Posted By: Bob_Coomer
Rotating assembly problem ... - 01/10/10 05:09 AM
Man...
Number 1-2 pistons fell right in, good side clearance about .020-.025...Next Number 3 went right in felt good floated good on the rod. Each rod and piston I install, I have a habit of checking how easy the rods float in the crank, and I spin the motor over etc..Install number four..uh oh...I have no side clearance, well maybe .003-.005 if that. The rod doesnt float on the crank very well. I notice if I pull only the number 4 cap it has the side clearance it needs, this is with #3 still torqued etc. I So I pulled the piston and rod mic the width of the rest of the rods/caps..they are within a thousandth or so.
I have some plasti gauge in the tool chest i throw a piece on and re check it..It looks like it has some taper. Its good toward the outer thrust, but toward the center of the rod journal it looses a good .001. Its not binding on the radius or fillet of the crank...I could turn the engine over with the both rods installed, and there was no binding, no mhar'n of the bearing..nothing. I take it back apart, swap bearings..look..look..and look some more...
I dont know.
I gave up for the evening, but Im going to have a go at it in the A.M...Any suggestions????
I thought about swapping out another piston like #6, or #8, they are all ready installed and have idea clearances/margins etc..I figure if this fixes the problem..It is in that rod, if its still there..its in the crank.
This stuff was suppose to be checked out. I paid to have all rods check, and the crank checked, all bearings clearances set to my spec.
This really is starting to @!@$ me off.
Yes, some problems occur during a build..I feel this type of problem shouldnt have happened. This isnt some $500 small block Chevy that he hurried through the machine shop...Its been there for a year too.
This really sucks..
Its going to be fixed what ever it takes. I can still knock out a few things as work goes.
I can continue degree in the camshaft, clay the pistons, check valve to valve through the #4 bore. Figure out a length for Manton push rods.
Number 1-2 pistons fell right in, good side clearance about .020-.025...Next Number 3 went right in felt good floated good on the rod. Each rod and piston I install, I have a habit of checking how easy the rods float in the crank, and I spin the motor over etc..Install number four..uh oh...I have no side clearance, well maybe .003-.005 if that. The rod doesnt float on the crank very well. I notice if I pull only the number 4 cap it has the side clearance it needs, this is with #3 still torqued etc. I So I pulled the piston and rod mic the width of the rest of the rods/caps..they are within a thousandth or so.
I have some plasti gauge in the tool chest i throw a piece on and re check it..It looks like it has some taper. Its good toward the outer thrust, but toward the center of the rod journal it looses a good .001. Its not binding on the radius or fillet of the crank...I could turn the engine over with the both rods installed, and there was no binding, no mhar'n of the bearing..nothing. I take it back apart, swap bearings..look..look..and look some more...
I dont know.
I gave up for the evening, but Im going to have a go at it in the A.M...Any suggestions????
I thought about swapping out another piston like #6, or #8, they are all ready installed and have idea clearances/margins etc..I figure if this fixes the problem..It is in that rod, if its still there..its in the crank.
This stuff was suppose to be checked out. I paid to have all rods check, and the crank checked, all bearings clearances set to my spec.
This really is starting to @!@$ me off.
Yes, some problems occur during a build..I feel this type of problem shouldnt have happened. This isnt some $500 small block Chevy that he hurried through the machine shop...Its been there for a year too.
This really sucks..
Its going to be fixed what ever it takes. I can still knock out a few things as work goes.
I can continue degree in the camshaft, clay the pistons, check valve to valve through the #4 bore. Figure out a length for Manton push rods.