anyone who has put a 5.4 sohc into their mustang let me know what they had to do for mods or if there is anything to look out for. starting tomarrow and i want to get it right... any help would be great.
Welcome to StangNet, myillwillinc!!!
Actually there was only a small hood clearance problem when 50mustangsandsuperfords mag did this swap back in the 11-03 issue. Although the intake, plenum and TB fit under the stock hood, the linkage required a hole to be cut on the inner liner of the hood, but nothing to the outer skin. They fabricated adapters to allow the 4.6 manifold to fit onto the 5.4. This is a great article.
On the dyno, the stock motor generated 205 RWHP/254 FTLB TQE. The 5.4, basically stock as a rock, generated 215 RWHP/306 FTLB TQE (at 2500 RPMs - hey, it is essentially a truck motor!) With a bit of tuning, they got 226 RWHP and 329 FTLB TQE (still at 2500), but it was obvious the long runners of the manifold (as well as the cams' grinds) were limiting the potential power. HP gains down low were as large as 44 RWHP over the 4.6.
They used a 5.4 motor out of a wrecked 00 E-150 van with only 4k miles - $1150. They sold the 4.6 (with 98K on it) for $450, leaving a net bill of $700. Plus another $200 or so for various gaskets and billet aluminum for the adapters.
I think everything is the same but the rods.... or everything but the crank... not sure witch one..
I know a manufacturer makes adapters to fit either the stock manifold/bullit from a 4.6 on a 5.4. that would prolly fit np under your hood. I have been wanting to do this for a while. Don't know if I will or just hold out and save cash for what ever the next svt mustang is. Don't even bother thinking about a lightning engine... WAY to tall, like halfway up the windshield. I really want to know what a stock 5.4 would do with a pi/bullit/p51 intake and ported pi heads with a nice grind... if I can get 375-400hp.. I'm gonna do it, but I wont waist my time and $ for anything less... It's just me but I don't want the Navi engine because it's a 5.4 iron DOHC, I think that would weigh just a bit more than I wanna deal with, especially becasue the cams are up so high. Not to mention, talk about a tight fit. I bet if I keep my eyes open I can get a 5.4 block for 500-700 bucks pi heads for 200-400. then all I have to do is pay for the porting adapters and whatever intake I wanna put on the thing. I have been pricing this project for a long arse time, since before I ever purchased my mustang . then maybe te next guy that pulls up to a mustang with a cobra R kit will find out the hard way that it's not really a v6 .
He suggested the navigator engine because if you change intakes (there are a few options now) you unchoke the 5.4L DOHC and its the most readily available 5.4L DOHC engine and can be had relatively inexpensively. Your going to run into more problems than its worth though...just try to locate a 4.6L DOHC engine or just start from scratch on a SOHC setup.