Hello Bus Board,
We have been taking care of this 1971 MC 7 for about 20 years now.
Searched the archives for info on a muffler but have come up empty.
Does anyone have a cross up for the MCI muffler, maybe a Nelson or Donaldson? Was on the phone with Donaldson today with no luck. MCI
will have them available but at cost of $1260.00.
Any help is appreciated, Peter
Don't need the muffler just replace it with a resonator and it will run cooler, less smoke on acceleration, just all around better. I cut mine out and what a difference. Phil Lyons and Gary Hatt did it on theirs also you want be disappointed, I think. The slight extra noise you want hear.
My 2 cents worth, I did it on mine and couldn't be happier and mine is a 8V92 with turbo
92T is MUCH quieter with a straight pipe vs a NA motor. Sounds nice ... when you're 19, at 60+, not so much. There are several options that are in between that will work and be reasonable db wise.
This holds true for gas or diesel engines. The turbo reduces exhaust noise by a fair amount. It especially removes the sharp edge.
Donaldson makes a 5" oval muffler with inlet and exit on the same side of the muffler that is a turbo muffler that flows well. I have it on my turbo 8V-71 and like alot. Good Luck, TomC
I drilled an additional 4" hole in the end of the factory muffler on my '74 MCI MC-8, 8V71 with turbo, to the left of the existing 4" outlet. I now have (2) 4" outlets. It sounds only a touch louder, but the output is double. I've only taken it on one 200+ mile trip since, with no real hills to speak of, so I haven't really tested it on any mountain passes yet, but I'm very confident it will make a lot of difference. It genuinely feels like there is more power. The exhaust pressure from both are nearly equal, and now double. I'm not afraid to remove it all together as is recommended on this board, but I only have $60.00 invested in the 4" 90's, etc., so if it doesn't work well, out it goes. We'll find out this coming spring.
While this doesn't specifically apply to your post, and I don't know what issues your current muffler has, I only wish to show that there are options, and I would not be afraid to follow the advice of those on this board and remove your old muffler and install a resonator, or (?) for more power, less heat, better performance.
Good luck, Glennman