401 cam suggestions

[rezod1]

Greetings all, i am wanting to install a new cam in my 401 motor, just a good street cruiser and small trail off roading, just want a real nice lope. any suggestions on brand and lift? motor has about 6000 miles on rebuild that is pretty much stock. thanks

 

[CJ]

One word... Lunati! The best custom grinds!

Lunati Cams, Cranks, Pistons, and Rods - Lunati Power

 

[Scooter402]

Welcome!

Without knowing the rest of your setup, I'd say that for a decent noticable lope, you'll want your duration at .050 lift to be above 230-235 degrees. That's not all that makes that lopey idle sound, that all plays in with intake centerline and lobe separation, too. But most hydraulic flat tappet cams (that's what your best bet would be to install) that are over 230+ degrees at .050 will do.

Now, without doing a bunch of other mods, I'd be modest with the amount of lift and duration you do get. If you get into the 250+ degree lobe separation at .050, then you'll need different carburetor, lower gears, headers, a performance intake, and so on. Not to mention, more duration always calls for more lift unless you get a custom grind. With a stock valvetrain setup, I wouldn't go much over .500" lift.

Another thought -- do you have an automatic or manual Transmission ? if you have an auto, you'll need a stall torque converter, or it will fall on its face off idle.

If I had to make a suggestion for one that will work well all around, I had one in a SBC 383 stroker (right now I don't have much time to look up an AMC equivelant) that was somewhere around .480 lift, advertised duration somewhere in the 280 degree range. I believe off the top of my head it had it's .050 duration in the 235 range. It had a healthy idle, great torque, and peaked at about 6000 rpms. That one was a Comp 280H, just to get you started.

When I have more time, if you would like, I can try to look up some more options for you.

 

[Scooter402]

One word... Lunati! The best custom grinds!

Lunati Cams, Cranks, Pistons, and Rods - Lunati Power

Quoted for truth!

I do have a Lunati custom grind in my SBC 402 right now...but trust me, it's not one that you want.

SBC 402 400 Jeep CJ7 with Holley rebuilt/home built carburetor - YouTube

This one is .670 lift, .050 duration is in the upper 270-280 range, and advertised duration is in the 310-315 range. It's a solid roller. That's the only way you'll have a cam profile that steep. But it's strictly for racing. I'll probably be changing it out, as I don't really have the time (and opportunity due to my current location) for racing anymore.

 

[CJ]

Quoted for truth! ~~~

Lunati, worked the 770 time on our 10.5 car....

 

[rezod1]

Scooter, appreciate all the great information, Motor does have a GM Turbo 400 tranny. previous owner had the 401 rebuilt and currently trying to track down the builder in vegas and find out particulars on it. I am planning on headers and intake also, probably just a 650 carb. good call on the stall kit for tranny, Planning on gathering items this summer for a fall/winter reconstruction top to bottom.

 

[OLD 9]

I agree with everything stated above. Lunati is also my favorite and there is a lot more to cams than most people understand. Be honest with yourself when you choose one. Cams are kinda like the brain of your engine, telling it when to make power, how fast to make the power and for how long. If you use your Jeep as a driver and trail rig that lopy idle may cost you preformance and turn into a "wish I haden't a done that" pain in the a**. Cool, rumbly idle only goes so far when a smooth ideling 360 with properly matched parts (including cam) kicks your b*tt.
My opinion--Keep your duration @ .050 below 220*. That, and a rather tight lobe seperation angle around 110* should get you a "noticable" idle and a hot runner on the street but still be OK off road. Check out the Lunati #00171 (in their cat. but not on their site) or Comps #10-202-4.
Scooter401 gave a quick explaniation of some important things you should understand. I put this together a while back for those that ask "what cam for me" Its worth reading.
Chevy Xtreme Classic Chevrolet Enthusiast Forum & Web Link Directory

 

[Scooter402]

Old 9 -- Great info you have on your link.

I did just give a quick "down and dirty," and was probably aggressive with my cam selection. But I can tell you exactly how a miss-matched engine can run -- kinda like . It took a lot of trial and error and building and re-building a 383 I had years ago to run like I wanted it to. I thought it was merely a "suggestion" when cam choices said to use aftermarket or ported heads, performance intake, etc. etc., and found out very quickly that a hot cam doesn't perform well with a stock set of heads. If you're still confused or unsure, as Old 9 had put it, you need to be honest with yourself about how you're going to use it. If you're unsure about selecting one for yourself, you can call up Lunati or Comp or whomever you choose to help you select the right one.