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A couple points from the 232 SAE Paper

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CornFed Rebel View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CornFed Rebel Quote  Post ReplyReply Direct Link To This Post Posted: Aug/29/2017 at 11:34pm
I've owned a Chevy 230, 250, and 292, a Ford 300, a Chrysler 225 slant 6, and now an AMC 232. All of them have been good engines. I'm partial to the 232 and the Chevy sixes, but I've got nothing bad to say about any of them. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote vinny Quote  Post ReplyReply Direct Link To This Post Posted: Aug/30/2017 at 10:24am
The early Chevs and Fords would break cranks with their 4 bearing sixes. At least I've seen or done it to two of them, one of each brand. Their 7 bearing sixes were much stronger.

I've never heard of a crank breaking on the 4 bearing Chrysler slant six or the AMC 196.

I find it surprising that Chrysler went back to 4 main bearings because I recently saw a 1929 Dodge straight six flat head in a show that had full pressure oiling and 7 main bearings.

Before I was old enough to have a driver's license I had a 58 Dodge Crusader that had the flat head. I think by the end of its run they may have been up to 150HP. It had been parked in the bush and some other kids got it started and jambed the gas pedal to the floor. Apparently it ran like that until it ran out of fuel.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ollie Quote  Post ReplyReply Direct Link To This Post Posted: Aug/30/2017 at 3:57pm
I am of opinion the /6 was the best gasoline engine ever made. Seen them running generators and pumps.


The AMC 6's deal is all the bearing support. I own a 199, 232 and 258.

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1966 American Convertible -- "The Rambler"..SOLD
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1969 Rambler 220 post car--"Road Warrior"
1989 Jeep Comanche Pioneer, 4.0L, auto, 2wd
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Post Options Post Options   Thanks (0) Thanks(0)   Quote vinny Quote  Post ReplyReply Direct Link To This Post Posted: Aug/30/2017 at 4:59pm
We had the small /6 in a 60 Valiant wagon. I don't think it ever gave any problems.

My former neighbor has a 66 Plymouth he restored. He was complaining that his mother had taken the car in a few times for new mufflers. I pointed out that his exhaust manifold was cracked in 3 or 4 places so there was a problem with some of them. Also his valves were clacking wildly and I think at least about .010" loose. It sounded really nice after the manifold was changed and we got the valves adjusted. Just minor maintenance though.

I was reading up on the flat head six and they don't jive with the 29 at the car show that had the seven main bearings.

Last time I had the 232 out at the car show it ran really nice. Buying new I think I'd go for it over the /6.




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Post Options Post Options   Thanks (0) Thanks(0)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Aug/30/2017 at 10:32pm
Dodge/Plymouth kept that old flathead six until 1959 or maybe even 1960 and then it's bottom end design heavily influenced the slant-6. I had a good friend in college who had a 1940 Plymouth truck with the 219 flathead which I helped him rebuild. They used those engines in a lot of industrial applications like tractors, generators, and irrigation pumps. Definitely a strong and durable design. Not the smoothest or quietest, but definitely bulletproof. 

My favorite flathead six is probably the Continental 226 used in Kasiers and Frazers. I drove a 1952 Kasier for a while that had one and I was a sweet engine. Ran a little hot at times, but it pushed that big Kasier along quite nicely. 

Pretty much the only 7 bearing six after WWII was the Nash. Everything else was 4, but they had hefty forged crankshafts and wide bearings. I've found they run just as smooth as later 7 bearing engines at low RPM, but the 7 bearing designs show their superiority at high RPM. The early flatheads couldn't breathe at high RPM anyway so it wasn't an issue, but later in the 1960s when sixes started revving just as high as the V8s the need came about to support that crankshaft more evenly along its entire length to maintain high RPM durability and smoothness. My 7 bearing 232 is balanced within a gram and is just as smooth at idle as it is at 4500 RPM. The old 4 bearing sixes couldn't deliver that. 
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1966 Marlin
1972 Wagoneer
1973 Ambassador
1977 Hornet
1982 Concord D/L
1984 Eagle Limited
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Spin Doctor Quote  Post ReplyReply Direct Link To This Post Posted: Sep/29/2017 at 9:25pm
One reason for reliability issues with the 199/232/258/4.0 over the years IMO is what I call owner apathy. Its part of the "hey, its just a $%&#+-* Rambler" attitude that unfortunately far too many owners suffered from. A second was the typical owner using the I6 powered cars for in town transportation. I think we would all rather have a vehicle if we are buying used that has mostly highway miles vs a cream puff that never got over 35. I remember in the late 70ß and early 80s taking blocks or heads in for inspection when we had dimensional issues. layout would be inspecting Ford and GM components and talk about junk. Extremely poor machining and castings.
The AMC seven main bearing six is a good engine. With proper care and attention it was perfectly capable of providing a better than average service life for its time. The engines had their faults though. Water pumps come to mind. But let's face it. There were better I6 engines built. BMW, Nissan and Toyota come to mind. The Beemer is an example building an engine like a watch. The two Japanese I6's combined the best of both worlds. Built like brick outhouses and capable of some astonishing power. Unfortunately AMC never had the resources to fully develop the sixes like they could have. It is my understanding that OHC versions were built and tested. Fuel injection IMO should of been adopted much earlier. Aluminum heads at least With the possibility of blocks by the early 80s. Cross flow heads. If Pontiac could put a cross flow head on the Iron Duke. People have talked about putting different heads on the 4.0, mostly welded up SBC & SBF V8 heads. The Fords bore spacing is dead on. The SBC 0.020 off. Another source of heads might be the DOHC GM V6. Same bore spacing as the SBC. Of course if I won the lottery it might be interesting to see what could be done. Stereo lithography would make casting patterns a lot easier. Engine management systems today make the ones from the 60s look like a stone axe. One can dream
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: Sep/29/2017 at 10:58pm
by early 60's standards, at least, at least one engine builder thought very highly of AMC's "new" six -- Barney Navarro. when he built Indy car #50's engine he says he surveyed the current selection of American sixes and no contest, AMCs was strongest. this was 67 i think. it is true they stopped innovating too early but at that time it was at least a high quality product. head selection is the limiting factor now it is true.

the poor 195.6... while it's true that the crank and rods are quality forged parts, and journals are very large diameter and good oiling, the crank is not very stiff -- according to the guy who built mine, pete fleming. the rod journals are outboard on very thin castings that make up part of the counterweight system, they're only 5/8" - 3/4" thick. it's just not a very good engine overall, just a very old-world probably somewhat rule-of-thumb designed. 

i've considered -- on "paper" im unlikely to undertake this -- but to fabricate a cylinder head in sections, a stack of layers. each could easily be made on a CNC mill. a combustion-chamber slice, with valve seats and the lower half of the ports; a middle slice which would be the middle of the ports and all water jacket, then the top with port tops, valve guide bases. just use a lot of small fasteners. no slice would require end-wise machining (except for relatively high-tolerance tapped holes for studs and accessories). though it has a lot of gasket area given that it's all utterly flat and totally controllable it wouldn't be a big deal. the combustion chamber/valve seat area is the only hard stuff, and that's all in one slice.


1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Oct/04/2017 at 9:18pm
Originally posted by tomj tomj wrote:

The poor 195.6...the crank is not very stiff -- according to the guy who built mine, pete fleming. the rod journals are outboard on very thin castings that make up part of the counterweight system, they're only 5/8" - 3/4" thick. it's just not a very good engine overall, just a very old-world probably somewhat rule-of-thumb designed. 
And yet you don't hear of them blowing up. They're plenty strong, and here is why.

That is a small bore, long stroke engine design. That makes it a very short engine with a very short crankshaft. It is short even by inline-6 standards. Sure, it doesn't have a main bearing on each side of every cylinder, but you can get away with that just fine when the entire engine is very short.

That was typical for inline engines before the 1960s. Small bore and long stroke. It made the engines tall in height, but it made them short in length.

Large bore, short stroke V8s came out in the 1950s and were all the rage. That technology eventually trickled down to inline-6s. They started making inline-6s with large bores and short strokes too. This made them very LONG, almost as long as the old straight-8s. My AMC 232 straight-6 is only 3 inches shorter than my friend's Buick 263 straight-8! Now they needed more main bearings to support that longer crankshaft. They also started increasing the RPM that inline-6s operated at and the compression ratios. Those both put more stress on the crankshaft and made a stronger bottom end necessary. 

So because it is a small bore engine with a low intended maximum RPM and low compression ratio, it can be plenty strong with just four main bearings. The engineers knew what they were doing. The number of main bearings that is "adequate" for an engine has far more to do with the overall length of that engine than it does the number of cylinders. This is why V8s only have 3 or 5 main bearings: they are short engines. Many of your old straight-8s were either 5 or 9 main bearings. The longer engines were 9. 


Edited by FSJunkie - Oct/04/2017 at 9:21pm
1955 Packard
1966 Marlin
1972 Wagoneer
1973 Ambassador
1977 Hornet
1982 Concord D/L
1984 Eagle Limited
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