xe256 cam

[drdmanti]

I'm just about to pull the trigger on a comp cam xe256. Just looking for some feed back on the cam choice. Give me the good, bad, or ugly! Thanks

[PlasticBoob]

I have this cam and love it. It's more of a tractor cam but strikes a very good balance between low end torque and mid RPM power. Do a search and you will find lots of posts by me talking about it/comparing it.

Here's a link to get you started: http://socalfsj.servebbs.net/storage.../cams/cams.htm

Don't pay as much attention to the actual numbers as you do to the differences of power numbers between cams. If you want an extremely low-end tractor cam, get the 4x4 version.

I have not had a chance to really strut it since I am still running 32" tires with 3.07 gears, but I still get pretty darn good acceleration. Downshifting to 1st at about 15mph really pushes you in the seat, and it even has a thump when cold: http://www.youtube.com/watch?v=6JdYl-F8NJQ&t=0m50s

In short...this is a perfect everyday cam and even works great with fuel injection. Might be a tad small for a 401, but still I have no complaints. Just don't go cheap and make sure you also replace your springs, retainers, locks, blah blah blah. Throw in a double roller timing chain while you're in there too.

[FSJunkie]

So how do you feel the factory cam would compare on the same engine?

I've been thinking about a cam on a 360 project in the future. I'm giving myself lots of time to think about the cam. I want a smooth idle and I want the torque peak at the same RPM as stock, 3000 RPM. I just want to increase torque at all RPM's, right from idle to 5000 and increase by an equal amount through the whole range. Basically just move everything up.

Perhaps you've seen my thread on the comp 252h and 260h. The trouble with cams is, everybody wants something different and has a different opinion. It's hard to find a logical conclusion.

But for the price I'd pay for a cam and the intake and carb to go with it, I've spent $500 easily for all of 30 more horsepower. That's if I tune it right, otherwise all that expense could get me nowhere.

[PlasticBoob]

That is a very good question, and unfortunately it has a complicated answer that requires me to explain a bit of history. When I first bought my Jeep, the factory cam (cam 1) had a flat lobe or two, and was almost effectively running on 7 cylinders. Despite that, it still ran great, and on tiny stock (or smaller than stock, I forgot) tires with a 4350 carb shoehorned onto a 4300 intake, it was still surprisingly quick. The Jeep had true dual exhaust.

After I had the engine rebuilt, I thought that I would gain a lot more performance, but in reality, it the same as the previous setup, even with an intake and properly-tuned Truck Avenger. I strongly suspect that the engine shop may have used a stock 360 cam (cam 2) in my 401, but can't prove it. Something just didn't seem quite right. Had true dual exhaust and switched to a single 3" system some time afterwards.

I then installed the Comp Cams 256XE (cam 3) after I installed 32" tires and a 4" lift, so unfortunately I cannot directly compare it to the factory cam because I did not regear. I can say that it is much faster and has much more grunt than cam 2 had with the same tires. I suspect that the Desktop Dyno numbers are not that far off. I think you'll get a bit more than 30hp. My 401 was rated at net 215hp and 320ft-lbs at 2800rpm, now I estimate I'm at around 270 with 400ft-lbs at 3000rpm. So that nets around 50hp or so.

These modern grinds are amazing, it just depends on what you want and where you want it, like you said. I won't be using the 256XE in future engines because now I know that with a slightly larger cam, I'll still have enough low-end torque from sheer displacement to make me happy - I want my next 401 to be a bit of a hot engine with MPFI, headers, and maybe a dual exhaust.

I'll give your thread a look when I get some time. I think the 256XE or a similar "RV" cam would fit your needs as described perfectly...you want that feeling of pressing down on the gas and getting instant acceleration, without much RPM rise, right? That's what I call torquey!

[FSJunkie]

Yes, I like the insane big-block feel of planting my foot and instantly having things torque up, not calling up the gearbox and ordering a different gear to bring the engine up to operation. I think the stock torque curve had a pretty nice balance between bottom and top RPM, at least with the proper fuel and exhaust systems to sustain it. I want to raise output, but not change it's nature, you know?

Of course, the more displacement, the more torque can be produced and at lower RPM. This is where the "no replacement for displacement" comes from. Sure a SB can produce just as much power, but at what RPM? I like it at as low a RPM as possible, it makes things snappy.

You also have a 401, which will like more cam than a 360. You're talking the 256h cam in a 401, which a 360 should behave about the same with a 252h. Actually, I think the 252h is about the same as the stock 401 cam, which was a pretty nice grind.

California 304's and 360's for a few years actually had a split pattern cam. 263 int, 293 exh vs. 263 on both for the 49 state cam. That's advertised duration at whatever lift AMC measured it at, but you get the idea. I almost had one custom ground just to see what one would be like.

[Ristow]

i have the litle lunati voodoo in a 360. i like the performer grind better,but the lunati -barring it's horrible quality control-is easy to live with. it doesn't rev out as nicely. i won't pony up the extra money over a performer grind again.

the little voodoo is slightly smaller than the 256xe. the 256 may be a little stronger across the rpm range.


rod length,and ratio,and dynamic compression is also something you want to look at in regards to different displacements of the same block,over displacement alone. the 401 (longer stroke/shorter rods) has a significantly numerically lower (sharper angle) than a 360 (shorter stroke/longer rods). it has an effect on how power is made,all things being equal.

interesting stuff,once you grasp some of the terminology and processes.

http://www.stahlheaders.com/Lit_Rod%20Length.htm

http://www.tildentechnologies.com/Cams/Take_RodLen.html

http://users.erols.com/srweiss/tablersn.htm

[serehill]

Lot's better input I think this cam got a bad rap in the last thread.

I think the 256 is a great medium performance cam.

[dusty]

you need to provide some more info.

What displacement?
what compression ratio?

on a stock 360 i liked the 256ex a lot. on a stock 401 it performed well too

if you want simple thats going to idle strong and be reliable
displacement determines how a cam will perform in a motor. the cam that works well in a 360 will be a little short legged and peak earlier than in a 401 lowering your operating rpms which can sometimes give the impression of stronger lower end power but worse cruising power. as well how you install the cam straight up, advanced or retarded also affects performance

you’ll be fine with the 256XE but imho it is small for a 9:1 401. there is alot to the lift with amc's, , the larger diameter lifter in the AMCs is advantageous because it allows you to use the higher lift capabilities without having to increase duration. my 9:1 401 with the lunati cam .484/.507 213/220 dur @ .050. idles at 500 rpm and will snap to 5k without issue Similarly Engle really takes AMC cams and motors to their limits with the high lift, .500+ with very short durations. lift allows the fuel and air in duration sets your rpm range. Comp makes a nice cam but the last couple of engines that have thrown on the dyno's i am pretty much a believer in Engle's cams with Lunati running a close second.

We can all throw out numbers at you your setup but i thinks were a little ill prepared to tell you enough on so little info

Couple of examples here’s Donwags build and dyno numbers.
401 - 30 over
Decked, align bored and balanced
10/10 crank, resized rods, all ARP bolts
Cast stock style pistons with head 9.1:1
CC XE256
Edelbrock heads (ported and polished) w/ roller tip rockers
Edelbrock performer intake dual plane (heads and intake port matched)
Edelbrock shorty headers
Holly Truck Avenger 670
MSD ProBillet and 6AL

Results after the build including dyno
“The idle is just a little rough, lopey, lopey” 550 rpm idle Very mild lope almost not noticeable

it made over 400ftlbs from 2-4200rpm with peak torque of 428 at 3400 and 348hp at 4800 on the engine dyno.

Second motor is mine running TBI im in it close to 3k but that’s exhaust, repairs to the TBI and aluminium radiator and lots of messing around with things I could have avoided.

401 - 30 over
Decked, align bored and balanced
10/10 crank, resized rods, all ARP bolts
Bulltear Forged 9.1:1 pistons
Lunati 58501
Advertised Duration (Int/Exh): 256/262
Duration @ .050 (Int/Exh): 213/220
Gross Valve Lift (Int/Exh): .484/.507
LSA/ICL: 112/108
RPM Range: 1200-5500
Cast 502 heads (Mild Port match) w/ roller tip rockers
Edelbrock dual plane performer intake
ported exhaust manifolds
670 TBI GM injection 85lb/hr injectors HEI distributor

idles smooth at 500 rpm red line 5500 rpm spins hard to 4500.

You can end up splitting hairs with cams, a well tuned system makes a world of difference, if i had done headers i might have picked up another 5-10 hp and another 15 ft/lbs and the TBI was probably robbing me a little on top end performance think we had a refuel issue above 4000 rpm. the motor with the 256ex that don wag built had edelbrock heads which have better port velocities. The motor with the edelbrock heads could have taken advantage of a higher lift cam with similar duration numbers and pulled another 30 ft/lbs out of that motor without trying. You are going to be happy this engine regardless will have fantastic off the line snap.... it might lack a little top end but like i said i think you are splitting hairs to regret your decision you know best what wioll be a good fit on the engine and seat of the pants is everything. a 214-216 dur at .050 is sure nice for well mannered


For some other cams to look at

Engle
.489/.489 254/254 adv 209/209 dur @ .050 112
.501/.501 260/260 adv 214/214 dur @ .050 112
.538/.538 272/272 adv 224/224 dur @ .050 110


Comp Cams
Extreme energy
.477/.484 256/268 adv 212/218 dur @ .050 110/106
.493/.500 262/270 adv 218/224 dur @ .050 110/106 ** i liked this cam a lot and sometimes contemplate it on my next 9:1 401 build


Lunati
.484/.507 256/262 adv 213/220 dur @ .050 112/108 *** this is the one i have in my current 401 build, I’m certain this cam could be run in a 360 and perform well even with stock compression
.507/.527 262/268 adv 220/226 dur @ .050 112/108 **A friend of mine is running this in his 9:1 401 and it idles and pulls just as hard as mine but when he down shifts his 3500-5000 rpm power is far and above mine. thats probably carburetor and also cam vs my TBI but worth noting.


For a given duration it seems that Engle pushes the limits of the amount of lift possible with a hydraulic lifter equipt motor. They are all good cams fun to look at em side by side and then take into consideration the cam timing. mind blowing

i would have had one ground with cam .520/.527 220/222 dur @ .050 on a 110 or 112/108 with an advertised duration of 262/264 or .516/.524 218/220 something like that for my 9:1 401 but i was trying to emulate the build that i posted above my build from Donwag for my cj7 crawler motor. Then again that’s splitting hairs and there are already good cams out there. Engle will argue as will a couple others that amc's flow so well on the exhuast side that single pattern cams are more than sufficient. i knew the lunati i chose would work and i wanted a super low rpm stable idle.... i have been able to adjust things down to 400 rpm and keep it running there and actually had it barely sustain a 250-300 rpm idle with the TBI system but currently idle is set at 550 with no stall saver programming

[drdmanti]

This will basically be a stock rebuild of an '87 360. I'm assuming it will be bored 30 over to clean things up. It will be decked to give a 9:1 compression. The motor will be used in a grand wagon used primarily in the mountains in Utah. It will pull a Boy Scout trailer, snowmobile trailer, along with a tent trailer. I also use the vehicle to drive to the farm and back in the winter (40 mile round trip). I need it to cruise at 65mph yet have some grunt to pull. I plan on replacing springs, lifters, etc.... I'm going to do it right. From every thing I've read the xe256 seems to fit the bill. I am totally open to suggestions as I want to make this build perform in the above described uses. Thanks for the help and suggestions. Keep them coming. - Darren

[FSJunkie]

Wagoneers used to pull trailers all around the country back in their day, and in perfectly stock form. That being said, there are ways to improve their towing.

That cam will tend to increase engine output pretty evenly across the RPM range, which is what you want for towing. You'll want to run an HD double roller timing set, because some of the stock style sets have retarded timing. The factory carburetor is great at low RPM, but will restrict things above about 3800 RPM, so you might think about a 4bbl carb and intake swap. You could go with the factory carb and intake if you just want a bolt-on and go type thing, but you can go with an aftermarket universal carburetor if you know how to set them up and tune them in. If you've got a bigger carb dumping in more fuel, then the stock 2.5" exhaust system should be upgraded to a 3" to get it out.

The way the rest of the vehicle is modified or not depends a lot on if it has the factory trailer tow package.

[babywag]

This will basically be a stock rebuild of an '87 360. I'm assuming it will be bored 30 over to clean things up. It will be decked to give a 9:1 compression. The motor will be used in a grand wagon used primarily in the mountains in Utah. It will pull a Boy Scout trailer, snowmobile trailer, along with a tent trailer. I also use the vehicle to drive to the farm and back in the winter (40 mile round trip). I need it to cruise at 65mph yet have some grunt to pull. I plan on replacing springs, lifters, etc.... I'm going to do it right. From every thing I've read the xe256 seems to fit the bill. I am totally open to suggestions as I want to make this build perform in the above described uses. Thanks for the help and suggestions. Keep them coming. - Darren

You realize the right way to get 9.0 CR is not w/block or heads but pistons?

[drdmanti]

Anybody have experience with the engle cam .501/.501 260/260 adv 214/214 dur @ .050 112. This cam intrigues me. Let me know what you think. Thanks for the input guys, this is really appreciated and helpful.

[drdmanti]

Is there anyone who has a desktop dyno that would be willing to run some comparison numbers using a 360, 9:1 compression, with the following cams?

Engle
.501/.501 260/260 adv 214/214 dur @ .050 112

Comps cam
Extreme energy 256
.477/.484 256/268 adv 212/218 dur @ .050 110/106

Lunati
.484/.507 256/262 adv 213/220 dur @ .050 112/108

Edelbrock performer grind
I don't have the numbers for this

It would be very helpful to me and a ton of great info. If it can't be done, understand.

[jdaniel83]

Edelbrock performer grind
I don't have the numbers for this

Lift: .448/.472
Dur: .280/.290
Dur @ .050: .204/.214

Cent: 110

RPM Range: 1200-4700

If you're considering the Performer grind you might want to check this out:

http://www.ebay.com/itm/AMC-Jeep-290-304-343-360-390-401-MTA1-Torque-RV-Cam-Lifter-Kit-Lifters-Camshaft-/310674360008?pt=Motors_Car_Truck_Parts_Accessories&hash=item4855a286c8&vxp=mtr

A few members here (myself included) have installed this Cam/Lifter combo and I can't speak for others but I've been very pleased with it.

[FSJunkie]

The only cammed AMC engine I've driven was in my friend's Grand Wagoneer. 360, 600 CFM 4bbl, dual exhaust, 9.2;1 compression, cam is a Wolverine, but it's nearly identical to the Performer he says.

It actually idled as smooth as my stock 360. I've found the Gen-III AMC V8's tend to have a little lope in them anyway, so you can get away with some cam before you notice any difference.