P-51 exhaust surround...........

[Alexandre Jay]

I'm sure someone will be able to help out on a question about P-51 exhaust surrounds...............In original photos, some have a surround while others don't....this is B,C, and D models.

Any ideas?

[ZRX61]

In the field they were often left off as it saves time when working on the aircraft.

[Alexandre Jay]

I guess that makes sense..........so what was its purpose to begin with I'm now forced to ask?

It obviously did no harm not to have it fitted back on after engine maintenance.