"Master Cylinder" (mastercylinder28)
04/18/2016 at 20:11 • Filed to: None
5
10|
"Master Cylinder" (mastercylinder28)
04/18/2016 at 20:11 • Filed to: None | 5
| 10 |
This weekend’s project was to build a new exhaust for my 944. I removed all the old, busted stuff and installed a new (aftermarket) header, and cut/fit/welded a new exhaust from scratch. I’ve done exhaust repairs before but this was my first full system. It was really rewarding and mostly fun, and my 944 sounds really nice now.
This is what I started with (new next to old):
It ended up being 15 pounds lighter than stock, and as I said before, it sounds great. BUT, the failure that is mixed in is that there is an audible leak from the header. I used new gaskets and torqued to spec, but I can hear and feel a leak from the header. I have read a few accounts of people installing new headers and having leaks that resolved themselves after a few heat cycles and re-torquing the manifold nuts. That’s what I am going to try first, I guess, since removing the header is kind of a PITA.
Has anyone run into this issue before? Is it something that can “go away” on its own with some time? I’m not super thrilled about driving the car with an exhaust leak, but I figure a few short trips just to bring the head/header up to temp can’t really hurt.
Needmoargarage
> Master Cylinder
04/18/2016 at 20:44 |
|
I’ve never had an exhaust leak just go away on its own, but heat cycling it a few times, loosening things up and re-torquing them seems like the logical next step.
plak424
> Master Cylinder
04/18/2016 at 21:15 |
|
Buy some copper RTV then back the nuts off of the header enough to apply to both sides of the gasket then tighten and let set. I’ve done multiple downpipes on turbo cars using this method without any issues.
What kind of muffler is that? I’m planning on building my miata a full header back system and that looks to be the perfect size that I’m looking for.
gmporschenut also a fan of hondas
> Master Cylinder
04/18/2016 at 21:38 |
|
I had to retorque my nuts after a few. out of 8, 6 barely moved, 1 was 1/4 turn and the last took 3/4 of a turn. the copper. I think it is less the copper softening (copper melts at 1900F, Al 1200F) than vibration resetting the gasket.
One trick I saw is to file the headers flat, to make sure they are flat, though I would expect new ones to be flat out of the box.
uofime-2
> gmporschenut also a fan of hondas
04/18/2016 at 22:18 |
|
It it is not a high quality piece I would not assume it was flat out of the box! It'll take some work but as you say it can be fixed with some time with a file
|
Master Cylinder
> plak424
04/18/2016 at 22:22 |
|
It was a generic “performance muffler” from
www.performance-curve.com
. It ended up being higher quality than some name-brand mufflers I’ve bought in the past.
I think this is the one I bought: http://performance-curve.com/MF2256.aspx
They also have good prices on high-flow catalytic converters.
|
plak424
> Master Cylinder
04/18/2016 at 22:58 |
|
Nice yeah I thought it looked like a quality piece. Better than the flowmasters I’ve bought before.
|
gmporschenut also a fan of hondas
> Master Cylinder
04/18/2016 at 23:04 |
|
http://www.ephotomotion.com/914engine/page…
heres the page
Meatcoma
> Master Cylinder
04/19/2016 at 09:36 |
|
When I installed my headers on my f250, the instructions said to run it for 5 heat cycles(20 minutes worth of driving) and then re torque the bolts which I did. I did not have an exhaust leak after the initial installation, but I have not had one at all since.
|
gmporschenut also a fan of hondas
> uofime-2
04/19/2016 at 21:01 |
|
true. All that welding could easily warp the mounts.
|
uofime-2
> gmporschenut also a fan of hondas
04/19/2016 at 22:15 |
|
Yup, even with thick, 1/2" flanges distortion from all that heat is a problem. If the manufacturer isn’t resurfacing after welding, you might have to.