Purple, green, and white paint on NOS parts

[Steve Antonucci]

Good evening all !

I have a fast question for the group. We probably have all seen NOS engine
parts for sale that have purple, green, and possibly white paint splotches on
them. I would assume that each of these colors signify the completion of some
particular sub-process in the overall manufacturing process.

I am referring primarily to NOS rods, crankshafts, and possibly blocks.

Can anyone tell me what these particular colors signify? This has always
intrigued me.

Thanks,
Steve

[Geoff C.]

It passed inspection or ID'ed part to assemblers *NM*

[Chris H.]

Re: Purple, green, and white paint on NOS parts

Many many years ago I spent a summer inspecting L6 and V8 cranks that had been ground on this huge grinding machine. They would come down the line and I would place each in an inspection machine that used air pressure to measure the journal diameters. If they passed the test I would dab some color on the crank and send it on its way. If it was too large it went back to the grinders for regrinding.

[Kent K.]

Re: Purple, green, and white paint on NOS parts

Chris --- Out of curiosity, were you assigned an inspection paint color to use and were there other inspectors who used the same or different colors? Was it paint or some other material used and could you describe it? Did you always dap color on the same/similar spot or did it vary? Tell us more, please.
Thanks, Kent #6201

[Mike McKown]

At the risk of being corrected

SHP 327's:

hardened tip pushrods had a purple stripe around the top end. Looked like ink.

the hardened crankshaft had a swatch of blue/green paint on a crank throw and back on the flywheel flange.

the 097 cam had the same color on it back by the distributor gear, I think.

the block had the same color paint on the side of the block by the drain plugs.

the valve springs had an orangish/yellow stripe on them I believe.

I don't recall anything else.

[Chris H.]

Re: Purple, green, and white paint on NOS parts

As I recall we all used the same color. Now this was back in about '76 so it has been 30 years and it was a summer job while going to college. Worked the 2nd shift, 60 hours a week and it put me thru college.

It was a point that we dabbed on but no idea what color or where. Sorry.

[Terry M.]

Re: Purple, green, and white paint on NOS parts

The connecting rods used on the SHP 350 cid engines had a pink paint mark to indicate they had received the special treatment (shot peening and special heat treat, I think). They became known as pink rods as a result. I'm sure that mark was to distinguish them from the same size rods, which had not received that treatment.

[Michael H.]

Re: At the risk of being corrected

Mike,

Yes, here's a shot of the block bottom end and rotating assy color ID. The block, crankshaft and piston/rod assy' were marked with blue on this particular engine to indicate 365/375 HP (Sp. H/Per) for a 1964. These items would have been unique to that particular build. The assemblers on the engine line then knew to install components with blue ID marks into blocks with the same color ID. There would also be a large blue paint ID on the side of the block that is not visible in this pic.

[Jack Y.]

Re: Purple, green, and white paint on NOS parts

Thank you for that. I always wondered where 'pink' rods came from!!! You all are good.