3900 LZG Metalurgy

[NateD4]

So I had the opportunity to check the metallurgy of the 3900 engines. I was specifically looking for crankshaft and valve metallurgy.

The results are posted below. Unfortunately the analyzer I was using can't read carbon content so I can't exactly determine which of the 10 series steels GM used (I suspect 1053). I was however able to verify the exhaust valves are a high Chrome alloy.


Crankshaft:
Element % composition delta
Mo 0.021% 0.065
Cu 0.154% 0.050
Ni 0.105% 0.050
Fe 97.83% 0.21
Mn 1.32% 0.09
Cr 0.161% 0.030
V 0.086% 0.037
Ti 0.119% 0.056

Exhaust Valve
Element % Composition delta
Mo 0.167% 0.013
Nb 0.028% 0.006
Cu 0.370% 0.081
Ni 3.58% 0.22
Fe 67.65% 0.45
Mn 7.96% 0.29
Cr 19.82% 0.27

Intake Valve
Element % Composition delta
Mo 0.016% 0.006
Cu 0.145% 0.050
Fe 97.86% 0.27
Mn 1.50% 0.12

Block
Element % Composition delta
Mo 0.024% 0.006
Cu 0.276% 0.059
Fe 98.24% 0.26
Mn 0.40% 0.076
Cr 0.230% 0.041
Ti 0.210% 0.077


I'll try to get some more readings on the cam next.

Not sure how useful that is to anyone. I found the exhaust valve material rather interesting as it is a high heat alloy.