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360 assembly

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Samuelsc360 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Samuelsc360 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/15/2018 at 2:07pm
Plastiguage says .002 which is within spec.  
1971 SC360
1973 Ambassador Sedan 360
1973 Hornet X 360
1973 Javelin AMC 401
1975 Sportabout X 258
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SC397 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/15/2018 at 3:46pm
Originally posted by Samuelsc360 Samuelsc360 wrote:

Frank
That would make me mad also. The pistons are installed correctly on the rods. The crank will turn with the rod caps torqued. 


Sorry I didn't see this before: "The crank will turn with the rod caps torqued."

So does that mean that when you install the rod and piston assembly, it does not turn? If so, check the clearance at the bottom of the piston at the crank throw.


Edited by SC397 - Jan/15/2018 at 3:51pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Samuelsc360 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/15/2018 at 3:49pm
Originally posted by SC397 SC397 wrote:

Originally posted by Samuelsc360 Samuelsc360 wrote:

Frank
That would make me mad also. The pistons are installed correctly on the rods. The crank will turn with the rod caps torqued. 


Sorry I didn't see this before: "The crank will turn with the rod caps torqued."

So does that mean that when you install the rod and piston assembly, it does not turn? If so, check the clearance at the bottom of the piston at the crank throw.
The pictures are gone but you can get the idea.
http://www.ifsja.org/forums/vb/showthread.php?t=177234
It WILL turn with the rod caps torqued. As I torque the main caps, it gets progressively tighter until it won't turn at all.
1971 SC360
1973 Ambassador Sedan 360
1973 Hornet X 360
1973 Javelin AMC 401
1975 Sportabout X 258
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SC397 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/15/2018 at 3:55pm
Was the block Line Honed, or checked for Line Bore?
At this point, I would be taking all of the parts back to the machinist and have him double check all of the clearances.

Edited by SC397 - Jan/15/2018 at 4:00pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2018 at 6:20am
Bent crank??? If the bearing clearances are good you're running out of possibilities fast. Either a main cap is in the wrong position or the crank has a slight bend to it -- only possibilities I can think of.  I understand the line-hone questions, but if it wasn't line-honed everything should go back in and turn, with proper bearing clearance. Block doesn't move, but crank can. It can have an imperceptible bend and cause things to be tight, or one or more of the mains could have been turned with a slight offset. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Samuelsc360 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2018 at 7:27am
I've been in touch with the machinist. He said it was checked for alignment and found no issues. He also suggested that I have it align honed if I didn't get it figured out.  
1971 SC360
1973 Ambassador Sedan 360
1973 Hornet X 360
1973 Javelin AMC 401
1975 Sportabout X 258
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Lyle View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lyle Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2018 at 8:57am
Try to identify the offender:
Take the pistons out and install #1 and #5 main bearings, using plastigage to ensure clearance spec and then lube, re-torque to 75%. Rotate the crankshaft and ensure it runs free. Install #2, #3, #4 one at a time the same way and repeat. If all is good it's not the crankshaft.
Install the 2 pistons and rods on their respective journals and repeat the same procedure until you find the bind.
Tedious but cheaper then paying someone else to go through this.
Honing at this stage is a shot in the dark in my opinion.
It could be one bearing tab not seating for all you know at this point. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Samuelsc360 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2018 at 10:36am
Excellent advice. Will try that next.  
1971 SC360
1973 Ambassador Sedan 360
1973 Hornet X 360
1973 Javelin AMC 401
1975 Sportabout X 258
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Samuelsc360 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2018 at 1:19pm
OK. I took the rods out and took the main caps off. I put the mains back on individually in random order. I torqued each one as I put it on to 75%. #5 was the first. Crank won't turn at all at 75% torque. Loosened it back up and put on the remaining caps in random order torqueing  individually at 75%. The crank turned ,as each one was tightened. At the end the 1 through 4 are tightened to 75% the crank turns. When #5 is tightened it doesn't turn. When I torque #1 to 100lbs, the crank doesn't turn. I appears the 3 center ones are OK.
1971 SC360
1973 Ambassador Sedan 360
1973 Hornet X 360
1973 Javelin AMC 401
1975 Sportabout X 258
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Lyle Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2018 at 4:01pm
Did you check #1 and #5 with the plasigage?
If you did and the clearance is good, then there is a problem with the crankshaft straightness.
If the clearance is not good then the crankshaft was machined wrong or the bearings are out of spec.
The block should be the last concern if this is a rebuild and it ran fine before.
My bet is they dropped the crankshaft if clearances are good.
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