where knocking is typically found. It then compares the signal to some threshold level and if it's above that level then the computer assumes knocking is taking place and, if it pulls timing globally then it starts pulling timing from all cylinders or, if it only pulls from the affected cylinders, it looks to see what the last cylinder to was that fired and pulls timing from that cylinder. I'm not sure which method the MK VIII use.

Well the 5.4 sensor has a hole in it and a bolt goes threw the hole to attach it to the block. But the 4.6 one kinda looks like a water temp sensor in that the part that threads to the block is not a bolt but part of the sensor itself and you spin the whole sensor into the block to tighten.

 

[StangYellow]

If the Mark VIII motor has two knock sensors (I don't know for sure one way or the other) .

98 mark viii has 1 knock sensor

 

[95Vert383AOD]

98 mark viii has 1 knock sensor

Then what are the 2 things screwed into the oil valley? ....they look identical and look to share a common ground. The 5.4 only has 1

 

[95Vert383AOD]

UPDATE

So i started beating on this project again.

Making bottom end stuff line up and work is a Royal PITA!!! I can't use the Canton pan because of severe cross member clearance issues. So im stuck using the 4.6 Lincoln pan. I now have to shorten the oil pickup by 1". Using the 4.6 pickup isnt an option because the pipe diameter of the 4.6 is bigger than the 5.4.

The Ford racing 5.4 shorty headers look like theyll clear...They dont stick out as much as the factory 4.6.

I have to use Factory style motor mounts because they're different than the 4.6 mustangs. BUT although the holes on the block lineup the surface of the block on the 5.4 wont allow them to bolt up clean. So i have to Notch the motor mount plate. Once this thing actually gets bolted in the car there shouldn't be many issues.

About the Knock sensors....the 4.6 lincoln motor indeed has 2 knock sensors in the oil valley. The 5.4 only uses one but has 2 more holes in the same locations that the knock sensors in the 4.6 are.

I may have to get a smaller brake booster from a mustang or something seeing how the factory one is gigantic.

Its moving along slowly but surely. Ive hunted alot of the Mark 8 forums for swap info but it seems noone had really done this in a Mark. I could be wrong but i see alot of Nay sayers. Most guys just say supercharge the 32v 4.6. I like being different. This motor WILL go in this car if i have to "massage" every fender to get it in!!!!

All i can say is its going to be one helluva sleeper. From Pan to intake top looks around 28" Ill have to cut the hood and get a Cowl from Harwood.

I'll take some pics Soon.

Chris

 

[chris2523]

did this ever go anywhere?

 

[Nomad GT]

The mark 8 has b-heads and the 5.4 has c-heads. The intakes will not work, you also going to have to get a tune on there for all of that to work.

Well also the 5.4L has a taller deck height so the intakes would not interchange if the ports were the same. Best bet is to fab one. Unless he could find a cobra R intake.