Today I decided to have some fun so i took out the chevelle for a spin and after i drove around for a while i decided to have some real fun so as i started out onto the highway i punched it and as soon as i shifted into 2nd gear my mufflers exploded,yes both of them.The double ply outer skins just split right open at the seams and on the ends.I thought the car exploded for a second,scared the $#&# out of me.anybody else had this happen or any ideas why this happened? I have dynomax 3" headers with 2.5" exhaust back to mufflers then down to 2.25" out back, 454 with approx 425hp.I wonder if the 2.25 exhaust pipes created more back pressure than the mufflers could stand? They have been on there for about a year so you would think it would have already done it by now.Any ideas would be appreciated,thanks.Jeff.

Mufflers were 3-chamber cherry bombs

Running a little rich or got a dead cylinder? Sounds like gas ignited in the pipes.

Tim.

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Proud Owner: '69 Chevelle
Malibu: 454, Richie 5, 2.56 open dif. ???

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(Sounds like gas ignited in the pipes)

That, and I think that ice accumilated in the low spots of the chambers from the water by-product of exhaust, blocking full air flow, and when pressed to do full service, just explodes. Yea, that's what I think.

It happened to me with regular mufflers many years back. Was ok, till I started out on the expressway, punched it, and then "BANG". Shook the car, and me. My eyes were sooo wide!


http://www.thenebula.com/carpics/pics/tach.gif

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Joe G.
ChicagoChevelle68
Any car past 1972 is just simply transportation, really!

Same thing happened to my dad's 78 GMC, except the end result was the truck becoming engulfed in flames and 2 fire departments showing up. The right side muffler exploded, then heated up the rubber fuel line that was right there and then burst into flames. Flames were 25 feet in the air.

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Tom Rightler
MCC # 497
Team Chevelle # 978
70 Chevelle SS (http://bluess454.freehomepage.com/70sshome.htm)
Maryland Chevelle Club (http://www.chevelles.net/mcc/mcc.htm)
AOL/AIM screen name: MICRLASER or BlueSS454

If anything kills the ignition momentarily it'll make it backfire. A little longer interruption and it'll backfire BIG and blow mufflers up. Loads up the exhaust system with fuel mix and the ignition lights it up. Used to backfire the cars and motorcycles at work. Open the throttle and flip the kill switch on the Harley's and they'ed backfire as fast as you could flip the switch off/on.

same thing happend to me my mufflers got flooded from over cranking I had an ignition problem then when I finally got spark boom!

When I was growing up in the 60's my cousin had a 55 olds(nice), and He used to turn the ignition off after winding it up, while still in gear, then just turn the ignition back on. It would shoot a flame out the back at least 2-3 feet with a huge explosion. Well, as you can guess one too many times and he blew off the right pipe just in front of the muffler.
Sounds like you had some unspent gas in yours as well.


My 55chevy was never quite as fast as his olds, but it sure lasted alot longer.

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73 Malibu
400ci 425/470
TH700-R4, 3:42 posi
Lovin my afr 190's!

Definition of an expert: Someone who knows more and more about less and less.

[This message has been edited by Gary_E (edited 01-28-2003).]

Hi I blew up the muffles on my car one time, so loud that my ears were ringing. I was driving it, shut it off for 20 minutes, then when I started it bang ripped both mufffles open. Turns out the needle & seat stuck open and poured fuel into the motor while shut off. I'm not sure if this would relate to your problem or not. Dave

Yeah,i think it may be the carb,i havent been happy with it since i put it on,i,ve had to adjust it a lot and it may be too rich, although the plugs seem ok.I,ll lean it down as much as i can before puting the new mufflers on,dont want that to happen again.I have a 750cfm edelbrock carb,has anybody had any experience with them?Thanks,Jeff.