232 exhaust pipe diameter.

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   Several years ago my son installed a 2” exhaust system with a Magna-flow in his 69 Gladiator  . He thought that he get better engine performance. It had a flat flange and always leaked after blowing out the gasket The pipe also hit the motor mount. I want to put the stock system.back in the truck. We can’t remember what size the original system was. I do recall that the donut was beveled on the pipe end and flat on the manifold side with a metal sleeve that fit into the manifold. 

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69gladiator Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Sep/15/2013 Location: stratford,ct Status: Offline Points: 242	Post Options Post Reply Quote 69gladiator Report Post Thanks(0) Quote Reply Topic: 232 exhaust pipe diameter. Posted: Jul/29/2018 at 7:09pm
	Several years ago my son installed a 2” exhaust system with a Magna-flow in his 69 Gladiator . He thought that he get better engine performance. It had a flat flange and always leaked after blowing out the gasket The pipe also hit the motor mount. I want to put the stock system.back in the truck. We can’t remember what size the original system was. I do recall that the donut was beveled on the pipe end and flat on the manifold side with a metal sleeve that fit into the manifold.

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19675	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 5:10am
	Stock size was 1-7/8", at least on the cars. The 2" should be fine, just have a proper connection to the manifold made. The good news is a 1-7/8" pipe just fits inside a 2" pipe. You can cut the flange off the 2" pipe and slip the cut end of a stock pipe into it then weld. I've done that a couple times...
	Frank Swygert

FSJunkie Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/09/2011 Location: Flagstaff, AZ Status: Offline Points: 4742	Post Options Post Reply Quote FSJunkie Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 1:48pm
	I think my 232 Hornet had a 2" exhaust system from the factory. I replaced the entire exhaust a few years ago, but the pipe that was on there was 2" and appeared original. I replaced it with 2" because 4.0L's use 2" exhaust and they seem to perform quite nicely with it, making nearly twice the horsepower of a 232. If it's enough exhaust to support a 4.0L, it should support a 232. It's always been really bad about blowing out the manifold to head gasket and the manifold to pipe gasket when driven at high speeds, but I think that is mostly due to exhaust heat rather than exhaust pressure. I finally got it to seal by installing a Remflex gasket to the head and a steel flange gasket to the pipe. No more problems. I think 2" is a good setup. 2.25" is certainly more than enough.
	1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited

purple72Gremlin Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Charter Member Joined: Jul/01/2007 Location: Illinois Status: Offline Points: 16611	Post Options Post Reply Quote purple72Gremlin Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 6:47pm
	I know some people will not agree. But a 2 inch for a 6 would be fine. I dont believe you can go too big on the pipe. I had a 2.25 on a 4 cylinder. And it broke, and I put a stock exhaust on it and it lost alot of power and torque. And this was a 1.6 L. Every time Ive put bigger pipe on anything Ive fooled with, they always ran better, and more torque and this was 4 cylinders and 6 cylinders.and anymore I put 2.50 exhaust on all my V8s.

69gladiator Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Sep/15/2013 Location: stratford,ct Status: Offline Points: 242	Post Options Post Reply Quote 69gladiator Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 7:50pm
	Today I pulled out the pipe and measured the hole in the manifold and it measured 1 3/4”. It’s been a few years and just don’t remember the pipe being 2”. Who knows what a previous owner installed v

73Gremlin401 Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Mar/02/2013 Location: Stmbt Sprgs CO Status: Offline Points: 946	Post Options Post Reply Quote 73Gremlin401 Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 8:16pm
	The longevity of the downpipe donut is absolutely dependent on the bracket and clamp that typically attaches to the bellhousing to create a rigid, triangulated structure to keep the downpipe from moving. Without that, you'll blow out the doughnut regularly. Also - my 77 Gremlin with the 258 2bbl motor was 1 7/8" throughout, and included, like most late 70s-80s AMC 6 cyl systems, the anti-backfire crushed area just ahead of the catalyst - an indication that even 1 7/8 is gracious plenty for good flow.
	73 Gremlin 401/5-spd. 77 Matador Wagon 360/727. 81 Jeep J10 LWB 360/4-spd 83 Concord DL 4-dr 258/auto

69gladiator Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Sep/15/2013 Location: stratford,ct Status: Offline Points: 242	Post Options Post Reply Quote 69gladiator Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 8:38pm
	That’s interesting because there was no bell housing bracket. Wondering if trucks had these brackets. You make a very good point.

69gladiator Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Sep/15/2013 Location: stratford,ct Status: Offline Points: 242	Post Options Post Reply Quote 69gladiator Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 9:40pm
	I read over the TSM and in typical TSM form it was stated in some cases a bracket attached to the exhaust pipe from the engine to the pipe. There was no further discussion as to where it attached

tomj Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7539	Post Options Post Reply Quote tomj Report Post Thanks(0) Quote Reply Posted: Jul/30/2018 at 11:34pm
	in my experience replacement exhaust systems ruin the dont because as the engine moves around in normal operation it pivots on the donut, grinding the asbestos donut and loosening bolts. the factory limited relative motion with the bracket to the back of the block, but replacements don't get the subtleties right. my 195.6 used the ball socket and three-bolt flange clamp, but no one can make those any more. so like everyone else i had 'em weld 2" pipe directly to the flange, but also added one of those late-model car braided stainless steel flex sections. the exhaust hangs on modern type rubber donuts, but the flex section minimizes interaction. even though this car is totally non-stock those flex things would solve this problem in a stock installation.
	1960 Rambler Super two-door wagon, OHV auto 1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com

FSJunkie Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/09/2011 Location: Flagstaff, AZ Status: Offline Points: 4742	Post Options Post Reply Quote FSJunkie Report Post Thanks(0) Quote Reply Posted: Jul/31/2018 at 3:19am
	Yeah, my 1977 232's original exhaust had the bell housing bracket too. The curvature of the bracket and the clamp on it was for 2" OD pipe. I don't think it was 1-7/8" unless we're talking about ID instead of OD. It was 2" OD. There was a deliberately crimped down section near where the pipe crossed the speedometer cable to keep it from burning the cable. As some have said, the outlet diameter of the manifold is only about 2" anyway and the gasket reduces that a little more. Not much point in bolting on a pipe larger than that. The new manifolds don't use a gasket. They have a flared flange cast into the manifold itself that seals to the pipe. I like them because there is no gasket to fail and leak, though the outlet on these manifolds is only 1-3/4" due to a thick casting. I ported mine out to flow better. That bracket on the bell housing is important. Without it the entire front half of the exhaust system would hang its weight from the manifold. That's a lot of force and can definitely cause leaks, bolts loosening, cracks forming, and other problems. That header pipe also needs to be formed precisely so it both lines up straight to the manifold and bolts into that bracket without forcing the pipe to fit at either one. Forcing it to fit will only cause stress and leaks. Ask me. I fought exhaust leaks on my 232 for a long time.
	1955 Packard 1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited