401 Build Up Feed Back

[radjeeper]

What I have done:
'78 401 freshened up at about 70K miles with rings and bearings
- Edelbrock Performer Cam
- Edelbrock Performer Intake
- Holley #4010 750 cfm w/ Vacume Secondaries
- MSD Pro Billet Distributor
- Jacobs Omni Pack and wires
- NGK Plugs gapped @ .40
- 390X Small Chamber Heads
- Aluminum Roller Rockers w/o guide plates
- Edelbrock Roller Timing Chain
- Flowcooler Waterpump
- Doug Thorley Tri-Y Headers

The engine is in a Wag that will be used for slow four wheeling, trails, sand dunes and cruising. I will install a 3" single exhaust w/ a Magnaflow long 3" muffler. Other drive train specs include 4.56 gears, 35" tires and T400 trans with lower 1st and 2nd gears. Will be heavier than stock with HD bumpers, roll cage, etc. Eventualy plan to install the Edelbrock Pro-flow fuel injection.

What do you think? Any suggestions? MC suggested his oil filter adapter and oil pump gears. What oil pump spring should I use? What should I expect in the way of horse power and torque?

[jeepsr4ever]

Std. spring
at least a upgraded oil filter adaptor
a better cam 260h or 270h from comp or summit k8600 *the performer falls flat in a 401 really fast

The rest sounds good with exception of the roller rockers. Roller rockers and a RV camshaft arent a efficient mix. Once the engine starts to rev up and utilize those rockers it will rev past the power band of the camshaft and you will never see the increases that roller rockers make. Rollers are a very small increase in a low to mid rpm engine.

I will let someone else chime in here to offer a different point of view possibly.

[radjeeper]

Thanks for the feedback. What I am thinking is the new oil filter adapter, std. spring, new oil pump gears and stainless steel plate. How does this sound? What do all these parts do for me?

[jeepsr4ever]

The oil filter adaptor actually has the oil filter bypass cast in while retianing the pressure bypass. Chrysler did this in 87 to make the AMC V8's service life longer. The midplate allows the oil pump to last longer by giving the gears a hard stainless steel surface to ride on. The Std. spring is the stock replacement for the original pressure spring that fatigues over time and becomes weak allowing more oil to bypass the galley's. We sell the spring with a new oil pump kit.

[radjeeper]

I am not sure I understand, does this mean that when I put on the new oil filter adapter that I don't need the midplate? Also what do the new gears do for me?

[jeepsr4ever]

The oil filter bypass and midplate are two different things. New gears tighten up the tolerance of your pump by adding a new edge to the gear the dimension between gear and pump cavity get smaller and you get mor eefficiency which it turn gives you better oil pressure when warm.

[radjeeper]

OK, so it sounds like my initial evaluation was right, to get the new oil filter adapter, a new standard spring, new pump gears and a s.s. midplate. Are the new gears able to be installed through the bottom of the cover where the adapter bolts on? I don't want to take the timing cover off, I have just put the new water pump on for the second time. Would all of these parts be advisable? How much for a package deal on all of them?

In addition:
At what RPM would the Performer cam max out? I just put the top end to together and dont want to tear it down again. Also, I assume the roller rocker issue is not a big deal, I got them with the 390X heads as part of the deal so I put them on.

I am thinking that our Jeep shop, The Rad Jeeper, is going to specialize in AMC V8 motors. We like their simplicity, uniqueness and power. I have another 401 that I will be putting in my CJ-6 project. It has stock heads, flat top forged pistons (about 9.5 ratio), mild RV cam and some type of Edelbrock intake. I can get in to it a little and do few things.
Any recommendations? Also, what about commercial pricing for parts?

[jeepsr4ever]

We have a dealer program send me a pm.

The performer camshaft will have a sharp power loss at 4000rpm but with your roller rockers it may last untill 4600 and then drop off (probly get there quick as well). Yes you can install new gears and a new oil filter adaptor without taking the timing cover off (bolts to the bottom).


The biggest gains you will see on your 401 are CAM,INTAKE,CARB,PORT WORK,HIGER COMP PISTONS. Usually in that order of most powerfull mod first (without mentioning stroking the crank). A performer intake and a rv cam really liven up a 401, dont forget a carb a edelbrock offroad carb is a great way to go (we are also a dealer for edelbrock) Or the stock mc2100 2 barrel is killer off camber and works well with a rv cam.

[radjeeper]

Thanks for the info!

[Dusty]

too many people under cam the 401 IMHO time and time again that motor is under-estimated

that 270H is an awesome cam for towing and crawling in a 401.

A close friend of mine is running an airgap intake, 750 Holley, 270H with 9.8:1 compression, roller rockers and long tube headers single 3" exhaust with a T18, 3.73 gears and 33's on his trail jeep....crawler amazingly enough that thing has a mild lope to it and still crawls all over the rubicon with ease its mean when its wide open and spins to 6400 without any hesitation best power is from idle to 4500/5000 doesnt ever seem to fall off nor struggle to get started. ive have seen that thing idled down to 400 and 500 rpm and pull itself right up and over and then wind the motor up again without ever stalling out

Crowler had a few nice grinds if i remember right. I ended up having to be different and used a howards cam very similar to the 270 in lift and dur at .50 but my lobe seperation is 114 vs 110, in my 401 then later i added efi and aluminium heads at 10.12:1 comp who knows where i'll be at 111!!! :?:

[radjeeper]

Thanks for the info. Let me know how you like the EFI. Sounds like a new cam will be in my future. Most likely when I upgrade to the Edelbrock EFI. Let me know how your set up works. Thanks.

[jeepsr4ever]

We got some feedback from a customer in Texas....claims a ton more power and easy starts with his MPFI. I would love to dyno a setup

[Dusty]

If i ever get my tranny done, i'll put 5k-7k miles on her and then i will run my setup down and get her dyno'd just for you MC. but like i told you before i'll have to pull a few sparkplug wires to make the SBC guys feel better :lo1l:

[radjeeper]

I mentioned on the phone that I was at the Moab Easter Jeep Safari a few weeks ago talking to the Edelbrock guy. As you know, he had his CJ-5 with a 304 in it. He said that with the Performer cam, springs, headers and MPFI he went from 160 hp to 200 hp. I told him he needed a 401. He aslo told me that they are coming out with the old "Retro" style Edelbrock valve covers for the AMC V8 in about a year. Very cool! They are making them for all the "old" American V8's eventually. Its a matter of finding the old molds and then refurbishing them.

Also, I saw today that Edelbrock is advertising their new AMC Performer RPM cam. What do you think about this? Perhaps their heads, RPM Cam and MPFI will work well together? Would be interesting to see a dyno test on a mid '70s AMC 401 with such a package.

[Dusty]

FYI Frank's red CJ-7 with the 304 and MPFI was stolen about two weeks ago, not long after EJS... shame, the rig was stripped out almost completely.

he has said that Edelbrock is working on some different cams for the 401 specifically because the performer cam that they have doesnt take full advantage of the RPM range of the 401 engine, it was designed with a 304 in mind. They have a 401 dyno motor in thier shop that they are experimenting with and claim that within a year they hope to be coming up with something just like you are talking about, an all inclusive package of parts and pieces that work well with the EFI and the 401 + other parts ect.


RAY just put a 1977 stock 401 back together with just rings bearings a fresh set of heads, Torker intake and the howards .479/.479 292/292 dur 222/222 dur@.50 114 lobe seperation and it is impressive for such lowcompression, great idle characteristics down to 700-750 not as peaky a HP/TW point when compared to the 270H but smooth high torque from idle all the way to 6000rpm and still wanted to pull more. peak was right at 4000-4500 and between 4500-5500 she was screaming and pulling you back. but it never seemed like there was a point in the cam cycle that truely stood out as when she ccame alive it was just there all the way through where as the 270H came in and in an agresive fashion there is a point where it is slow to come on and then bam its there where this one phases in gingerly, but the power is very similar.

Interesting forsure cause i had my doubts

[newt]

Just for referance:
Edelbroc cam: 204/214 @ 0.05, .448/.472 lift, 110 lsa
Comp 260H: 212/212 @ 0.05, .447/.447 lift, 110 lsa
Comp 270H: 224/224 @ 0.05, .48/.48 lift, 110 lsa
Howard: 222/222 @0.05, .48/.48 lift, 114 lsa
Summit 8600: 214/224 @0.05, .47/.495 lift, 112 lsa

Others to consider:
Comp 268H: 218/218 @0.05, .46/.46 lift, 110 lsa
Comp XE262: 218/224 @0.05, .49/.50 lift, 110 lsa
Comp XE256: 212/218 @0.05, .477/.484 lift, 110 lsa

From playing w/ DeskTopDyno and reading all I can find, I'm leaning toward a cam w/ the specs like the summit 8600. The split durations seem to do the best for having a good idle, building low end TQ and extending the rpm range. It also increases the volumetric efficiency.

[radjeeper]

Interesting info on cams. Would sure be nice to see some actual dyno results with 3 to 5 different cams. I think Crane also has a dual pattern cam that I have read about. I think it was more of an RV grind? I am wondering why the Howard cam would be so different than the Comp 270H when they are very close in specs, must be the lobe seperation?

[newt]

I'm no expert, but I've been doing alot of research, so take this w/ a grain of salt.

The LSA, combined w/ the ADV duration and lobe shape, have a big effect on valve overlap which greatly influences performance. A wider LSA should produce a wider power band but give up some peak output while improving the idle quality (reducing valve overlap). The wider LSA also increases volumetric effeciency.

One thing that still confuses me is with the significantly different flow levels for the intake and exhaust side of the heads, why isn't everyone running split cams? There must be some reason, but I don't know what it is. Anyone care to explain this one?