63-65 chrome oil cap question

[Mike M.]

Re: 63-65 chrome oil cap question

i'll take it. 5 buck. seriously, i like the dimple but dislike absence of scars on its sides. mike

[Joe R.]

Re: 63-65 chrome oil cap question

i'll take it. 5 buck. seriously, i like the dimple but dislike absence of scars on its sides. mike

Mike,

You'll pay 5 bucks for a rusty cap with a dimple, no stamping marks and according to the experts, the wrong cork gasket?????

I have a lot of rusty junk that I will bring to Florida NCRS meet. Bring yo 5 bucks and come by my tent please!

JR

[Joe L.]

Re: 63-65 chrome oil cap question

i'll take it. 5 buck. seriously, i like the dimple but dislike absence of scars on its sides. mike

Mike------


Here's what I don't understand: usually, the striations ("scars") are die marks caused by progressive wear of the tooling. So, I would expect early-manufactured examples of a stamped part to show few, if any, of these marks. Later-manufactured examples would then show increased scarring. As far as I know, the cap in question, either the plain or chrome version, was first used for the 1963 model year. If so, I would think that very early examples of the cap (i.e. those manufactured about 1963) would show little scarring. However, I suppose it's possible the cap may have been manufactured using tooling from some earlier, non-Corvette application.

[David L.]

Re: 63-65 chrome oil cap question

Mike------


Here's what I don't understand: usually, the striations ("scars") are die marks caused by progressive wear of the tooling. So, I would expect early-manufactured examples of a stamped part to show few, if any, of these marks. Later-manufactured examples would then show increased scarring. As far as I know, the cap in question, either the plain or chrome version, was first used for the 1963 model year. If so, I would think that very early examples of the cap (i.e. those manufactured about 1963) would show little scarring. However, I suppose it's possible the cap may have been manufactured using tooling from some earlier, non-Corvette application.

Joe,

The 3714893 oil cap (not chrome) used on early 63 Corvettes is also listed in my 1957 Chevrolet Parts Catalog in Gr. 1.516 for 1955-1957 D-D, 2 TON truck models. The 3723688 gasket is listed in Gr. 1.517.

Dave

[Joe L.]

Re: 63-65 chrome oil cap question

Joe,

The 3714893 oil cap (not chrome) used on early 63 Corvettes is also listed in my 1957 Chevrolet Parts Catalog in Gr. 1.516 for 1955-1957 D-D, 2 TON truck models. The 3723688 gasket is listed in Gr. 1.517.

Dave

Dave------


Well, that probably answers it. The 3714983 would have been about a 1957 released part. However, I wouldn't think that too many of them would have been manufactured for the 2 ton truck application.

[David L.]

Re: 63-65 chrome oil cap question

Dave------


Well, that probably answers it. The 3714983 would have been about a 1957 released part. However, I wouldn't think that too many of them would have been manufactured for the 2 ton truck application.

Joe,

Besides my 1957 Chevrolet Parts Catalog the 3714893 oil cap also appears in my 1960, 1961, and 1963 Chevrolet TRUCK Catalogs (Nov. 1959, Apr. 1960, Feb. 1961 and Oct. 1962) for 55-59 ALL, 60-62 Ser. 60-80 w/pos. vent (8 cyl.), 60-62 TDM, and 63 ALL (8cyl.) trucks models.

Dave

[Mike M.]

Re: 63-65 chrome oil cap question

Mike------


Here's what I don't understand: usually, the striations ("scars") are die marks caused by progressive wear of the tooling. So, I would expect early-manufactured examples of a stamped part to show few, if any, of these marks. Later-manufactured examples would then show increased scarring. As far as I know, the cap in question, either the plain or chrome version, was first used for the 1963 model year. If so, I would think that very early examples of the cap (i.e. those manufactured about 1963) would show little scarring. However, I suppose it's possible the cap may have been manufactured using tooling from some earlier, non-Corvette application.

joe: the individual scars/stiations on the caps i have are concave, not convex. i agree the tooling wore out as the 63 thru 65 caps were stamped, but would a tooling die "grow" protrusions on its surface contacting the sides of the oil cap? i believe the dies were initially roughly machined with protrusions that caused the concave scares beginning in 62 and that as they were used, and the protrusions wore away, thus the caps in 64 and 65 lacked the scars. i ain't not tool and die worker but can't explain how the dies "wore" in such a manner to go from concave to smooth. regards, mike

[Joe L.]

Re: 63-65 chrome oil cap question

joe: the individual scars/stiations on the caps i have are concave, not convex. i agree the tooling wore out as the 63 thru 65 caps were stamped, but would a tooling die "grow" protrusions on its surface contacting the sides of the oil cap? i believe the dies were initially roughly machined with protrusions that caused the concave scares beginning in 62 and that as they were used, and the protrusions wore away, thus the caps in 64 and 65 lacked the scars. i ain't not tool and die worker but can't explain how the dies "wore" in such a manner to go from concave to smooth. regards, mike

Mike------


Maybe we're talking about different things. I thought you were talking about the vertical "striations" or lines seen on the side of the cap in Dave Liukkonnen's posts #15 and 16 of the NOS GM #3828373. These are the kind of die marks that develop as tooling wears.

[Wayne M.]

Re: 63-65 chrome oil cap question

FWIW, here's a zoom-in on an overall engine pic I took in spring of 1968, of '65 L79 #04835, which I ended up buying.



c

[Gene M.]

Re: 63-65 chrome oil cap question

That part would be made with draw and form dies. Most likely draw, stamp and form. Tooling draw tool marks are just the nature of the beast at the time.

[Mike M.]

Re: 63-65 chrome oil cap question

so gene, as the tool wears out,do the striations/scars become more or less noticeable? thanks,mike

[John D.]

Re: 63-65 chrome oil cap question

My Pal FI Art has put many a dimples in caps. Can't tell you his real name. It's called massaging the part aka JB term.
No he will not put a dimple in your cap as dat wood be cheating.
I learned this trick from an MD in MD. JD

[Mike E.]

Re: 63-65 chrome oil cap question

FWIW, here's a zoom-in on an overall engine pic I took in spring of 1968, of '65 L79 #04835, which I ended up buying.



c

Great shot Wayne! Good old film holds up pretty well when blown up. If you have time could you post the whole image. I would love to see what a 3 year old L79 looked like.

Mike

[Mike M.]

Re: 63-65 chrome oil cap question

notice the fuel filter is a service replacement. m,ike

[Gene M.]

Re: 63-65 chrome oil cap question

so gene, as the tool wears out,do the striations/scars become more or less noticeable? thanks,mike

Mike the draw dies wear just as one would expect as you drag a hard steel over another softer steel (the part). Form dies also result in die marks. The dies do wear more than you think and clearances increase. Thus more movement and the "scars" do get worse. Now if the tools were maintained the "scars" would pretty much be consistent over life of the tool. Depending on the initial tool quality and expected life has a lot to do with the effort put into tool maintenance.

Tooling that does not produce mark is generally more expensive and not considered for "machine type" parts. But it is more prevalent in visual sensitive parts.