Piston pin bushings

[gingrass179]

Hey guys getting everything wrapped up on my short block build. engine is in the machine shop. I was going to use nmb2 pistons but my cylinders would have already been at the high end of the tolerance. so I bought new pistons. My question is about the pin bushings. I ordered some from sealed power. but once they got here they were steel and not one piece?! Some others I have seen are a one piece copper? Which ones would you guys go with? I'll get pics up in a second...will buy the coppers if anyone feels there's a difference im mainly worried is the split gonna damage or wear the wrist pin or connecting rod?

 

[gingrass179]

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[idiabuse]

I would use the steel it will last just fine for you. Did you resize the big end of the rod? hope you did.

 

[riotwarrior]

I'd duplicate what the factory uses, then go from there.

 

[gingrass179]

Ya they had to cut the crank .010 and the factories are a 1 piece copper

 

[riotwarrior]

Ya they had to cut the crank .010 and the factories are a 1 piece copper

Probably a Bronze bushing actually and once installed will need to be sized correctly for each piston pin just like Big end should be done too!

 

[idiabuse]

I would never waste my time in any engine not resizing the big end on the rod. unless you like to add a remove&replace engine on top of crank reground new bearing and rods being resized or replaced

 

[icanfixall]

Please do resize the big end and see if these steel looking bushing really are made from steel. No matter what they will have to be sized for the pins and the joint wont hurt the pin either. But, you can try international for the oem bushing too. Where did you fine these after market bushing of question.

 

[OLDBULL8]

They reground the crank 0.010 under. Did they grind the mains also? If they did, you need a whole set of rod and main bearing inserts for 0.010 undersize. When you install the bearings, use plastigage to check clearance. Rod bearing clearance 0.0011 to 0.0026, Main bearing clearance 0.0018 to 0.0036. Use shims on the caps to get the correct clearance. Piston clearance is 0.0055 to 0.0075.

 

[Knuckledragger]

The rods can afford a lot of attention. Mine were rebuilt and balanced. Big ends were out of round by .0015.

The bushings you show are one piece, they just have an exposed seam, no problem. Actually, it is probably better for the wrist pin, allowing a little extra oil to stay in the bushing area. No matter which style you buy, the bushings all have to be machined and honed to size after installation anyway.

Try to avoid using shims if at all possible, especially on crank caps. That is not the best way to adjust bearing clearance. Align boring and honing is the way to do it.

 

[OLDBULL8]

Try to avoid using shims if at all possible, especially on crank caps. That is not the best way to adjust bearing clearance. Align boring and honing is the way to do it.

I agree with that whole heartedly, just seems like he is going about rebuilding the wrong way, I may be mistaken. Every thing should be taken to the machine shop for fitting and balance. It doesn't appear he is doing that.

 

[riotwarrior]

Ok this is a first, I"VE NEVER HEARD OF SHIMMING CAPS FOR BEARING CLEARANCE.

RE machine as needed ONLY no shims...

JM2CW

but what do I know....

 

[icanfixall]

I have been familiar with main shims for many years. Its a short cut for a web thats not correct. align boring or align honing is the only true way to make the crank spin freely in the bearings.

 

[gingrass179]

Yes line bore is done that's how we know they had cut .010. the machine shop gets everything as soon as I get it. Right now they have block crank rods new pistons pins pin bushings and cam bearings....getting my rings from total seal since they are local too me and haven't got bottom end bearings yet

 

[icanfixall]

The statement of... " Yes, line bore is done thats how we know they cut 0.010". A machined crank wont tell you the block needs to be align bored or honed. Only measuring it will tell you that. Please also deck the top of the block to even up everything there too.