Just my pennyworth.. During my PPL training on Cherokees in South Africa, shock cooling was not really a problem with air temps regularly above 25 degrees. So we did glide approaches on every landing.
I queried whether the prop would stop with an engine failure, so we stopped the engine overhead the airfield to see what would happen. Result it kept going until approx 60 knts, thereafter we followed the checklist and cracked open the door. Can't remember the actual rather high rate of descent, but the sight of that prop blade sticking up in front of me was quite intimidating.
