401 Rebuild Help

[Lifted79CJ7]

Here is the skinny on my engine: I yanked it from a 78 Jeep pickup, presure washed out the inside of the block (replaced the freeze plugs), put in a new edlebrock performer cam, lifters, timing set, intake, 650 carb (with off road needles and seat kit), new push rods, stock style rocker arms, new timing chain cover, new oil pump gears, new fuel pump, and other little odds and ends. I am using the stock CJ Motorcraft ignition system (with an MSD Blaster 2 coil). I am also using a new stock style replacement radiator (think this will hold up to the heat of a 401??). I dropped it in my jeep, primed the oil pump and fired it up, it ran a little rough and while I was breaking in the cam, I heard a knock start :evil: , so I cut it off and here I am!!

So now I am at the point where I need to due a complete rebuild of my 401 and need some advise on parts selection. I want to run a 9.5:1 compression ratio, so who makes a good piston? I don't neccisarily need forged pistons, but I want something that will hold up to my heavy right foot. Of course, price is always being considered as I can only throw about $300 a month at this project. I am not looking to spend $800 on pistons if I can get away without spending that much.

Also, what all should I have done to the heads when I rebuild? Any easy mods I can do at home to free up some HP? I am also considering doing some of the oiling upgrades as well. I have had a few 304's die on my due to oiling problems. Finally, does anyone know of a good source for good gasket kits or for AMC parts in general?

Thanks guys!!
Jack

PS-I'll take pics of the rebuild if you want!

Here is a pic of my Jeep as it sits this afternoon:
http://community.webshots.com/photo/99527165/99527424mYIByo

Here are some pics of the engine is question:
http://community.webshots.com/photo/99527165/99527604FsVFhK

http://community.webshots.com/photo/99527165/99527806xJOsNa

http://community.webshots.com/photo/99527165/99528036ojiltE

OK, so I can't get the pics to show, so here is the web add'ys:
http://community.webshots.com/photo/99527165/99527424mYIByo
http://community.webshots.com/photo/99527165/99527604FsVFhK
http://community.webshots.com/photo/99527165/99527806xJOsNa
http://community.webshots.com/photo/99527165/99528036ojiltE

[jeepsr4ever]

Northernautoparts.com sells some great kits for the 401 and make sure you upgrade to fel-pro gaskets.

As far as pistons go, Fuzz can answer that one

You should have thrown the old cast pistons to the curb and started with new ones or forged, the cam bearings probly had some good wear as well. Make sure you are getting oil (what does your pressure read?) Have you taken a valve cover off to see if oil is coming out of the rockers. Did it knock before?

We may be able to save this one!

[Lifted79CJ7]

The engine did not knock before hand, but it had a rough life in a mud truck. Guy drove it into some deep mud, blew the BW1330 tcase, walked out of the pit and sold it to this guy for $100 as is. I yanked the engine and started working on it. As for the pistons, the stock ones are still in there, so I have some options here. I put in a pretty think oil (can't remember what weight off the bat) cause I knew that the cam bearings, as well as the all the other bearings were probably pretty well worn. I just wanted to drive it around the block once. As for pressure I think I was getting around 60psi, and yes oil was coming from the push rods to the rocker arms. I think it might be a main (Nooo!!) bearing gone south. I just wanna build a decently strong engine that will last a good 80,000 jack brunson style of driving miles. 8)

[jeepsr4ever]

you can run that higher viscosity oil but be aware that you are running the risk of overheating, its probly a wrist pin or even a main, you know the old AMC MAIN DEAL.......I hate that! Time for tear down and winter rebuild i think, check out the how to section for oil mods

[Lifted79CJ7]

Yeah, I was looking at those oil mods the other day. As for the thicker oil, didn't think about it heating up the engine. Hmm. Who knows. I agree though, definitely time for a winter rebuild. I guess you guys can walk me through all this stuff since I have never done a complete rebuild. I have replaced just about everything that there is to replace, just never all at once, so be ready for questions!!!
Jack

[fuzz401]

oil mods do this under the intake

http://volcano.photobucket.com/albums/v11/fuzz401/dcbbb7f1.jpg
http://volcano.photobucket.com/albums/v11/fuzz401/3a2369b4.jpg

gaskets a lot of people are looking at ROL gaskets or feltpro

pistons with 9.5:1 this will give an ideal it all amc had small chamber heads yours are proble around 58 to 60 cc chambers
http://www.flatlanderracing.com/trwamc.html
or costom ross - venola - wesco

from the pic of your jeep find the 6 or 7 blade fan and run the fan shrould or go electric

with push rod it is good to have a set of checking push rods - stock rods do not always put your rocker in the middle of the valve stem some times you have to make the rods longer to keep valve angles right

Motorcraft ignition system is a good system

heads a little port and polishing never hurts make the ex as smooth as you can take out sharp courners intake clean up any sharp edges and get a 3 angle valve job

[Lifted79CJ7]

Sweet! Thanks FUZZ! I also found this as well:

http://www.performanceamstyle.com/Cart/description.php?II=75&sessid=5553b352d153e85fb163920fda501f51&divi=amc

Ever heard of badger? As for my engine, It was rolled off the line on Nov 2nd, 1978. Any idea off that generic info on what my cc would be for the chamber?

[Lifted79CJ7]

Oh, I and I jsut ordered the oiling bypass kit just now:

http://www.performanceamstyle.com/Cart/description.php?II=852&sessid=5553b352d153e85fb163920fda501f51&divi=amc

:D

[fuzz401]

badger is a old name in pistons had them in my 360 held up for me

[fuzz401]

http://www.bulltear.com/forum/viewtopic.php?t=541 look here to get an ideal on what heads you have

[fuzz401]

i would also recomend getting the motor balanced to

for extra reves you could go with free floating pistons too

[Lifted79CJ7]

Whats the difference with a free floating vs a non free floating piston?

[fuzz401]

free floating wrist pin floats in the rod
std it is pressed in the rod

[jeepsr4ever]

htey last a super long time and they have clips on the ends of the wrist pins

[Lifted79CJ7]

So will they fit on any piston, or do I need to order my pistons to accept these? Also sounds like it is easier to do at home since I don't have access to press right now. True? So how do they "float" without causing more wear? Sounds like they would wear out faster, and how do they do at higher revs vs pressed in wrist pins? Wrist pins are one of the few things that I have never messed with before.
Jack

[fuzz401]

and forgot this that 650 might be a little light might end up going to a 750


did I cover every thing MC lol

[fuzz401]

they reduce friction due to the pin moves in the rod and piston instead of just the piston
the rods would have to be bushed for the pin the slide in they are also 1" wrist pins in a 390 and 401

probley have to order them that way most replacment pistons are for push in pins

[jeepsr4ever]

Fuzz you do an exellent job around here and bulltear will need you more and more when this board starts to explode, thanks fuzz!

MC

[Lifted79CJ7]

:?: So here's another Q for you guys, where online can I find a cam bearing replacement tool for an AMC, and do you have any tips for me when installing them?

:?: Also, any tips on installing freeze plugs? I installed my last ones with a socket and a hammer and had leaks :cry: , even though I did put some RTV on them before hand.

:?: And last but not least, do you have any suggestions for valves or springs for my heads? I am gonna be replacing them as well.

Thanks!
Jack

[fuzz401]

1 cam bearing tool snap-on http://buy1.snapon.com/catalog/pro_det.asp?P65=&tool=all&item_ID=11748&group_ID=1584&store=snapon-store&dir=catalog what i have take your time doing it and mark your block were the oil hole comes through at to line the oil hole up in the bearing at and do not mix the bearings up they are diff sizes

2 thats what I use a hammer and socket but I use the dark brown sealer that comes in a tube and it is thick smear it around the plug and drive it in then wipe the excess off

3 use the springs that the cam maker say's to use and get new retainers and no rotators the springs will have to be installed to the right hight spec. = seats may have to be cut or shimed

[Lifted79CJ7]

OK, so what do you call the freez plug looking thing in the back of the block that keeps the cam from coming through the back of the engine? How can you tell where to set it exactly? Will it depend on the cam that I use, or is it a standard depth?
Jack

[fuzz401]

were it goes in the back of the block there is a chamfer in that hole the edge of the plug should be at the edge of the chamfer

[Lifted79CJ7]

I would assume that I should replace this when I do my rebuild....does this part come in a Fel-Pro gasket kit, or is this gonna be an extra part that I need to order - and if so, what is the correct name of the part?

Jack (probably annoying you guys to death with questions by now!)

[jeepsr4ever]

when you get a engine kit it usually comes with freeze plugs, if its a master it always does. When you get your engine block work done (boiled, bored...ect) a good builser will install the freeze plugs and cam plug so you wont have to mess with them. I like the questions because it helps other members and lurkers so dont hesitate to ask, this site isnt just for garage engineers

[fuzz401]

no just peons like me ask any ques you have a dumb ques is better then none asked

[jeepsr4ever]

yeah and if you can ask a dumber question than any of mine you win the boobie prize

http://www.a1partysupply.com/product_images/1017004381.jpg

[fuzz401]

http://volcano.photobucket.com/albums/v11/fuzz401/3416c5a3.jpg

rear cam bearing plug

401 8.5:1 & 390 pistons 10 :1

http://volcano.photobucket.com/albums/v11/fuzz401/678f0450.jpg
http://volcano.photobucket.com/albums/v11/fuzz401/0c8f3fcb.jpg

[Lifted79CJ7]

OK guys, so I have decided that I want to break the 400hp mark when I do my rebuild. Any suggestions? Think with my edlebrock performer cam and 9.5:1 or so pistons I might be able to pull it off? I am thinking floating pistons, oiling mods, and maybe some head work. The question is, what type of head work should I think about? 3 angle valve job? Polishing job? Think porting would be necessary?
Thanks guys!!
Jack

[jeepsr4ever]

I personally dont think porting is as effective as polishing for your application, you can hit that mark, i suggest 3angle valve job on the heads, this will allow a positive seat for some great revving! :) You can get there, i have some new items coming out to help you achieve 400+ and still keep that engine reliable

[Lifted79CJ7]

As for the porting, from what I understand from you guys, really wouldn't affect me unless I am going to be doing high revving (above 5K) and higher horsepower type stuff (over 500hp), am I correct on this assumption? As for the polishing, I was definitely thinking about having that done. 3 angle valve job? I can do that. So what all is involved with a 3 angle job, and will I need to order special valves, or have the vavles machined at the same time as the head, or do the valves just stay as they come out of the box?
As for the new items that you have floating around in that head of yours, can you give us any sneak peaks????? I promise I won't tell!! :wink:
OK, and last but not least, I know I have asked this a couple times, but I am still a little hazy on it...what all do I need to have done to my new timing chain cover and new oil pump gears and spring? I remember you talking about new gears for higher pressure, but I haven't seen much more on if you are selling these or not. Will the stock style ones hold up to my goal of an engine?
I do plan on doing the oil mods to the crank and adding in the oiling kit that I got from Perfromance AM Style, any other oiling mods I should think about?
And FINALLY, I am worried about distributor gear wear. How do you set these correctly for a long life. I read that you guys are against doing oiling mods to improve oil flow here, but it still seems to make sense to me. I saw a nice write up using a welder tip to shoot oil right on the contact area, but now I am not so sure after hearing everyones side on this board. Any suggestions?
Thanks for helping out so much with such a novice engine builder!
Jack

[jeepsr4ever]

Jack,

Where to start!
1. You can easily screw up a 3 angle on your heads if you do it yourself, I would let someone else do the worry-ing for you
2. Oil pump gears and a high pressure spring are what i sell right now in that area
3. We have discussed the dizzy gear oiling before, as far as my opinion goes it gets oiled fine when the oil passages are clear. Personally i think overoiling it is a bad idea, what is lacking in oil if you are over-oiling the dizzy gear?....the MAINS are.
4. I am making under drive aluminum pulley's for the AMC V8 soon and will increase hp substantially, a few other items i wont suggest yet but they are coming....soon

[Lifted79CJ7]

Cool, thanks!

1) As for the three angle valve job - I will definitely let the machine shop do that one. But will I need to order special valves, or will the stock style valves that I but need to be machined, or will they need to be left alone and just the head machined?
2) What type of work will I need to do to my oil pump gears and the TC cover to ensure long life? Both of these are new units in my engine.
3) Sounds good to me, I'll leave it stock.
4) Pulleys eh? You should make pulleys and brackets for AMC V8's that allow the use of a second AC Compressor so us off road folks can have comfy AC AND On Board Air. Just a suggestion! Can't wait to hear about the other products due to come out!!
Jack

[fuzz401]

i would go with a after market valve with single or double grove valves instead of the triple grove and new retainers for the springs

[Lifted79CJ7]

So what would be the pros and cons of single vs double vs triple grooved valves? What is the physical difference?
Jack
(I will be replacing the springs, valves, retainers, seals, etc in the heads, I want this engine to last a while)

[Lifted79CJ7]

UPDATE: OK, so I just got done pulling one of my heads and oh this poor little engine. I took some pics that I will post later tonight. Looks like at some point something metal wasknocking around the inside of one of my cylinders and majorly did some damage to one of the pistons. Also I saw what heads I have: According to a spec chart I have they are cast number 323 1475 which came on 360's in 1978, have 57.92 cc chamber, are Dog-Leg Bridged (whatever bridged means), and have a 2.025 intake and 1.680 exhaust. Anywho, I am making great progress since it is unusally warm out today, so back to work I go! I'll post pics later tonight.
Jack

[Lifted79CJ7]

OK, so here is a link to some pictures that I took lassst night in the driveway:
http://community.webshots.com/album/99527165jPYmrz
Looks like I have 3 cylinders with some damaged pistons. This thing is defintiely gonna need to be completely rebuilt. So what do you guys think about the heads? Think I can just do a polish job to the chamber or should I go get new heads from the junk yard?
Jack

[fuzz401]

double or single groove valve are what most builders use for motors that will see some power and beating they are to hold better ( keeper to retainer ) then the triple grove

bridged rockers are like ford style they have the u shaped pc with a alum. pc that goes against the rocker u tighten down the 5/16" bolt to 15 ft lbs and that is it

adjustable rockers have a screw in stud that the rockers and 1/2 ball go on then you can adjust your valves like an old chevy to preload your lifters

the pistons I would not be comcerend about if you are going to rebore the motor if you are going to reuse them you might want to get new ones for those holes

the heads can u post some pic of just the chamber that are marked up to get a better look at them :idea:

have you gotten to the crank yet ? and what do the bearings look like ?

[Lifted79CJ7]

Gotcha on the bridged rockers. Wish I could afford roller rockers, thats for sure!

As for the pistons, I am definitely gonna replace. I want to run a higher compression ratio (9.5:1 to 10:5:1) for some extra HP. As for the cylinder walls, they all seemed ok, no major scaring or knicks. They do have LOTS of wear though. You can see where they have an up/down wear pattern from the piston and rings over the years. I will try and snap some pics later this week. I can't gurantee anything good though, my camera is a $40 Wal-Mart jobbie. I haven't gotten to the crank yet either. I was hoping to today but I got hung up on removing the timing chain off the crank, so I moved on to some other projects (making the doors close, bolting the bumper on, trimming and putting the plastic Jeep logo back on with the new bumper). I am still trying to track down the knocking noise, so I am sure I am getting close. I think its something in the lower end like a rod bearing. :-|

Jack

[Lifted79CJ7]

OK, so I dropped the oil pan today and pulled the pistons out, along with the cam. I have some pictures here of the engine:

http://community.webshots.com/album/99527165jPYmrz

Take a gander and let me know what you think of the beraings, pitsons, cylinder walls, etc. Tomorrow I hope to have the crank out. I also found a good machine shop locally. They do a lot of porche racing stuff, but have done work on 401's before as well. I am gonna give them another call tomorrow and get some pricw quotes. Anywho, hope you kids enjoy the pics and let me know what you think!

Jack

[fuzz401]

cam bearing did not look to bad except were it got hit taking the cam out lol the grove looked like it was still in good shape
rod bearings were about gone with showing the copper on them
crank look good
piston skirts do not look that bad eather

[Lifted79CJ7]

Thanks, That is kinda what I thought. As for the cam bearing, there is one side near the top that was a little more worn than the rest, but not by much. The rod bearings were toast. They have definitely seen better days. I am still confused, cause I cannot tell what was making the loud knocking noise. I can spin the crank free by hand and don't here any grinding, but that is all thats left. Any idea where to look? The noise would come and go, come and go, then it just stayed there.

This was all during the cam break in cycle, whch lasted about 20 minutes. I did find in the oil pick up screen what looked like a blade of grass made out of metal. If I can find it tomorrow, I will take a pic. Lord knows where it came from.

OK, so I am gonna call the machine shop tomorrow. What all questions do you guys like to ask to see if they know there stuff or not? I really don't want someone screwing the pooch with this block or crank. I need all the normal stuff done, plus I am gonna get them to install the oil bypass kit to allow better oiling to the rear of the block.

Thanks!
Jack

[Rocky]

Lots of stuff that could cause a knocking sound: bad rod bearings/journals, bad mains/journals/ bad wrist pins. I've also seen broken cranks that caused a knocking sound. Although broken clean through, the mains hold the two pieces of crank in close enough proximity that the engine continues functioning, until the mains finally go, the knocking gets louder, and the whole thing finally comes apart. (I've pulled 'em apart before total destruction, to find everything seemingly right in place... no crack even visible in the crank until pulling the main caps... then it falls apart!)

The cam bearing wear in your photos is fairly advanced. (Are those strips of bearing metal in the shot? ..Your "blade of grass" could be a strip of bearing metal, forced out by overheating and friction.)
The rod bearing wear is pretty bad, and there appear to be some pretty good grooves on the one journal you show.
The wear on the pistons isn't abnormal, from what I can see. Don't jump at boring it until you have it mic'ed. If it doesn't need boring, you'll give yourself the possibility of one extra rebuild on the block if you just hone it and put new pistons in.
Nothing wrong with ring gap... it allows expansion. Remember that the ring gap on new rings will measure out at only a couple of thousandths, and will be less than that w/ expansion. Be sure to measure your ring gap (w/ rings square in their respective bores) and file/fit the rings, if necessary.

[Holeshot]

IS it a rod knocking, or is it a cracked vibration damper????

I got a '71 401 from a salvage yard and darn thing seemed to have a rod knocking. Yanked it out and tore it down. Looked good - except for the crack in the vibration damper, right at he keyway slot.

[Lifted79CJ7]

That is a good one on the Vibration Dampner. I have never heard of that one, but no, it was OK. As for the knock, it would just come and go like a light switch going off and on. I think if might hve been that nail I foooound in the piston, or could have been something else. Not sure yet. IT defineitly wasn't like a normal bearing going south where the noise gets louder and louder. It wasn;t there, then it was, then gone again, then would return. Then it was there for good. Oh well. I will figure it out!

On another note, just talked with the machine shop today to get some quotes (haven't been out there yet to check it out, but the guy knew his stuff and has done a some 401's), here's what he rattled off to me rather quickly. How do these sound to you guys?

Hot Tank Block and Heads $45 Sounds ok to me
boring and honing: $Crap, didn't write down Doh!
Install new freeze plugs: $75 You have to be kidding me
Press old pistons off and new ones on: $80 Maybe Mud can help me???
New piston studs: $120 Forgot what all he was talking about here
Deck the block(depending on what needs to be done): Up to $175
Regrind the crank (if needed): $120
Align hone the block (if needed): $175
3 angle vavle job (magna flux and light mil work): $300 Ouch!
Balancing Rotating Assembly: $150 A little high, but doable
Rod work to accept Chevy full float pins: $180 If using KB pistons-ouch!

Of course some of this stuff I can do myself, but overall, sounds like a lot of moo-la to me. I will need to swing by after doing some more homework and talk with him in more detail about each step and see what will actually need to be done. Overall, this guy knew his stuff though.
Anything left out or think I can do myself?
Jack

[ILUV2XLR8]

Some of those quotes sound pretty steep, I pulled the reciepts from my last build here's what I paid:

Bore .030 = $96
Grind C/S .010R .010M = $90
Magnaflux Block & Clean = $20
Balance Rotating Assy = $185
Mount Pistons on Rods = $40
Install Cam Bearings = $25

My block was within tolerances, so I didn't line hone or deck it.

[Elliott]

That is a good one on the Vibration Dampner. I have never heard of that one, but no, it was OK. As for the knock, it would just come and go like a light switch going off and on. I think if might hve been that nail I foooound in the piston, or could have been something else. Not sure yet. IT defineitly wasn't like a normal bearing going south where the noise gets louder and louder. It wasn;t there, then it was, then gone again, then would return. Then it was there for good. Oh well. I will figure it out!
Jack

Have the crankshaft endplay checked out, may of had slop.

[Gremlin4ever]

Also check the flexplate if it is an automatic (they crack as well and makes a knocking sound) didn't see anywhere as to which type trans your running prolly standard in a CJ.

The best tool you can have for a rebuild are: "Engine Builder's Handbook" or "Guide to Engine Blueprinting" in my opinion :-| They can be had for under $20 each at you local book store.







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