Water pump, C-3

[Scott Sims]

I am posting this question for another C-3 owner. I guess I need two answers, one for 1970 only due to the short production run and the other as a general answer. I thought most engine components were to be within a few days to a month prior to the build date of the engine, however, my intake has the same casting date as my block. The question is:

Can the casting date on the water pump be within 6 mo. of engine build date or
is it 6 mo. within car build date?

Thanks,
Scott

[Joe L.]

Re: Water pump, C-3

Scott-----

The intake casting date could very well be the same as the block and is often very close to it (for cast iron intakes). The block, heads and intake manifolds (cast iron) for small blocks in Corvettes were done at the Saginaw Grey Iron Foundry. They were casting up heads, blocks, intake manifolds, water pump housings, etc. all simultaneously.

The block on my original owner and known original 1969 300/350 was cast on August 12, 1969. The heads were cast on August 11 and August 13, 1969. The intake manifold was cast on August 2, 1969. So, all of these components were cast within an 11 day period. It's possible for much closer dates, too. My original waterpump was cast on May 18, 1969, so it's 3 months prior to the other engine castings.

I believe NCRS allows 6 months for dating between the engine build date and the dates of its components. However, I don't think that the date on waterpumps is judged. For the most part, it can't be seen when installed on the car. I understand that new judging criteria may call for the cars to be completely dis-assembled prior to judging, with the parts all laid out on the judging field. Then, each-and-every component can be checked microscopically and spectrophotometrically for conformance with original build specifications.

Castings, for example, will be checked to ensure that the sand-cast surfaces match the sort of sand dredged from the Saginaw River by the ship Niagara and brought to the Saginaw foundry for use in the sand castings. Castings with sand grain indentions "not typical of the sand carried on the Niagara" will be rejected as "bogus". Owners will be allowed, however, to document that the castings are original notwithstanding the apparent lack of the use of original type sand in the casting.

[Jack H.]

Joe, embellishes a bit....

Your copy of the applicable Judging Guide, in addition to the NCRS Judging Reference Manual (the 'white' book) will tell you about date coding standards. Some parts vary, but the normal rule is dated parts must preceed by 0-6 months. Now, preceed what?

In the case of engine components, some were installed at the engine plant(s) (Flint for SB and Tonawanda for BB) and these should preceed the engine assy date embossed on the engine stamp pad. Other parts came together at the St. Louis final assy line (these are typically called out in the Assembly Instruction Manual or 'AIM' book) and they should preceed the car's final assy date (interpolate from the VIN number of the car using published end-of-month Chevy production figures) by 0-6 months.

The intake manifold was assembled onto the engine at the engine plant. Therefore, it should preceed the engine's final assy date. Some specific engine components (carb, alternator, fuel pump, Etc.) weren't installed on the engine until it arrived at St. Louis, was pulled from inventory and started down the power train 'feeder' line to feed the final assy line. You'll find MANY prior answers to this generic question in the archieves as you're not the first to ask.

The reason for the 0-6 month window is to absorb 'most' of the abnormal cases of date coding 'slop' because sub-assy parts were NOT under LIFO/FIFO inventory control and were pulled at 'random' from existing inventory stores at both plants. There were also isolated cases of a given part failing, being pulled and sent for rework, then being re-introduced to inventory after it was fault-isolated and repaired.

There were also cases where an 'incoming' load of parts fresh from the foundry were loaded into inventory at the 'front' of the stack or 'top' of the and just happened to be pulled on the same day they were cast for an engine or vehicle going down the line that same day. Hence, the allowable time window includes 'zero' days prior....

[Chuck S.]

Embellishes??!!...

He jumped the track...he took off on a tangent...He wandered off the subject like an old uncle at the rest home. Then you saw his tongue in his cheek. Most unlike Professor Joe...Somebody go out there and check on him.