sounds can be affected by a lot of things. sound card settings, the card itself, speakers, your or my ears.
afaik this aircraft has a packard merlin fitted which is different to a RR merlin, which is different to a griffon. all of these had blown non blown versions.
if it sounds wrong to you and it is a recording of the real thing then it just sounds wrong to you.
if they (FIX) it for you then it will probably sound wrong to me or someone else.
BTW it sounds fine to me.