d82u

Year of build is 1946
Original standard bore pistons part number is 5F7487
Block part number is 4B3892
Your probably reading the casting number 4B3840.

Didn't the 2U start coming out in 1948 ?
firekat

The info I have shows the 8R series ending and the 2U series beginning in 1946.
So far as I know that is correct but you never know about some of these old stats 😊 😊

My S/N book says D8 2U1 to D8 2U57 were built in Dec 1945.

D13000/D8800 pony 3 5/8" x 4" specs
Cylinder bore 3.628-3.629"
Maximum out of round 0.003"
Maximum taper/wear 0.008"
Piston skirt clearance 0.006-0.008"

Main bearing journals 2.1243-2.1245
MB clearance 0.006-0.0097 MAX 0.016"
thrust clearance 0.005-0.010" MAX 0.020"

Rod bearing journals 1.998-1.999"
Max out of round 0.003"
RB clearance 0.0035-0.0055 MAX 0.009"

I wasn't sure I have always been told (from my old cat guy) that 2U's started coming out in 1948 but I don't have that much knowledge (books) to tell me. Thanks for correcting me, now I can take that back to the old guy and see if I can get his hair standing up.

firekat

Watch out the "old Cat guy" doesn't snag you on the other "U" models....The D2, D4, D6 "U" models came out in 1947.

My book shows std piston== 2F3666
.O2O--2F3660
.040--2F3661
semi-fimished up to.060 --2F3662