Exhaust Repair Question

[Whistler]

Have a question For the "real" mechanics here; neighbor has a Ford Expedition he managed to rip the exhaust pipe in half & asked if I'd weld it up for him. It's a bit mangled, needs to be trimmed back to square and sleeved so here's my question; should I sleeve it on the inside or the outside? Would the wall thickness of an inside sleeve impact the back pressure enough to affect performance?

Not a huge deal just helping a neighbor but it's as easy to do either way and want to do it right for him.

Thanks guys.

[clublights]

Not a " real" mech here but I'm assuming only a foot or two or even 3 foot of replacement pipe, the increase of back pressure ( by reducing inner diameter ) or the decrease ( by increaseing inner diameter ) mathmatically is so insignificant that there will be no to EXTREMELY minimal performance impact either way .

Assuming a 16th or so of an inch either direction .... I don't think performance would take hit till you got at least in to the 1/4 of an inch range

[spleify]

Would the wall thickness of an inside sleeve impact the back pressure enough to affect performance?



Not on a Ford Expedition....

Sleeve it however its easier, I would assume an inner sleeve will be easier

[ray1970]

I'd just wrap some old beer cans around that sucker and secure them with hose clamps. [Tooth]






(Seriously, it doesn't really matter how you do it. Personally, I would get a replacement piece from the parts store that is the same size that is expanded on both ends to slip over the existing pipe.)

[Mtn.man]

First off it's a FORD.

So just cut it off and let her roar.

Or go the beer can route.

[UncleDave]

Is this a single or dual exhaust system? If it is stock single side exhaust then unless the owner is very sensitive to performance he will not notice a difference. Me I have high flow systems on every vehicle I own, and can tell the difference. If you want to do it right, weld replacement pipe replacing everything downstream of the damaged area. The replacement sections are flared on one end to fit over the old pipe. That is his call though. BTW I was in the service side of the business for over a decade myself a master level tech, and grew up in the business.

[Whistler]

Single, stock 3" broken between the cat & muffler. He wants to patch it, guess by "right" I meant "better than a beer can" or flex :)

T'was mine I'd... what am I talking about I don't drive Fords!

Thanks for the replies one and all, about a 4" long internal sleeve welded solid is the route I think I'll take.

[UncleDave]

Sounds like the perfect time for a flowmaster upgrade to me! [Flower]

[Cman]

Im a "real" mechanic been at it 40 years. Weld it up the easiest way it wont make any differance in performance.

[soldier-of-the-apocalypse]

Sleeve the outside

[TFOGGER]

Even with modern monolith cats, the converter has way more backpressure than anything you are liable to do to the connecting pipe, do whatever's easiest/strongest.

[zteknik]

I worked for For for over 10 years and now for Lincoln.
Expidition with a 5.4-sleeve it and be done....
Do outside since its easier to do..

[streetglideok]

Yep, sleeving it outside is far easier. I've done a few of them over the years, as its common on them to stress there. Can usually go to an exhaust shop, tell them the size you need it and the length, and they can cut and expand it as needed. All you need is a mig.

[sniper7]

I wouldn't mess with it. Now the engine will blow up. It is a ford after all.

[ben4372]

muffler nipples go on the outside of exhaust pipes. The muffler shop is the best route. have them make you a piece that will go into the muffler nipple and around the piece from the cat. I'd use clamps and a 3/4 inch tack weld just for good measure. I spent some a couple years at a Midas in my youth, the custom piece should be 10-20 bucks.

[spittoon]

2 colt 45 beer cans and hose clamps

[wctriumph]

Send him to the muffler shop, there are lots of them and they need the work.

[streetglideok]

I worked for For for over 10 years and now for Lincoln.
Expidition with a 5.4-sleeve it and be done....
Do outside since its easier to do..

Heck, I could have gotten you a job at a local indy chain if I knew you wrenched.

[zteknik]

Heck, I could have gotten you a job at a local indy chain if I knew you wrenched.
Ah,good to know,never know what might happen.
I will keep that in mind ;)