Friday Update, June 08, 2012

[Bokononist]

Originally Posted by Skoshi Tiger

This posses the questions, were there any modifications to the merlin XII engine that allowed it to work at the higher boost for the extended periods in 1941?

Or was it a decision based on accepting reduced engine life to keep the aging MKII competitive in air combat?

Or were the 1940 limits too conservative so they were increased?

The Merlin in the 1a had to be modified to accept 100 octane, the Merlin variant in the IIa was already adapted for 100 octane. The 100 octane 1a had similar performance to the IIa, as despite the fact that the IIa had a more powerful Merlin it also had extra weight due to more armoured plating around the pilots seat etc. So the IIa's advantages were, the ability to run at higher boost levels for longer, better protection for the pilot and better high altitude performance.