Anyone experience exhaust flange breakage with Corsa?

[johnny248]

Happy birthday to me. I just got my engine back after being rebuilt and a bunch of port work on the Corsa. I was going to enjoy my birthday off by reinstalling the engine and trying it out. Well, that didn't go as planned. With the engine on the bench, I was installing the exhaust flange for the C16 pipe. Back and fourth between both bits to evenly tighten in down. I had my 1/4" calibrated torque wrench set to 7 ft lbs and before it reached that, the casting snapped right off. I am going to see if I could possibly have it brazed or something, but I don't know if it can be done, and if it can, how strong of a repair it would be.

I know that some other people have had these break, and was just trying to get a feel for how common this is. I know that cast iron doesn't have much "give", but it seems to me that this shouldn't brake with such low torque. I guess I could have done something wrong, but I was being extra careful putting this together. The flange wasn't crooked or anything to cause flexing, stress, etc. Just a gakset between the two surfaces. To me, it broke too easily. This was on the bench with just the exhaust flange. I could see someone trying to simply get their pipe mounted and lined up at the mounting points and have this break. Kind of scary.

Just wanted to maybe get a list of people who have had this happen. Maybe it is user error, maybe it is poor casting, maybe it is poor design. Who knows.

[benji]

Nice plate over the oil pump plug, looks clean.

[motormike]

I hate that for you...whadda bummer...

[bonesv]

OH MAN!!! THAT S U C K S!!!
I have broken the lower corner and stud off the corsa's bottom flange.....it's soooo thin!
It's welded back on and ok now!
But I have not seen this before!
Just have it welded back on and be careful?!?!?!

[johnny248]

I was going to take it over to a local place this week to see if they can braze it for me. I don't know what the heck happened. I've seen people break the lower tab off which is why I was being so careful when I was installing that flange. Went back and forth from stud to stud in steps to ensure even clamping force. Then flipped from 5ft lbs to 7ft lbs which should not be an issue and snap,pop, followed my a lot of french words coming out of my mouth. I went back and doubled checked to make sure that the buts weren't bottoming on the threads or something that would cause it to break. The exhaust flange slipped right over the studs without any forcing or pushing , so I guess that rules out the flange not fitting properly. Crazy. If I can get it repaired, I'd almost be afraid to try to install the exhaust again.

[johnny248]

And on a positive note, my gf just gave me this sweet S6 Kicker from Brandon for my birthday. Shout out to Scooter Swap Shop!

I think it will look great once I refinish the front cover and if I ever get it on the road .




Btw, first time I really had my cut up Clutch cover on. Im pretty happy with the way it came out

[benji]

Ooohh nice kicker, I'm jealous! I need a new one myself. I've been stealing the one off my bros zuma.

[Just Joel]

Now I'm worried about mine. Same setup, corsa/c16 but everything snugged down fine... For now at least

[johnny248]

wow johnny that rear cover looks great! Did you have it laser cut?

Thanks! That's just my die grinder and a carbide burr.

[1man8scoots]

Looks great minus the broken part! Hope for warranty!

[1man8scoots]

You saw my broken flange. Plenty of meat left just crazy.

[1man8scoots]

Dear lord I hope not.

[johnny248]

Looks great minus the broken part! Hope for warranty!

Lol. Right now it is making a good look paper weight

I remember reading something in the Polini book that came with it that mentioned something about warranties being void if there had been any modification done to it. So that there doesn't sound good.

I've contacted several places around here trying to find someone to braze this. So far I've struck out everywhere. I did talk to one guy on the phone who said he thinks he could do it, but had to see it. I'm going to take it there in the am and see what he says. Hopefully there will be some good news. I wonder if it makes sense, or if it's even possible to have it brazed all around to reinforce the stength, especially near the lower flange mount where most peoples seems to break.

[ped]

Hi j. About 12 years ago I ordered a Polini BBK from Daywot/ Patrick.
I did some light Porting on it and found a crack near the exhaust I think it was a casting flaw.. the BBK was brand new never installed. I contacted Patrick he said Polini will not warranty it because I had it ported. Back then the cost was about $320 for Polini big bore.
I ended up installing it like that and ran fine. I got lucky I didn't have to buy another one. Maybe someone on this forum with a good welder can help you?
I have a harbor Freight mig welder but I don't think that's going to work?

[johnny248]

You can't really weld cast iron. I dropped it off today to a guy who says he can braze it. The only concern is the braze trail running through the packing slip and exhaust port. He said it shouldn't be a problem to use a dremel or whatnot to clean the exhaust port up afterwards. So we will see. He said he'd probably have it done Friday for me, so I will update on how it turns out.

I still don't personally think that something should break that easily, especially looking at some others who have had the bottom flange break. It's not like the tap snaps off where the stud is, everyone breaks off through the exhaust port. I'm not a metallurgist or anything, but it seems like that cast should be stronger through there.