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rod bearing binding?

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Old 04-22-2010, 11:29 PM
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Mike C.
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Yea but he's saying it does turn easy and then gets more difficult at a certain point. The valve springs/cam should make the resistance vary with crank position. I just never made any notes on how many degrees ATDC does this occur and I sure can't remember...
Old 04-22-2010, 11:37 PM
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Van
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Originally Posted by Mike C.
Yea but he's saying it does turn easy and then gets more difficult at a certain point. The valve springs/cam should make the resistance vary with crank position. I just never made any notes on how many degrees ATDC does this occur and I sure can't remember...
4 sets of valves... 2 crank revolutions per cycle... that means the spring tension on the crank will be every 180 degrees. (And the tension usually comes when it's on the exhaust stroke and the intake valve opens before the exhaust valve closes.)
Old 05-04-2010, 04:54 PM
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markvtg
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Default Rod bearings binding? - Resolved

Thanks to all that posted suggestions. Painfully I disassembled, seems like half the car to inspect my rod bearings. The issue, I believe, as I previously mentioned, was an overtightening of the nuts that hold the bearing caps. After inspecting the bearing caps, they were all aligned by the numbers. Though I did remove the caps and relubed the bearings, I tightened everything back up, according to specs. I did add a step to ensure that the engine turned over. I pulled the fuel pump fuse, installed the timing belt and start motor and then cranked the engine for a couple of rotations, no problem. Now it is all buttoned up and running smoothly.
Old 05-04-2010, 07:06 PM
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krystar
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glad to hear it all worked out in the end with no damaged parts
Old 05-04-2010, 07:56 PM
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carlege
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Originally Posted by markvtg
Thanks to all that posted suggestions. Painfully I disassembled, seems like half the car to inspect my rod bearings. The issue, I believe, as I previously mentioned, was an overtightening of the nuts that hold the bearing caps. After inspecting the bearing caps, they were all aligned by the numbers. Though I did remove the caps and relubed the bearings, I tightened everything back up, according to specs. I did add a step to ensure that the engine turned over. I pulled the fuel pump fuse, installed the timing belt and start motor and then cranked the engine for a couple of rotations, no problem. Now it is all buttoned up and running smoothly.
what was the cause of over torquing them? Did you just not torque to specs the first time?
Old 05-21-2010, 06:29 PM
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markvtg
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I used a craftsman click type torque wrench, it was reading about 10lbs less than it was actually torquing at the required rod bearing nut specs.
Old 05-21-2010, 07:49 PM
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Jfrahm
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I think you could torque those bolts nearly to yield and not change the shape of the big end. Maybe a bearing was clocked a bit or had debris on the backside or something.
Old 05-21-2010, 10:51 PM
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Perry 951
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Originally Posted by Jfrahm
I think you could torque those bolts nearly to yield and not change the shape of the big end. Maybe a bearing was clocked a bit or had debris on the backside or something.
I agree. Cap and rod end is a lot of material to deflect at 100ft/lbs much less 10ft/lbs. Heck, 10lbs extra could be from frictional losses on the nut itself! Probably had one just a hair off center or not locked into the tab.



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