I was checking the end play getting ready to install my 2056 and could not get enough play.
I know I had noticeable play before loading pistons and cylinders, so I took of the the P&C this morning and all the end play returned.
The wrist pin is not rotating in the small end of the rod, only the piston is rotating on the pin. Which means the small rod end wasn’t sized correctly. So the fix is I imagine the rods have to come out of the case and the small end honed to match the pin.
Or can the rod end be honed while still in the case? if so can a DIYer do it or does it need to go to a builder?
Full Version: End play problem discovered
Send a pin (some old guys require 2 pins) to a GOOD automotive machine shop and have 'em do it. You can't possibly hone 'em accurately by hand, ESPECIALLY on the engine.
The Cap'n
The Cap'n
From the "Engine Knocking" thread:
Stu
QUOTE
When I reassembled my engine this last time, I used some rods from the PO and some brand new KB pistons & wrist pins.
I sent in the rods to be rebushed and checked.
The shop complained that I did not send them any wrist pins.
I thought why the hell would they need the wrist pins, arent they all just one size?
Well the shop told me that the rods did not need to be rebushed as they had just been done, BUT they guy said the engine would have probably siezed almost immediately because the wrist pin bushings had not been properly sized after being replaced.
He also straightened one rod for me.
SO.... make sure the wrist pins are not binding in the rod bushing too.
I sent in the rods to be rebushed and checked.
The shop complained that I did not send them any wrist pins.
I thought why the hell would they need the wrist pins, arent they all just one size?
Well the shop told me that the rods did not need to be rebushed as they had just been done, BUT they guy said the engine would have probably siezed almost immediately because the wrist pin bushings had not been properly sized after being replaced.
He also straightened one rod for me.
SO.... make sure the wrist pins are not binding in the rod bushing too.
Stu
Didn't you notice they were tight during install?
Engines that need a hammer to assemble don't last very long. Well oiled machines assemble without any force.
Engines that need a hammer to assemble don't last very long. Well oiled machines assemble without any force.
First time I have done this. It did require a lot of for but I couldn't just slide them in. I didn't know if it was supposed to be tight till things broke in or not.
I guess just one more thing learned on this adventure at least I caught it before there was damage.
I guess just one more thing learned on this adventure at least I caught it before there was damage.
I've always found it best to set end play before installing the pistons and cylinders.
I don't especially like the springiness the P&Cs produce.
Marty
I don't especially like the springiness the P&Cs produce.
Marty
If it took more than the force that could be exerted with your fingers to slide the wrist pins in, the pin bores were too tight.
Assembly is done by feel. If it feels too tight, it is too tight.
Assembly is done by feel. If it feels too tight, it is too tight.
QUOTE(Jake Raby @ Aug 23 2013, 08:20 AM) 
If it took more than the force that could be exerted with your fingers to slide the wrist pins in, the pin bores were too tight.
Assembly is done by feel. If it feels too tight, it is too tight.
You know he is right, if it doesn't feel right it isn't right, end of story. If more people closed there eyes after measuring and actually felt what they were putting together their engines would be much happier.
"You know he is right, if it doesn't feel right it isn't right, end of story."
Except if you have never done it before you do not have a baseline to call "right".
If I asked you to perform a blind mate on a circular avionics connector, could you tell me if it "felt right"?
Jake probably could...
Certain things are based on experience: no experience, no baseline.
Experienced mechanics typically dont need torque wrenches for 90% of things. If you have never even operated a torque wrench, that is impossible.
Stu
Except if you have never done it before you do not have a baseline to call "right".
If I asked you to perform a blind mate on a circular avionics connector, could you tell me if it "felt right"?
Jake probably could...
Certain things are based on experience: no experience, no baseline.
Experienced mechanics typically dont need torque wrenches for 90% of things. If you have never even operated a torque wrench, that is impossible.
Stu
QUOTE(stugray @ Aug 23 2013, 09:16 AM)
If I asked you to perform a blind mate on a circular avionics connector, could you tell me if it "felt right"?
Stu
With my background in aviation I could most likely perform as you have requested, you know like behind a bulkhead, where you can't see anyway but I do see your point if I asked you to time the Cams and Magnetos on a Merlin you'd probably have difficulty at first.
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