Question about assembling rods onto crank
 

I was re-reading the overhaul manual and saw a line about installing the case so that the numbers are pointed towards the sump. First, which numbers, part numbers, or the stamped numbers matching 1-1, 2-2, 3-3, 4-4 (they are on different sides)? When I bolted them on I did not have the rods "sequenced" in the right direction so I now end up with two up and two down. I cannot see any reason why it would change the oiling characteristics, so is it worth it to turn them around? Also (I think I know the answer but i'll ask) since I have not run the engine and do not have the torque to length bolts, if I need to change should I use new nuts or since the engine has not been run can I just back them off, turn the rod around, and put them back on?

Thanks,
Scott

connecting rods
 

Scott, we are building my engine 0320 now also , the a&p that is doing it said
it must be done this way.. the numbers 1,2,3,4 I saw nothing that would
have made any difference either.. but lycoming says and the ntsb & faa do
look for these issues on engine failures , and he made a big deal about, anyway I am not going to argue with 30 years of success building engines.. :) when doing the balance ect.. he said, you can mix pins and pistons but the rods much be in the proper position and proper direction..
I have built alot of drag motors, hot street rods , and one circle track car, all worked well, (except a porsche 911 motor I built failed) so I am keeping my mouth shut and doing exactly what the a&p ,manual, says.. I can't pull off to the side of the road as easy in this project.. the porsche motor was very complicated I wouldn't be a porsche machanic for nothing.. great cars but they are a pain to rebuild.. I would loosen and use the same nuts, they have not been stressed yet.. cheap insurance (26 $ bolts 4 $ nuts :)

thats my take on this subject..

Danny...

After the paint on everything drys and I untape everything I will swap the two around so that the numbers that match them (1-1, etc) will all face down.

Thanks,
Scott

Might not be an issue on Lys, but on some auto motors the piston pin boss is offset slightly forward or aft of the center of the bore. Sometimes the rods are offset in a similar fashion so that the big end and little end are not quite in line with each other. This means that the rods should only be installed one way.

Steve Zicree