Rod and Crank Issues

Put motor together, same block and rods; new pistons and crank. Made 5 runs with aluminum in the filter. Pulled it down. Rods had .010 to .020 worn off the sides. The thickness of the crank side is about .380. Piston boss has enough clearance for top of rod. Gap between rods is .050. Anyone ever run into this before. Call me.
512-619-0999
Reeper

 

Did you put the rods in with the radius towards the side off the counterweight?

 

yes rods were in correctly

 

Bump to the top

 

Are the sides of big end of the rods worn on only one side or both? Are all the rods worn, or just some?

 

side of big end worn just on crank side, some as much as .016 others .003 & .004

 

Rod Wear

Any signs of damage or contact on the top of the pistons? How is the rod bearing surface? Even side to side wear pattern? I would at the very least change the rods if no other signs of piston contact. JMHO

 

To much end float on the crank.
Cheers Jason

 

Thrust ?

Just a thought, I've seen some crazy stuff through the years, including this:

New crank, pilot bearing was .080 too shallow, meaning old input shaft too long, tore up thrust first then most all else.



Bob Meyer
Meyer Race Cars / San Diego
2015 Our 50th Anniversary

 

My best guess with the information given would be that something is not square to the crank forcing the rods into the side of the crank, could even be the rod journals at a slight angle to the main journals. If this is the case, it should show on the rod bearings.

 

Many years ago, I had a set of custom pistons that the pin bore was not square to the head of the piston, some were only a few thousands, some were .020+ out.