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Possible knock - pucker factor 5

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TheBirdman View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheBirdman Quote  Post ReplyReply Direct Link To This Post Posted: Dec/04/2018 at 7:29am
Originally posted by DaemonForce DaemonForce wrote:

I can say based on where you're at, you have a good pick of the litter when it comes to 4.0 donors and that should be really easy but you're nowhere near ready to do the stroker build until you're absolutely sure you're not going to need so much garage space. Also, make sure you setup a kickback for that process and I would estimate somewhere in the $1500-2000 range. There's nothing bad or embarrassing about the stroker but the thing with speed shops and parts is that the stroker project can get real stupid real fast. The odd geometry issues with the Eagle multiplies this difficulty a few times over. Plan out your purchases if you're really going to do that. Thank God I did.
Yeah, the strokers probably not happening, but a guy can dream. I might have a line on a 150k 4.0 for around 300, otherwise Ill probably look into fixing mine. Do you suppose if I put it on a stand and popped the oil pan off I could change the mains and rod bearings, and clean out the oil passages without having to take the head and cam out? Im not afraid of the head and cam, Ive done them before, but I already know this cam is fine, I replaced the timing set last year, and if I can get by without hoping I dont break a head bolt, that would be fine too.

Originally posted by farna farna wrote:

Probably just a stuck lifter. The back firing may have caused it to stick, took a little time to loosen back up. The lifters will collapse over time as the springs weaken with age. I've had them stick in the AMC six when it sat for a long time, like several years, with a good many miles on the engine (80K+). Had to replace 3-4, but at the price I replaced all. 

One observation -- did you have that open air filter on the old carb, or the stock air filter assembly? If you had the stock assembly with a heat stove (or even without that) that's your old weather running issue. The closed filter housing even without a heat riser tube (heat stove) will run better than an open filter element sucking in lots of cold air.

Hey, good call. I had the old frying pan on the carter, although the vacuum motors for the heat risers never worked. Ill keep that in mind for when I get back to tinkering.


Edited by TheBirdman - Dec/04/2018 at 7:31am
1983 Eagle Wagon
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motorcraft 2100
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DaemonForce Quote  Post ReplyReply Direct Link To This Post Posted: Dec/04/2018 at 4:22pm
That's another complicated issue. Most of the equipment I use is from my grandfather who was never really that smart about shop equipment, so it's old, rusted, some rotted and all of it really far from ideal by today's standards. The engine stand I used to build my stroker is one of those old high center of gravity models where there is a wide beam at the base and narrow at the end, kind of like an H beam. The L6 is TOP heavy, so while you will have no problem with my type of setup getting the engine to turn on its head, you're going to struggle getting it upright again without a hoist or the assembly going kerchunk. Get a reinforced engine stand and make sure you get one with a reduction crank so that you have full control of the rotation. My stroker was a mix of parts from the Lakewood and Portland junkyards but I bought a 180K block from some dude's gf in N. Seattle who rolled his Cherokee. It was $200, without any manifolds so I know for a fact you can do better.
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Post Options Post Options   Thanks (2) Thanks(2)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Dec/04/2018 at 5:28pm
Your first post was you were picking up the sparkles with a magnet. That means it's not main or rod bearing, piston or soft metals, The magnetic "particles" are usually lifters, cam, push rod or rocker. The cam may have been new but if a lifter is disintegrating then the cam is a goner. If the rocker is a goner then the rod and lifter are goners as well inspect the cam.
Other then this it's cam gear, distributor gear, oil pump, timing set.
Have to find were the "magnetic" particles are coming from. Just replacing mains will not fix this.
Check the mains for "magnetic" particles embedded. If they are, then replace all your mains, rods and cam bearings.
Sorry but his is a total rebuild in my mind. Anything less will not last that long and just cost more again in short order. 
 


Edited by Trader - Dec/04/2018 at 10:03pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Dec/04/2018 at 5:34pm
As long as you can get the oil pan off without lifting the engine you an change out the bearings. BUT... some bearing material in the oil pan is normal. That doesn't necessarily mean the engine it that badly worn. Whicle there shouldn't be a lot, some of it may have been in the pan for a LONG time before the magnetic plug was put in. There is some sludge in the bottom of the pan no matter how often you change the oil. Again, not much, but some, and metallic partials being heaviest will settle to the bottom.

Do you have an oil pressure gauge? Good oil pressure and no knocking sounds from the bottom end indicate the bearings are at least in "okay" condition. Might be "well worn", but unless you intend to run it really hard (like racing or something... maybe you drive it as if in a daily rally?? Wink ) that shouldn't be an issue.  I've pulled an engine apart that had copper showing (OLD engine!) on the mains and it still had acceptable oil pressure and wasn't knocking. Rebuilt because it had started using a good bit of oil and was a bit low in power... rings worn.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheBirdman Quote  Post ReplyReply Direct Link To This Post Posted: Dec/05/2018 at 2:33pm
@trader I never said the cam was new, just that it was good. And by that I mean that it runs alright and when I put the 4.0 in last year I took a look at it with the oil pan off and it wasnt pitted or worn too badly. Im no expert, but it seems there are magnetic particles and nonmagnetic particles with a more brass or copper like color. Im sending a sample to blackstone, so I guess theyll let me know what it is.

@farna there wouldnt be a buildup of sludge in the pan because when I put the 4.2 pan on the 4.0 I cleaned it out all nice. The 4.0 pan didnt have much noticable sludge at all, but it was hard to tell if it was already losing material, because the junkyard drained all the oil from it before storing it. 

Im probably going to put oil in it, button it back up, stick an old speaker magnet to the oil pan for good measure, and park it outside for now, maybe drive it to the car wash on the next above freezing day to get all the salt off, or for a nice drive or two. I just ordered an oil pressure gauge, so between that and the oil sample, that will decide what Im going to do. Currently Im sort of leaning towards getting a basic 400-500$ rebuild kit and doing that over the bleak and boring times of january. It does make a good bit of blue smoke, but its got good compression and a can of engine restore and it even better, but still burns oil, so I was planning on changing the valve stem seals this week. It only really lost about a half quart since June, so I dont think its that bad.

Hm, I think Ill pop the distributor out and inspect the gears too. I had a machinist buddy check out the gear on the HEI and he said it was the same hardness as the old stock gear, but worth a shot to check.

Whats a good range of oil pressure on these things?


Edited by TheBirdman - Dec/05/2018 at 4:01pm
1983 Eagle Wagon
4.0 from 93 cherokee
motorcraft 2100
skip white hei
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Dec/06/2018 at 5:52am
It should have 12-15 psi at idle fully warmed up. It will run 20-25 at old startup, then ease down to 12-15 one fully warmed up. Should go all the way up to 70-75 psi on the highway. The "ball park" pressure usually tossed around is 10 psi for every 1000 rpm, but that's for an SBC (maybe SBF). The AMC six has more pressure than that! You should see 70-75 psi (the limiting spring is calibrated to 75 psi, but with age might be "popping" closer to 70 psi, which is fine) around 2500-3000 rpm, 55-65 psi at 2000 rpm (cruising speed). That's about what my (low mileage, may 20-25K since rebuild) 4.0L holds. The TSMs just say 37-75 over 1600 rpm, with the 37 @ 1600 the minimum. So think of it as 35 psi every 1500 rpm... a lot more than 10 psi/1000!!

If you're 5-10 psi lower on a well worn, high mileage engine don't be upset. As long as it's holding at least 10 psi at hot idle and 25+ psi around 1500 rpm, at least 50 around 2500, you should be good to go.

One more thing -- I've never head of an AMC six with a distributor gear issue. That would be the V-8, which an have alignment issues in the timing over. The block would have to be messed up for the six to have similar issues.

The only issue I know of can be with the HEI distributor. Some of the Chevy six HEI bodies sit slightly further in the block than the AMC dizzy. If you run into that (dizzy doesn't sit against block when just dropped in) DO NOT just clamp it down that extra 1/16" or so! Get a big washer or make a spacer to take up that space (yes, people usually get a big hardware store washer, and one that size is usually thick enough) before clamping. The oil pump drive shaft is what holds the dizzy up from the block. Clamp it down and you bind the oil pump. Could ruin the pump and the dizzy drive gear! Only good thing is the drive gear strips and engine shuts down before the bearings are ruined.


Edited by farna - Dec/06/2018 at 5:58am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheBirdman Quote  Post ReplyReply Direct Link To This Post Posted: Dec/06/2018 at 8:17am
Yeah, I know, but I figured Id check it just in case. The gears are fine, wearing normally. I did notice I had set up the hei with the cap clocked completely wrong too. Jeez, what was I drinking back then?

Im getting the oil sample shipped today, and the oil pressure gauge gets here on monday, so if Ive got good oil pressure and blackstone says my level of sparklies arent catastrophic, Ill probably just put good oil in it with some lucas and call it a day.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheBirdman Quote  Post ReplyReply Direct Link To This Post Posted: Dec/11/2018 at 12:59am
I got the oil analysis back and the oil pressure gauge in, Oil pressure is around 50 with fresh 10w30 at 15 degrees F, I havent gotten it really warm since then, but the lowest I saw was 40.
Here is the analysis:
Unfortunately the engine restore additive I put in it last oil change makes it hard to see if there is much bearing wear, since that additive adds a lot of copper and lead, which are also the bearing materials.
I may make a post on BITOG asking if they think those copper and lead levels are in line with a can of restore, but for the most part, I think the levels would be a lot more dramatic if there was something seriously wrong.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Dec/11/2018 at 12:05pm
I've seen engines backfire hard enough to bend pushrods or damage lifters.

It's kind of like sneezing so hard that you fart.
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