Bad bottom end- fix it or 5.4 swap?

[PDHSB]

Recently discovered I have bad piston rings on cylinder #5. It's only holding 120psi, compared to the others which are at 160-180psi.

I'm considering buying a remanufactured 5.4 short block and swapping it in for 1300. Would this be worth doing or should I just try to fix the ring/get a junkyard 4.6?

Either way just don't want to deal with this problem any more.

 

[africansnowowl]

You'd need the intake spacers or one of those outrageously expensive 5.4 manifolds. Your exhaust might also need quite a bit of adjustment, and the flywheel may or may not need to be changed. Not really too bad. You could probably find a junkyard 5.4 for cheaper than 1300. I've seen a few of the 3v ones on marketplace for around 700ish

 

[Chipss36]

A 5.4 swap is not all that great In a car.
It’s basically a truck motor with a bunch of torque. Just not what a car needs.
Also the 5.4 intake issue , also the ejector issue with the 5.4, I was talked out of doing this swap pretty fast many years ago.
Been very happy with a cammed/ported head 4.6 for many years now.

I would rebuild the 4.6.

if you upgrade later you will be much better off....

more displacement is good, but me personally feel the mod motor needs more bore in a car than stroke.
Dyno sheets and track times seem match this idea.

currently building a modular boss 3.7” bore on a stock stroke.
Gonna find out soon..


the 4.6 powerband wise is just a better choice for a car.

 

[PDHSB]

the 4.6 powerband wise is just a better choice for a car.

After some research I definitely agree. The power number is a lot more important when you're trying to go fast.

I think I'm just going to save and take it to a machine shop to get the cylinder walls rehoned. Not sure if I want to bore it, but either way the thing holding back these engines is the poor flow of the heads. Time and money much better spent on Trick flow heads tbh.

 

[Adieu]

You'd need the intake spacers or one of those outrageously expensive 5.4 manifolds. Your exhaust might also need quite a bit of adjustment, and the flywheel may or may not need to be changed. Not really too bad. You could probably find a junkyard 5.4 for cheaper than 1300. I've seen a few of the 3v ones on marketplace for around 700ish

The 3v 5.4s are absolute garbage, and not worth swapping into anything.