Ok so i have a gsr block that had 2 bent rods from hydrolock. the crank was undamaged and i replaced the rods with used rods and pistons from a good donor. (I replaced all the rods because the other 2 got bent when pressing off the old pistons, ctr's) so the problem is the crank measured out to 1.7707 on all rod journals. as best as a snap gauge can do the rods bore is 1.8899. this gives me .001 in clearance with the bearing size green that i have. Ive plastigauged it to double check and it reads .001 in. This all sounds good till i removed the bearings, cleaned all the surfaces and reinstalled with assemby lube. the crank is difficult to turn over and the rod will not slip back and forth for a side clearance check. All rods are a #2 and the crank stamping is a C. Just what was in there before. I went back and found the bearing surface polished in streakes going with the bearing rotation, mostly at the edges. right after 10 ftlbs of torque the rod still be slipped back and forth but at 14 ftlbs it can not be. The rod is smooth clean and burr free. I'm stumped I've built motors before and never ran into this, anyone have any ideas outside of taking it to a machine shop(can't afford it) anything might help i've been looking at it way to long and i mihgt be missing the obvious. Thx

 

come on, 51 views and nobody has anything to say?.......

 

The oil clearance is too tight at .001". Simply get a thinner bearing. Get 4 pairs of Hondas Reds and call it a day.

 

yes, but only by .0005 from what i call ideal. the nominal is .0013 to .0020. but still at .001 the crank should have enough clearance to turn over without marking the bearings and should be able to slide the rod for a side clearance check. If the rod would allow for a side check id just get another bearing for this rod.

 

I guess Im confused. The title says SIDE CLEARANCE but then you are talking about rod bores. Which is it? You should be able to mic the thickness of the big end of the old and new rods to be able to verify that.

You're right the bearing oil clearance should not cause the crank not to turn, even at .001". However the side clearance may.

 

yeah soory i was unclear. The ability to measure the side clearance goes away after the first stage of tightening them down. Meaning that the rod will slip side to side with the nuts fingure tight and i can slip a feeler between. After i tighten the rod bolts to 14 ftlbs, the rod no longer slips back and forth and the feeler will only go between one side for clearance. Something is binding when i tighten the rod but can't find a source. Im just wondering if anyone has seen a problem like this and how they fixed it. I was wondering if a thinner bearing for the rod would solve the prob. Oh btw the other 3 rods are perfect, and i did try to swap the rod to another journal, but the same happens on the others so it tells me it is a rod issue. I hope this clears up the confusion. Thx guys!