PICS & QUESTIONS ABOUT MY 401

fuzz401

But it'll be a screamer once it's in there!!!

:shock: :shock: :shock: :shock: :!: :!: :!: :!: :-|

GADJIT98

WTF IS THIS? Is it necessary, or overkill? I found it on a motor on ebay and was curious because I have never heard of or seen this modification.

https://forum.bulltear.com/assets/migrated-images/6b_1_b_053c74e2.jpg

dave

Mudrat

GADJIT98 wrote
WTF IS THIS? Is it necessary, or overkill? I found it on a motor on ebay and was curious because I have never heard of or seen this modification.

https://forum.bulltear.com/assets/migrated-images/6b_1_b_053c74e2.jpg

dave

Ah Grashopper, it's an early edition oiling mod. Let us listen as the Master speaks =D> :wink:

jeepsr4ever wrote
... that was one of the first set of mods to do to a AMC V8 to decrease the rear mains from spinning. Its a great little bandaid however it was found to be less than effective when the oil foamed and the pump started gurgling bubbles. The valley line or smaller feed holes (cam bearings) or "pills" (smaller feed holes in the pushrods) are the better answer.....besides extra capacity pans....ect.

This and several other oiling improvement mods are covered in the AMC Oiling Thread. This is one of the lesser obvious modifications because most of us don't know our way around inside the oil-gallerys of an AMC block - MC is small enough to fit in there :idea: So I need to rely on "He that shall be named" as well. :t:

Pat
Is it Monday still?? #-o

GADJIT98

OK, I have hit a MAJOR dead end............. I was referred to a machine shop by a friend who said they knew how to build an AMC V8. I spoke to the guy there and he really impressed me with his willingness to get me the HP I was shooting for. He even started quoting me some prices on parts.....$9 per OEM rocker, $22 per OEM Valve, $175 for labor on the heads doing a 3 angle, etc. Now the labor doesnt sound that bad, but DAMN, his parts prices are high! He also stated that he would do everything for me using parts that I purchase but there would be absolutely no warranty unless he supplied the parts. Again, I am new to building engines, so please be gentle. Other than rocker arms, valves, valve springs, could someone give me a complete parts list for the heads? My thinking is that I will get the parts myself, let this guy do the machine work, and build this damn thing on my own or with some knowlegeable person in my area ****************JACK************************ looking over my shoulder and consuming as much free beer and pizza as possible. The heads will be the hard part, but the block, I assume, will be pretty straight forward. Line bore if needed, cyls bored, hot tank & magna fluxed, new pistons, bearings, cam, pushrods, lifters, and bolts. Am I forgetting anything other than the oiling stuff for the front? And speaking of the oiling stuff on the front, would a MOD or Owner PM me and discuss the Bulltear items for the oiling system. They appear to be what I am looking for, but I dont want to spend tons of cash and put it all together and miss the $10 part that makes it all work and blow my motor up....... As you can tell, I am pretty nervous about this, I dont mind spending the cash, I just dont want to spend it and do something stupid, or more likley, forget something stupid, and have to spend it all over again. Anyone got an AMC V8 builders manual? Thank you again for all the info and also for your patience with my stupid questions. I should have more pics up soon ( havent made it to WMT for batteries yet ) Dave

Mudrat

Well you can do what I did - buy the parts have them delivered direct to the shop and have them do the work (I didn't/don't have the time or space to do a clean build). My guys gave me 1 year or 36K miles on the warranty, plus the first 500 mile break in check (change the oil and retorque everything). That's for a street motor - not one of their race jobs, but both the 258 and 360 are well past "street stock" (cammed, jammed, bored, decked, balanced, cross drilled, ground and polished, etc...) If your builder won't give you a warranty by doing that - find a different shop 'cause he's trying to find a way out. Just my 2C Pat

tufcj

I like this book. I didn't do everything he described to my 390. I incorporated some of BJ's ideas with some of MC's from the "AMC oiling" thread.

http://www.hobbyobsession.com/bjsbook.html

Bob
tufcj

fuzz401

that is a very good book

GADJIT98

Thanks for the recomendation on the book.....I ordered it today.

HOUSTON, we have a problem......

I took the pistons out today and the main caps. Rod #1 had NO bearing material at all in it and was flopping around so badly that the piston was bottoming out on the crankshaft counterweight. The bearing surface on the crank is visably smaller on the #1 side than the #2 side. Does this mean all will need to be ground or just the first? I was hoping to get away with polishing, but it will require turning the crank to some degree.

Judging by the photos, can anyone tell anything about the crank that may be helpful? I also took off the thing that the oil filter screws on....like 7 small bolts...what is this called? There are 2 gears underneath it which did not turn when I turned the crank. I have removed the dizzy. Is this normal? Does the dizzy somehow drive these two gears or have I found the reason the first 2 rod bearings were shot?

Do you have to remove the H-Balancer to get the crank out? Do you need a puller for this? Do you need to make sure the balancer is "clocked" in the same position when it is put back on?

After I get the balancer off, can I just unbolt the stuff on the front of the motor ( timing cover, etc ) and pop it off or is there more to it? I know I will need to do some thing with the timing chain & cam, but what? Is there a thread that details this part of the disassembly?

I know this is alot of questions and I do appologize for my ignorance , but I am getting pretty excited so far, and a bit nervous , at the idea of building this thing myself.

Thank you again to everyone, please keep the info coming.

Dave

:lo1l:

jeepsr4ever

Crank needs a new grind on it. Your oil pump wont turn if the distributor isnt installed. The cam gear drives the distributor gear and that drives the oil pump. Those bearings look pretty roached

Mudrat

Hard to tell scoring from the pics (the focus on my PC doesn't work :wink: ) but the color? Gotta agree with MC - 'don't look good'!!!! The shop should be able to measure the scoring in the crank to see if you can turn it under and then oversize the bearings. I went 10 under, cross drilled, and a mirror polish with the 10 over bearings. The balancer should have a keyway to align it on the crank and that keeps it "clocked". The rest of the 'stuff' just un-bolts. I had a problem getting the cam out because I couldn't get the timing chain and gears off. THAT was fun!!!! I wound up taking all the main caps off and tilting the crank to get the chain off then pulled the cam and gear together (they were getting replaced anyway :roll: ) Pat

GADJIT98

Today I took a Dial caliper and measured the first rod journal....I think that is what it is called....anyway, the place where the rod bearings go, and the #1 position was .003 smaller than the #2 position. Assuming this is the maximum damage, a -10 will be mathmatically sufficient for a grind. This brings up a second question. How reliable is a 10 under crank? A friend of mine said that if I was looking for 400 HP, to get another one because turned cranks were crap and always gave him problems later..........of course he is a Toyota mechanic, but I let him in my shop anyway :shock: There is very little bearing material in both of the front rods. Do I need a machine shop to tell me if I can re-use any or all of these rods? Where can I get used rods, and are the OK to use in a rebuild? If I go with aftermarket forged rods, can anyone tell me the price range and what to look for? I hope to soon be done with the basic questions and on to more performance oriented ones. Right now I have ordered the book that was recommended and would like to find a TSM. Anyone know where to find one? Thank you again, Dave

Mudrat

Dave,
You need to take your measurements then subtract from the original (stock) diameter of the journal (I don't know that number but can try and find it if you don't have it) - not another journal on the crank. Doing that will give you relational wear (#1 ears faster than #2), not total wear (#1 wore .005 more than stock and #2 wore .002 more than stock).
Seen and heard lots of folks with turned cranks that haven't had a problem. As for HP?? Desktop dyno has me over 400 HP and I'm not worried (yet 111!!! )
Curious what you mean by "There is very little bearing material in both of the front rods." If it's just the bearing face that was worn, the rod's should be OK. But again, measure them and compare to original dimentions. I've heard and read that shot-peening to relax the stress in the rods will also shorten them a bit. Can't be much, but one of the 'big block' guys whould be able to confirm that. ;-) If it's true then decking the block will compensate for the shorting :t:

Pat

GADJIT98

Pat, In my next post I will give the specs per my dial caliper and photos of the first two rods & bearings. What I meant was there is virtually no material, meaning that there is a piece about the size of a quarter left and the #1 rod had a ton of slop in it before I un torqued it. My assumption is that the rod is shot as well as the corresponding journal on the crank. Is it OK to use another single rod from another used engine? If so, anyone got a couple of rods for sale? Thanks Dave

tufcj

If the rod bearing was "spun", meaning no longer positioned in the cap correctly, then you MUST have the rod end resized. If it's too far out of spec to resize, then replace it, you'll be money ahead in the long run. Too bad you didn't hear that 401 run before you bought it. It would have had a noticable rod knock. Remember that a .010" undersize is a total measurement. To go .010" under, they only take .005" off the surface. If you're seeing .003" smaller already, scratches are probably deep enough that it won't clean up at .010". Bearings are made all the way to .030", and you can get respectable life out of it in every use except all-out racing. I've seen the old Jeep L-head 4 cylinders with rod and main journals all the way to .080" undersize. I once rejected an old Jeep crank because it was .030" on the rods and mains. My machinists response, "Go back and get it, it's just a baby." Bob tufcj

Mudrat

tufcj wrote
Remember that a .010" undersize is a total measurement. To go .010" under, they only take .005" off the surface. If you're seeing .003" smaller already, scratches are probably deep enough that it won't clean up at .010". Bearings are made all the way to .030", and you can get respectable life out of it in every use except all-out racing.

Good point on the size thing Bob. Fatal error assuming something ](*,)

And who say's size doesn't matter? :-|

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