5.4 question

[BurningRubber]

Just tossing around ideas, but 2v 4.6 and 5.4 heads are interchangable correct?

So what happens if you take a 5.4 bottom end and put 4.6 heads on it? Tourqe monster? Also, would it create a problem to run a mild set of cams due to too long of a stroke from the 5.4 bottom end?

Does everything else hook up the same way? Timing chains, accessories?

Just tossing around ideas in case my engine goes south one day...

 

[XtorT'r]

I often stick my foot in my mouth but I'm pretty sure 5.4 heads with the exception of navi heads are the exact same thing as 4.6 heads.

All you really have to worry about is potential romeo vrs windsor crap like valve covers and flywheels that kinda stuff.
Also that whole intake issue.

 

[BurningRubber]

Cool, thanks for the info.



If you took a 5.4 bottom end, and put 4.6 heads on it you would be able to keep the same 4.6 intake though, right?

 

[SilverBullet00]

I know I have seen adapter plates for 5.4L heads to use a mustang intake for a 5.4 swap, so I dont know if the heads are interchangale or not.

 

[SaleenGT2001]

i think the heads are the same but you need adapters since the block is different

 

[BCB00GT]

Heads and cams are identical. The taller block makes the engine taller and thus wider where the intake bolts on. You need adapter plates to bolt to 4.6 intake on. Lots more low end torque.

 

['01 Steed]

How tall are these "adapters"? They'd need to be ~2.75" high in order to maintain the runner's line to the valve. If it's short, the angle changes. This is bad for a number of reasons. One, the air charge must change directions twice, which kills flow. Two, the injector won't be pointing at the valve anymore, which is bad for valve cooling. Hell, just moving the injector upstream 2" or more will affect valve cooling.

Low end torque is a benefit of the 5.4, but throwing a 4.6 intake on it may kill some of what it's capable of.

 

[BCB00GT]

Best intake is a 4.6 intake for high rpm (boost application). This will actually great a very broad torque curve. One of the mustang magazines did it a long time ago. The stock 4.6 intake made great torque low but the engine died on the top. With a high rpm intake, the low end looses some (still MUCH higher than a 4.6) but the high end doesn't suffer.

 

['01 Steed]

When you're talking 5.4L, high end really isn't a consideration. You can't spin them like a 4.6L. Not without spending large amounts of cash.

 

[BCB00GT]

You're right about the high end. But if you look at the two dyno graphs, you will see the usable high end is flat/slightly increasing with the high rpm intake. "High" rpm is used as a relative term, not specific.

 

['01 Steed]

I'm pickin' up what you're layin' down.

 

[BurningRubber]

Cool, pretty much what I thought it would be, a lower revving tourqe monster.

Just tossing around ideas like I said. Doesnt sound too bad, esp. since the adapter plates are available.

I figured it wouldnt be hard to get ahold of a 5.4 bottom end, lots and lots of trucks and suv's with that engine.



Id like to get ahold of a 4v 5.4... woohooo!!!