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Why The AMC V8 Engine Found In Some Of The Greatest Cars Of All Time Is Such A Humongous Pile Of Shit

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Imagine a huge 5.9-liter, 550-pound iron-block V8 engine that makes less horsepower than a late-model VW Beetle engine, that regularly fails in such a way that it literally stops sending oil to critical internal components, and that’s so large and smothered with emissions equipment that servicing it — even in a gigantic engine bay — is a chore. You don’t have to imagine, because that engine is real. It’s the AMC 360, a piece of shit that defiled some of the most beautiful vehicles of all time, including the Jeep Grand Wagoneer, Jeep Gladiator, my 1979 Jeep Cherokee Golden Eagle, the Bricklin SV-1, and many more. Let’s discuss this shameful bit of American Motors Corporation history.

[Before I get started, allow me to just vent for a moment. I spent all of Sunday trying to get my 1979 Jeep Cherokee Golden Eagle’s replacement AMC V8 engine running. Should I have been editing, writing, answering emails, researching, and hiring? Yes. But instead I was elbow deep inside what has to be the most poorly designed engine I’ve ever had the misfortune of dealing with. The shittiness of the AMC V8 is severely jeopardizing The Autopian’s future outlook; that’s fitting, in some ways. Anyway, it’s not solely my frustration that’s leading me to write this article; the AMC 360 truly is a poorly-designed motor, as I will now show]. 

You may know American Motors Corporation as builder of the greatest Jeep engine of all time, the AMC inline-six, a motor that came primarily in 232 cubic-inc, 258 cubic-inch, and 4.0-liter displacements. This long iron-block motor, found in pretty much every Jeep between 1970 and 2000 — was absolutely unstoppable (If you want to be “in” with the Jeep crowd, just say “That foar leeter is bulletproof I tellya” anywhere near a gas station) thanks to its simple design, ease of serviceability, and plentiful low-RPM torque.

It’s surprising, then, that the same company that built that amazing off-road motor developed the AMC V8, a contraption whose only reliability was liability, and that was ubiquitous in AMC products for decades. The thing went in damn near everything as the “step-up” from the six cylinder, even though, really, it was a huge step down. Let’s take a look at some machines burdened with hauling around this iron menace.

Probably the best-known example is the Jeep Grand Wagoneer, which got the AMC V8 as an option over the inline-six:

Pasted

The AMC Gremlin also offered the V8 if you didn’t want the standard six:

AMC Javelin? Yup, AMC V8 option:

Jeep CJ-5? Sure, you could get this motor instead of the trusty 258:

Jeepster Commando? Yup, 258 standard, 304 optional:

AMG Pacer: Oh yeah, standard six, 360 optional:

That huge anchor weighed down the front-end of lots of AMC products, including — sadly — my 1979 Jeep Cherokee Golden Eagle, which I worked on this past weekend:

Sadly, some non-AMC products also got this awful motor, including Malcolm Bricklin’s Canadian creation, the SV-1:

I’m fairly sure fellow AMC-lovers are going to come out of the woodwork to defend the AMC V8, which came primarily in three variants: 304, 360, and 401. “Mine has driven over 200,000 miles,” some will say. “This guy just doesn’t know how to wrench,” others will claim. “It was a torque, stout motor,” many will cry. “Some of these have been built into highly successful race motors” others will assert. And to them I say: Wake up.

I was a sheep like you once, having fallen head-over-heels for the American Motors way of life. The soulful designs; the charmingly weird blend of Ford, GM, and Chrysler parts; the generally-stout hardware; and just the bold, Smallest-Of-The-American-Automakers rough-and-tumble way of doing things. Like you, I used to see AMC vehicles, especially Jeeps, through rose colored glasses. Hell, I currently own seven AMC-era Jeeps, and I’ve owned many more in my past! I even visited Kenosha a few years ago solely to pay homage to AMC, and I recently snuck into the old American Center former headquarters in Southfield, Michigan. I’m a diehard AMC fan, believe me.

But I have no choice but to call a boat-anchor a boat-anchor, because that’s exactly what the AMC V8 is. Yes, as much as it pains me to admit it, the engine powering the beloved Jeep Grand Wagoneer and my badass 1979 Jeep Cherokee Golden Eagle is one of the worst powertrains in Jeep history. Here’s why.

The Oil Pump Literally Eats Itself

Let’s start with what’s absolutely ruined my experience with my 1979 Jeep Cherokee Golden Eagle, a beautiful machine dripping with soul, and one that I should love, but — thanks to this motor — I actually deride.

Of all the things a motor has to do to survive, right up at the top when listed in order of importance is “make sure metals don’t rub against each other.” The way engines typically make sure bearings don’t rub against journals and camshafts don’t wear against lifters is they put a little cushion of oil between moving metal parts. Oil is the lifeblood of any internal combustion engine, which is why the AMC 360’s lubrication problems are such a big deal.

I ran my engine last summer and heard a loud noise at the top end, making me think that perhaps there was some kind of oiling issue. I removed the valve covers and, sure enough: bone dry. There was no 10W-30 making it up top.

Why was this? Well, the oil pump on the AMC 360 is driven by the distributor; this is fairly common among old engines. So, to see what was going on, I bought a priming tool, chucked it up in my high-torque handheld drill, and spun that pump at 500 RPM through the hole where my distributor once was. Thirty seconds in, I saw no oil flow to the top end. A minute in: Nothing. Two minutes in: A tumbleweed rolls across my rocker arms. Sonuva bitch.

I removed my oil pump from the bottom of my motor and re-packed it with vaseline, as is the recommended procedure to ensure that it primes properly. With the oil filter off, I turned the pump and, sure enough, oil poured out of the oil filter adapter. And yet, with the filter back on, no matter how much I spun that pump, nothing got to the top end.

Worse, I noticed very little resistance on that drill when I spun it clockwise (which I’m fairly sure is the right direction). So while there appears to be some amount of oil flow, there’s very little oil pressure — the fresh 10W-30 appears to be flowing freely…somewhere… instead of to the top of the motor. Something ain’t right.

The bearing clearances on this motor looked fine the last time I checked them, and there was no sludge in the pan. Plus, the oil pickup tube looked fine. And what’s weird is that I did an oil pressure test while the engine was idling and read over 40 PSI while cold using a mechanical gauge; that’s not amazing, but not horrible, either. So I’m confused why there’s no oil getting to the top of the engine, though at the same time, deep down, I know what the issue is.

One of the most common failure points on an AMC 360 V8 is the oil pump itself. American Motors engineers found a clever way to integrate a number of items into the aluminum timing cover at the front of the engine. That cover not only fulfills its purpose of enclosing the timing chain, but it also houses the water pump, distributor, fuel pump, oil filter, and oil pump. I’d consider it clever integration if it hadn’t been so poorly executed.

As you can see in the image above, the oil pump consists of two steel gears riding in an aluminum housing. As is probably unsurprising to many, the result of this setup is that the gears wear into the aluminum housing, and over time, the distance between the oil pump gears and aluminum part of the pump increases, causing a severe reduction in oil pressure. What you end up with is my situation — pumping action is severely reduced, and while there may be oil pressure when cold, you can forget about it when hot. And lack of oil pressure when hot is a very, very bad thing — it will lead to failure of your rod and main bearings, camshaft lobes, rings and cylinders, and much more. Basically, the engine will destroy itself in short order.

Lack of oil flow is a terrible thing, and the fact that the oil pump on the AMC 360 is basically a wear item is pathetic.

And to be clear, when I say the oil pump is a wear item, I’m referring to the entire timing chain cover. That whole aluminum piece that houses the distributor, fuel pump, oil pump, and oil filter adapter. The thing whose replacement requires one to remove the crankshaft pulley using a special puller tool. Of course, you also have to take out the radiator, fan, unbolt the whole accessory drive — it’s a nightmare (more on that job in a bit). And when you’re done, you get to drop $250 on a new timing chain cover, and even then, many forum-goers complain about performance even with the new pump and cover.

 

Even When The Pump Works, The Rear Cylinders Still Don’t Get Enough Oil

Image credit: AMC Forum

The sad thing is, even if the AMC V8’s timing chain cover and oil pump cover haven’t worn themselves out yet, the engine still may suffer from lubrication issues. That’s because the block’s internal oil passages are designed in such a way that, when the engine is run hard, the rearmost cylinders can be starved for oil. Here, let Great Lakes 4×4 member Leanz break it down for you:

AMC V8’s are notorious for having oil system problems. The oilpump housing is the same as the timing cover so when your oil pressure starts to drop when a oilpump rebuild kit will in most cases do you no good at all. This bypass is for the lack of oil at the 7 – 8 rod and main bearings. The oil system flows the oil from front to back, and under quick acceration, leads to lack of oil in a VERY critical area.

The bypass consists of an AN fitting inside the intake valley between the lifters for number 6 and 8. Drill and tap for the fitting in to the oil passage.

The bypass, shown above, is a fairly common modification, though it’s no easy job. It requires one to remove an absurdly heavy cast iron intake manifold, along with everything that mounts to it — and that’s a lot of stuff, especially on a smog-era vehicle like my 1979 Jeep Cherokee Golden Eagle.

It’s Really Not That Easy To Work On

You might think that an old engine like the AMC 360 has a huge advantage over modern cars when it comes to serviceability, but I don’t know that that’s true. My 1979 Jeep Cherokee Golden Eagle was built right in the middle of the smog era, meaning it’s outfitted with more vacuum lines, air pumps, and other emissions-reduction equipment than you can even imagine. Add the fact that my Jeep is a high-end machine with power steering, air conditioning, and cruise control, and the rather enormous engine bay begins to shrink, yielding — as Chrysler’s packaging would often say when I worked there as an intern — “a basket of snakes” or, my favorite, “ten pounds of shit in a five pound bag.”

Even simple things aren’t that easy to service. The rearmost spark plugs, especially the one on the passenger’s side by the heater core, are a pain in the arse to access:

And like I said earlier, replacing that timing chain cover is an awful job. One that I will likely have to do soon. (Dammit). The cover is wedged between the water pump and engine block, and damn near everything is bolted to it. To remove that cover will require dismantling the whole front of the engine.

And to dismantle the front of the engine means removing the giant harmonic balancer on the crankshaft — a job that requires a special tool and, critically, space. To get that space, I’d have to remove the fan on the water pump and take out the radiator. It’s all just a huge pain in the butt.

It Makes No Power And Sucks Gas Like You Wouldn’t Believe

Here’s the thing. Many, many great engines have achilles heels. The unstoppable Buick 3800 V6 has intake manifold problems. The beloved Cummins 12-valve has the Killer Dowel Pin issue. AMC’s own inline-six — one of the greatest engines of all time — tends to crack cylinder heads if it overheats even once. But those engines generally don’t require as much work to fix their maladies, and their fixes tend to yield a lifetime of reliable service. What’s more, none of those engines are as inefficient as the AMC V8.

The 1991 Jeep Grand Wagoneer — the last vehicle to use the AMC 360 in the U.S. market– was a 4,400 pound behemoth whose AMV V8 made 144 horsepower.

144.

That’s less horsepower than this 2011 Hyundai Elantra:

That Hyundai, by the way, scores 32 MPG combined. And while you might expect it to offer better fuel economy given its relatively diminutive size, newer powertrain and transmission technology, slipperier body, etc., I bet you wouldn’t expect it to offer nearly three times the Grand Wagoneer’s combined fuel economy of 11. Three times.

Okay that’s still not fair due to the size difference, but let’s compare the new Grand Wagoneer, which literally weighs one ton more than its predecessor. It makes over three times as much horsepower at 471 HP and scores roughly 33% better fuel economy (15 MPG versus 11).

Obviously, comparing modern cars to old ones is silly, but that’s not the point. The point is that the poorly-designed AMC 360 has singlehandedly ruined my relationship with my beautiful 1979 Jeep Cherokee Golden Eagle. I should be cruising down Woodward in style, listening to that three-speed General Motors TH350 shift through those three gears, enjoying the gentle rumble of that V8, and looking over that distinctive hood. I should be living the dream, but because of the AMC 360, I’ve been dealing with the Amber Heard of automobiles — something so beautiful, and yet so troubled.

All Images by automakers or David Tracy.
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115 Responses

  1. While I agree the 360 was a huge pile of shit. I do like the 390s and 401s. Where the worthless 360 had not only cast pistons so were its rods and crankshaft. On the big brother 390 and 401 all those same parts were forged. I worked for 2 different AMC factory off-road racing teams. James Garner’s American International Racing where we raced AMC sedans and La Paz Racing where we raced Honchos. We used the 390/401 engines and there just were never engine problems.

    1. A few weeks ago my daughter and her fiance couldn’t find anything worth watching on the streaming services and decided to go retro, watching ‘The Great Escape.’ Before that she’d only seen James Garner in ‘The Notebook,’ ‘8 Simple Rules,’ and reruns of ‘The Rockford Files.’

      She was shocked to discover Garner was a big-time racer in the ’60s and ’70s. I told her about how Garner and Steve McQueen were neighbors and both raced when they weren’t acting. She wasn’t all that impressed with McQueen but said Garner was a hunk in his youth.

    1. We tend to romanticize these old lumps, but the truth is most of them were dogs with major design flaws. Someday, I will run you through the one engine that’s the WORST ever made, the 70s Benz diesel. Every possible bit of engineering stupidity is on that turd, and the fatal flaws are kind of works or art in their own right. Yes yes…2.3 million mile taxi cab. Bullshit and hype. It makes the 360 look like a good engine.

      1. LoL, between running the show here, rescuing a wayward Cherokee, selling of the Red FC, hanging out in Walmart parking lots, researching the AMC madness and wrenching his broken Lil heart out, you think he has time to read gossip?

  2. If you’re interested in performance, they can be a pretty good base to build off of. However, if you’re interested in a relatively stock engine, I struggle to think of any smog era V8 that’s worth a damn in stock form. Almost all the automakers resorted to low compression nightmares while they found themselves again.

      1. I had a 460 in a 1992 Club Wagon XLT. We moved cross-country in it, loaded to the gills, towing our camper trailer also loaded to the gills, and that 460 did not break a sweat for 5500 miles worth of Great American Road Trip. One of the smoothest and most reliable engines I’ve ever owned, with enough torque to pull your house off its foundation.

  3. I’d be curious to know the real reason these wear out and loose prime, because ‘steel gears in an aluminum housing’ isn’t a de facto bad design. In fact I have the oil pump for a modern Volvo 13L diesel engine sitting under my desk, a part that is designed to have a 1 million mile service life, and it has steel gears in an aluminum housing. They work just fine.
    At first I thought the pictured diagram was showing that AMC had done the unthinkable and installed the oil filter on the suction side of the pump, but looking closer that doesn’t seem to be the case – the filter is between the pump outlet and the main gallery, as it should be. I went on to wonder if the oil pump was maybe situated too high, losing prime and therefore starting dry every time, causing wear. Well, maybe, but most modern oil pumps are driven off the crank and thus are similarly up above the oil level in the pan, so I don’t think that is it.
    The only notable difference I can see between the design of the AMC pump and the aforementioned Volvo D13 pump is that the pump gear shafts are only supported on the top side of the pump – they do not pilot into holes on the filter pedestal. Maybe if those shafts get sloppy the oil pressure tends to push the gear mesh apart, causing wear on the housing and loss of volumetric efficiency? They’re pretty stout looking shafts, but stranger things have happened.
    Maybe the grade of aluminum those covers are made out of is too soft? That would be a typical penny-pinching self-own by a company in perpetual financial dire straits.
    I was about to opine that maybe the gears were too helical, causing too much thrust force and thus wear against the thrust bearing surface, but I see from the picture that these are straight spur gears. No dice there.
    I think I’m down to material spec or suction tube design, or both. Maybe the pumps were designed with too-loose tolerances from the get-go.
    Whatever the flaw is, I conclude it is ‘in the details’ (material specs, tolerances, oil tubing/drilling diameters) and not a flaw in the overall architecture of the engine – save for the serviceability nightmare caused by the too-integrated timing cover. But as you say, an oil pump *shouldn’t* be a service item over the lifetime of an engine.

    1. Lack of maintenance is the cause. There will always be a film of oil present that should be protecting the aluminum from wear. When the oil is ancient and full of grit or has no film strength left is when the problem starts.

      And you’re correct, iron gears in an aluminum housing isn’t an inherently bad design. I can’t think of an engine designed in the last 30 years that uses anything else, though they are usually crank-driven pumps nowadays.

  4. David, you know full well that comparing it to a 20 year newer compact engine isn’t a fair comparison…
    However, your point still stands compared to 1991 F150 with I6: same HP with 1L less displacement!

    1. Particularly good choice of comparison there, with the vast difference in reliability.

      There’s always a trade-off with power, efficiency, and reliability. That the 360 manages to be on the wrong side for all three is kind of impressive.

      1. Rather than the Mopar, go for the original wagoneer V8 option, the Gladiator aka, the Buick 350 V8. Unique, AMC history, torquey, and when tuned correctly relatively fuel efficient. I’ve had a 74 buick with one since ’99 and loved it the whole time, except when going to the parts store because they have no idea what you’re talking about when you tell them it’s not a chevy.

        Also TA performance had plenty of hotrod parts and the 3800 V6 is just that 8 minus 2 cylinders so plenty durable.

      2. DT, the same amount of work you are going to do in making the v8 run like crap while still having an Achilles heel to kill it and you could source a good 4.0 or sbc and actually have a reliable machine you can be proud to pass on to a new owner.

      3. Well, then you’re choosing to stick with an unworkable combo you hate. If downsizing to a 4.0 isn’t an option, seriously reconsider, if not an LS, then just a regular carbed SBC. You already have a TH-350 transmission in there, right? Make this thing drivable, reliable, repairable, upgradeable, and just drive it. There’s no upside to consigning an otherwise swell Jeep to the hell of an objectively bad engine when you have so many better options. The Eagle deserves better. Don’t curse it to continue limping along with its unfortunate birth defect.

        1. I was thinking the whole time why not swap for the modern (eh…late 90s, 2000s) 4.0 I6, not sure if plausible, but it has more horsepower and likely better fuel mileage, and while maybe not keeping it a classic, still maintains the AMC lineage. My pig TJ weighing over 4400 lbs (how in the h*ll did I get it to weigh so much?) averaged nearly 16 mpg Maryland to Ohio and back!

        2. The bellhousing might not be the same, but I agree that a small block chevy would be an excellent option. Cheap as dirt, reliable, loads of aftermarket parts, and plenty of power to move that size of a rig around. Do it, David!

      4. David, I was thinking about this last night on my drive home. There’s got to be a company out there, or even one guy, that is making steel shim kits for these so that they don’t eat into the timing cover.

        If there isn’t, I might be able to work with you to get something put together. You’ve got my email, I sent in a craigslist link about a Jeep Commando about a week ago.

      5. Believe me, I feel you. For 20+ years I’ve been having people tell me to swap a V8 into my I-6 Mustang, it just doesn’t feel right.
        Still, doesn’t mean you gotta stick within limitations. T5 transmission replacing the C4 helped massively, and the 2x2bbl Weber carb swap I’m working on should wake her up completely.

  5. Had a ’72 CJ-5 with the 304. Man I miss that thing. I won’t say the engine was bulletproof, far from it. However, it was fairly reliable considering the age and lack of previous care.

  6. 1976 Jeep Cherokee Chief, my first car in 1983. The vacuum lines drove me nuts; it ate starters and the quadratrac chain stretched so I had to convert to locking hubs. Still in the day, in my 16 year old mind, this thing was a beast. I crushed my closest high school competitor on the dirt hill in front of school. Took the back seat out for 8 feet of high school fun at the drive in. Power back window always broke.

  7. I say dig through the toyota parts bin for a nice reliable plant. The G16E-GTS gets you 300hp and 273 pound feet of torque. Did I mention that this is a 1.5 litre 3 cylinder? I’m sure that it would be tricky to mount that longitudinally when it is intended to be done transversely in the ‘yotas. Regardless, a high strung 3 in a massive animal such as the golden would make for some fun conversations at your local “jeeps not sheeps” night.

  8. AMC always had quirky and fun designs. I grew up with Gremlins, Concords, and Eagles roaming the mean streets of my rural community. We even had a few Javelins and a Rebel Machine that were hiding in old garages or in the back 40 of someone’s property. Although, my mom almost bought a Grand Wagoneer in 1991 (she passed on it, and the cool wood panel minivan for a Olds Delta 88).

    But I fully agree! Outside of the straight six, their engines were…..engineered as if a fun and quirky car design company built them. I feel like I’m living out their legacy dealing with the AMC designed, Daimler Benz produced 4.7L PowerTech. It has notoriously bad heads (valve seat drops, oil guides plugging, carbon build up) that cause a generally healthy and low mile engine to fail pretty quickly. It also has a fairly complicated SOHC set up, that requires half of the engine to be torn apart to take a head off. I’ve been told by a lot of shops they won’t touch a 4.7 head gasket job or, its cheaper to replace the engine with a junkyard unit. They’re also now hella hard to find in junkyards because these failures happened years ago.

  9. Another way that I think of it:
    The ’79 Jeep Cherokee Golden Eagle is now 43 years old. If my conversion math works out then this would be equivalent to an 86 year-old patient in human years. Geriatric but still loved by great-grand kids and the like.

    If the Jeep had replacement parts like artificial knees (suspension bits), resected gall bladder & appendix (smog apparatus removal) but now needs a heart transplant (modern engine), she would still be grandma and loved just the same.

    A modern functioning engine (read: Chevy heartbeat) may be the way to go…hint, hint.

  10. My buddy had an AMX with the 401 and it was flawless all the time he owned it- about 2 days- he had the hood painted and the shop didn’t attach the hood latch correctly it opened on the highway and beat the roof of the car to death

  11. Has anyone ever engineered a fix for that oil pump? If not, forgo any V8 swap and do a more David Tracy worthy vintage diesel swap with a Perkins 6.354 and claim it’s a,rare export version. FWIW Dodge used Perkins diesels in the 60s and 70s.

  12. Wow, such much to comment on, so little time. Let’s get started.

    First off, while the AMC six can run with a remarkable amount of wear, I’ve seen plenty that didn’t make it to 400k miles (or even 150k miles) as everyone who owns one thinks they can. Most common problem I see is rod bearings, and people drive them 50k miles after they start making noise so the crank is worn slam out. They have bad fuel economy, a ton of hoses and low power (until the 4.0) as well.

    Secondly, many of the complaints about the 360 are rightfully to any V8 of the era, not just AMC V8’s. Tons of hoses, bad access to many things in the engine bay, need of a harmonic balancer puller, low power etc.

    Now to some solutions: I had a 82 Cherokee Chief, and found a stock Motorcraft 4350 4bbl and manifold from a 70’s Waggy in junkyard. I threw them on my Chief and instant power upgrade was in effect. It ran so much better. I currently have a 76 Jeep CJ-7 with a 304. I needed the heads rebuild (it ran pretty good even with leaky valves on 3 cylinders) and while it was apart I threw in a cam (Crower Baja Beast) and a Edlebrock 4bbl intake and Edelbrock 600 cfm carb I had laying around along with a new timing chain. Instant massive power increase. Since you need to take the timing cover off – what a great time to do this upgrade. Note when you do this swap you can throw most of the vacuum hoses in the trash. The AMC log manifolds are pretty good, actually so you don’t need to splurge for headers (although I like the sound with dual exhausts.)

    The other option is an engine swap. To all the people saying 360/5.9L Dodge, why not a 360 Ford? I mean they all have 360 cubic inches, so they must be the same, right? The answer is no, they aren’t all the same, they all have different bellhousing patterns and mount locations; understandable given they are build by competing manufacturers. A Chevy small block is the easiest as the mounts and bellhousing adapters are readily available in the aftermarket. Just make it easy and pickup a junkyard 5.3 (or 6.0 if you want to splurge.) You can either get a 4bbl manifold for it, or wire in the FI system.

  13. In fairness, a lot of Malaise Era American cars had shockingly bad torque and horsepower for their engine size, employed what a friend looking at the underhood rat nest of my ’84 Grand Wagoner dubbed the “heart-lung machine” school of engine controls, and were not so much packaged as besieged by several departments that didn’t seem to be on speaking terms.* AMC’s ever diminishing ability to afford two pots of coffee at one time in the engineering department probably didn’t help with any of the above.

    The 360 wouldn’t be my choice for an engine to really hammer on, but mine did okay considering the above.

    * I once pulled a factory original plug out of a 1980 V6 Cutlass with 80k on the clock; removing and replacing it took about half an hour and one click at a time from various combinations of every socket extension and flex joint I owned. Why, yes, it’s the rearmost one on the passenger side, down under the heater/AC core. Not the only way that car reminded me that “aint” is at the heart of “maintenance”!

    1. > I remember even in the 1970’s people said to avoid the 360. Word was the 383 and the 440 were far superior, so I bought a 440 Bluesmobile at the police auction.

      I wouldn’t exactly throw a Chrysler B-block outta bed for eatin’ crackers, but I think Matadors and the big Ambassadors with the police package usually carried the 401, which as others have pointed out was the same block but with stronger innards. They were very popular and might even have been the fastest police sedan for a year or two, admittedly when that was a low bar; Los Angeles, both city and county, used them a lot.

  14. That timing cover was cracked, when came forward in my 304, and smashed it hard enough for the Water pump to pump water thru the Crack created and pour cooling fluids into the crank. A ticking sound was all I head ( the fins of the water pump hiting the dented timing cover ). I pulled a 401 out of an International Harvester which AMC supplied (they called it a 400) and had no issues after that.

  15. I went through this with a die hard FSJ buddy years back when I had bought an 83 Cherokee WT off of him. That one had a tired 232 in it. I told him I was either going to throw in a 4.0 or do an LS swap. He swore up and down AMC V8 was the way to go. Couldn’t see it then and I can’t see it now.

  16. Can relate to this. I’m currently looking at a coolant leak on the intake manifold of my ‘92 Roadmaster wagon and I thought “No sweat!” Wrong. GM basically plumbed everything into the intake manifold so I have to disassemble like half the top end.

  17. Your struggles with this engine is oh so familiar to me. Sometimes I’m glad they don’t make things like they used to, only when it applies to fixing instead of driving your own pride and joy.
    The timing cover is very similar to the one on a 1985 Olds Ninety Eight I used to have. The Olds still had the nylon timing gears!
    Still do not understand the reason for bolting everything to the timing cover as was common for the period. It certainly made any job like this frustrating.

  18. Let me get this straight. You replaced a terrible V8 engine with another of the same while you knew a legendary six would fit right in and be still appropriate?

    You apparently are not so up on cultural references, so might I suggest you Google “Stockholm Syndrome”. 😉

  19. This isn’t an ‘old car’ motor. It’s a ‘malaise era’ motor. By definition, American engines of this period were amalgamations of penny pinching and poor understanding of ICE design. Truly efficient ICE V8 power was only really perfected in the last 20 years. It took computer modeling and combustion chamber research to get what we have today. The stuff you see at the end of AMC, is ‘good enough’ econobox engineering.

    That is not to say you can’t make one of these machines sing. You most definitely can. But you are going to have to re-engineer some of the piss poor design choices those guys in the 1970’s left you.

    In my opinion, that should not dissuade you though. I kind of like the AMC 327, despite the fact that it is inferior to the Chevy of the same displacement in almost every way.

    Take it for what it’s worth, put external oiling solutions on it, and make it your own, David. You are the guy who made a mail Jeep into a rock crawler, right?

    It’s time to reframe your attitude and expectations. Let your inner creativity blossom.

    1. Once over on that other website, I described 70s American cars as trying to meet the emissions standards of the 80s with leftover engines from the 60s. And if there were new engine designs, they were dogshit, like the Chevy 305, Pontiac 301, this damn thing.

      Their saving grace, by now? A lot of them are great cars that take engine swaps really well.

    2. >I kind of like the AMC 327, despite the fact that it is inferior to the Chevy of the same displacement in almost every way.

      People forget just how advanced the Chevy small bock was when it first came out. It was designed with the learned lessons from three previous V8 design efforts (Cadillac, Buick, and Pontiac) in the preceding five years integrated into it. AMC’s V8 was their first – and only – shot at V8 engine design, so the odds of them getting everything right (or nearly right, since even the SBC wasn’t perfect at first) was pretty low. It’s honestly impressive that AMC’s V8 was as good as it was considering contemporaries like the Ford Y-block and Buick Nailhead had much more limited development.

  20. Well David, I truly sympathize with your engine oiling issue. it sucks, that’s for sure.

    And if I may offer a bit of advice, I have purchased many used cars over the years, some were DD some were collectables , and the one thing I always did before buying any of them is that I obsessively researched the hell out of all the vehicles looking for common failures/issues. This has saved my ass so many times from buying shit piles.

    Stick with the I-6’s, they’re rock solid, the V-8’s are crap, the V-8’s are useful when hanging on a chain, swinging from a crane to demo small buildings! 😉

  21. Man, that sucks! Do you have any machinist friends? If it were me, I would look at machining down the bearing surface where the vanes turn, and install some flat needle bearings with some shims to take up the additional play. Either that, or just dump the boat anchor and be done with it.

  22. “The 1991 Jeep Grand Wagoneer — the last vehicle to use the AMC 360 in the U.S. market– was a 4,400 pound behemoth whose AMV V8 made 144 horsepower.”

    A reminder that in 1990 Toyota Released the 80 series with an old (VERY old) 3F-E motor, a holdover from the 60 series…which was a holdover from the 40, which was based on a chevy from the 20’s. Even that engine had more power (155) than the 360, and with a lot fewer cubes (256 vs 360). And NOBODY thought that was enough engine for the 4600 lb 80 series.

  23. Oh, David. This is a disappointment. There are a lot of myths here, and some unfairness.

    The oil pumps don’t wear like that, except in cases of severe neglect. I’ve pulled open 200k engines that had minimal wear on the housing. By default, there will be a film of oil preventing wear, unless that oil is neglected and becomes abrasive. Steel gears in an aluminum housing have been ubiquitous for decades, so it’s clearly not inherently a problem.

    And the valley oil line is a “fix” cooked up out of a complete misunderstanding of the problem. Drag racers in the 70’s were turning 7000 RPM, and frequently finding the rear main bearing worn or destroyed. They diagnosed the problem as lack of flow, and latched on to the line. It addressed the symptom- now when the engine blew, the rear main looked just as bad as the rest, but it didn’t address the problem at all. The real issue isn’t flow capacity of the pump or even the galleys. It’s actually a lack of adequate drainback. In completely stock form, the heads and valley cannot drain back as much oil as the pump produces above about 5000 RPM. That lead to an empty pan, and as the rear main is the furthest point of real failure from the pump, it spun almost immediately. I can connect you with a former engineer who raced his own AMX in SCCA B/Production and who found the drain back issue on a dyno in Kenosha in the ‘60’s, if you’d like to publish a story on it.

    To the unfairness: In the time of vacuum lines and carburetors, most of the performance and emissions complaints you have were standard across the US industry. AMC and then Chrysler just kept those antiquated systems in use so late because the Wagoneer was on borrowed time, but still immensely profitable. And the 360 is a pain in the ass in that engine bay, but that is mostly to do with that engine bay being designed around Kaiser’s I6 back in the stone age. The Buick V8’s are equally miserable to work on stuck way down inside that deep, wide engine bay, but they didn’t tend to have the AC, and cruise, and vacuum controls in the way. An AMC V8 in a passenger car is a walk in the park for serviceability.

    1. Thank you. The AMC V8 has it’s share of limitations, but you’d never run into the critical oiling issue in it’s intended application – low RPM passenger car use.

      The wear in the combined timing chain cover wouldn’t be an issue if the part was readily available as a replacement. Most people are more than willing to toss worn out parts on Chevys and Fords, where parts are plentiful and rebuilding isn’t worth it, but AMC guys (and Pontiac and Buick etc) are stuck rebuilding the parts produced 50+ years ago since there isn’t the same level of aftermarket support. The core design probably could have been better, but you’re living with the limitations of design choices, development costs, and manufacturing processes from the 1950s, so on a long enough timeline this sort of thing will crop up.

    2. I knew I’d get some pushback from AMC fans, and certainly the vast majority of 360s last a long time without issues. But the reality is that oil pump wear is a CHRONIC problem. Search it on the internet and you’ll find scores of cases of low oil pressure. That’s simply unacceptable; I’ll deal with intake manifold or water pump issues or even head issues, but issues of bearing lubrication? That’s just not okay, and I’m gonna call that poor design out every time.

      Also, this is hardly a defense of AMC’s engineering: “In completely stock form, the heads and valley cannot drain back as much oil as the pump produces above about 5000 RPM. That lead to an empty pan, and as the rear main is the furthest point of real failure from the pump.” But I will grant you that 5,000 RPM sustained is just a bad idea in general, so I probably should have mentioned in my piece that this mod really isn’t necessary for most drivers. So I’ll admit fault there.

      As for the emissions equipment: Yeah, that was standard for many big American engines. And yeah, lots of other American V8s were hard to work on. But just because other engines sucked doesn’t mean the AMC V8 didn’t!

      Look, I’ve had my fair share of nicely-running AMC V8s. Usually they DO work great, but even then, they’re underpowered, thirsty, often overrun with emissions equipment, hard to work on (in SJs), and yeah, in the back of my mind I’m worried about oil pump failure. That’s just not cool.

      1. I generally agree with most of your opinions, but yes, that is a solid defense of AMC engeneering. the factory put the redline right around 5000 rpm. If anyone buys a vehicle with a stock engine, and then expects that engine to survive 1500 or 2000 RPM above redline without having to make some changes. That is not the engineers fault. that is the fault of the person revving the thing to death. If you want a race engine, build a race engine. also, Oiling issues are abundant on many early smog V8 engines. Cadillac 500s blow up regularly at less than 5000 RPM. 351 Clevelands have some oiling issues (if I remember correctly it is actually excessive drain back in the Cleveland.) all of these can be solved for high performance applications, but in my Grandmas Fleetwood, she wasn’t revving past about 3000 ever. there are still plenty of things to fault, but as has already been said, most of those can be said of most engines saddles with early smog tech.

  24. We tend to romanticize these old lumps, but the truth is most of them were dogs with major design flaws. Someday, I will run you through the one engine that’s the WORST ever made, the 70s Benz diesel. Every possible bit of engineering stupidity is on that turd, and the fatal flaws are kind of works or art in their own right. Yes yes…2.3 million mile taxi cab. Bullshit and hype. It makes the 360 look like a good engine.

  25. Was the 304″ engine faced with the same problem or was it just the 360?
    I vaguely remember a guy when I was in college swapping a 327 Chev. into his Gremlin, the a major stumbling block was a conflict between the distributor and the windshield wipers, everything else went as expected with off the shelf aftermarket parts.

  26. About 15 years ago I borrowed my father’s ’86 Grand Wagoneer with a recently rebuilt 360 for a bit of light hauling. It ran great! Such road presence! On the highway at a steady 60 mph, however, I could actually detect the gas needle moving. When I checked mileage over a couple of tanks, I found it was getting 7.7 mpg. Yet somehow it was so gutless that climbing a 3-mile grade on the highway with no load was a mighty struggle. There’s just no excuse.

  27. I’ve never had the privilege/misfortune of owning an AMC V8. My AMCs were a yellow ’74 Hornet two-door sedan with a 232 six and a beige ’84 Cherokee with a 150 four. Both of those powerplants were absolutely bulletproof!

    I sometimes toy with the idea of scrounging up another Hornet for my amusement, mostly because it’s a car I am capable of actually working on myself. I think I’ll avoid getting one with a 360 like the plague based on your very detailed and passionate argument.

  28. “My 1979 Jeep Cherokee Golden Eagle was built right in the middle of the smog era, meaning it’s outfitted with more vacuum lines, air pumps, and other emissions-reduction equipment than you can even imagine.”

    To be fair, that’s at least not unique to only AMC-V8 powered vehicles of the era.

    My ’81 Z28 (305/4-Speed car with AC) looks similarly absurd underhood, especially considering half of the Quadrajet is computer controlled.

    When I installed the longtubes, I removed the smog pump and the spiderweb of piping/tubing that encompassed. That helped, but only a bit.

      1. It’s certainly overwhelming at first. Once you know where everything goes – more or less – it’s not so bad.

        I expected the Camaro to be easy to work on because “old car” and was immediately greeted by spark plugs easiest to change through the wheelwell.

    1. OK, now I’m really confused. My 79 CJ7 had the 304 and was very trouble-free for me even though I had no idea of the vehicle’s history.

      On top of that, it routinely passed inspection despite having little to no emission-related vacuum lines, etc. under the hood. (It failed mostly because shops didn’t know what to make of the independent dual exhaust with twin cats or the fact that the fuel filler neck had been drilled out years before, but that was easily handled)

      The 258 in my Scrambler, however, was a real pain to pass emissions inspections despite having a maze of vacuum lines more difficult than a black and white Where’s Waldo book.

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