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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?
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!
11-11-2003, 11:13 AM
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)
11-11-2003, 11:16 AM
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
11-11-2003, 11:24 AM
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
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
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?
11-11-2003, 11:40 AM
Lifted79CJ7
Oh, I and I jsut ordered the oiling bypass kit just now: