Quote:
Originally Posted by reflected
weird..I have the pilots notes, and it says 120C for 30 min, and even 135 C for 5 minutes. Good to know about the minimum rpm though, thanks! Oil temperatures are always around 95, nothing I can do...can you achieve combat performanced with these limitations? or do you just cruise and do some sightseeing?  |
The figure of 135ºC for 5 minutes would apply for pure glycol cooling.
The 120ºC max is for 70% water, 30% glycol at 15 psi.
The Merlin III should be pure glycol. However, the pilot's notes which ship with the CE have limits appropriate to pressurised water/glyclol; since the page with the engine limits on it is dated January 1942, I suspect that what probably happened was that by then the engines had been modified to pressurised water/glycol cooling.
A complicating factor is that the Merlin III was the last Merlin to use pure glycol cooling; from the Merlin IV onwards all subsequent marks used pressurised water/glycol.
This means that the 120ºC limit is correct for the Spitfire II with Merlin XII, and would also be correct for the Hurricane II with Merlin XX. But AFAIK the Spitfire I and Hurricane I were both still using pure glycol cooling during the battle and should be subject to the limits you have posted.
NB - I am assuming that the 120ºC limit in the Pilot's Notes that ship with the CE is correct for 1942 and that the various mods for water cooling had been embodied by that time (the other option might be that it's a typographical error). I don't have documentary evidence as to when/if the Merlin III was converted to water cooling.
However, as far as the sim is concerned, the engine will break if you exceed 120ºC coolant temperature.