|The MGA With An Attitude
CASTING NUMBERS - BE-102
On 6/13/05, "Mike L" wrote:
>" I have two 1600 motors. On stripping them down the earlier one has 1H702 and 1H704 pairs of con rods. Parts book says they should be 1H701 and 1H703. The later 1600 has beefier 12H92 and 12H94 con rods. Here the parts book calls for 12H91 and 12H93. Anybody know if there is any significance to this 'odd vs even' parts number discrepancy?"
After machining the finished part has a different part number than the raw casting/forging. They are often very close. For some larger castings or forgings like cylinder heads or crankshafts which may be finish machined for different applications, the phsyical number on the part and the actual part number can be further removed from each other (with multiple numbers for the machined parts).
Here are some connecting rod part numbers to go with casting numbers:
MGA 1500, 1955 through August 1956
Part Number Cyl 1&3: 1G2370 On the rod: 1G2371
Part Number Cyl 2&4: 1G2367 On the rod: 1G2368
MGA 1500 and 1600, Aug 1955 through March 1961
Part Number Cyl 1&3: 1H703 On the rod: 1H704
Part Number Cyl 2&4: 1H701 On the rod: 1H702
MGA 1622, March 1961 through May 1962 (and 3 main MGB)
Part Number Cyl 1&3: 12H426 On the rod: 12H427
Part Number Cyl 2&4: 12H424 On the rod: 12H425
The 12H91/92/93/94 parts may be rods from the MGB 3 main motor,
as their part numbers were 12H997 and 12H998.