Jump to content

Well This Explains the backfire


Bill Hagan

Recommended Posts

Developed a pronounced backfire on decel during docc's great ride in the Tennessee and N.C. mountains last weekend.

 

http://www.v11lemans.com/forums/index.php?...ic=7421&hl=

 

Hmmmmm. Usually, that means an exhaust leak, but none to befound.

 

Well, on trying to fix my ad nauseum harmonic vibration, I tried loosening all exhaust fasteners.

 

Whoa! What's this? See what I found on exposing the left-side exhaust-header pipe. Yikes!

 

CrackedLeftHeaderPipe.JPG

Link to comment
Share on other sites

Guest ratchethack

post-665-1154295654_thumb.jpg

Bill, this happened to my Pal's '04 LM also. As I recall, you'd been running with a coathanger wire supporting y'er crossover? :bbblll: FWIW, not having a correct support installed with his Stucchi crossover, even though the Stucchi has a provision for it, is what broke my Pal's in the same place. He had the cracks welded and installed the stock rubber hanger, and all's been well since. ;)

Link to comment
Share on other sites

The same thing happened on the left side pipe on my 03 Rosso, luckily replaced under warranty. I think the mandrel that they bent the lefties on had a burr or something and left a stressed area on a lot of the pipes....many cracked lefts, few rights. :( ?

Link to comment
Share on other sites

Now Bill ...tell us the truth...did you find itt or did Wayne come over.... :drink:

 

andy

 

That was hurtful. :D

 

OK, OK, the odds are it could have been true, but I actually did this myself. After the Tennessee trip and advice from the crew there (grappa-based inspirations considered and discounted), decided to lossen the entire exhaust and shift some to the left. When I backed out the left-side header pipe, well, "Thar she blows!"

 

For more pics of that and other weekend wrenching, see: http://snipurl.com/u5q1 :luigi:

 

P.S. thanks to all for the other suggestions and comments. I dropped off pipe at a "possibly too neat" welding shop this a.m. We shall see. [And, oh, yes, I took in the flange and mentioned it had to be on before welding nd be able to slide! :P ]

Link to comment
Share on other sites

  • 2 weeks later...

Check out the "a professional welder did that?" shots as opposed to the fix by Ray Clay.

 

Ray welds stainless steel every day: he specializes in whatever you call those teat & cow udders things. Burrs are a bad thing in that business! :D

 

http://snipurl.com/uxks

 

Now, it's out to the GarageMahalo to see if I can put it all back together. :luigi:

Link to comment
Share on other sites

  • 1 month later...

Check out the "a professional welder did that?" shots as opposed to the fix by Ray Clay.

 

Ray welds stainless steel every day: he specializes in whatever you call those teat & cow udders things. Burrs are a bad thing in that business! :D

 

http://snipurl.com/uxks

 

Now, it's out to the GarageMahalo to see if I can put it all back together. :luigi:

 

Well, here we go again ...

 

As you may recall, had the right-side crack fixed. On way back from 2K-miler over Labor Day weekend, noted the classic "you've got an exhaust leak" backfiring. Weighed down with some "eldercare" issues, finally had time this past weekend to look more closely.

 

CrackedRightSideHeader.JPG & CrackedCrossover.JPG

 

The whole set-up must be too rigid. In fact, as grateful I was for the shim "fix" (and it certainly did fix the "flop") I cannot help but wonder if putting up with flopping around a bit would not be preferable. 'Course, that may not be the real culprit, but rigidity somewhere seems to be the issue.

 

If the gaskets are available, I might buy a case. :blush:

 

Also noted that the forward end of the left side of crossover is up agains the engine case and its leading edge is gouging it. Wonder if--assuming as is, I think, the case, the crossover can't be nudged a bit to the left--it might be possible to slip some flat metal barrier in there. Hmmmmm.

 

And, OBTW, check out the pic of my Pilot Power, with only 2K miles on it. Sigh.

 

PilotPowerBoinked.JPG

 

Not sure when I picked those up, but I'm starting to feel paranoid about nails. :huh2:

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...