Introductions and newbie M&K muffler install problem - can't get flange seal tight
 

Hi,

After several years of unregistered lurking and then an extensive hunt for a G50 Carrera I joined the club and bought my first 911 a few weeks ago. (I know, pics are requisite, here's a poor one attached, better to follow).

I'm trying to install an M&K 1 in 1 muffler out onto an otherwise stock exhaust system (with cat) and I'm having a hell of a time and hoping someone might be willing to help.

My issue is that it appears in order for there to be a good seal at the gasket, the passenger side of the muffler needs to move forward toward the front of the car - however it's hitting the other heat exchange tube (probably butchering the description of this piece) that contains the bracket piece the shorter strap goes around.

I've tried as best as I can to see if things would just snug up - but it's now at the point where I'm concerned I'm going to damage something if I continue trying to brute force bolts. The lower bolt toward the driver's side rear wheel can get things snug between flanges, but there is maybe 1MM of visible space along the top side facing toward the passenger side of the car.

In case this is a poor description - were there to be an imaginary 'spacer' that was 1/4" between the M&K flange and the muffler gasket this would provide ample clearance to allow me to get things snug.

Any thoughts?

Thanks much,
Lars


http://i.imgur.com/f2jRNua.jpg?1

Lars,

Welcome to the madness :D:D:D

You are right, the description of your problem is hard to visualized but i'm guessing that your bolt might need to be trim back by 1/4".

If that is not the problem, a photo or a sketch could help.

Here are some photos to hopefully better explain things.

From the bottom
http://i.imgur.com/1CeUYplh.jpg

Top piece = muffler, up against 'pipe'
http://i.imgur.com/A74MrA7h.jpg

Pic of the gap in the seal - bolt closer to the camera = driver's side and furthest = passenger. Note the Gap increasing towards this bolt
http://i.imgur.com/iF8sTeOh.jpg

My problem appears to be simply binding w/ the 'pipe' noted in the 2nd picture, if this piece was 1/4" towards the front of the car I could get all 3 bolts tight w/ out these gaps. As it stands now I simply cannot, through tightening the bolts to any reasonable torque 'pull' the seal tight and am not sure what the next step is.

Thank you all for any assistance.

The heat crossover pipe isn't really that rigidly fixed in place. It is attached to the two heat exchangers with a silicone hose and hose clamps and it is attached to the heater duct work above the engine by a large black sleeve that penetrates the engine bay tin in the back left corner next to the distributor.

If you loosen up the hose clamps at those three points it should move around a fair bit so you can get the muffler hooked up. It that doesn't work I would try removing the heat crossover tube so you can get the muffler cinched up and and see what might be in the way.
I really doubt it is needed (MK is very well made...) but the stainless in the muffler has a fair bit of malleability until it is heat cycled. You can always clamp it up and then use a jack or something to bend it a bit to give clearance.

And BTW: I'd recommend getting copper plated nuts and some copper or nickle based antiseize for your bolts. You will really appreciate it a lot when it comes time to take them off.

Thanks very much, will try that shortly and will replace the hardware after a Hardware store run to get another 13mm box wrench.

+1 on the antiseize paste

The heat exchangers and catalytic converter will warp with heat and age. The muffler should be hung first with the tailpipe exactly where you want it. Loosen the bolts on the catalytic convert (or premuffler or test pipe) and bolt to the muffler (leave loose). Wiggle the cat into place and begin tightening the bolts on both ends to distribute any warpage gaps.
If the heat tube interfers it can also be loosened and re-tightened to fit.
That should do it!

Thanks so much,I hadn't loosened the cat bolts at all, will try and sneak up all of these bolts on final tightness.

Will reply in a bit today hopefully with a finished sound clip.

Cheers!

Well got it sorted out, one of the most brute force installations I've ever done on a car. Problem was the heat tube.

Solutions (though out of my technical wheel house) were:

1) Somehow space muffler another 1/4-1/2" back from cat (plenty of room at the rear of the muffler, but not enough space contacting on the heat tube.

2) Remove heat tube, and cut the same amount from each of the 2 pieces that mate w/ the heat exchangers (didn't have a hack saw guide nor a chop saw handy)

3) Guesstimating that this heat tube wasn't critical to flow like an exhaust tube - take a big hammer and hammer down slightly the rear most side so that the M&K fit.

I chose 3 - and *believe* I have no exhaust leaks (not sure how I'd check to see if I do). Haven't driven the car yet besides re-arranging cars in the garage/driveway but it sure sounds good!

I got both straps on but there was zero change of doing it w/ the included spring. I was careful to not crank down on them too much, so hope this is sufficient (given the nylock nut included I'm confident it's not going anywhere.


Thank you for all of your help, I'll get a video up as I couldn't find one w/ the M&K 1 in 1 out WITH a cat - everything had pre-mufflers or bypass during my searches of PP/Youtube.

Nice looking car. I guess I am partial because it looks like mine. Welcome. I was going to say sometimes if a flange is not true to the mate you can double up on the gaskets. Use some red heat silicone and it usually will help to seal. With any system it is best to loosen all the bolts and let the components seat and align themselves. Then tighten. Nice looking car. Thanks rob