I had a zex dry kit on my 91 Integra LS running a 55 shot @ at the stock timing and i was dumb and ran 89 octane gas while racing a guy. midway through the race is starts detonating so i stop and pull over. there is smoke coming from under my hood and my pcv valve popped out of the hose it connects to. i pull the dip stick and smoke is pouring out the dip stick hole, i open the oil filler cap and smoke is pouring out through there also. i do a compression test i get 110 90 100 50 from left to right all my plugs look perfect except my number 3 cylinder plug tip is melted, smokes is always coming from under the hood but doesnt burn much oil. all the symptoms tell me i have cracked ringlands but what throws me off is my car feel perfectly fine like it never happened maybe even faster (nitrous is gone btw). i have never cracked ringlands before is this normal? could i have blown a headgasket or something else?
Thanks

 

only way to really know is just to take it apart and look for what broke.