Looking for AMC 401 build suggestions

[Jeep8499]

Looking for some suggestions for building my 401.
I'll probly go .30 over but am unsure of what pistons, cam, etc. to run.
Really like the sound of this 401: http://www.youtube.com/watch?v=pHGTmDHWuyE

Any suggetions would be great.
Thanks,
Nate

[sungoesdown]

what do you plan on using for, towing, mudding, rock crawling, dd?

[Jeep8499]

what do you plan on using for, towing, mudding, rock crawling, dd?

Just for somewhat of a weekend show jeep. Will not be used for towing, mudding, rock crawling....

[sungoesdown]

So you want just decent power and a good sound?

[Jeep8499]

So you want just decent power and a good sound?

Yup, exactly. :)

[dusty]

the one i just built runs strong. No chance of a engine dyno on this one.

.030 over running speed pro pistons at a 9.6 CR

lunati cam 64501
Advertised Duration (Int/Exh): 256/262
Duration @ .050 (Int/Exh): 213/220
Gross Valve Lift (Int/Exh): .484/.507
LSA/ICL: 112/108
Valve Lash (Int/Exh): Hyd/Hyd
They claim RPM Range: 1200-5500
with the compression ratiop and performer intake its idle to 5000 and at 4600-4700 it falls off and by 5300 its done at 5500 you are without anymore rpms

performer intake nos tuble off the line hard torque off the line and up to 5000-5500 for a little more lope id look at something with a dur @.050 of 218-224.......

mine is in a cj7 the idle is 525 rpm and it has no problem doing that and no problem spinning 35's on demand. its actually stronger than my old 454 TBI sm 465 equipt wrangler off the line. so much so i'm really concerned about that rear dana 44 that ive never broke. all my previous motors were lazy but torquie till 1200-1500 notw its instant throttle

for a light rig i probably could have got away with a slightly bigger cam. with my compression ratio the cam i think icould have still got away with is with some rhodes lifters and my psitons with a mildly port matched performer i might have even stepped up to a airgap, 9.6:1 pistons and this cam from lunati

Advertised Duration (Int/Exh): 262/268
Duration @ .050 (Int/Exh): 220/226
Gross Valve Lift (Int/Exh): .507/.527
LSA/ICL: 112/108
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1600-5800

[Al Johnson]

A suggestion: Because 401's are getting harder to find, and because you may want to rebuild again in the future, don't bore unless it's necessary to clean up worn cylinders, and only bore as far as necessary. You gain very little displacement with a small overbore, but you reduce the chances of successfully rebuilding that block in the future, especially if something really goes wrong that requires a bore.

Of course, it's your motor, and you should do what you want, but that's my $0.02.

Have fun!

[mathman]

...but you reduce the chances of successfully rebuilding that block in the future,...

Uh, you mean 'increase' the chances, not 'reduce' them, correct?

[Al Johnson]

Uh, you mean 'increase' the chances, not 'reduce' them, correct?

No, because if you have "used up" the available metal to rebore this time, it's not going to be there in the future if you need it. Therefore, you've reduced your chances of another future rebuild going well. See what I mean?
:o

[billyrb]

you can always sleeve them ;)

[mathman]

No, because if you have "used up" the available metal to rebore this time, it's not going to be there in the future if you need it. Therefore, you've reduced your chances of another future rebuild going well. See what I mean?
:o

Got it - took a second, third, and fourth read but I caught up. :o)

[billyrb]

Be careful with your build.....these 401's have a way of getting out of hand ;)

http://www.fullsizejeeps.com/gallery/albums/userpics/10030/097.jpg

[mattmopar440]

I wouldn't Bore it .030 mine bored and has some heat-soak issues unless you have too 8600 cam 4bbl intake

[funhog]

Show off, but shouldn't that be in a jeep?

Be careful with your build.....these 401's have a way of getting out of hand ;)

http://www.fullsizejeeps.com/gallery/albums/userpics/10030/097.jpg

[billyrb]

it is, and has been for a while.....albeit not connected to the trans sitting on my garage floor ;)

[JERSEY JOE]

Sleeving is agreat way to save a block from overbore. I had one that was a low mile unit and had very little bore wear but two of the cylinders had rust and damaged cylinders. I quick hone and 2 sleeves and it a standard bore motor running fine. Might not be for an untra high performance unit

[PlasticBoob]

Be careful with your build.....these 401's have a way of getting out of hand ;)

http://www.fullsizejeeps.com/gallery/albums/userpics/10030/097.jpg
HOT 401!!!! But whose E30 M3 is that?!?! :hide:

[wickedwagon767]

I also recommend not boring .030 unless that is what is necessary to have clean and true cylinder walls. You may only need a .010 overbore

The 9.6:1 Speed Pro pistons the other member mentioned are ideal IMO. When combined with a 214/224 degree duration cam from a quality manufacturer like Lunati,Crane or CompCams I believe it would get you in the ballpark you're aiming for.

Remember the oiling issues with AMC motors. Search on here for the list of them. There are a few upgrades/modifications out there to help keep these engines oiled sufficiently and running for a long,long time. Bulltear makes a nickel-plated timing cover and H.D. oil pump kit that is a worthwhile upgrade. Performance Distributors' D.U.I. HEI distributor is GREAT.

Have the stock heads fully rebuild with some mild porting to clean up the flow and a set of roller rockers like the ones Harland Sharp makes would reap benefits

[Jeep8499]

Thanks for the suggestions guys. If anyone has any more, I'd be happy to hear them.

[midmichfsj]

just want to throw in my agreement. my 401 is built very similarly to what wickedwagon said except it was 30 over when i got it. pulled 388HP at about 5500 and 420LB-FT at about 3500 on 93 octane. great driveability with the HEI and a reworked/tuned holly. good luck on the build.

[billyrb]

M3 belongs to a customer of my buddy, the guy that helped me build the 401. He's a BMW certified mechanic and all the dealers in the state bring their problem cars to him if they can't figure it out / fix it. He also is an instructor for Road Atlanta racing course, as well as a famed AMC engine builder and racer. Nice fella, also has some nice AMC's, AMX's and Spirits in the other side of his shop. Never know what I'm going to see when I go to his shop :)

[Artisan]

I might suggest you look into the special oiling systems available for I believe it is the lack of oil to the rear mains. Talk to Matt at Bulltear.com