Casting (Engineering) Numbers

[Xcudame]

OK, from my experience with non automotive casting houses, no one keeps track of mold revisions. They do add -# to distinguish which mold was used to cast a part. Also, it's my understanding that what most of us call casting numbers are actually engineering numbers. Below are some pictures of three 340 blocks. All are cast between October 1970 to June 1971. Notice there's a -2, -6 and -8.

 

[Xcudame]

Here's some "516" heads that came from a 1966 440 and 1966 383.

 

[Xcudame]

Notice the "516" heads first appeared in 1964 I believe and where used on just about every big block through 1967 except speciality engines (1967 440 HP). In one of the photos the "516" head has a -7 and 1964 casting date. Seven revisions in a year doesn't really add up to me. But having Eight (-8) molds for heads used on every block makes sense.

 

[Xcudame]

Now we come to some "906" heads which where used from 1968 through 1970, again on just about every big block. Notice the -11 on a head cast January 23, 1969. Again, eleven revisions seems unlikely, but I can definitely see there being twelve (12) or more molds to cast 906 heads!

 

[Xcudame]

Industrial 413 was cast in November 1969 with a -2. Following the revision logic, this mold made it from 1965 (when industrial 413/426 casting started per the part number 2658836) to late 1969 with only two revisions? Or is it simply mold #2?

 

[Xcudame]

Late model 440 cast from 1975 to 1978. Notice the -1 for a 1977 block casting. No revisions or one revision in two plus years when a cylinder head casting had 7, 8 or 11? Not likely, but mold #1 makes sense.

 

[Xcudame]

I could be wrong and they aren't mold numbers, but from the small sample of blocks and heads I have, they appear to be mold numbers and not revision numbers if you consider how often a mold would be tweaked in production. They put a lot of 340s in a lot of Mopars so eight molds (-8) don't surprise me. Chrysler built thousands of cars with "516" and "906" big block heads so -11 makes sense for having 12 or more molds. The number of industrial 413s would probably require no more than four block molds, so my 1969 casting being a -1 indicates mold #1.

Be sure to add more information regarding the -#s. Someone might have higher numbers with an earlier date or lower numbers with a later date.

I do know that quality control in the 1960s and 1970s was pretty pathetic to what companies have now. I love our e-bodies but they have lots of manufacturing flaws that wouldn't be allowed today!

 

[MoparCarGuy]

I would love to see pictures at the foundry area showing how many engine blocks were being cast at one time.
The mold number theory lends itself to the required number of blocks per day. There were hundreds of 340 engines built per day at the Windsor Plant.
Does anyone have 340 "# of engine assembled" numbers in excess of 600? 700? Stamped 0700 or more?
It is incredible that the plant could have that many assembled engines per day.
Could it be that 50, 60, or 70+ employees were assembling engines for 8 hours straight to get 1 engine/hour for each employee. Amazing.

 

[Mr Cuda]

I heard from old machinists, that the suffix, -2,-4, up to -10 is the number of casting core plugs used to make the mold.
The machinsts said the higher the casting mold number, the more core shift.
I do know that later model blocks had higher numbers, possibly a manufacturing, money saving attempt, using up more portions of the casting plugs.
I also thought there was a reference to this in the original direct connection racing manual.
Without an engineering spec, i'll go with the old machinist's.