Questions on 360 Rebuild

[BlaSSer]

First off hello all, newbie here, lots of great info here!

I just finished the tear down of a 360 I picked up. Motor for the most part is in great shape, very recently rebuild. My goals are a DD with about 300ish HP. Nothing crazy, just a decent running motor. Found some issues with the bottom end and not sure how to proceed. Most of the bearings were golden in the middle so I'm guessing some oiling issues. My best guess is that they didnt prime the pump before trying to start it becuase it couldn't have been run long. It was bored 40 over so it obviously has new pistons.

1) One of the rods was installed backwards so the piston was correct but the taper was on the inside, instead of out.

2) All of the rods there out of order in comparison to their stamped numbers.

3) One fo the cylinders looks "washed" pretty good from fuel. The cylinder walls look ok but the piston shows some scuffing. That same piston and rod assy. were VERY tight, it took above normal effort to pivit the rod on the wrist pin.

What do you guys thing? Does the rods being out of place matter since the pistons were new? Also, can I just replace the one piston that has some scoring or do I have to replace them all?

Thanks for any help!
Craig

[82Waggy]

Rods being out of order may or may ot make a difference, depending upon if they were all resized when the rebuild was done - not to say that putting them in out of order is good practice.

However, if the cylinders were honed to match the tolerences of each piston for proper wall clearance, as is good practice, and the pistons were then installed on the corresponding rod to indicate the proper bore, then placing them out of order could very well have resulted in improper clearances from one bore to the next.

In addition to the above, the fact that one rod was also installed backwards suggests that at least the assembly of this engine was done in a haphazard fashion.

Regarding the bearing condition and stuck piston pin, hopefully this was the result of an initial dry start and that no serious damage was done to crank journals, etc.

Probably best to tear it all down and start measuring everything to see what you got and if you can juggle things around to make some sense of it all - replace and remachine what you need to.

[jeepsr4ever]

When you have your rods on the wrong wide the oiler in the side of the endcap is facing the wrong way. This can cause damage to the cylinder wall is some cases but rarely. If you could post a pic of your piston is would be very easy to tell what happened. 82 is right that it isnt critical most times if they are mismatched. The AMC pistons have a offset wrist pin but they have twin reliefs on both sides of the piston so you can install them facing forward or backwards and on a non-performance application it isnt critical. My guess is that this engine was slapped together.

[AMX69PHATTY]

Does one dare to bring up the discussion about that the Rod Bearings
are no longer manufactured with the Oil Squirter notches ?

BlaSSer,

do the old Connecting Rod Bearings have a semi-circular cut-out
in the abutting ends opposite the locating tang ?
When the two halves are installed they create a round hole about 1/8" dia.
This feeds oil out to an Oil Squirter hole in the split line
between the Rod Cap and Rod that's supposed to oil the piston pin.
It's like a little "V" notch in one side at the split line.
Don't think it's the issue, just curious is all.

[jeepsr4ever]

Does one dare to bring up the discussion about that the Rod Bearings
are no longer manufactured with the Oil Squirter notches ?

BlaSSer,

do the old Connecting Rod Bearings have a semi-circular cut-out
in the abutting ends opposite the locating tang ?
When the two halves are installed they create a round hole about 1/8" dia.
This feeds oil out to an Oil Squirter hole in the split line
between the Rod Cap and Rod that's supposed to oil the piston pin.
It's like a little "V" notch in one side at the split line.
Don't think it's the issue, just curious is all.

:?: .......oops

[BlaSSer]

I'm not sure off the top of my head. I'll take some pictures tonight and post them. Thanks for everyones suggestions!

[BlaSSer]

Ok, yes the bearing did have the 1/8" hole on the V side. Here are some pictures..

http://www.craignheather.com/gallery/gallery%2FCars_Jeeps_%26_Trucks%2FProject_Beast%2F 360%20Build%20032.jpg

http://www.craignheather.com/gallery/gallery%2FCars_Jeeps_%26_Trucks%2FProject_Beast%2F 360%20Build%20031.jpg

All the pictures so far can be seen here.. http://www.craignheather.com/gallery/gallery.asp?categoryid=56

[Mudrat]

BlaSSer, you've got a nice start compared to some of us :t: In pics #21 & 22 you can still see the cross hatching from the last honing job!!! :idea: ... when they bored it 40 over ... pics #23 to #27

'Rat

[jeepsr4ever]

That looks like it was overheated. Usually you get the thicker parts of the pistons rubbing the walls if it was overheated

[questmann]

hey guys, I'm working on this motor project with Blasser, it's for my jeep. After reading the 19 pages of the collapsed piston thread I'm determined to measure, spec out and understand EVERYTHING about this motor. What is a good resource to find out all the critical measurements for a stock 360 from an 87 grand wagoneer. This is my first complete rebuild and I wanna be ejamicated when I'm done.

p.s. where the hell can I get replacement connecting rods!

[jeepsr4ever]

If you need new replacements I can get them but if you are just looking for a few used replacements ask in the wanted section.

[AMX69PHATTY]

There's a little booklet in reprint called "Performance American Style"
that has a whole lot of specs and info on AMC motors.
It's available from a number of sources including www.AmericanPartsDepot.com
in West Manchester Ohio west of Dayton (937) 678-7249
Another book is the "AMC Power Book" from www.planethoustonamx.com
I haven't seen this one though but it's supposed to be pretty good.

Rods in a 360 are the same as those in a 304 so you could find a junkyard 304 for used ones.

Of course there's always eBay.

[questmann]

I'd feel better with new replacement rods if they're affordable. I'll see if I can order that book you mentioned. I originslly chose the AMC for my motor swap because they are cheap out of the yards and it bolts to my tranny with no adapters but now it's more about the original Jeep heritage factor and being part of an exclusive group.

Back to the rods, how can the rods be checked to see if they are still good and straight? I wanna limit the amount of work I need done by other people, I wanna know the ins and outs of every part of this motor and understand how it all works together. My head is still overflowing from the 19 pages I read. Great stuff though.