AMC Eagle

[MadMan]

Depending on the design of the suspension, sometimes I am able to put the spring in and finagle it without it being compressed. Alternatively, you could buy two sets of those spring-shorteners that people use to lower their cars, and use those to squeeze it. Not as safe, obviously.

[MIPS]

I ended up buying a different compression tool that is purpose built for the spring seats on later model AMC vehicles and it came to cost less than the previous tool. All good there.

So the engine is getting the head pulled in two weeks. I'm tackling the lifter tap before it destroys the camshaft. Also taking the chance to clean the carbon out and get the head looked over at a shop before the seals are renewed and it's buttoned back up. I've been still salvaging parts off another pair of Eagles so I now have a very extensive amount of parts, including a spare head, transmission and transfer case which I need top crate up and slide under the bench....just in case.
I also realized I am now in a position where if I wanted to I can add air conditioning. It does mean I'll be forced to install the tray package but by this point the salvage car was so pulled apart the air boxes, hoses, compressor and vacuum routing was pretty easy to remove. The condenser was beyond the point of salvaging as the fins are coming apart like an accordion but that's been a shared part for over a decade so spares are easy to find. Thing is, do I want to go through pulling the dash apart to install the new system?

[MadMan]

Originally Posted by MIPS

Thing is, do I want to go through pulling the dash apart to install the new system?

I don't know, have you been sweating your balls off like I have this summer?

[MIPS]

It would make for a much more comfortable ride, yes.

[MIPS]

Guess what's happening this week????




I'm fed up with the lifter tap and my water pump decided to start warning me of impending failure so I gathered my parts together and going to town.

-Replace lifters
-Replace head with a rebuilt 4.2L
-Replace water pump
-Replace thermostat
-Replace timing chain and sprockets
-Clean up the manifolds
-Replace fuel pump
-Change the coolant
-Change the oil (because it's going to be dirty after this)

As it turned out I was not planning on a head replacement but got pushed into sending my spare to the shop last week to be rebuilt anyways. As the old head was unbolted it pried itself up which was a sure-sign the head's warped, so I'm happy that actually turned out okay.





The cylinders have a lot of carbon buildup. I was able to get most of it off using WD-60 and a wire wheel at TDC but there's still some deposits I wasn't able to get off, so it will soak overnight.
The fuel pump was not palnned but when they start weeping form the vent it's only $15 for another one. The chain on the other hand was not planned. The recommendation was since I don't know when it was last done and pretty much everything is pulled out of the front of the car it's a REALLY good and convenient time to do so. That's another $50 in parts but DAMN that damper bolt is tight. With the head removed I can't use the rope trick to pop it off and an impact driver can't make the fit so yaay.

[MadMan]

Block the flywheel by jamming a screwdriver into the gear teeth. Might need an assistant to do that while you put a big bar on the crankshaft pulley bolt. Alternatively, remove the radiator to fit an air gun in there. Can't tell if you have already. If I'm desperate, I'd use one of those chain wrench things. It'll chew up the pulley a bit, but with it out, you can file off the nicks.

Run the wire brush over the cylinder block deck to remove all that crud in prep for the new head gasket. Don't use anything else like surface blending discs (cookies).

Don't stress about the carbon on the top of the pistons. Not really a big deal. (Carbon in the rings is more concerning, but you're doing enough work right now lol)

How do the cylinder bores look?

[MIPS]

I went a bit further than that and because I have the TSM there's a note from AMC that if you can't torque the bolt without the crankshaft turning you can fabricate a tool that stops it from turning by holding it against the body/ground.
The spec is only 80 foot pounds, so nothing says that a modified tool can't be made that lets me do it both ways.



This is an approved method.

Because the water pump was coming out I pulled the radiator as well and had to clean it up a bit. As the bearing drifted there was a radial mark on the fins where the fan was juuust starting to clip it and I wanted to flush and repaint the damaged area. Likewise I'm already ahead of you with the wire brush but man I should of dressed the area more because WD-40 and a brush attachment paints everything with black gunk. I left the old lifters in for now so that any crud that falls into the galleries can be vacuumed out instead of making its way deeper into the block but carbon removal was also why I am in here because there was a LOT seen on the borescope. Cylinders otherwise look okay but I'm having a hard time seeing the crosshatch, though at this point if we have to go deeper, forget it I'll probably just get the whole block rebuilt.

[ESigma25]

Wow, been a while since I last saw one of these...I'm surprised you're able to get a rebuilt 258 head, it wasn't that long ago that parts for AMC engines were barely even being made at all.

[MIPS]

The Jeep guys still need blocks so there's a lot of cores out there and the parts are dirt cheap. $40 water pumps and $25 fuel pumps kind of cheap. Heads on the other hand are a challenge because they all want the later 4.0L and I want to stick with the inferior 4.2L. I grabbed a spare off an '84 eagle being scrapped and that turned out to be the game saver here.

[ESigma25]

Is the 258 really as much of a dog as it seems? I heard it only made like...112 horsepower, which is rather laughable for such a large engine, though still better than the utterly hopeless Ford 250 six.

[beat_truck]

I briefly had an Eagle that I bought to fix up, but ended up reselling it. It didn't run too bad, but it was a 5 speed.

Those old straight sixes didn't have a lot of HP, but they had great low to midrange torque.

I had an '83 Dodge 1/2 ton pickup with the 225 slant 6 and automatic. It ran better than I thought it would, and I even towed a couple vehicles with it. It struggled towing through the steep mountains, but it just wouldn't give up.

[MIPS]

American domestic cars having large displacement engines with no horsepower to them was really just a thing until it actually mattered in the early 80's. Before the energy crisis and emissions regulations there was technically nothing wrong with building engines that way because most people were not going fast and gas stations were on every other street corner with prices below 10 cents a liter.
Allow me to use RegularCars for a moment to get the point across with a 72 Ambassador with an EVEN BIGGER engine which displaces another liter and a half in exchange for 60 more horsepower. https://youtu.be/NLBHDjlpm1A?t=112

That all changed in the 70's when North American automakers were getting thrashed by imports with smaller engines with equal or greater horsepower at higher economy and better combustion. For a solid 10 years a lot of blocks were retooled to still remain pretty much the same process but mechanically crippled or factory tuned to be as efficient as they could be at the expensive of EVEN MORE horsepower. The 258 for example is anemic with a dual barrel carburetor and a reverse flow head. Not enough air can get through the carb and the ports are not big enough to move exhaust gases out fast enough.

[ESigma25]

And yet, somehow still less anemic than the utterly miserable Ford 250 six of this era, which had an integrated head and manifold and made an utterly depressing 88 horsepower, making it the slowest of an already slow class of engines (Chrysler Slant Six, Chevy 250, Ford 250, AMC 258). What a horrible engine that Ford "Thriftpower" six was.

Well okay, the Chevy 250 also had an integrated head and manifold at that time but it still made almost 20 more horsepower (105 horsepower in 1979) because the Ford 250 was just that terrible!

[MadMan]

Eh, massive American engines were not really a result of laziness or however you want to describe it. It was a result of a lust for power, and their inefficiency and lack of power was a result of government emissions regulations.

Also, it's important to note that these engines were low-revving, which necessarily meant they had little horsepower. But horses aren't really a big deal, it's torque that really matters, and they still had plenty of that. And emissions regulations really began in 1975 (I think) when catalytic converters became legally required. Before that, those big American engines that we now consider 'weak' were often making hundreds of horsepower, sometimes 1 per cubic inch. They were made weak to meet emissions standards.

The thing about little foreign cars dominating the market was two-fold. One, yes they had small engines, but they were much smaller and MUCH lighter. Where a normal American full-size car would be around 4000lbs, a VW Beetle was literally less than half of that. So a small engine, despite being very weak compared to a big American engine, even one bogged down with emissions crap, could easily handle a much lighter vehicle. And it would be doing literally half the work, so better gas mileage. The other part of the story is that back in those days, many of the much smaller displacement engines were not required by the American government to even have emissions controls. No catalytic, no EGR, basically nothing. They were largely exempt from all the things that made the big engines weak and inefficient. So the concept that the little foreign engines were so much better than the big American engines is really a myth. The little foreigners were literally playing the game with a different set of rules.

Granted, little foreign cars appearing on the open market drove competition, even if the big three were slow to adapt, it did happen. (Unfortunately that's kind of led to all new cars being the same crap.)

[nasadowsk]

"Before that, those big American engines that we now consider 'weak' were often making hundreds of horsepower, sometimes 1 per cubic inch. They were made weak to meet emissions standards."

I think it was Super Chevy that dyno'd a prestine version of the supposed "monster '70 Chevelle LS what that everyone brags about how it made more horsepower than GM would admit to.

288 HP at the rear.

That's barely an entry level high HP car these days.

What "killed" horsepower ratings in the 70's was the feds clamped down on car makers basically advertising whatever number they wanted. It was the same thing they did with stereo equipment. Then you added emissons regulations later on, which the big three figured if they moaned enough, it'd go away. It didn't, and the Japanese ate their lunch.