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uhm......are my pistons in backwards?

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Old Nov 5, 2014 | 06:50 PM
  #16  
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From: Clarksville, TN
Originally Posted by robbyredneck
ok done being lazy i pulled them and flipped them. on to the next oil leak. thanks for the help guys.
lol sometimes the hassle to have them fix it isn't worth the hassle.
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Old Nov 6, 2014 | 04:01 AM
  #17  
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From: Ireland
Originally Posted by 94AWDcoupe
the piston pin is not centered. it is offset to one side. this is done so piston doesnt rock at top dead center. results in a quieter running engine. with the piston installed backwards there would be noise being created since the offset is in the wrong direction. piston would rock more than pistons that dont have an offset. rods are not directional. they can be installed either way.
not really the rods are designed so the big end bearing tangs are away from the thrust side to do it correctly you have to remove the pins and turn the piston only
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Old Nov 6, 2014 | 04:50 AM
  #18  
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From: michigan
It looks like the valves touched the pistons in the picture.
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Old Nov 6, 2014 | 08:38 AM
  #19  
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From: upstate ny
"touched" is a bit of an understatement.
Attached Thumbnails uhm......are my pistons in backwards?-wp_20141028_002.jpg  
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Old Nov 6, 2014 | 10:30 AM
  #20  
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Originally Posted by robbyredneck
"touched" is a bit of an understatement.
Holy *****. That sucks. I couldnt tell if it was carbon build up or what. But yes, the dots on the pistons should point towards the water pump side. Im not sure if someone mentioned that already. Looks like you have some work ahead of you.
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Old Nov 6, 2014 | 10:46 AM
  #21  
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From: Tampa
Originally Posted by todd6027
not really the rods are designed so the big end bearing tangs are away from the thrust side to do it correctly you have to remove the pins and turn the piston only
wrong. rods can be run in either direction. PERIOD. they are not offset in any way. you can run two tabs forward and two tabs back if you want. only thing that matters is orientation of pistons.
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Old Nov 6, 2014 | 11:30 AM
  #22  
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From: upstate ny
Originally Posted by evolve_VIII
Holy *****. That sucks. I couldnt tell if it was carbon build up or what. But yes, the dots on the pistons should point towards the water pump side. Im not sure if someone mentioned that already. Looks like you have some work ahead of you.
allready spun them 180 and lapped in a new set of intake valves. guides were marginal but still ok. just waiting on a -4 oil feed fitting.
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Old Nov 8, 2014 | 02:57 AM
  #23  
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From: Ireland
Originally Posted by 94AWDcoupe
wrong. rods can be run in either direction. PERIOD. they are not offset in any way. you can run two tabs forward and two tabs back if you want. only thing that matters is orientation of pistons.
disagree on the rods they are put that way for a reason
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Old Nov 8, 2014 | 03:35 AM
  #24  
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From: Tampa
Originally Posted by todd6027
disagree on the rods they are put that way for a reason
and you are wrong. rods are symmetrical. tabs are put in the rod to hold the bearing in place, they have nothing to do with orientation.
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Old Nov 8, 2014 | 05:48 AM
  #25  
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From: Indiana
Don't the rods have a squirter that needs to be oriented so that it faces the higher loaded piston thrust face (in this case the backside of the engine).
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Old Nov 8, 2014 | 11:48 AM
  #26  
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From: Ireland
Originally Posted by 94AWDcoupe
and you are wrong. rods are symmetrical. tabs are put in the rod to hold the bearing in place, they have nothing to do with orientation.
and you are not right and to keep the tabs away from the thrust side stop the bearing turning
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Old Nov 9, 2014 | 05:37 AM
  #27  
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From: upstate ny
the physics put the load in the axis of the rod. i doubt the rod angle gets steep enough to put the load on the tangs. but i have no proof, data or experience either way but what i can tell you is that my car is a totally different animal. idles smooth no leaks, other than the scab weld i knocked off the radiator. shocking that it didnt grenade sooner. can't wait to blast it.
double dot btw the squirters are in the block. if your talking about feed holes i noticed no difference.

Last edited by robbyredneck; Nov 9, 2014 at 05:41 AM.
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Old Nov 9, 2014 | 06:24 AM
  #28  
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From: Indiana
Originally Posted by robbyredneck
the physics put the load in the axis of the rod. i doubt the rod angle gets steep enough to put the load on the tangs. but i have no proof, data or experience either way but what i can tell you is that my car is a totally different animal. idles smooth no leaks, other than the scab weld i knocked off the radiator. shocking that it didnt grenade sooner. can't wait to blast it.
double dot btw the squirters are in the block. if your talking about feed holes i noticed no difference.
You are right, the cylinder pressure loads never actually push the crank against the tanged section of the rod. It rides over that location due to inertial loads, but those r much less. Also if u look at a V engine, rods face both directions, and the tanged side see different inertial loads left bank to right bank (normally its a small difference).

As for the squirters, I know the ones in the block shoot up into the actual piston cavity. I was talking about the oil drilling in the rod (see picture of the stock rod in the link). The drilling in the rod shoots off to the left from the large end bore

http://www.tscomptuned.net/_images/a...n/stockrod.jpg
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