Engine block alloy composition

[AEX_Weller]

In preparation recently for attempting a repair of an early Ace engine block that threw a rod five decades ago, I had a local metallurgical firm do an analysis of the elemental composition of the block.
   
   Below are the details of the alloy (element/%).  Totals don't quite add due to rounding, I assume.
   
   carbon/0
   manganese/.31
   phosphorous/0
   tin/0.11
   silicon/5.81
   lead/0.15
   nickel/0.38
   chromium/0.03
   copper/3.76
   iron/0.98
   aluminum/87.15
   titanium/0.03
   magnesium/0.12
   zinc/1.40
   
   Hope this helps anyone who may be working on a repair.

[Robin A Woolmer]

The Aluminium Specification on Post War Blocks was DTD 424
   3%cu 5%si 0.5%mn
   You may need to refer to a material specification listing also, I believe this specification was replaced by L79 later.

[keithpenny]

Looks like someone's got access to an Atomic Absoption spectrometer! The numbers these things chuck out are far from accurate! Ball park figs for the Si, Cu and Mn though.
Depends how the sample was taken and who was doing the analysis. Out of interest did they give you  the results of a known reference standard measured on the same day?