Rod bearing question?
Rod bearing question?
My torque wrench arrive, today, and I immediately started tightening everything right and proper.
The mains seemed to do as they should. When I got to the rods, number one cylinder tightened OK. Number two is a problem. At about 40 or 45 foot pounds, I can still turn the engine by hand (with the fan blade). When tightened to the recommended 55 foot pounds, I can no longer turn the engine by hand. It will turn with a short bar inserted in one of the lightening holes on the counter balance, but not with the fan .
Problem is, I don't what's acceptable, and what isn't.
Am I in trouble?
Gary Fossen
The mains seemed to do as they should. When I got to the rods, number one cylinder tightened OK. Number two is a problem. At about 40 or 45 foot pounds, I can still turn the engine by hand (with the fan blade). When tightened to the recommended 55 foot pounds, I can no longer turn the engine by hand. It will turn with a short bar inserted in one of the lightening holes on the counter balance, but not with the fan .
Problem is, I don't what's acceptable, and what isn't.
Am I in trouble?
Gary Fossen
Yes, I lubed them with a light lithium spray grease. I don't know if it's exactly ten pounds difference in that I didn't check torque at the point where it starts to balk. I could be a bit more of a difference.
I might try one of the sets of old bearings that I removed, and see what happens with those.
As I recall, there wasn't a lot of difference between the two rod journals when I mic-ed them, but I'm not sure of that. I may have to remove both rods, and check a little closer...but not tonight.
Gary
I might try one of the sets of old bearings that I removed, and see what happens with those.
As I recall, there wasn't a lot of difference between the two rod journals when I mic-ed them, but I'm not sure of that. I may have to remove both rods, and check a little closer...but not tonight.
Gary
Good plan. I didn't think about that. I will play with things in the morn, and see where I am. If I don't get it straight, I probably will have to go to town in the PM, and I will get some someplace.
I think I will pull the pistons, and check things again.
In my book, I notice that the "pip" on the rod and cap is suppose to be facing the cam. I put the rods and pistons back in as I found them, but not all the "pips" are on the correct side. Could that make a difference?
Thanks,
Gary
I think I will pull the pistons, and check things again.
In my book, I notice that the "pip" on the rod and cap is suppose to be facing the cam. I put the rods and pistons back in as I found them, but not all the "pips" are on the correct side. Could that make a difference?
Thanks,
Gary
Rod bearing Question
I'vr made a lot af machine slides, which have a clearance of .002"(I don't know what clearance a crank bearing has). When any grease is applied class1 or 2 it will lock it up, because grease takes up about .0025". 10W oil takes up only .0005" so it will slide. My 2 cents worth.
Country 53,
Your have to be close on the clearance figure. One reference says .001 per inch of shaft plus .0005. They measure 2.4980, so I figure .0025 to .003 oughta be right.
I will remeasure everything as soon as I get some coffee in me. I need to check the journals closer to make sure they are round...enough.
I didn't know that about the heavier greases, but intuition led me away from the heavier stuff. It may be, though that the spay-on stuff I'm using is thicker than I thought. I will check that, too.
Thanks,
Gary
Your have to be close on the clearance figure. One reference says .001 per inch of shaft plus .0005. They measure 2.4980, so I figure .0025 to .003 oughta be right.
I will remeasure everything as soon as I get some coffee in me. I need to check the journals closer to make sure they are round...enough.
I didn't know that about the heavier greases, but intuition led me away from the heavier stuff. It may be, though that the spay-on stuff I'm using is thicker than I thought. I will check that, too.
Thanks,
Gary
Gary,
If all the pips are not on the same side, then you have it assembled wrong. The tabs on the bearings have to be on the same side. The rod was machined with the cap in this position, putting it together the other way will definitely cause problems, and will absolutely cause the problem you are having. You better look everything over real carefully to make sure that you have not damaged the crank, the rod, or the bearings.
Lavoy
If all the pips are not on the same side, then you have it assembled wrong. The tabs on the bearings have to be on the same side. The rod was machined with the cap in this position, putting it together the other way will definitely cause problems, and will absolutely cause the problem you are having. You better look everything over real carefully to make sure that you have not damaged the crank, the rod, or the bearings.
Lavoy
To all the uninitiated out there, or rank amatures, as I am:
I reinstalled the pistons so as to have the pips facing the cam side, as the book instructs. Then I changed the rod caps on the assumption that I may have mixed instead of matched. Apparently, that was the problem. Now, everything turns as it should when fully torqued.
Lavoy,
The bearings appear OK, but I really don't know what might indicate a damaged bearing. Any pointers?
Gary
I reinstalled the pistons so as to have the pips facing the cam side, as the book instructs. Then I changed the rod caps on the assumption that I may have mixed instead of matched. Apparently, that was the problem. Now, everything turns as it should when fully torqued.
Lavoy,
The bearings appear OK, but I really don't know what might indicate a damaged bearing. Any pointers?
Gary
Lavoy,
I saw none, and I expect the bearings would be the first to go...before the rods, and then the crank.
I will go with what I have.
For the record, it appears that there is something in the neighborhood of one thousandth between the old and the new, so they weren't really that bad. Now, it should out-last me.
Thanks,
Gary
I saw none, and I expect the bearings would be the first to go...before the rods, and then the crank.
I will go with what I have.
For the record, it appears that there is something in the neighborhood of one thousandth between the old and the new, so they weren't really that bad. Now, it should out-last me.
Thanks,
Gary
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