1971
Mattel introduced 35 new castings in 1971, the high water mark for the original Spectraflame era. While there were 6 new Heavyweights, a full contingent of new Mongoose & Snake cars, there were only 3 new Spoilers, and no Grand Prix series cars introduced.
While you could still get any Spectraflame color this year, the number of colors per casting was reduced. Very few castings this year were manufactured in both the US and Hong Kong. There were also a large number of castings with an included sticker or decal sheet.
On a less positive note, Mattel had a metal supply problem in this casting year. Several castings were prone to 'crumbling'. Crumbling is a flaw in the zamac alloy that results in the metal forming cracks, and ultimately separating into pieces. See the list of crumblers below.
Interiors
1971 castings included the following interior colors: ivory, midtone (bronze (HK)), dark brown, black, and the one and only white interior during the redline era.
Exteriors
19 Spectraflame colors were available in US castings this year.
Two US castings came in white enamel.
Hong Kong cars were produced in 11 colors.
Some Heavyweights were available in enamel white, and one other casting came in enamel blue.
Wheels
Wheels were now exclusively capped style. See the 1968 Wheels section for more!
Crumbler
Crumbling is a flaw in the zamac (predominantly zinc, with aluminum, magnesium, and copper) alloy used in the diecast process that results in the metal forming cracks, and ultimately separating into pieces. The flaw is possible when the zinc metal used in the alloy is not sufficiently pure (99%+).
The following castings have examples of crumbling of either the body or base. Note that some '70 castings are listed here, they were possibly produced in '71 or at the end of '70 production. Are all crumblers produced in Hong Kong, the evidence seems to indicate it.
This Bye Focal shows an extreme case of base crumbling.
A less severe case of base crumbling on this Crew Car.
Casting Names and Part Numbers
An almost random assignment of numbers this year. Where did those Mongoose and Snake numbers in the 5951-5954 range come from? There are no other numbers in this range used in this time frame.
Then a large jump to 6000 with many small gaps, until another large jump to 6175. We see a couple of small gaps in this range, possibly castings that didn't make it to production, ending at 6194.
Then something interesting happens, the remaining castings begin to fill in gaps in the 1970 sequence in the 6400s. Are these castings that had been intended for release in 1970, or just commissioned that year? If they were intended to be 1970 releases that would have been 10 more castings in that year, pushing it's total to over 40. An interesting idea to consider.