Connecting Rod Conundrum

[Old Man]

On breaking down the engine of my Cub I found rods #1, 2 and 3 marked and oriented toward the camshaft side as expected. The #4 rod is marked with 4 irregular hammer marks( ?) and 4 irregular file marks and oriented toward the magneto side of the engine. Based on the serial # and casting dates my Cub is a 1950 model with a 1952 engine. I suspect the work of a shade tree mechanic, like me, in the distant past. On rebuild should I orient the #4 rod and piston as found or should it be rotated toward the camshaft side of the engine? TIA

[tst]

#s face cam, on another note is your crank ok ?? the bearing looks nasty, rod and cap need to be matched also as they are machined together, any doubts replace that rod if they are not matched

[Old Man]

The crank journal measures within specs but exhibits significant scoring near its center. The other journals appear to be in good shape. To do a thorough rebuild I’m certain that the crank should be turned. However, I only use my Cub to plow snow and to take an occasional ride on a sunny day. If I were to just install new bearings, along with valves, guides, springs etc, what would the likely prognosis be?

[SONNY]

it would last forever with light use. On the rod marks----better face them like you found them! ---someone wasnt thinking when they marked them. just my.02, you could get a good used rod and face it the right way for sure.

[tst]

use plastic gauge to measure the clearance that will tell you if it has a chance, or use a micrometer on it on 4 spots to make sure the journal is round, I have my doubts by the way that bearing looks

[SamsFarm]

Is your crankshaft gauling make the journal bigger than normal like material from the bearing has attached itself to the crank, or is the crank journal gauling like grooves?

If it bigger than normal, then you better clean it off with some fine paper abrasive maybe like 220 grit being extra careful not to take away from the crank metal!

Or have a shop clean it up!

If that journal (or any other) is too big, you will trash your new bearing instantly!

[Nelson 634]

Pictures! The best way to explain what you have as a problem is good quality pictures. You will have a greater chance of getting the help you need as well help others who don't have your knowledge or others here on this forum. The pictures you've posted are good of the marks for location. I would suggest pictures of bearing journals and the crank shaft at least.

[Clemsonfor]

Is your crankshaft gauling make the journal bigger than normal like material from the bearing has attached itself to the crank, or is the crank journal gauling like grooves?

If it bigger than normal, then you better clean it off with some fine paper abrasive maybe like 220 grit being extra careful not to take away from the crank metal!

Or have a shop clean it up!

If that journal (or any other) is too big, you will trash your new bearing instantly!

220 is not that fine especially when talking crank journals. Heck that's not even fine if your talking paint prep!!! Visible scratches if you sand with 220 and paint.

[SamsFarm]

220 is not that fine especially when talking crank journals. Heck that's not even fine if your talking paint prep!!! Visible scratches if you sand with 220 and paint.

Well.......

If the soft bearing metal is built up on the hardened surface of the crank journal and you want to spend all week getting it wittled down, feel free to use 400, 600, etc, etc. Use what YOU feel comfortable with!

This is ONLY if the metal has built up on the journal from the bearing!

If your not comfortable doing it, then dont do it!