? - Case number issues
 

I'm only asking this because I have come across 2 "sets" of cases but the numbers don't match. Is there a good reason for using mis-matched case numbers? Other than that was what someone had available to use. Is there any reason (other than the obvious) these case sets will not work together?

What I have;

- 1st case set; 901.101.102.1R w/ 901.101.101.2R, 901/16, ser#6196718

- 2nd case set; 901.101.101.4R w/ 901.101.102.3R, 911/61, ser #6129111

This would have been covered by a search. Those aren't case numbers, they are casting numbers for the left and right halves. All things being equal condition-wise, go with the second case. The 4R & 3R refer to the casting revision status - the higher the number, generally, the beefier/stronger the case, up to 7R (the last revision of the magnesium case). Yes, it was normal to have different levels of casting revisions between the left & right halves.

The 1/2 or 3/4 pairing is just a transition thing, and is of little consequence by itself. However the pair is really only as good as the lower of the two numbers. What you should check is the case pairing numbers on the top where the halves are bolted together. The 3 digit numbers there should be the same on both halves to indicate that the pair were machined as a set.

Dave - thanks for the info. I tried a search but since I was looking for "case" numbers I wasn't getting anything. Now I know why. Since I've only dealt with 7R cases in the past all my engines have always had 7R on both halves.

djpateman - where are those 3 digit numbers located? I don't see anything but serial #'s. I'm aware of the 9xx/xx number on the one side of the case but I don't recall ever seeing the 2, 3 digit numbers you're refering to.

The three digit number is located above the center 8mm flange bolt on the center case line behind the alternator/fan
Bruce

Look here:http://forums.pelicanparts.com/uploa...1252638615.jpg

BTW, on the 901/16 case what is the build # next to the type #?