Superior Air Parts has grounded all of its XP-382 and XP-400 experimental engines due to detonation problems found in some XP-400s, according to AVweb sister publication Kitplanes. The company has also implemented a mandatory buy-back program for both engine types. Both the grounding and the buy-backs are effective immediately.
This is a companion discussion topic for the original entry at https://www.avweb.com/recent-updates/business-military/superior-grounds-xp-382-and-xp-400-engines