AMX 360 need help!

Check the lower bushing in the distributer. Unless the car has a billet roller cam that is eating iron gears it is more than likely a bad bushing in the dizzy.

 

I buit a '69 S/C Rambler with a 390 about 25 years ago with a friend, I remember having somekind of cam or distributor problems but I can't think of what they were or how we fixed them. I'd ask him but he passed away several years ago. The last cam we installed was a Crower and I think the problems went away, but there were so many changes done to the engine everytime it was torn down I don't think it was the cam. We also ran a custom grind from Sig Erson that I don't remember having any problems with.

 

check out "planethoustonamx" website. eddy stakes has lots of info on amc oiling problems. from what i read there is a problem with getting enough oil to the dist. gear. there is an external oil line kit avalible that sends oil from the oil pressure sender area directly to the timing cover. looks as if you drill and tap a fitting into the cover above the dist. gear and the external line spews oil on the gear.

 

all good points, sir. i will be checking into these as best i can. i do not have an original cam, nor do i know what is in there. i PRESUME it is an edelbrock cam, based on all the other edelbrock pieces that are relatively new on the engine when i picked it up, ie intake, carb, valve covers, and timing set.

if i pull the fuel pump out, will i not get splashed there? i would figure with the way the gears are sprayed, its hitting the eccentric and fuel pump arm. dont get me wrong, im not afraid of some oil, i just dont want to make more messes in the street in my neighborhood. my neighbors already dont like me. i guess im too redneck for them, with my yosemite sam 'back off' mudflaps on my doo doo brown javelin on the sidewalk... lol.

dont wuote me just yet on the timing set, because its been a few years since ive looked at it up close and personal, but i WANT to say the cam sprocket was solid. i dont remember though, it will be a point i look into when i tear it apart. if this is the case, i will be purchasing a new timing set to replace.

this wouldnt be a surprise, as many people dont service, or do work on amc's very often. its usually few and far between, but those shops do good work, know what i mean? i could believe they had a set lying around and threw it on because the teeth matched, not knowing about these oil sprayers out of the block.

there is almost 0 shaft play on the dist.. (i would guess the actual play is around .015)i have yet to measure it specifically, but its the tightest i have had yet, but very free to turn.

i had read on one of the posted sites that bad gears were being churned out not too long ago that were hardened metal and chewing up the other gear, whatever the other may be, ie cam or distributor gear that ISNT hardened. that specific thread makes me want to go for the matched sets, but all of these other things with the cam itself need to be verified before i install another gear that might end up in my oil pan.

 

weekdays, weekends, evenings, let me know what's convenient for you. I need to get over to that neighborhood anyways.

 

i tend to agree with you, but im just saying what i hear from other people. i am by no means an engine builder, but with the appropriate information, it cant be that difficult to ASSEMBLE an engine. as far as machine work, etc. thats a different topic. again, i didnt think .000 of any kind of tolerance makes sense, because as you say, nothing is going to be that precise.

with an engine with no button and as far as i know, no type of thrust plate or something on the front of the block, how can you prevent walk? i might be asking a dumb question in that, because it HAS been so long since ive been in there, but these are things that are 'from my understanding'. ive also heard alot of mention on a 'cam plug'. i presume its the freeze plug on the back of the block against the cam, and it can possibly be machined improperly, but there are no 'new' freeze plugs on the engine, as they are all still painted to match the trademark blue amc engines.

ive heard alot of this mod also, and i would look into it, but it still seems like a band-aid to the real issue. this would definitely be a must if the cam sprocket for the timing set from edelbrock doesnt have the slots in the face to allow the oil to spray through to the drive gear and dist. gear.

 

the cam lobes are ground with a taper, and the lifter faces are slightly convex, so the force of the valve springs pushing the lifters down pushes the cam back. This is on flat tappet cams, rollers need some positive way (button or thrust washer) to keep the cam from moving forward.

 

also, i forgot to mention the engine was not 'rebuilt' in the traditional sense. guns was referring to the job i had done here in AZ after the second dist. gear was shot.

my guy had popped the main cap of the rear main to check the bearings, which looked good, and then it was sent to the engine shop to look into why the gears were being chewed up. ill also say that the guy who popped the main cap is NOT an engine builder or engine mechanic, but a body guy who also does alot of performance work with running engines. hes pretty well versed with engines, but not to that extent.

the engine guy is the 'best' for amc in town, but define best... he replaced the cam gear (and from where he bought this gear, i have no idea, which makes it a suspected culprit, though this was the issue i had before, but who says the first wasnt already a culprit also), replaced the timing cover, oil pump and innards, and reassembled the engine. common parts that can still be suspect is the timing set, cam and valvetrain. all other parts AROUND the problem have been replaced, but can still be suspect. heres a list:

timing cover - the one on is aftermarket, i still have the original, but the pump well on the housing has a ding on the outside of the cover, which hit the oil pump gears. i can dremel that out and use the new gears. i have the old set also, to verify lengths and tolerances before reinstalling the new set again.

oil pump and innards - kinda goes in line with the previous, i still have all the parts to verify spacing, shape, length, etc.

cam - dont know if its new or original, i have no original to verify against, but im sure on the other site i can get lengths, tolerances, etc.. before pulling the cam, i would LIKE to verify things around it, because this will entail removing the engine, ultimately. one check that WILL happen is a straight edge from crank sprocket to cam sprocket to see if its riding forward or back, and i will figure something out to see if i have any movement forward and back and feeler gauges to check that movement as well.

reman dist. - gear is probably suspect, a matching set of cam and dist. gears should solve this issue, and after installing new dist. gear, i can check the play up and down in the housing with feeler guages and have it preferably .015 nominal.

cam gear - goes along with previous. a matched set should resolve this. edit: i will be using some gear paste to check the mesh before throwing it all together to try to run it, thanks bulldogmafia

timing set - i have the TSM, so counting teeth should verify the size. i will also check for the slots machined into the face for oil spray. i know also that when i checked the gears for TDC, it matched up with what was in the book for '13 links from the right side, crank to cam, that were not engaged with teeth of the sprockets'.

valvetrain - pulling the valve cover tells me that its all stock valvetrain, as they are stamped rocker arms and look to be fairly well used but maintained push rods. my understanding is that the stock type is hydraulic lifter setup, and i presume it is still the same. with the possible edelbrock replacement, it would be the performer cam which calls for stock valvetrain. i would prefer again, not to pull this stuff, but if its required, then so be it.


hope this helps people see my plan of action. BTW, the original miles is approx 81k on engine, and only about 1k or so, from the supposed rebuild before i bought the car.

 

thats a big help on the understanding, thanks much.

 

Yes. Plus the load imposed by the oil pump itself. It can't go back into the block because of the cam timing gear.
The external drip line to the distributor gears is completely unnecessary. Think about it, AMC built millions of these V-8s with no drip lines, and they worked just fine. These distributor gear problems only seem to come up on rebuilt engines. And usually related to aftermarket parts from what I've seen.

 

69Rebel pretty much summed everything up. Check all of those items. If you have an aftermarket timing cover it can be suspect. The only one I'd trust is one that came from Bulltear. They have a jig to check for proper alignment and check every cover they sell (or at least used to). It's not something you can do at home. Their gears are matched too -- you MUST have a matched set of gears! The main reason is that some of the aftermarket dizzy and/or cam gears are cut slightly different from the factory gears. Happened when the gears were reverse engineered. A matched set from the same manufacturer should mesh together properly.

The deal with the timing covers is that Chrysler "lost" the original tooling to make them shortly after they stopped making the AMC 360 (last ones in the 91 Grand Wagoneers). Crown reverse engineered them, but there was a slight error in the first batch made in the late 90s. Crown pulled them off the market, but either the original Chinese manufacturer or someone at a warehouse sent some of them back out to other vendors. The covers were originally made in the late 90s, sent back out in the early 2000s. Most have either been used or discarded, but one will still occasionally show up. They aren't bad off, just enough to chew up dizzy gears. Bulltear can check this, and at least were checking every one they got before sending out.

If it's an original timing cover it should be fine. A new Crown cover (from many Jeep vendors and Chrysler) *should* be fine, as long as it can be verified that it was made around 2005 or later. One from Bulltear *IS* trustworthy, but I'd get a set of matched gears from them at the same time then replace cover and gears. At that point it's all a bolt-on and everything should be good. A cam button or retainer at the same time (I'd get that from BT also so they know you replaced everything with parts from them for warranty purposes) is a good idea.

There is NOTHING wrong with the oiling system in AMC V-8s for the intended purpose -- a normally driven car. Even drag racing you don't need the valley oil line or any oiling mods -- just blueprint the pump, paying special attention to end play/gap between the gears and cover. The stock pump delivers plenty volume and pressure. All I'd do is run an extra quart of oil in the pan (six instead of five total) even in a drag racer. If you're road racing the internal line is a good idea, but something like an AccuSump system is even better. The rear rod bearings can starve for oil, but that only happens when pressure drops, usually due to not enough oil in the pan. Not too big a problem with drag racing, really big with road racing since oil is sloshed around in all directions. A good baffle system in the pan helps too, but keeping adequate oil in the pan one way or another is the most important thing. The only difference between a police spec AMC 401 and the standard model was the oil pan. It had a slightly better baffle, but not much -- and that was all. AMC also spec'd that extra quart of oil, but the pan stamping was the same as a stock pan, just the baffle was different.

 

there was a tag bolted to the pass. side valve cover facing the front of the car, denoting the engine code. i believe this got tossed with the original valve covers, which i wish i could have back, for sure.

 

I think he's asking what you want the tag to say

 

yeah, bulltear seems to be the best option, farna. i like what they're doing, i just wish they would offer more street stuff. i know they are primarily a 'jeep' setup to improve off-roading, but they would open a whole new door if they started running more street application parts too. either way, they are where i will be going to replace the gear setup i have now.

 

honestly, i dont know WHAT the tag is supposed to say, because i never saw one personally, but its not going to increase the value of the car overall, as the VIN wasnt stamped on any blocks, just the cast number. technically if i dropped a 401 in it, the only way it could be refuted is decoding the VIN to be a 360... even then 401's were a dealer installation option......

 

Nope.

That right there tells the story. It ran fine for 81K miles until somebody messed with it. A factory cover and gears may be all you need. But double check all the other stuff too while it's apart.

 

To get a little O/T; none of that stuff really matters with AMC anyways. I love 'em, but I know that they're never going to have the status of the Big 3 cars. I can live with that and just enjoy them for what they are.

 

negative, negative... i had original cover, chewed two gears, replaced cover, and chewed one. i drove it back from buffalo NY to clarksville TN and one was ate through. replaced it, chewed that one, then engine went to shop. new gear chewed through in about 5 miles of driving.

 

Ok, I musta missed something there, I thought I read that you had an aftermarket cover. But what was changed after 81K that made it start eating gears? That's what we need to figger out.

 

yeah, after 81k, gear was shot, replaced dist. because gear is equal in price, it was easier and i was naive about matching sets. that gear shredded and then the new timing cover went on because of the dings on the inside of the oil pump housing and another dist. went in again, still because of my naivety of matching gears. chewed that one, and here we sit.

 

When you changed the dizzy gear, did you change the gear on the end of the cam at the same time?

 

after the second dist., yes. after the first one, the gear still looked untouched, but the second time it started to shine around the edges, so to play it 'safe', my engine guy bought a new one from an 'unkown to me' source, which ended up chewing the thrid. thats why im saying its more than just matched gears to fix the problem, because through three dist gears and two cam gears im still with the same issue...

 

yep, that will be done when i get the new set... forgot to mention that in my previous 'troubleshooting steps' post. ill edit that now, thanks for the reminder.

the mesh will definitely be something i have to check, but throwing double gasket is still only 'band-aid'ing the problem. whatever the issue is with the gear should be resolved instead of working around the problem, you know? in a pinch i would absolutely do this, but obviously it is not my daily driver, to limp in until i can fix the issue.

 

The AMC oil pump and dizzy are linked together like most cars, but in the timing cover like a Buick. They run at a slight angle up beside the cam drive gear, which bolts to the front of the camshaft right in front of the fuel pump eccentric (which is between the cam gear and dizzy/oil pump drive gear). So cam walk will create quite a few problems! There is a cam walk kit available from some of the AMC vendors, but a button bolt would do the trick.

Cam walk may have been the initial problem here, or it could have just been the bronze gear on the iron factory gear (hardness or mesh difference). The "dings" in the original cover shouldn't have affected the oil pump, it was pumping after all! While body cavity wear does affect pressure, clearance between the ends of the gear and cover has a greater effect. I'd consider putting the original cover back on with a set of matched gears, preferably from another AMC engine, or a set from Bulltear. The replacement cover is made by Crown even if it came from the Jeep dealer (Crown cover in Mopar box then, with price hiked accordingly). If it was recently made it should be okay, but may have been on a shelf somewhere for a while. Talk to the guys at Bulltear, they can tell you how to check it for alignment. I don't think it can be fixed at home, but you can tell if it's off... I think. Talk to them!! It might be best to try their forum -- lots of info already there (http://www.bulltear.com/forums/forum.php).

 

I'm going over saturday to take a look at it, should be interesting. Not that I'll be able to find anything...but you never know....

 

We will figure it out! And a couple beers with friends always makes for a good time

 

Not trying to be a smart ass here - but have to wonder - why would cam walk result in gear wear?? I know cam walk is undesirable - I'm not arguing that - the question wrestling in my head is to visualize how the cam walk would change the gear clearance, alignment, etc. Since these gears are "straight" (yes helical I know) the axial position of the gear (it seems to me) doesn't matter until it goes so far to actually ride on the edge.

It seems to me that the issue would have to be in the alignment - can you compare the gear clearance on a factory setup to your aftermarket version??

Don't shoot the messenger - I'm just thinking out loud

 

i wish i had a factory mock up, trust me. the best i can do is TRY to get someone else to give me their tolerances, but the other thing you have to think about is if its walking, since the dist. is locked into the oil pump shaft, thats the fulcrum point, applying pressure to the oil pump gears, eventually, and the dist. gear teeth.. in a perfect world it would simply increase or decrease timing if the gears were matched, which is the key word, because one is not stronger/softer than the other.

the common consensus ive seen is the gear riding about 3/4 the way down the cam drive gear, so oil can still get between the drive and dist. gears.. but i reiterate matched gears are the sticking point here. it makes sense now that ive rolled it around in my head for two weeks... my thought is that a softer gear would be more suitable, as it would 'mold' to the other gear better, but on the downside, it would wear out that much quicker...

 

Hemi is right... if the gears are perfectly matched they should be able to move along their axis and not bind or wear. When perfectly matched... The main problem with aftermarket covers is indeed alignment. Poppa has it with the softer gear problem. You can't get in there to see or measure clearances with everything assembled. I don't know how Bulltear does it. Maybe they took a known good cover with a bad oil pump and cut the front out to take some measurements then use those to check others?

 

who knows. its all ridiculous that an aftermarket part of ANY kind causes internal damage to an engine. and its not like we are talking about a supercharger on 22 lbs. of boost here either. a FRIGGIN TIMING COVER.... it baffles me, but anything is possible. either way, i have a laundry list, and as soon as the dishes (literally) are done, i will be getting started. how does thanksgiving make dishes that have over a week to do... its crazy.