Are you pressing the pins in using sockets and a vice? Just curious how that is working. I guess you need some kind of Stop or line to indicate when you are centered ...
As you can see, connecting rod griped the wrist pin before I could properly center it and now we have about a 1/4 inch off-center.
Unless the design of wrist pins and connecting rods has changed a heckuva lot since I last rebuilt an engine, the connecting rod should glide freely over the wrist pin. Did you oil everything up prior to pressing the wrist pin in? Seems to me you had the connecting rod cocked off on a slight angle as you were trying to press the wrist pin through the piston. In my experience, the connecting rod needs to be wiggled back and forth while starting the wrist pin through it... to help avoid the "jam" you're now in.
Just push the pin back out and try it again.
[This message has been edited by Patrick (edited 06-08-2020).]
I prelubed everything with assembly lube. I also had the wrist pin pre-inserted into the first bore on the Piston. That way once the connecting rod is ready, I place it into the Piston and then push it through.
As for the adjustment, I was planning on putting a long bolt through it with a large thick washer and nut on the other end. Then place a vice between them and crank it through with a ratchet.
That way once the connecting rod is ready, I place it into the Piston and then push it through.
Were you wiggling the connecting rod during this process... to make sure the pin was going through straight and that the rod continued to move freely on the pin?
Don't force the pin through if the connecting rod is "stuck" on the wrist pin. Push/tap the pin out until the rod is free to move again... and then start over.
Were you wiggling the connecting rod during this process... to make sure the pin was going through straight and that the rod continued to move freely on the pin?
Don't force the pin through if the connecting rod is "stuck" on the wrist pin. Push/tap the pin out until the rod is free to move again... and then start over.
I'm not sure I understand what you mean.
After I took the connecting rod off the flame and pushed the wrist pin through, there was a split second of adjustments as I was lining it but it eventually slid through smoothly until the connecting rod cooled and gripped the wrist pin securely.
That being said, I can freely (and smoothly) move the wrist pin with the connecting rod attached left/right/forward/back. All I need is to center it.
Originally posted by Patrick: Unless the design of wrist pins and connecting rods has changed a heckuva lot since I last rebuilt an engine, the connecting rod should glide freely over the wrist pin.
What you're describing is a floating wrist pin.
OP is talking about wrist pin that is press-fitted into the connecting rod (but free to rotate in the piston). I think that press-fit pins are pretty commonplace.
The shadetree mechanic method of assembling these is to freeze the pin to shrink it, heat up the connecting rod to expand it, and then quickly drop the pin into the hole. You have a number of seconds to get everything centered before the temperature differences subside and the connecting rod permanently grips onto the wrist pin.
With a hydraulic press, the pin can be pushed to the correct spot using the appropriate fixturing to support the piston (I don't know what this entails exactly). The local engine rebuilding shop should be able to handle the job.
[This message has been edited by pmbrunelle (edited 06-08-2020).]
With a hydraulic press, the pin can be pushed to the correct spot using the appropriate fixturing to support the piston (I don't know what this entails exactly). The local engine rebuilding shop should be able to handle the job.
Ok so (with a press) moving the wrist pin over a little to center it won't be problematic or do I need to remove it entirely and redo the process again?
OP is talking about wrist pin that is press-fitted into the connecting rod (but free to rotate in the piston).
Oh... Thanks for clarifying that. I've only ever installed floating wrist pins. I wasn't even aware that there were wrist pins that rotated in the piston, but were stuck in the connecting rod. Damn, never too old to learn new stuff I guess.
When the wrist pin is pressed into the connecting rod, no additional clips are needed to secure the wrist pin, so that saves parts, and thus money.
Most* of the time, pressing A into B is simple to do in mass production.
*When I arrived at my job fresh out of school, I took it for granted that press-fitting item A into item B was going to be a walk in the park. I didn't really study the problem enough, a production line was built, and then inserting A into B resulted in many scrapped assemblies ($$$) and a bunch of unhappy folks. I ended up learning about the importance of good alignment when pressing things together...
[This message has been edited by pmbrunelle (edited 06-08-2020).]
Thanks for clarifying that. I've only ever installed floating wrist pins. I wasn't even aware that there were wrist pins that rotated in the piston, but were stuck in the connecting rod. Damn, never too old to learn new stuff I guess. 
