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vwsteve Samba Member
Joined: March 18, 2004 Posts: 1047 Location: Virginia
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Posted: Tue Dec 27, 2011 5:34 pm Post subject: Piston Pin Retainers |
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What issue would not using any cause? |
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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76902 Location: Sneaking up behind you
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Posted: Tue Dec 27, 2011 5:42 pm Post subject: |
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The wrist pin will walk out and gouge the cylinder wall which will lead to loss of compression and engine failure. _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare |
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anthracitedub Samba Member
Joined: June 20, 2007 Posts: 3241 Location: Michigan
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Posted: Tue Dec 27, 2011 5:42 pm Post subject: |
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Your Wrist pin would slowly work its way over and rub the wall of the cylinder and wear a groove into the cylinder... Eventually causing engine failure. |
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Joey Samba Member
Joined: August 12, 2005 Posts: 5366 Location: Nova Scotia - Canada
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Posted: Tue Dec 27, 2011 5:43 pm Post subject: |
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The pin moving back and forth and hitting the cylinder wall and gouging it all to hell. _________________ Joey
‘60 Kombi - '74 Bus - '79 Panel - '65 Beetle |
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61SNRF Samba Member
Joined: March 29, 2009 Posts: 4657 Location: Whittier 90602
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Posted: Tue Dec 27, 2011 5:45 pm Post subject: |
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Severe cylinder wall damage.
The wrist pins must be held in the center of the piston, otherwise they are free to float back and forth, thus scoring and damaging the cylinder walls. _________________ -Bruce
An ounce of prevention is worth a pound of cure. |
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vwsteve Samba Member
Joined: March 18, 2004 Posts: 1047 Location: Virginia
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Posted: Tue Dec 27, 2011 5:58 pm Post subject: |
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Does anybody have any pics of the damage? I was thinking it would throw the piston out of balance when it slides to one side, but I can't picture it tearing up the cylinder. |
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HRVW Samba Member
Joined: May 01, 2011 Posts: 2531 Location: Rosarito, Mexico
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Posted: Tue Dec 27, 2011 6:27 pm Post subject: |
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Imagine the damage on the side of your car if it were keyed by someone.
A wrist pin scoring the cyl would be the same but on a LARGER scale.
Compression LOSS and burning of oil will be the end result having done many repairs to such damage at my shop. |
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wayne1230cars Samba Member
Joined: April 05, 2010 Posts: 2685 Location: Canada
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Posted: Tue Dec 27, 2011 6:29 pm Post subject: |
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Not exactly what you are looking for but this is what happens when a circlip ring breaks. I did not take a photo of the cylinder but it was badly gouged. The amazing thing was this 36 hp engine was still running pretty well. The motor had some work done to it before I bought the car. I never did find the broken off piece of the circlip. [img][/img][img][/img] |
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67type0ne Samba Member
Joined: February 22, 2008 Posts: 426 Location: Alcolu SC, Oakdale CA
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Posted: Tue Dec 27, 2011 6:32 pm Post subject: |
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vwsteve wrote: |
Does anybody have any pics of the damage? I was thinking it would throw the piston out of balance when it slides to one side, but I can't picture it tearing up the cylinder. |
You could conduct an experiment on your motor and post some pics for us |
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61SNRF Samba Member
Joined: March 29, 2009 Posts: 4657 Location: Whittier 90602
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Posted: Tue Dec 27, 2011 7:20 pm Post subject: |
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vwsteve wrote: |
I was thinking it would throw the piston out of balance when it slides to one side, but I can't picture it tearing up the cylinder. |
It's a boxer engine, it wouldn't effect the balance if it moved sideways, nor an inline either for that matter.
There is more than one very experienced engine mechanic here telling you what would happen, believe it _________________ -Bruce
An ounce of prevention is worth a pound of cure.
Last edited by 61SNRF on Tue Dec 27, 2011 7:23 pm; edited 1 time in total |
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vwsteve Samba Member
Joined: March 18, 2004 Posts: 1047 Location: Virginia
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Posted: Tue Dec 27, 2011 7:23 pm Post subject: |
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The reason I ask is because I just pulled a head to remove a piece of metal that fell through the carb and was pounding the top of the piston. The one cylinder came loose from the case, so I pulled it out to reseal it to the case. In doing so, I noticed there were no piston pin retainers. I checked the other cylinder and it didn't have any either. I can put them in, but the other side probably doesn't have any either, so I would have to tear the other side down also. The cylinders show no signs of damage, but there aren't many miles on the engine either. I see the damage in the pic above with the broken retainer getting wedged in between the piston and cylinder, but that is totally different in my mind. Has anyone actually seen damage from a pin itself rubbing the cylinder? I just can't imagine it. I still wonder if it isn't more of an issue with balance being off. I am not looking for an argument, just trying to decide whether adding them is worth tearing the other side of the engine down. Thanks for your input. |
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61SNRF Samba Member
Joined: March 29, 2009 Posts: 4657 Location: Whittier 90602
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Posted: Tue Dec 27, 2011 7:33 pm Post subject: |
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vwsteve wrote: |
Does anybody have any pics of the damage? I was thinking it would throw the piston out of balance when it slides to one side, but I can't picture it tearing up the cylinder. |
Do you have computer?
Just did a Google image search on mine for "Loose wrist pin damage". Got this from a motorcycle forum on page one. Same part, same effect on an ACVW...
_________________ -Bruce
An ounce of prevention is worth a pound of cure. |
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drscope Samba Member
Joined: February 19, 2007 Posts: 15273 Location: Baltimore, Maryland USA
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Posted: Tue Dec 27, 2011 7:53 pm Post subject: |
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just trying to decide whether adding them is worth tearing the other side of the engine down.
How can I put this nicely? DON'T BE AN IDIOT! Pull the other side off and correct the problem BEFORE it becomes one.
Even if it is just a balance issue, would you run it like that? Do you think that the engine shaking is just a small annoyance? Or do you think it shaking itself to death is an issue you should deal with?
News flash! The piston does NOT touch the cylinder wall during normal operation! It is riding on a film or oil.
If the wrist pin walks over and contacts the cylinder wall, it's death.
At highway speeds the engine is turning over 3,000rpm. Divide that by 60 seconds and the piston is going up and then down 50 times every second. Do you think that may do some damage?
Man you are right there! The engine is out and on the stand! FIX IT!
Unless you like fixing busted stuff and buying parts ALL the time. _________________ Mother Nature is a Mean Evil Bitch! |
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