Piston pin bearing replacement

[ldmack3]

I'm replacing my upper rod end bearing sleeves need they need to be honed to fit the new pins/pistons.
The machine shop is asking for a rod center to center measurement which I cannot find in the TMs.
I've got 3 TMs on the engine but nothing going to this detail.
Is there a depot level/overhaul TM available that might have this or does anyone know?
Herc LDT-465-1D
Thanks

 

[davidb56]

maybe

I'm replacing my upper rod end bearing sleeves need they need to be honed to fit the new pins/pistons.
The machine shop is asking for a rod center to center measurement which I cannot find in the TMs.
I've got 3 TMs on the engine but nothing going to this detail.
Is there a depot level/overhaul TM available that might have this or does anyone know?
Herc LDT-465-1D
Thanks

message Gringletuab

 

[ldmack3]

Thanks got it done...I hope.

 

[87cr250r]

There should be no need to know the rod center distance. Sounds like the shop is trying to get you for resizing the big end as well. Rod dimensions don't change over time so if your big end bearings were in good condition when they came out and you didn't mix up the caps there is zero reason to do that unnecessary machine work.

Shops that must warranty your disassembly will insist on resizing the big end bore because they don't know if you mixed up caps. That is all.

 

[ldmack3]

I just took them the two pistons, pins and rods. I think they were just stalling me. First it was the needed a bigger hone,, then the center to center and lastly the caps for the big end. Not many shops around here can do this kind of work so they are busy.

 

[87cr250r]

I am not an expert on engine part refurbishment, I just have a lot of general knowledge about machining. I know they needed the caps for fixturing the rods, the bores need to be parallel. However, they should have been able to measure the center distance. The small end bore prior to installing the bushing is at the correct distance. The center of the bushing after install should be pretty dang close to the point that its center could be used.

 

[ldmack3]

Finally got all the parts back from the shop. got both pistons in and rods torqued.
Doing a final clean before putting the head on and found this.



I pulled the piston and liner back out. Can almost/barely feel the marks. Looks like a ring was not slipping like it should. See nothing on the piston or rings that doesn't look right.

Anyone seen this before?

 

[Mullaney]

Finally got all the parts back from the shop. got both pistons in and rods torqued.
Doing a final clean before putting the head on and found this.

View attachment 882565

I pulled the piston and liner back out. Can almost/barely feel the marks. Looks like a ring was not slipping like it should. See nothing on the piston or rings that doesn't look right.

Anyone seen this before?

.
Uneducated guess, but when rebuilding a small block Chevy, one of the really important measurements for piston rings is the end gap.



A little bit of reading:

Gap Rap: How to Measure and Set Piston Ring End Gap - OnAllCylinders

When you shop for high performance piston ring sets, you’ll no doubt find there are many different sets and styles available (no big secret). And many of these ring sets are …

www.onallcylinders.com

 

[ldmack3]

Could be I suppose. Don't remember or didn't catch it mentioned i the TMs. The other one didn't do it but now is the time to check if necessary....
Keeping in mind we lost 20 degrees for the high in two days. So I'm reaching the end of the outside work (engine) and need to get the head back on and oil pan installed. After that it can keep or work very slowly.

All I lack is finishing up!

 

[87cr250r]

What is the cylinder wall coated with?

 

[davidb56]

if it has a lower oil ring with the two bands on the side of it, they have to be perfectly seated on each side, or it will do that, especially where the ends meet. I use Lucas assembly lube too. its sticky and gets on everything even if you dont touch it somehow.

 

[87cr250r]

I just assembled my 6.5 with the Lucas assembly lube. I don't mind the stickiness but every time I walk in the garage that dang bottle is on its side, leaking. I always used the Lubriplate stuff from work because I end up with cases of it after an overhaul but we've been buying mostly new engines lately.

 

[ldmack3]

if it has a lower oil ring with the two bands on the side of it, they have to be perfectly seated on each side, or it will do that, especially where the ends meet. I use Lucas assembly lube too. its sticky and gets on everything even if you dont touch it somehow.

The oil ring ends were at a different position. The first or top ring ends were at that position. I used lots of motor oil but this time I'll use the assembly lube.
I can't see anything I can do as a fix. I will reassemble with the ring ends in a different position.

 

[87cr250r]

The oil ring mistake most make is that the ends of the expander spring must butt. They must not overlap. The gap location is unimportant.

 

[ldmack3]

Good point. I did not check that when it came back from the machine shop. They had to take the rings off for a different reason.

Thanks

 

[davidb56]

I just assembled my 6.5 with the Lucas assembly lube. I don't mind the stickiness but every time I walk in the garage that dang bottle is on its side, leaking. I always used the Lubriplate stuff from work because I end up with cases of it after an overhaul but we've been buying mostly new engines lately.

Same here???????? I wonder if they made the bottle to intentionally spill, so we have to buy more......sneaky bastards, must be made in china.