AMC 401 Build up, Matching a good setup for jeepin.

[Dusty]

For the sake of Explaination Im taking the 354 hemi out due to a long drawn out story not worth repeating. Im installing a 401, which already has set between the frame rails once. (I own 2 401's now) the tired one used for measuring is now out to have a freshened up 401 installed. :t:

The 2nd 401 that I bought for installing came with low miles, 10k, but in pieces, with the Old school Edelbrock R4B intake, and a Crowler Cam spec'd at .521 and .534 lift and a really bad valve job. As a result the heads have a few broken spings and few damaged bad valves, #-o Hence the reason the guy did a teardown. And why i am freshening up. Also She came with .30 over 9.8-10:1 Forged pistons & the heads are the big chamber 57/58cc Dog leg's.


Now that you know the Details What Im asking for is to Discuss the AMC 401: :-|

II want to know what cam's your running, specs, if you made the jump to 3/8 studs and 1.6 roller Rockers, (reason being these heads came with them). Im looking at a few cams in the .472 -.488 neighborhood 260 or so on Duration. Any thoughts comments concerns, don't want to cut my RPMs off too soon. :-# what about Engle cams?
Everyone so far has said stay stock there is less problems, problem is this motor came modified, so why go back in HP, so now i need to make everything work.

Im wondering if anybody is running the R4B as it was more of a high flow intake, 1000-6000, I know its oldshool Edelbrock AMX stuff seems like it would work but i don't want to improperly match this setup. I'd love to hear Problems you've had when getting away from stock with these, especially on the trail & rocks, problems, things you'd change and why. Stick or Auto, im running a stick. I had a 401 years ago and loved it, idling down to 400-500 was no problem, ive built an AMC 360 but didnt use enough cam on it died at 3800. Ive heard that the 401 reacts even more differently to cams, intakes and engine mods, I have heard most outa box cams weren't enough for it. Most people dont have clue with AMC's so im reaching out and seeking experienced help. :scratch:


Any tips or tricks with the 401,, i already have drilled the lifter valley and installed the oil flow improvement kit, what about better timing covers, oil pump kits and oil filter adapters, any performance models out there. I saw the nickle plated timing cover, whats up with that only for high rpm models or good in an idling jeep. I looked at the anti cam walking kit i dont think it's necessary. I also am debating drilling and tapping the timing cover to pipe a little more oil onto the distributor gear and timing chain but any thoughts is it even necessary. The engine came witha DUI HEI setup thank you previous owner. 670 Holley Off road carb too.


As to keeping this thing cool, ive already got an aluminium radiator so i should be OK.


Any help definately will be appreciated
Thanks

Dusty
111!!!

[Mudrat]

Dusty,
Sounds like you have the right ideas from the git-go. Unfortunately I'm an I-6 guy :? The big dogs will weigh in shortly and can give you some good pointers. You might also go back thru the 14 pages in this thread and get some ideas.

Mudrat

[jeepsr4ever]

Whoa man where do we start :mrgreen:

here is my combo and i am very pleased with it

401 .030 over
summit K8601 cam (see performance parts section for specs)
9.6-1 forged pistons
R4B intake
edelbrockl 600cfm carb (junk)
nickle timing cover (good at all rpms)
lifter valley oil line
.339 drilled mains and bearings

My take on the distributor Line.

When your engine is built right you will get sufficient oil to your distributor gear. When you take and plumb a line from your oil system to feed your distributor you are taking oil from your mains and cam bearings (even if its a .050 hole) If you eating dizzy gears something else is going on either lack of oil caused by mechanical failure (sometimes no oiling holes) or a alingment problem. That timing cover fills up pretty fast with oil.

The R4B

The R4B performed well with a 8600 or low end camshaft in a 401 I had last year however it didnt perform as well as a performer in a 360 with a low end cam. The 401 is a larger motor that needs the aspiration ..you know if you can afford the gas :mrgreen:

Roller rockers

Roller rockers are a wonderfull thing to discuss and look great installed. The true power from these comes in the mid to higher rpm range 4000-8000rpm. Horsepower costs money and you may gain 15-22hp from rollers but it wont be with a low end cam. If you want to go with rollers expect larger gains with a higher lift camshaft with a smaller duration :idea:




Building a AMC is a learning experience to say the least, once you get this thing right building a rat motor or a ford smallblock will be like chewing gum :wink: Good luck and let us know if you need any help :t:


-MC

[Dusty]

MC

when i built my 360 i was told to avoid the summit cams as they "Supposedly" have bad manufacturing, I have always been interested in thier grinds though they seems to be mild yet have great performance potential. With the 8600 was it pretty close cutting out around 5000, how was the idling characteristics, :mrgreen: Mild lope? also with the 8601 what are the characteristics (since you have run both), I was looking at the Comp cams 270H grind .480 lift 270 duration I&E, now i am rethinking, especially since reading through all the articles on this page. I'll also shop around for a some specs on a cam like you said with higher lift and less duration.

I will have to say for the price the summit cam kit is pretty nice about $100 less than all the others.

Like i said before i dont want to Asphyxiate the poor thing yet too much, like the guy who had the motor before me, is going to make this thing tough to idle over the objects on the trail. My Hemi was borderline too much with 505 lift and 298 duration on the trail, but like the AMC it had the low end idling down ability and still could pin 5500-6000 when needed, those summit specs come close, but i also didn't have the advantage of the longer roller 1.6 rocker arms for more lift like i do with the 401.

Thanks for all the info, ill definately pass on the dist gear oiling, no point in wasting time doing something that isnt necessary. I'm still out on if i want to run the 670, carb I had an 800 Edelbrock on the Hemi and that ran really well, i hate to not have enough, plus i have a kid here in town who has a 770 which is too much for his 350 SB.


Dusty

[Mudrat]

EBAY (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=34198&item=7901022280) 6 days left, current bid $100 "Reserve not met" Buy it now = US $325.00


Mudrat :mrgreen:

[jeepsr4ever]

The comp cams good cams, they are a little better quality than a summit brand or what was prepackaged SSI camshaft. The 8600 was good over 5000rpm but started fading at around 4500 with a smooth idle. The 8601 is lopey and with the R4B amazingly has a decent low end and a very powerfull midrange. Highs for this jeeper are 5800+ :mrgreen:

[Dusty]

Alright i looked at a bunch of cams, Schneider, Engle, Isky, Comp, Crane, Summit and i finally went with a Howards cam

http://www.howardscams.com/page12.html

.479 lift with a .222 duration @.050 and a 114 lobe seperation. I'll let you know how I like it. if i dont I swap it out its not that hard to change Cams and ill go a little more radical, this has been a wealth of info in a short period of time. Supposedly they say the Cam dies around 5500+ a little less than id like but it will work, and comes on at idle.... 1000 rpm strong, sounds like a warm but mild grind with some mid/upper level improved potential, we will see.

Dusty

[pyagid]

EBAY (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=34198&item=7901022280) 6 days left, current bid $100 "Reserve not met" Buy it now = US $325.00


Mudrat :mrgreen:

i belive that is being sold buy AMXCHRIS (http://www.bulltear.com/forum/profile.php?mode=viewprofile&u=341)
A member of this board. Same name and same location !!!

[Elliott]

Personally I think you can get a better grind then what you're lookin' at with that Howard cam .
Might check out Lunati and Reed:
http://www.lunaticams.com/Camshafts/AMC1.html These are box cams, but they can do a custom grind to better match the longer 401 stroke.
http://www.reedcams.com/cams.htm

As far as the anti-walk button, that's not something you should need unless your cam was incorrectly ground or it is a roller cam. A correctly ground hyraulic cam will have a taper built into it that keeps the cam in position. When your read of cam walk and gear crash in an AMC it's because the cam was improperly ground, it will typically happen to a fresh motor.

Here are some more cam links:
http://www.powermechanics.com/camlinks.html

Here's your man for a cam consult:
http://www.harveycrane.com/

The problem I see with going with a "box" cam is that you get the same cam that is ground for a 360... which isn't going to make the most out of your 401 with the longer stroke. Having someone very familiar with AMC engines, like Reed, grind a cam for your specific engine will make every difference in what you are trying to accomplish.
The guy building cams at Lunati is supposed to be a hot dog so I wouldn't hesitate to give them a call.

[Dusty]

Good tip i will definately give them a call in the next couple of months, I actually already stuffed the Howard cam in. Don claimed that when he was still grinding cams for his dad company that that profile was one that he cam up with for the 401 because it needed its own grind. I agree with you on a custom grind, a box cam is exactly that, a mainsteam product. I am going to run the Howard for the time being, it gives me a good spot to start, but dont be suprised to see me start working on a designer cam for this motor, saving money and picking up parts. I definately want to dial it into the happiest point, maybe a Roller. :razz: Ok maybe not a roller though that would be nice.

Dusty