In reply to Stefan (Forum Supporter) :
While that's possible, I'll likely stick with the Atomic 2 TBI. It's super easy to set up and deal with, and it looks just like a carb when you pop the hood, which I like. From a serviceability standpoint, there's not much to it, and the parts that can wear are readily available at most auto parts stores for cheap. Also, there's 4 wires to hook up instead of who knows how many in a stock Magnum truck harness. ECU is built right into the throttle body, so the packaging is super clean as well. Also, it will basically be plug and play; swap the engine, plop the Atomic 2 and Hyperspark distributor in, reset the base tune, and fire it up.
One issue I've seen is that Magnum squarebore carb intakes are limited to very few manufacturers: basically just Professional Products and Edelbrock make them right now. I have a Professional Products Crosswind intake on my Trans Am that works well enough, so that's likely what I'll use. It's also less than half of what the Edelbrock costs.
Between yesterday and today, I tore into the front of the engine to see if my suspicions were correct. Just getting to the point where I could remove the timing cover was a real pain.
First thing was removing the radiator. I had to be extra careful, since it's a real mess. Somehow, this thing still holds coolant! But I'm thinking that now that it's out, it's probably a good idea to replace it with something else. This is the original, 42 year old radiator, and it's never been out of the truck.
More evidence that this has never been apart: there's a good 2 inches of gunk on the lower core support. Sandy, oily gunk.
I was not the one to shear this bolt head off, which acts as the adjustment for the power steering pump. This was going to be a problem.
Somehow, the truck made it until now with the original water pump. Wow. And it works fine!
This bolt, which held the alternator bracket on, took about 20 minutes of spraying with penetrant, hammering, and the power ratchet to come out. At least that didn't snap.
Getting there.
After removing the crank pulley and balancer, I had a problem. The timing cover was stuck on the engine due to that long, broken power steering adjuster bolt. I let it sit overnight with half a bottle of penetrant eating away at the bolt. This morning, I wasn't able to get the bolt out, but all the wiggling and hammering ended up snapping the bolt off close to the block. Ooof.
After finally getting the timing cover off, this is what I found. The chain had jumped off! After rotating over the engine to get it back onto the sprocket, I noticed that it's probably the loosest timing chain I have ever seen. This is the original timing set with the nylon cam gear too. They are notorious for being terrible. Either the teeth snap off, or the chains stretch. I didn't find any broken teeth, but this chain is downright sloppy.
Two bolts snapped in the process: one in the timing cover and one in the block. This is the remnant of that long, stuck bolt in the timing cover that held me up before. I noticed that it was actually moving in the block before it snapped, so there was a chance I could get it out with a vise grip.
PHEW! That came right out. Got lucky here.
Where I didn't get lucky is that the intake valve pushrod for cylinder #1 is bent. I checked the rest of the pushrods and they all seem fine, but yeah, not good. I am going to try and get a scope camera down in Cylinder 1 to see if the valve hit the piston. If not, I'll probably change the pushrods, replace the timing set, and send it.
Glad my suspicions were confirmed, but I'm really hoping I didn't do more damage.
Tony Sestito said:
Glad my suspicions were confirmed, but I'm really hoping I didn't do more damage.
Result! That's looking pretty promising. Even if that piston got a little kiss...meh. Send it.
And FWIW, you didn't do any damage. It was going to break, and it did. You were just there when it happened.
Valve, meet piston. NOW KISS!!!! 
Yup, that one bent pushrod on #1 for the intake valve also resulted in a most-likely bent intake valve as well. Since that involves taking the heads off to confirm, I am thinking that this spells the end for the ol'318. It's the worst version of that engine with the worst, smoggiest heads, so investing time and money into making it work is better spent on another engine. While I'm still leaning Magnum, if I can find a cheap rebuildable LA 360, that would certainly be easier. The search is on.
A healthy 360 would be a great and relatively easy upgrade for the truck.
In reply to JeremyJ :
There's no question: if the 318 comes out (which it probably will at this point), a 360 of some sort is going back in. I've got leads on a few, but I'm not sure on availability yet or how much work they will need. Too bad the AMC's didn't borrow the LA 360 back in the 80's, because my friend has a late 80's Grand Wagoneer 360 that he keeps tripping over in his garage I could probably have. I'll find something.
LA engine long chain syndrome.
If you put a magnum or LA engine of some sort back in there please put a skookum timing set in it with a good chain and a tensioner from the LA based v6.
I am glad I tore my van engine ('78 318 88,000 miles) down this winter before that happened.
Good luck with your search.
I have a core 318 if you want it.. but my guess is you are interested in something not LA 318 based.
Greg
Tony Sestito said:
In reply to JeremyJ :
There's no question: if the 318 comes out (which it probably will at this point), a 360 of some sort is going back in. I've got leads on a few, but I'm not sure on availability yet or how much work they will need. Too bad the AMC's didn't borrow the LA 360 back in the 80's, because my friend has a late 80's Grand Wagoneer 360 that he keeps tripping over in his garage I could probably have. I'll find something.
Yeah, the AMC 360 would be an interesting swap. You need the AMC 727 case and the tailshaft from your existing rig and motor mounts are different as are the exhaust, etc. So while the EFI would help the swap, there's enough work there to make it a non-starter (as much as it would be to mess with people to do it, heh)
Folgers
New Reader
8/16/21 6:24 p.m.
I have a 360 la with a mild cam in it, attached to a 1982 Córdoba. I’ll let go for a song to the right guy. Located in Green Bay Wisconsin. I’m not sure how pms work here, but let me know if you’re interested.
In reply to Folgers :
PMs = email, but you have to have a certain number of posts under your belt to message folks. Tony should be able to message you though.
In reply to Folgers :
Unfortunately, I'm nowhere near Wisconsin (I'm in MA), so I'm probably out on that. Thanks for the offer, though!
So, after talking to my buddies about the demise of the 318, they are egging me on to see if I can salvage it. As long as that valve isn't bent too bad, I may just toss on a new timing set, slap a non-bent push rod in it, and see if it has compression. Since the valve covers are already off, it should be easy to check if that valve (or any others) are bent. One friend said to just pull the rocker shaft and get a straight edge and see if it all lines up. If they do, and there's compression, I'll toss it back together and run it for now while I piece together another engine. If not, back to our regularly scheduled swapping.
On my lunch break today, I decided to pull the rocker shaft and check the height of the valves with a straight edge. Talking to some friends, they said that if stuff was bent, this would be an easy way to tell without pulling the heads.
The straight edge made contact with the top of every valve on this side, which is the only side with any damage to a piston. What I did find are more slightly bent push rods; 2 more to be exact. I'm wondering if this was an old injury that I'm just noticing now. The ones that are bent are very slightly bent, so it could have been running terribly for decades. Remember, I've been complaining about timing issues and the engine running less than good pretty much since I've had it. A loose chain and bent pushrods will certainly decrease efficiency.
Next step is ordering a cheapo timing chain and a full set of push rods. I'll replace them and see if there's compression.
Just an opportunity for improvements!
I checked quick on Summit and cannot believe how cheap a basic timing gears and chain set is for these things.
In reply to pres589 (djronnebaum) :
It's going to be about $50 to find out if this works, but it's worth it to have an answer IMHO. I'll still need to get a bunch of gaskets and probably a radiator to get it running again.
EDIT: Parts are on the way. Hopefully I can save this old hunk of iron.
While I am waiting for parts to potentially revive the 318, I started looking in earnest for engines. Had a line on a LA 360, but it turns out it's weather seized, so I passed. And that's the problem with the old LA engines; as time passes, there are less and less of them out there in good enough shape to easily refresh and slap in the truck. The 400 in my Trans Am was a weather seized freebie, but ended up costing me thousands to build due to all the machine work involved.
Meanwhile, I'm still researching the Magnum swap. I've learned what works and what doesn't, and I'm leaning toward making the swap at some point in the future, even if I get the 318 running. They have a lot going for them:
-Modern head design
-More power than the LA
-Roller cam
-Availability and cost
-Ability to run a simple serpentine accessory system
-Less leaky than the old LA engines
The big limiting factors are in intake and cam choice. There are basically two carbed intakes on the market and only a handful of cams. And since it's a roller, they are much more expensive than a LA cam. The stock profile isn't too bad, and an uncorked junkyard fresh Magnum 360 is good for around 300hp and over 400 lb ft of torque, which is roughly double what the 318 came with. That's honestly good enough for me. Anything beyond that might require driveline mods. That will also make the EFI happy, since it's right in the sweet spot for what it's recommended for.
The other thing I'm having trouble with is finding a decent replacement radiator that's not going to break the bank. A lot of places are out of stock for the decent ones, so I'm finding either cheap aluminum Ebay ones or modern style replacements with the plastic end tanks, and I've had hit or miss luck with those on other cars. I'm weary on both, but if I can find a decent aluminum one for around $200ish, I'll probably bite.
Can you have the original rebuilt at a local radiator shop?
I cast my vote for the Magnum 360, but I am a little biased.
In reply to Stefan (Forum Supporter) :
Yes, that's possible, but it's not cheap. Only place around here that still does that costs a few hundred to do a rebuild/recore. The other problem is that my lower tank is pretty messed up due to the petcock and trans line fittings being completely stuck. When trying to loosen the petcock, it nearly ripped the tank!
So today, we are getting Tropical Storm Henri up here in southeastern MA. It's been largely tame, with some decent gusts early this AM and rain off and on all day. Perfect weather for wrenching outside!
My new pushrods and timing set showed up today, so I worked for a bit on the truck removing the old stuff.
Hope this makes sense: The 4 sets of push rods on the left are 1,3,5, and 7. The ones on the right are 2,4,6, and 8. Intake on the left and exhaust on the right. The ones pushed toward the cab are bent! That's FIVE bent pushrods. Again, I have no idea when that happened, but I can't believe only one piston was damaged. I checked valve height on the passenger side today and they all sit perfect when closed just like the other side, so I guess we'll proceed.
Old timing set was so out of whack that I couldn't get the dots to line up after turning it over countless times. So, I lined up the crank gear and yanked the set after getting #6 to TDC, like the manual says.
That's how things should look. Dots at 6 and 12.
After pulling the chain, I moved the cam to line it up at 6 and 12. Hard to see the dots with the grossness, but trust me, it's lined up.
The cam key is slightly chewy from getting the old gear off, so I couldn't get the new one on. At this point, it was pouring and getting windy again, and I heard a good sized limb fall across the street, so I opted to call it quits. But after I de-burr that key, I'll be back in business.
I will put money it will run like a top
In reply to Professor_Brap (Forum Supporter) :
I have a feeling like it will too. And I hope it does, because that will buy me some time until I can build a proper engine for the ol' rig.
Trying this is cooler than a swap. This old truck just looks like it'll take the bare minimum in maintenance and keep on going.
Had a few minutes to work on it a little today on an abbreviated lunch break. Sorry, no pics today. I was able to file down the cam key enough to get the gear to go on, but I decided to do some cleaning before I got the timing set on. Got the front of the block a bit cleaner, and then I remembered that the remnants of the dipstick tube needed to come out. The preferred method is to shove a bolt in there and "slide hammer" it out using sockets and wrenches. Tried that, but that didn't move it at all. After soaking it and picking at it, I broke it into bits and extracted as much through the top as possible. Some of it ended up in the pan, but I need to clean that out before running the truck anyway since copious chunks of gasket and grime got in there when I removed the timing cover. Now, I'm pondering painting the front of the engine or just running it the way it is.
In reply to Tony Sestito :
I'd just run it.
