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My "new" dream Scrambler

AK-RWC said:
I'm already VERY familiar with the AMC cam/distributor gear issues, and I have the internal valley oil-line for the rear-main. The oiling issue with the cam gear is relatively minor, and if you've got "the problem" more oil won't fix it. When I first built the 401 I spent a LOT of time on the AMC Forum learning from the drag-racing guys how to build a 401. The oiling issue is due to flashing left on a slot in the timing gear; if you file out the flashing you'll solve that minor issue. The external oil line is a waste of time; the AMC forum had a guy that kept going through gears so he added the external line, only to pull out oil-soaked and very broken cam gears.

The issue is cam walk. When I first did the 401, my builder machined a Delron cam-button for me, and I went with a bronze distributor gear in addition to a new Crown timing-chain cover. That got me home and the engine seemed fine, until I had a lifter die on my Summit cam. So when the new cam went in, 90+ miles later, it ate the distributor gear.

I mostly order parts from Randy Guynn at Performance American Style. I called him up for advice, and he said that when Crown first started making the replacement covers, about 50% of them had incorrect specs for the positioning of the distributor. He discussed the issue with Crown and they tightened up their tolerance, and he said he's seen no others come through with the same problems. He said it's possible that I got a bad one (I think I ordered it through 4WDH), and he recommended replacing it.

He also said that the sacraficial distributor gear, while it might save bearings, isn't a long-term solution, and told me about just getting the matched new set of hardened gears each time this happens. He's also heard of guys going through two or three sets of gears before a fresh set finally breaks-in together.

So I ordered a new cam gear and distributor gear, and a new timing chain cover. I ran that for another 90 miles and had another lifter fail. After two lifter bits and a distributor gear went through the engine, I thought it would be worth pulling the rear main cap to look at the bearing. Bad.

So the 401 had a rebuild with a new cam. That set-up lasted for several years, and then suddenly a cam gear went out. 90 miles later, it went out again. This time I added a thrust-plate that sits underneath a specially-machined timing gear to go along with my cam-buttom. 95 miles later, I was sitting on the side of the highway at 9:20 yesterday morning.

I think this time I'm going to tear out the cam and stab a new one in there, in addition to checking out the bottom-end (again) and the journals on the cam. I'm thinking that maybe the lifters have worn with the cam in the wrong spot, and there's only so much anti-thrusting that will keep the cam from walking.

In the meantime, I'm going to evaluate my options for the California fiance & top trip.
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Sorry to hear about your bad luck with your 401. I have had very simular problems with my amc 360. I did not make it to the part of having the cam button made. but it was a thought I did have. but I have blown the front end parts out my amc v8 mutliple times in my cj7. And have gone through multiple covers, gears, cams... stay away from summits cam. I smoked two of them. and finally bought a crane cam. The crane cam is working good. this last set of matching gears, timing chain cover, oil pump, and cam have lasted almost 5 years now. I think after I get done with my wifes cj8... I'll problem end up doing a 5.3l swap into the cj7. Thats if I like the 5.3L engine in her jeep?

also if you didn't already know try this website they have great parts:

http://www.bulltear.com/

its tuff running these amc v8 engines. i have a 401 on a engine stand that was going to go into the wifes cj8. but then I remembered I hate fixing stuff. LOL good luck
 
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7jeeps7kings said:
Sorry to hear about your bad luck with your 401. I have had very simular problems with my amc 360. I did not make it to the part of having the cam button made. but it was a thought I did have. but I have blown the front end parts out my amc v8 mutliple times in my cj7. And have gone through multiple covers, gears, cams... stay away from summits cam. I smoked two of them. and finally bought a crane cam. The crane cam is working good. this last set of matching gears, timing chain cover, oil pump, and cam have lasted almost 5 years now. I think after I get done with my wifes cj8... I'll problem end up doing a 5.3l swap into the cj7. Thats if I like the 5.3L engine in her jeep?

also if you didn't already know try this website they have great parts:

http://www.bulltear.com/

its tuff running these amc v8 engines. i have a 401 on a engine stand that was going to go into the wifes cj8. but then I remembered I hate fixing stuff. LOL good luck
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I've ALSO been through two Summit cams! What gives with those things??? The FSJ guys LOVE them though. I really like the power band that my current Comp Cams grind gives me, so I'm planning on sticking with that part number for now.

John N and Randyzzz also both mentioned Bulltear. I'm familiar with them, but like the customer service that Randy gives me from PAS.

I've had several people, most recently including my father, try to talk me into a different engine. But the whole reason I stuck with the AMC is to try to keep it more of a Jeep. Plus I've already invested so much in this 401 I don't want to ditch it. AMCs are like the black sheep, but I love what these engines can do!
 
Minor update:
Hard top should be on the barge any time now. I'm going to call the shipping company tomorrow to see what the status is. In the meantime, my buddy needs his shop space so I'm going to pull the engine on Saturday to leave with him and bring the Scrambler home. That's not a bad thing since I can get fitment of the doors done and wire up my center console. At this point I'm expecting a minor rebuild (if not more) and will probably miss the summer wheeling season. That's OK; with the hard-top I'll be ready to make glacier runs as soon as the river is frozen this winter. And I bet we'll love the seat heaters! With my fiancé's ZJ mostly complete we still have something to use for minor runs and camping/fishing trips. I'll post pics of the engine coming out and the top when it arrives.
 
From last weekend:

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Pulled the 401. Even with the headers, I still had the engine free in about 3 hours.


Just a couple photos before loading it back on the trailer to come home:
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So now it's in the driveway, and we've had some perfect warm weather. At least I still have my 7 to drive!

My hard top is in Anchorage and will be delivered tomorrow.
 
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"Watcha got in the box?"
"Ninjas!"


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Only minor shipping damage where the pallets bent/twisted enough that the top poked down through the cardboard and I think it got caught by a forklift. I would have put it on today, but it's been raining off and on since Saturday and I haven't had a chance at home to pull the soft-top off. Since the Jeep won't go into the garage with the soft-top up, I need to wait for a break.
 
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I just got it set on there to free up real estate in the garage. I had to let air out of the tires to roll it inside, but I got it in with minimal touching.

My friend who has my 401 said there's twice as much endplay in the crank as allowed, but the cam looks fine; maybe the crank acting through the timing chain gears is causing my problems? Either way, it's illustrating further that I got a bad rebuild when I was in Juneau. The upper rod bearings are all shot too. He's going to take it down to a short-block, and since Friday is my day off I'm going to take it to the machine shop that was subcontracted to do the last work on it.
 
AK-RWC said:
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I just got it set on there to free up real estate in the garage. I had to let air out of the tires to roll it inside, but I got it in with minimal touching.

My friend who has my 401 said there's twice as much endplay in the crank as allowed, but the cam looks fine; maybe the crank acting through the timing chain gears is causing my problems? Either way, it's illustrating further that I got a bad rebuild when I was in Juneau. The upper rod bearings are all shot too. He's going to take it down to a short-block, and since Friday is my day off I'm going to take it to the machine shop that was subcontracted to do the last work on it.
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That sounds like some real BS on the previous rebuild/machine shop work:angry:

I am sure you will get it running again soon, though:thumbsup:

Top looks good:wave:
 
Top looks great. Nice big windows. I think I may have to sell my old hardtop and save for one of those.
 
Randyzzz said:
Top looks great. Nice big windows. I think I may have to sell my old hardtop and save for one of those.
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It seems nice so far. It's single-wall, so it only ends up being barely heavier than a stock CJ-7 top. At first I wasn't sure I was going to like the carpet-liner, but now that I've sat in there I like it; it's going to make a big difference in both insulation and sound deadening. The windows even have bug screens! I ordered no options for this top either (roof rack, battery-operated dome light, sunroof, 3rd brake light).

With the exception of the integrated speaker pods, the photos and optioning of the Xtreme/Rallytops is identical to the Gr8tops (which stopped taking CJ-8 full-top orders, per their website).
 
I just got a quote with shipping from them, about 2K total to the local freight terminal. Not bad...
 
Minor update: I've had a few calls with the machine shop once they got everything completely inspected. The bearings are all trash, along with the cam. They measured my valve spring pressure and found out that's what's been causing me to wipe out lifters. He tried to talk me into a smaller cam, but I liked the performance I was getting with what I had (aside from all the non-cam problems), so talked him back up to my last grind.

The crank looks good and will just get polished. The bores are all on center and will be just fine with a hone. He prefers chrome-moly rings instead of the TotalSeals that I had been running.

This shop has dealt with AMCs in the past (including a recent 401 for a drag car), but hadn't ever heard of the cam-gear problem! They had me bring in my extra Crown and OEM timing chain covers to see which one will be the best. So far they like the OEM, but since that will be the last thing to go on, they're going to spend a little more time going through it to make sure that the oil pressure will be up to snuff.

$3550 will get my engine back to me, completely disassembled, cleaned, spec'd out, and reassembled into a long-block. It's about $1500 more than I was hoping for at the bottom end, but $450 less than my OMG-I'm-going-to-die-and-$h!t-a-brick price. :crazy:

Best part: they're going to work on it next week, and I should have the engine back around the week of 9/12/11.

Which means: I need to get back in the garage to finish my electrical, build my traction device, and get the top mounted. :evil:
 
Excellent, sorry about the $$$, but sounds like it's in the right hands.
 
Very nice looking build. That full hard top really adds to it. I think you will like it even more this winter. How is your heater? I have thought about mounting a rear floor heater out of a FJ40 to keep the truck warm in back.

Regards

Jim
 
Alaskantinbendr said:
How is your heater? I have thought about mounting a rear floor heater out of a FJ40 to keep the truck warm in back.
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I did the Chevy blower-motor upgrade several years ago, and that made the single biggest difference possible. It was way more than I could have imagined.

Now that it's in the 8, I don't know how it's going to be because I've done a ton of other things as well: I replaced the duct to the defroster (the one I pulled out of the carcass was literally shredded; I have no idea how it was ever directing heat to the windshield), and completely re-sealed the heater and air boxes. I also added seat-heaters when I did the upholstery. The tub is 1/8" aluminum, Rhino-lined inside and underneath, so that should add to the insulating factor.

I'm probably going to add a Mojave or RedDot, but I haven't gotten there yet. We'll see how this first winter goes before I do the extra work. If/when I add an auxiliary heater, I'm probably going to design a new center console around it so that it'll mount and blow directly on the rear seat area.
 
Minor update, no photos:

The machine shop finished the engine, minus the paint. I ordered the Seymour AMC Blue through Bulltear, but they got a clear-coat shipment and sent several customers those by mistake since they ONLY stock AMC Blue. Props to Bulltear since they sent out the correct paint priority mail without any additional problems or charges, and it arrived when they expected it to! I dropped off my Centerforce pressure plate for a local rebuild this morning, and am about to order the Advanced Adapters pilot bushing. If all goes well, the engine will be back in next week. I will have a photo when it's painted and pretty.

In the meantime, I've confirmed that my blower motor died, so I have to pull the box back out and and figure out what happened. I'm hoping that it's just a ground or something silly, but either way I'm yanking the box. Might as well do it while the engine is still out.
 
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My engine builder decided they need to stock some AMC-blue paint!

It's home now, but I don't have the engine hoist yet so it's still sitting in the trailer strapped to a pallet.
 
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And it's home!


mysunnshine said:
Now you need this-
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I would LOVE the Edelbrock MPFI system, but it's WAAAAY out of the price range right now. The 401 rebuild was something completely unexpected. I spent $1200 or $1500 on my Holley ProJection 4Di back in 2000, and it's still humming along. I'm going to stick with what I've got for now, at least as long as the old laptop and software hold up. In the meantime, I still need to build bumpers and a traction bar.
 
Nice build. I'm finishing up mine as well.

What diameter tail lights are those, 3" or 4".

Also in two weeks I'm having my exhaust done and taking him the mufflers/dumps. I'm sure I need a passenger hanger. Where did you buy your or did it just get fabed up.

Thanks,
Jim

Getting close after 7yrs :)
 
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