Hmm, why not try it out for the next update and see if it's a good addition or not.
I'll build the engine this week. The question is what would be the logical temperature rise? The Pilot Handbook states both +18 and +21 lbs as 5 min limit, with +9 lbs for 60 min. However if it takes 5 min to overheat the engine at +21 lbs, then using logic it should be a slower degree/seconds rise at +18 lbs. I'd estimate around 10 min for overheat at +18 lbs, sounds fair? +18 lbs is ~91% the BHP of +21 lbs. The P-51D's 61" Hg boost is also ~91% the BHP of 72" Hg. These boosts have a 15 min and 5 min limit, so a 10 min limit would hopefully be on the safe side for +18 lbs.
Regarding the 109G-14 it enters the arena at the same time as the 109K-4. The G-14 is pretty much a poor man's K-4, having the same handling as the K-4 but inferior speed and can't use the 30 mm cannon. I can't say the G-14 is to good to have in the game since the K-4 is better. Against the Spitfire IXe the 109G-14 is faster, but the Spit XIe turns better, have superior firepower, and doesn't suffer from the elevator becoming heavy at high speeds. I'd say the Spitfire IXe is quite on par with the G-14 and K-4, depending on the pilot's fighting style. I'd definitely rate the Spitfire XIV as overall superior to all Bf 109's if flown to it's strengths and altitude. Don't fight the Bf 109's at the deck in the Spitfire XIV, fight them at 10k or higher. The Bf 109G-14 and K-4 have great engine power right at the deck but suffers at mid and very high altitudes compared to the Allied two stage superchargers.
