5.4 Dohc Swap

98stanggt22

Member
Oct 10, 2011
65
0
16
Illinois
hey everyone, im putting pics and progress of my build on here. im putting a 5.4 dohc navigator engine in my 1998 mustang gt 5 speed. im on a tight budget right now so all im going for at the moment is a solid running stock navi engine in my car. early next year will call for bored out .020 pistons and stage 2 and 3 cams with upgraded valvetrain along with milled heads for higher compression. will def update as i upgrade. now, for some pictures.
new engine or just new toy???

up close pic of massive intake...
 
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pic of the new engine
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pic of massive intake
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rear view of intake
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rear view of engine
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i stripped everything down
the block was honed and new bearings and seals
i have a new gasket set and headstud kit
i fully rebuilt the longblock so far and pics will be added soon
i installed the lower intake manifold with the factory fuel rails and the new bosch 30# injectors
there is all new timing chains all accessories besides the alternator is on
my alternator and bracket came to my house today and ready to install
the new motor is a few things short of finished, waiting on parts especially custom fabbed upper intake manifold which will not get here for a couple of weeks im starting to get anxious :crazy:
by then, the new engine will be installed and ready to go
for now, im going to post a couple more pics, and thanks for looking!!!

my new 3.73 ring and pinion set-already installed :burnout:
http://img407.imageshack.us/img407/5955/img0033lt.jpg

when i first stripped it down to the longblock
http://img29.imageshack.us/img29/4031/img0149fhr.jpg

valve covers pulled (navi head intake ports are awesomely large):banana:
http://img841.imageshack.us/img841/5567/img0152ve.jpg

quick shot of navi head
http://img818.imageshack.us/img818/1078/img0150mo.jpg
 
update-
engine is on the engine stand and off the crate it was in
it has all new gaskets so far, have a few left to put on
i am paused right now.. waiting on parts
i went to install the last set of timing chains and the inside plastic the chain slides on was broken
shopped around for the new timing chain tensioner arm and it will be here by monday
the heads are installed with new head gaskets and headstuds along with the valve covers
also all new seals in the valve covers along with new exhaust studs and gaskets
worked all day yesterday, cant do much without timing chains on, so im off to a local mustang car show tonight
more updates on monday along with pics
 
update-
intake manifold should be here by thursday at the latest. my local machine shop is going to weld in 1/4" to 1/2" aluminum plates where there is no material and the coyote intake has bolt holes tom morning. pics will be here when i get that done. i am ordering either an 80mm or 75mm throttle body this week, whichever one will fit best, and the CAI to go with it after i fit that on. also for this week i need to get an alternator relocation kit which will put the alt on the lower side of the engine instead of the center and an alternator to go with that. pics will also follow as i acquire the parts. my plan is as long as all the parts get here on time is to have it mostly rebuilt by the end of the week. expect more updates and progress throughout the week
 
update-
still no intake yet expecting it on friday. but the longblock if 98% rebuilt except a broken bolt on the valve covers. the timing chains, timing cover along with all new gaskets are installed. crank pulley, idler, and tensioner is on. its starting to look like an engine again lol. ordered a throttle body and when i get the intake in it will be time to experiment with the throttle body. ive read of ppl trying to put a tb off a old 5.0. im going to attempt to put on an sn95 throttle body. fingers crossed
 
AWESOME man! I am waiting for my navi engine to get here. If you don't mind me asking what year and all that is yours. Also what did you pick it up for? I am doing a naturally aspirated setup in an 04 GT. I was considering doing a coyote but my daily driver was a 2012 GT and I wanted something more Frankensteinish to work on because its something different not to mention I can run the Navi with the harness that is in the car. I will be paying close attention to your build. Anything you could give me as a tip for intake? I am going with MMR it looks like at the moment. Also any advice would be highly appreciated.
 
hey man not a problem when im all done i also plan on doing a short and sweet right up with lots of pics. ill be glad to help. it will be a little easier for you since your 04 gt and the navi have more in common than my car. both use returnless fuel system and both use cop so it will be a more straight forward swap. i have a 2001 navigator engine straight out of the navi and it was pretty much fully dressed minus a couple things as shown in the pics. i had talked the junkyard down from 1600 to 1300 for the whole engine and not just a longblock from the throttle body to oil pan to exhaust manifolds and all sensors and wiring in between. i should also have some spare parts which i could put up for sale especially the fuel injector wiring with all 8 cops i have pics of everything. just send a pm if you need anything and ill see what i have. you can use your harness, cop, and fuel system that is in your gt. if im not mistaken, you can also use your 8 bolt flywheel or flexplate along with tranny (whichever you have). if you are wanting a high compression ratio(10.5 or 11:1) which would give you more power, on a N/A navigator motor with a few proven intake manifolds to run, bigger injectors and fuel pump, factory gt wiring harness, sensors (MAF included), factory ecu, and factory cobra exhaust manifolds with a tune you are going to be looking at a ballpark range of 350-380rwhp and probably 375-400+rwtq, and you will have a great torque curve. im sure there are many that would agree with me. there are many proven setups. the main things are the intake you choose, how much fuel you are pumping in and probably most importantly your compression ratio. there are obvioulsy with a few variables. lets just say if you do it right, you will not be disappointed. MMR upper intake is going to kill your torque. that piece really is made for boost and lots of it. it will make the intake runners really short. your best and affordable options are a boss 302, coyote 5.0 (what i have) or 99 or 01 cobra or even mach 1 intake with adapter plates (which are getting hard to find). all three will work. depends on the budget and what you want. boss 302: on ebay for around $475-$500, can use 4v alternator in top center possition, i think 8-9" runners so good hp and tq tradeoff, guessing better for wild cams and high compression setups. coyote 5.0: around $200, need to relocate alternator, i think have 13-14" runners so great torque, great for milder combos. cobra/mach 1 with adapters: intake around $500 (could find deals on forums) ive seen $300+ for plates. will work fine, easier to bolton, long runners and could port for a better hp and tq tradeoff. all work and hope i could help you out
 
I was really considering the MMR and port matching the runners and heads. I have read allot of things that say using the adapter plates is a bad way to go because it messes with the flow rate. If I can get this engine above 400HP I would be pretty happy with that. The torque is what I am really after. I would love to have 400+ HP and 430ish TQ. The TQ is the biggest reason I want to go with the 5.4.
 
the MMR piece utilizes the navi lower intake so you wouldnt need to port match it. this piece also has really short intake runners so it will kill your torque significantly and you def wont hit those N/A numbers with it. also if you want a torque monster, you will want an intake with longer runners. look on corral.net and you will find out more about this swap on that forum. there is actually a coyote intake for sale that was going to be used for this swap. for those numbers you will need custom pistons that put you at 11:1 or so compression, some nice head work stage 2 or 3 cams with upgraded valvetrain, the right intake, big injectors, fuel pump and need to pump some high octane gas. do your research and good luck
 
update:
i snagged a 75mm off ebay for $50 new. i wanted an 80mm but the cheapest one was $225 i need a spacer to mount it to the intake and thats in the works right now. as for an update: i started taking out the old engine. i have everything organized and i have it down to the longblock. tomorrow it will be out of my car and i will start putting cleaning up the engine bay. tom also calls for putting my new flywheel and clutch on the navi engine. waiting for the new 98 cobra valve covers instead of my COP valve covers. i also am going to start selling off some of my old parts. i also found the way i am going to make brackets for the reverse mounted alternator. got a lot to do in not much time. will post pics i you guys want to see them
 
Sounds like your coming along man. I have a spreadsheet with all of the parts I plan on using. The only thing that I was going back and forth with was the intake. I think that I may get a boss 302 intake and have some plates machined for it at my local machine shop. I will have to see what they quote me on doing some custom work like that. Good looking out on the intake though.

On a different note I am getting my rotating assembly and everything this week. I am going with all forged internals and the XE270BH-114 cam set with springs and all from comp. With decking the block and using the MLS head gasket and the way I am going with my build I should be just a little over 10:1 with the Keith Black flat tops in my build. 42lb green top injectors should be able to feed it into the higher RPM's.

Pics please for sure!
 
Marine- just want to let you know i saw the aussie boss 290 intake, the lower 2000R intake, full upper and lower 2000R intake, and the Sullivan piece ( which is a good intake) on ebay. most of them have a heftier price tag than the boss 302 intake. dont intend to confuse or make your decision harder but i wish these were for sale when i started buying parts, but i have a very short timeframe to get done. along with that and a tighter budget than originally planned, im keeping the longblock stock for about a year, then it will be a 5.4 beast. until then just need a running navi motor im my car now!!
 
That's bad ass man. I know how the budget thing is I have been saving to do this project for a while now. I am weighing the cost vs gains on intakes. I am looking hard at the Mach 1 intake. Do you know of anyone that has used that intake and gotten good results?

Also besides the intake. For an automatic car do you know of anything from an 04 Navigator engine to 04 GT that I am going to need to swap as far as mounting the engine and getting it to mate with the trans etc?
 
personally i do not but i have heard of it but the thing is cobra/mach 1 intakes usually run about 500 give or take (look around on a few forums especially corral.net). thats probably where you will find your best deal. on top of that the adapter plates run 350 or so. thats 850. for that price i would highly suggest a boss 302. i might just give in and get one but im going to keep on chugging with this coyote intake. as it goes for the tranny any 4.6 tranny will bolt right up. it prob will be easier for you because all navis are autos. while your at it i would also suggest a new set of polyurethane motor mounts. i just ordered mine this morning and will be patiently waiting lol. one bit of advise when getting the engine, it will make this easier if you get as much as you can for free, motor mounts if i good condition, any wiring, sensors, vacuum lines etc.. where are you getting your motor, what year, how much if you dont mind me asking