Engine Stamp Pad & Paint

[Tom R.]

Why did the engine assembly plants, Flint or T, remove paint from pads before shipment to St Louis?

[Jim D.]

Re: Engine Stamp Pad & Paint

They didn't. The pad was masked off prior to painting.

[Patrick B.]

Re: Engine Stamp Pad & Paint

I doubt if they did. I would say that St. Louis removed enough paint to stamp the vin on a clean serface. If the Flint or Tonawanda stamp was still painted, it would have been fine. It is NCRS that requires a pad without paint not the assembly plant.

[Tom R.]

Re: Engine Stamp Pad & Paint

They didn't. The pad was masked off prior to painting.

Why? What was the purpose?

[Paul D.]

Re: Engine Stamp Pad & Paint

Patrick, are you saying that pads actually were painted from engine plants? It was always my understanding that pads were protected from paint by either tape mask or grease applied to the pad. Chip.

[Jim D.]

Re: Engine Stamp Pad & Paint

Why? What was the purpose?

The pads were NOT painted. John Hinckley explains it in this thread - https://www.forums.ncrs.org/showthre...714#post384714

[Tom R.]

Re: Engine Stamp Pad & Paint

In the referenced post (re Hinckley's post...spot on I might add) McManmon wrote:

Yes the motor was stamped before painting. The pad was supposed to be protected from painting in most years -- except when the engine was blue.

Yes the painting process changed over the years, AND with the engine plant, so you should be a little more specific than "mid-years."

I add this because as the 75-77 revision team surveys Corvettes, one-owner cars orange-painted engines, we come across several with painted pads with the engine suffix while the St Louis stamp shows bare, rust-laced characters. Our thinking is that the process changed in these early years and perhaps the rationale for bare pads no longer required. However, when one looks at the numerous engine configurations due to emission requirements, why the change? If at all. The photo below is a 1975 L82 CHC. By 1978 with blue engines, actually starting in 1977, it becomes typical to see painted pads.

engine stamp pad_75_CHC.jpg

[Patrick B.]

Re: Engine Stamp Pad & Paint

Masking and painting practices probably changed over the years. Before 1960 no Chevrolet engines had vins stamped at the assembly plant, and there would have been no reason for the engine plants not to paint the pad. From 1960 to 1967 Corvettes, 1967 Camaros and a relatively small number of higher performance Chevrolets and Chevelles had vin stamps. They were not standardized and various assembly plants did it differently. Since this was a pretty small number of the engines being cranked out by the millions in Flint and Tonawanda, I doubt the engine plants felt any need to change long standing paint processes for the sake of individual assembly plant policies. I once had a drawing that I thought was part of an assembly manual showing what part of the pad to wipe with paint thinner before stamping but I could not find it this morning. Starting in 1968 most if not all Chevrolet engines where stamped with the vin derivative in accordance with a Federal Standard about theft prevention. At that point, the assembly plants would have had a reason to mask the pads, but Tom's picture casts some doubt on whether they actually did. How many of us can actually remember how a pre-68 engine looked on a new car? I'll bet unrestored cars judged by NCRS have mostly had the paint removed because that's how judges want to see them. Tom's picture is very informative. It is clear that the pad was painted at Flint, and the paint was chipped by the vin stamp at St. Louis.

[Jim D.]

Re: Engine Stamp Pad & Paint

This is my 65 that I purchased from the original owner. The engine had never been touched. Except for the grease, this what the pad looked like when new. Zero paint as John H. explained in the above link.
1965 300 hsp 031.jpg

[Jimmy P.]

Re: Engine Stamp Pad & Paint

I am also on the 75-76 Revision team with Tom, and as he mentioned above we have had a number of orange engine cars with painted pads, that the owners have verified. Here is an example from a very nice original 76 L48.

[Patrick B.]

Re: Engine Stamp Pad & Paint

Well, we seem to have good evidence that between Flint and St. Louis the pad painting, masking and cleaning practice was inconsistent.

[Richard F.]

Re: Engine Stamp Pad & Paint

It seems to me that the judging process needs to accept a margin of inconsistencies.

[Patrick H.]

Re: Engine Stamp Pad & Paint

I believe the process changed in the mid 70s (75?) such that you see blank or wiped-off pads prior to this, and painted pads after.

Note that the painting was done after the Flint stamping, so that stamp will have paint on in (in the characters) whereas the St. Louis stamp will have bare paint or rust in the characters.

This is not really a new revelation; we've known it for years for those with the blue engines
Determining the exact date of changeover for orange engines may be what we need to nail down.