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Unread 01-23-2013, 01:23 PM   #46
Matt1981CJ7
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Greek,

My Haynes manual says 33 ft-lbs for the AMC 304 and 360. The 401 gets 39 ft-lbs.

Did you try Shawn's suggestion of rotating the assembly after each rod is connected? Does it bind all at once, or is it a cumulative thing after each rod is bolted on?

Again, using the old bearings is not an option. The crank has clearly been turned, or the .020 bearings wouldn't be as close to spec as they are. The old bearings will be way too loose. I'm afraid your crank guy may have to take another 1/2 thousandths off the rod journals. The journals should be 2.0934 - 2.0955" in diameter, minus whatever they've taken off already.

Good luck,

Matt

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Unread 01-23-2013, 01:27 PM   #47
Greekcj5
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I'll Mic the journals tonight. Thanks for your help Matt.
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Unread 01-23-2013, 01:29 PM   #48
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Haven't tried one piston at a time yet. Wife's going on vaca tomorrow so she wanted some us time before she leaves. Only had time to plastigauge them. probably won't be able to try it till tomorrow night.
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Unread 01-23-2013, 03:29 PM   #49
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Hey gents. So i'd like you guys to verify something for me if you could. I found that the factory journal diameter is between 2.0934 - 2.0955. I mic'd the journals and got a range of 2.081 - 2.084. maybe I'm an idiot but to me it doesn't look like he ground down .020 like he said he did. At the most it looks like .010 - .015. Could this be the problem?
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Unread 01-23-2013, 03:36 PM   #50
Matt1981CJ7
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Glad "you found" the factory diameters in my post above....just yanking your chain a little.

It does appear your crank was only turned .010 under. That's pretty standard.

I'm still confused by your plasti-gauge numbers, however. If you used .020 bearings with a .010 under crank, there would be no clearance at all. They'd be tight.

Matt
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Unread 01-23-2013, 03:45 PM   #51
Greekcj5
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Dude I'm sorry haha. I didn't even notice you putting the measurements earlier. I didn't torque them to 33 either so maybe that 3ftlbs makes that much of a difference. Not sure but i know now my machinist was on something if he mic'd them before giving them back to me.
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Unread 01-23-2013, 03:47 PM   #52
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Also, the plastigauge's limits were only .001 - .003 so maybe some of those that were .001 were less its just it wouldn't flatten that much. Is that a possibility?
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Unread 01-23-2013, 03:54 PM   #53
Matt1981CJ7
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It's probable.

Your journals sound like they were well-turned, but only at .010. Tell your machinist to back away from the bong.

I bet a set of .010 bearings will be the ticket.

Matt
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Unread 01-23-2013, 04:05 PM   #54
Greekcj5
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As long as he pays for them. I already paid 40 for the .020s. Thanks Matt. I'll post my findings
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Unread 01-23-2013, 04:25 PM   #55
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i have been reading this thread and i have notice you didnt mention anything about stamping the main caps with numbers in order to have them in the correct location when you tore it down, also did you have the main caps aligned honed? also did you check the rods and mains for out of roundness? also i do know some manufactures would have 1 to 4 different bearing sizes in one engine and they would be in .001-.006 depending on the location because of machine/ tool wear from the machining process at the factory so they would measure each journal when assembling and then use the right bearing,

also there is a specific order that your main caps need to go in,
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Unread 01-23-2013, 04:34 PM   #56
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so now u need to lay block side main bearings in WITH LUBE ONLY ON THE CRANK SIDE OF BEARING, then install your rear main cap with the other half of the bearing in main cap and then TQ it to the proper spec the install the front main cap with its bearings properly lubed and then tq it down and then try to spin the crank by hand its should spin very smooth, if it does not then that is the wrong cap for the front, but first u need to find out if that is the right set of bearings for that crank that has been turned down
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Unread 01-23-2013, 04:43 PM   #57
Greekcj5
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Yeah the main bearing caps and rod end caps are stamped and in the right spots. The crank turns smoothly with main caps torqued and the plastigauge mic'd at roughly .0018 for 1-4 and .0025 for rear main. I called the machinist and told him what the journals mic'd at and he's ordering he some .0010 bearings. He said he's never had this happen before so i guess I'm just the lucky one.
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Unread 01-23-2013, 04:44 PM   #58
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Once i get the new bearings I'll post my result. Thanks again everyone
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Unread 01-23-2013, 05:08 PM   #59
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good deal hopefully .010 work out for you rebuilding engines can be a pain in the butt sometimes, i usually get handed a block and a bucket full of parts and they expect you to work a miracle lol,
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Unread 01-23-2013, 05:14 PM   #60
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Did the crank turn freely before attaching rods? Did you have main bearing caps line honed? are rod caps still on same rods. Were they honed? I gaurantee one of these is youe issue. Also, do not force it to turn, you may gouge something.
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amc 304 , cj5 , crankshaft , engine rebuild

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