Yes, you will have metal pinch in our engines for the first 1.5-2 gallons... until the pinch is gone you will not see full power or runtime, we see 2+ mins of runtime gain from the first tanks to the end of metal pinch. You can race it sure, I race mine after about 4-5 tanks, I keep a close eye on it and run the HSN slightly rich. Fully seating the piston wont happen quickly. Some engines metal pinch is completely gone after .5 gallons. Some take longer, but they also have incredible seal/compression for a very long time also Id rather have an engine hold strong compression for 5+ gallons than go away after a couple

note: metal pinch and compression are completely different, in a perfect world you want 0% leakdown, builds compression immediately after the piston covers the exhaust port and 0% pinch (unwanted heat and drag) to have the perfect engine.