401 Build.. NEED HELP!!!!!! Mystery cam problem.

[Revelc]

I got a 401 on craigslist for $2,000 recently ( because my 360 was a dog and finally started knocking )
Its a fresh rebuild.
Never been run.


WHAT I GOT

1976 401 Block
Cleaned up 502 heads
New valves and springs
.30 over
9.5:1 Cast plugs
Race hone... Whatever that is.
5 angle valve job
Mystery cam that only has CWC and random numbers all over the cam one possible part number is 3234 - 029
New timing cover
amyways.... The guy was going to put it in his Jeep and built it to be a hot little motor... or so he says. He said it has a high lift, but streetable cam and that id need a stall converter.

WHAT ITS FOR

I will be putting it to work in my DD that will see a lot of Gold Camp Road and light trails.... if I can help it.
So a hot cam wont jive with low rpm crawling.
I want grunt and plenty of it.
500-5000RPM
And something that will get the old girl down the interstate at 80 mph
Occasionally pulling a stock trailer with a few cows


85 Wag
31" Mt's
locked 3.35 gears
TF727
Aftermarket NP transfer case
Holley TA 670

WITH THIS STUFF

It also will be getting my Slightly used..
Summit Aluminum rad.
High flow coolant pump
Eedlbrock performer intake
MSD Matched gears, Dizzy, Wires, and Coil
And some free Edelbrock chrome bling.
Stock manifolds with single 2.5" straight pipe ( which Ill be switching to duals eventually )



THE DELIMMA

If we cant find the specs out for my cam I dont want to run it.
I have it sitting in my dorm room floor as we speak and I dont want to go through another Cam swap because I dont have a garage.
I am a missionary attending school in Colorado Springs so I cant afford to buy anything other than a Cam and accompanying gaskets, break in oil, etc..

I also am really worried about my selection because the Springs are brand new but I dont know their specs.
I want to run an XE262H (supposedly 344HP 454Ft/Lbs according to cam quest) for the setup.
Maybe a XE256H ( with 5 less hp but +2Ft/Lbs...but I dont want to sell this thing short.
I am open to other cams as long as you dont think they will break valve springs within 20k miles at which point I should be able to replace the springs.
They are 1.4 outer diameter according to my micrometer.
I wont be ripping RPM's past 5k

I will be ordering my cam next week so I hope some of the 401 guys have time to chime in and help a newbie out.


Sincerely ,Clueless

[Revelc]

Come on guys, I tried asking about this issue in Jeepforum and I didnt get much help. I have also been pouring over threads but nobody talks about the largest lift cam they have run with possibly stock spec springs.

[jeepsr4ever]

256 is a pile of crap for a 401 the lift isnt there for any power over 1800rpm. There is a crower cam that trumps the 256 but I dont have the specs in front of me (its the weekend shop isnt open and I am typing this at the dinner table with a 15 month old throwing spaghetti at me)

[tufcj]

The issue is if you're running stock guides and valve seals. At about .500 lift, the valve spring retainer will smash the stock valve seal against the top of the guide. If your heads have been machined for aftermarket positive seals, you can probably get around .580 before you get to a coil bind on your springs. I would never go with that much lift on a stock spring.

For an off-road 401, I'd keep lift in the .475-.500" range, LSA at 110.

Bob
tufcj

[Revelc]

Well thank both of you for your help. I looked at the Crower site, the custom grinds are not much more than the EXTREME cam and lifter kits from Comp. Maybe I should go that route since I already have new lifters anyways.

It looks like I am going to have to bite the bullet and change the springs after all.


Or are you saying the valve seals and guides will interfere at anything over .500 but the springs are okay?


I have never done head work before so I am a little hesitant/worried about it.

If you guys think a custom grind is over kill for my application I'm open to suggestions.

[tufcj]

The stock spec springs are OK for lifts under .500". Most cam manufacturers have a recommended spring for their cams, and I usually use their suggestion just for the longevity of the lifters and cam. I like Crower cams. AMC engines seem to like the split lift/split duration. I'm running one in my AMX and in the engine I'm building for my Rogue.

The only engine I've ever lost a cam lobe on was built (per the owner) with mismatched parts. I ended up rebuilding it a second time less than 2000 miles later with a matched set. Didn't hurt my feelings a bit to charge him a second time for arguing with me on the first build.

Bob
tufcj

[Revelc]

Okay that is a little bit of a relief. And for all I know these are not stock springs I just cant identify them or the cam that was in already. When you say mismatched parts do you mean the cam and lifters were different makes or the springs cam and lifter were all different?

http://www.crower.com/camshafts/amc/...m-276-hdp.html


This cam looks like it doesnt have too high of a power band but the lift isnt very big.

http://www.crower.com/camshafts/amc/...am-280hdp.html

This one also looks nice but I dont want to run either if they are too big for the 401. I want to have lots of low end power.

Thank you again for your insight guys.

[jeepsr4ever]

With a camshaft like that what it is attempting to do is build compression with an emphasis on a short backpressure. The small duration at .050 LSA at 110 or 112 and a lift not to exceed .495 will work well.

[tufcj]

For a 401, I'd go with the first one you listed. If it was a smaller displacement, I'd go with the second. All in all, I like the cam, lifters, and springs to all be from the same manufacturer. Lifters are the least critical, but recommended spring pressures of the cam manufacturer should be followed. Too lite a spring, valve float, too heavy, flat lobes.

Bob
tufcj

[Revelc]

So I guess that rules out the comp XE262 because it's exhaust lift is .500 . I guess I'll give the guys at crower a call and go with something with a managable lift and a lobe sep of 110. All of the cams have 112 or 108 so I'd need a custom grind.