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Woo 401! Ran out to Carbondale today and picked it up.

Not many pics but I took the important one:
Blew it apart and found some fun surprises. It's .040 over, the rods and cam bearings are standard and like new, but he pulled it for low oil pressure. And I found the problem. The mains are 020 under and all but one of the bearings are fine. Except the rear most. There was a significant layer of red RTV and a piece rear main seal between the bearing cap and block. Obviously that's bad, here's some carnage pics:

But not so bad. The ONLY machine work it needs is the crank. Everything else is ready to go! I believe there is less than 20k on the rebuild. Super excited.

Posting for my own sanity...

I've been racking my brain trying to figure out how to adapt a typical small block Chevy style breather or oil fill cap to an AMC V8.

Short of some modified valve covers the best I can come up with is a piece of 1.5" .120" wall DOM as a fill tube. With an ID of 1.25" it should work like a hot damn. And then I can run a properly sealed breather, or vent, or if I so desired I could even reverse the pcv flow. It might have to get slightly resized on a lathe or it may need to be glued in with ultra grey but either way it should work.

Nice score! I love when things work out for the good.

When I purchased my '77. The guy I bought it from told me it lost oil pressure. The mechanic said the mains were bad. Only had 96,000 on it. I pulled the motor, had a rebuilt motor already. Then I took the valve covers off the old motor and found a rocker nut had backed off enough to allow a lifter to pop out. Well no wonder there was no oil pressure! Put the rocker back on with a new nut and ran perfect. Just wish I would had bothered to look first before pulling the motor.

Good luck and hope to see you on the trail some day soon.

Nikkormat wrote:Posting for my own sanity...

I've been racking my brain trying to figure out how to adapt a typical small block Chevy style breather or oil fill cap to an AMC V8.

Short of some modified valve covers the best I can come up with is a piece of 1.5" .120" wall DOM as a fill tube. With an ID of 1.25" it should work like a hot damn. And then I can run a properly sealed breather, or vent, or if I so desired I could even reverse the pcv flow. It might have to get slightly resized on a lathe or it may need to be glued in with ultra grey but either way it should work.

I think I have a couple of AMC breathers in the shop if you need...

Blake wrote:

Nikkormat wrote:Posting for my own sanity...

I've been racking my brain trying to figure out how to adapt a typical small block Chevy style breather or oil fill cap to an AMC V8.

Short of some modified valve covers the best I can come up with is a piece of 1.5" .120" wall DOM as a fill tube. With an ID of 1.25" it should work like a hot damn. And then I can run a properly sealed breather, or vent, or if I so desired I could even reverse the pcv flow. It might have to get slightly resized on a lathe or it may need to be glued in with ultra grey but either way it should work.

I think I have a couple of AMC breathers in the shop if you need...

I appreciate the offer, but the stock ones are driving me nuts!

Now I know if I hear of a 401 I'm thinking about I need to keep my big mouth shut!

Charles Kline wrote:Now I know if I hear of a 401 I'm thinking about I need to keep my big mouth shut!

I hope I didn't undercut you Charles, I've been talking to this guy since March 1st.

Wrote this all down on a piece of paper and i lost it! Now I have to start over grumble grumble grumble.

So here is my shopping list.

Engine Assembly Lube: Lubriplate 105 or similar and a heavy oil.
Harmonic Balancer: Professional Products PowerForce Harmonic Dampers 80101 $139.58
New fan clutch: Hayden 2747 $36.79
Plug Wires:
Plugs
Head gaskets
Rear main seal
Ultragrey RTV
Valve covers?
Oil pan
Oil Pickup
Oil pump
Cam, rod, and main bearings
Flex plate
Starter
Battery cables
Alternator
Engine paint
Motor mounts
Carb spacer
Carb rebuild kit, maybe
Percy's plate
Innovate wide band 02
Cam bearing tool
Distributor or distributor pickup
Exhaust manifold gasket
Tachometer
Heater core
All heater hoses
EGR
Heater Core
Midplate
Maybe push rods?
One of those trick quick drain oil valves
Thermostat

Intake manifold gasket? Water pump? Thermostat and housing??


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tedlovesjeeps71 wrote:Intake manifold gasket? Water pump? Thermostat and housing??


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I should get a new thermostat, but I've got everything else.

Cam, timing cover gaskets, timing set, etc...

Not sure how you're set up but I've grown lazy in my gasket scraping endeavors. I have a die grinder that I run those spin on/off Brillo pad type things. They work great for cleaning gasket stuff off as well as cleaning the block before painting.


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Saw that too. If it actually is done right that wouldn't be a terrible price, I guess, given rarity of 401s... For me, too much of a crapshoot given how many stories I have read about rebuilds gone not quite right and the troubles I had with my 360.

Glad you found a 401.

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Over on Jeepforum.com the guys that do engine builds over there spend months going over cam grinds. deck heights, piston selection, rod weights, and on and on. I cannot believe you are so cavalier in your approach to this build. To just go do it is beyond my ability to absorb.

This is just my opinion and we all know what those are worth, but if you're not going with forged or hypereutectic pistons with a final static compression ratio of 9:1 or higher, there's no point in touching the rest of the engine.

az chip wrote:Over on Jeepforum.com the guys that do engine builds over there spend months going over cam grinds. deck heights, piston selection, rod weights, and on and on. I cannot believe you are so cavalier in your approach to this build. To just go do it is beyond my ability to absorb.

I've spent a looong time researching profiles. And in my opinion if all you're changing is the cam and lifters there is no better "RV" cam than the Summit K8600:
214/224 duration @050
.472/.496 lift
112* lobe seperation.

There are better tourqe focused cams: Jones Camshaft # H440D64307. Designed for 440 Dodge motorhome. 256 advertised duration .491 lift. 202* duration at .050. But I want more top end and more lift.

It may seem cavalier, but look at this thread. 8 pages and I've bought a Jeep. Passed emmisions. Bought some parts. And found some problems.

Nikkormat wrote:

az chip wrote:Over on Jeepforum.com the guys that do engine builds over there spend months going over cam grinds. deck heights, piston selection, rod weights, and on and on. I cannot believe you are so cavalier in your approach to this build. To just go do it is beyond my ability to absorb.

I've spent a looong time researching profiles. And in my opinion if all you're changing is the cam and lifters there is no better "RV" cam than the Summit K8600:
214/224 duration @050
.472/.496 lift
112* lobe seperation.

There are better tourqe focused cams: Jones Camshaft # H440D64307. Designed for 440 Dodge motorhome. 256 advertised duration .491 lift. 202* duration at .050. But I want more top end and more lift.

It may seem cavalier, but look at this thread. 8 pages and I've bought a Jeep. Passed emmisions. Bought some parts. And found some problems.

Gabe, just kidding. You have like thirty threads all going and my old brain cannot keep up. I think you already know what you want to do. Just go with that and tell us how it goes.


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Everyone seems to be getting annoyed with all my questions. So I'm temporarily self banning myself. I'll see you all next week.

Nikkormat wrote:Everyone seems to be getting annoyed with all my questions. So I'm temporarily self banning myself. I'll see you all next week.

Noooooo!!!!

Boo to the nay-Sayers! Stick around brotha! If I was smarter I'd be happy to answer your questions. You're just asking stuff beyond my ken. I'm hoping to learn.


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No one is annoyed. If it seemed that way it is not so. I jest. Which is hard to get across in this media. I am totally jealous though. A 401, a stash of FSJ's, you know you have a bunch. No self banning. It's all good bruh.


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I am not annoyed. I am hoping to learn a lot which I already have!

It's all good man. Keep the questions coming.

Now... Where did I put my old copy of desktop Dyno?? Hmmm.

I played with cam grinds on DD for ages. I recall simulating a (crane, I think) 256-ish adv on a 401 but it seemed to be really anemic on the top end compared to even a 260-ish. I keep saying ish of course because advertised duration isn't quite the whole story anymore than peak HP or even peak TQ. In desktop Dyno you input cam timing events which are what really paint the picture. So some 260 adv were better than others. In addition to modeling 256-270 duration cams for half a dozen makers, I also tried a couple oem cams I found posted on the interwebs. One that I was intrigued by was a particular Pontiac grind that seemed to do better than my other favorites in terms of flat torque, relatively low peak TQ RPM without giving up much top end (4500rpm). I tried stock AMC cam (per timings from some site) and either they were wrong our our cams stink.

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