SOHC conversion to DOHC

[DonMaximo]

- I'm a newbie to this modular engine technology.
- We have an aging 2001 GT (80K - still alot of live let to it)
- I'd like to educate myself on the details of converting from a
naturally aspirated 4.6 SOHC to a 5.4 DOHC (rebuild).
- The purpose of this thread is to find resources in which I can answer questions related to this conversion and following considerations:

- Reuse existing (rebuilt) Automatic transmission
Will the 5.4 engine fasten to the existing transmission (housing/shaft/converter) ?

- PCM
Can the stock unit be used or should I consider grabbing the unit with the used engine ?

- Motor mounts
Are the the same ?

- Exhaust
What changes if necessary to hook up with the existing stock system ?

- Engine compartment clearance considerations



Thanks in advance.

-D

 

[billfisher]

a search will answer most questions.

4.6 oil pan
navi lower with kar kraft upper
same mounts
your pcm
there are no headers that will fit
use 4v manifolds (03-04)
clock the hydro booster to clear
8 bolt flex plate
your tranny
cowl hood

 

[ChillPhatCat]

Probably not what you want to hear, but going 4.6 to 5.4 will not get you much power and it's quite a bit of work. You would end up spending less money and time dropping a blower on top of that engine and gain more power.

 

[bhuff30]

Yup, I would agree that the 5.4 isn't really worth it. You'll get some nice additional low and midrange torque, but the peak power will be similar to a nice NA 4.6 combination. The 5.4 intake options and poor bore to stroke ratio limit the potential power.