Timing chain slop question

AMC Diplomat

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How much slop is too much slop? I'm changing my fuel pump and reached in to poke the timing chain. There's definitely slop side to side but nothing up and down.

It also looks dirty and crusty in there
20230617_132818.jpg
 

Aspen500

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Maybe 1/2" is OK. However, if it's original, the cam gear is aluminum with nylon teeth (unless it's an AHB), basically a ticking time bomb after this many years. With the amount of crud, and obvious poor maintenance in the past, I'd highly recommend replacing the timing set before it leaves you sitting on the side of the road.

Speaking from experience. Had it happen twice on two different Barracudas back in the early '80's. Driving along just fine and poof, engine dies and cranks over like the plugs are out. On both, the nylon teeth broke off. Well, more like disintegrated than broke, lol.
 
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Camtron

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For sure looks like an original timing chain set up. Probably wouldn’t hurt to replace it. If you do replace it, get a good gasket set and take your time cleaning and installing everything to avoid an oil leak at the front of the pan when you’re done.
 

69-

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Not much nylon left in there. And looks just a liiitle bit too scuzzy to me. I'd open, thoroughly clean and replace with double chain rather today than tomorrow.

Slop's gone when.you're done.
 

AMC Diplomat

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Imagine my disappointment after cleaning the heck out of the area to avoid dirt getting in the timing cover only to discover how disgusting it is in there. 20230617_105915.jpg
This is after cleaning
20230617_123658.jpg
This is live where I'm at right now. New pump is in and this is the nos mopar alternator I picked up when I got the new starter.
20230617_150135.jpg
There's about 3/8" to 1/2" slop side to side on that chain when I wiggle it. I don't hear it slapping when it's running.

As far as timing failures go, if it lets loose on me are we talking catastrophic engine failure or I'm just broke down for awhile?
 

Aspen500

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No engine damage, it'll just quit running.

Most if the newer engines I worked on would do mass damage if the chain slipped. GM Eco Tec 4 cyl for example. Replace the rattling chain and guides before it comes apart, about $300 in parts and 4 hours labor. Wait until it quits, $1,000 in parts and 18 hours labor to replace all 16 valves, plus the timing parts. GM 3.6L, $700 parts, 28 hours labor. When the chains go, it's cheaper to replace the whole engine with a Goodwrench reman, about $4,500 parts, 26 hours labor. Why choose those two for examples? Because the failure rate for chains is extremely high and like 80,000 miles only. Damn, I am so glad to never do that kind of work ever again!
 

AMC Diplomat

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No engine damage, it'll just quit running.
Now I'll have to figure out if I want to just send it on a road trip and see if it fails or rip it all down and replace it before I drive it a few hours away.
 

Camtron

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I feel like once you lay eyes on it and start wondering about it, it immediately increases the likelihood of something going wrong, lol. Call me superstitious.
 

LSM360

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You may not have the ability (tools, hoist, etc.) but if you can it would be a great time to pull engine, clean everything real well, new gaskets, freeze plugs, timing chain, etc. So much easier out of the car, especially freeze plugs and oil pan gasket and rear main.
 

AMC Diplomat

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I feel like once you lay eyes on it and start wondering about it, it immediately increases the likelihood of something going wrong, lol. Call me superstitious.
Yeah I'm afraid you're right. Here I was all high on my nos $18 fuel pump and now ugh.
 

AMC Diplomat

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You may not have the ability (tools, hoist, etc.) but if you can it would be a great time to pull engine, clean everything real well, new gaskets, freeze plugs, timing chain, etc. So much easier out of the car, especially freeze plugs and oil pan gasket and rear main.
Oh it wouldn't be the first engine I've pulled. But if I pull this sombitch it's because I'm going to a junkyard 360. There's no way I'm pulling it only to put the same pig back in
 

AMC Diplomat

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When it was running earlier I could balance a drill bit on the air cleaner. So it runs pretty smooth.

And yes, I know I put the wrong sticker on my reman computer. It was all very boring and dirty under the hood so I wanted to church it up for $8
20230617_160123.jpg
 

AMC Diplomat

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Happy Father's day everybody

After sleeping on it, I'm left with 4 options and I'd like to solicit everyone's feedback on this.

Option 1: replace the timing chain on an engine that has over 200,000 miles on it and hope nothing else fails internally
Pros: timing chain won't grenade and I avoid the hassle of a tow
Cons: more time and money spent on an old poorly maintained engine and risk throwing money down the drain if it spins a bearing
I realize it's a roll of the dice if I fix it. It could last me years or something else that was going to grenade anyways decides to grenade the next day

Option 2: go and get a junkyard 360 and refresh it
Pros: moderate improvement in power, it would force me to delete the lean burn, already out of the car so its easier to get to everything
Cons: requires new differential and drive shaft (which probably needs doing anyways) and I just ordered new springs for the current set up

Option 3: get a junkyard 318 and refresh it.
Pros: all parts swap over from current set up, cheaper than a 360, already out of the car so its easier to get to everything, I can try and be cheap and skate on the 7 1/4 differential
Cons: replacing a pig engine with a pig engine

Option 4: send it
Pros: cheap thrills, kick the can down the road until I feel like spending more time and money
Cons: potential breakdowns, which leaves options 2 and 3

Late 80s 360s are pricing between 500 and 800 on car-part.com
Late 80s 318s are between 200 and 500

I'm not looking to make tons of power. I think I'm screwed every way, as I don't see a long term solution to avoid the time and money involved.
 

LSM360

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I like option 2. You don't need new driveshaft, just will have to shorten yours. Might as well do what you really want now and not any other options and then a couple months from now be thinking about a 360 again. If you do a Magnum Head you'll need the accessories brackets too.
 

Camtron

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Figure if the tow home will be cheaper and less a head ache than buying and installing timing chain; after that, decided on how much you really like the car and if you want to keep it for an extended period of time and how you want/would like to use it and go from there.
If you decide you want to keep it, you’d almost be surprised by how many 5.2 and 5.9 magnums are out there in complete, good running condition for a few hundred bucks. Wouldn’t have to swap the rear end/driveshaft either; it’s just makes for more fun when you do, lol.
 

Camtron

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I’ll add that with a stock-ish 318la paired with a 8.25”, 3.21 gears and suregrip, these cars pull pretty dang decent compared to a modern car/truck.
With a 360Mag, 300HP +\- and the same/similar rear end set up, it will almost feel like a stick of dynamite under your foot when you first punch the gas, lol
 
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