Actual operation of the Merlin boost regulator

[lane]

Perhaps this drawing of the cut-out valve for boost control on the Merlin II and III will be of interest:

[lane]

From AP 1590B Merlin II and III Aero-Engines:

[TomcatViP]

Injected you said ?

No seriously what afraid me the most is that duct full of boosted mixture right near the pilot arm and leg beyond the (relative) protection of the firewall.

I understand better now why the fire hazard was greater inside a Hurri/Spit than on the 109.

Conjecturing : won't it be a valid point to change the boost ctrl design from holes to valves ?

[camber]

Lane; thank you very much! That is EXACTLY what I wanted!

From a quick look it is consistent with the Rolls Royce Heritage trust document but with the actual structure and plumbing. The second diagram appears to show the whole thing pre-hole and the first where to drill the hole. Fantastic!

I will take a good look at it all however and work out if I need to edit the original post. At first glance it appears that pre hole, the "leak" is introduced from the pressure to the supply side of the supercharger thus maintaining a closed system. With hole it appears there is a possibility of fuel-air venting to atmosphere when you are using combat +12psi boost.

[41Sqn_Banks]

The text pages from AP 1590B Merlin II and III Aero-Engines about Automatic Boost Control. The drawing has already been posted.

[41Sqn_Banks]

Continued

[41Sqn_Banks]

And the last page.