Cortina-student 0 Posted July 30, 2025 Hello everyone! I have Xflow with Hepolite .030" pistons, bcf2 cam, larger valves (any larger cannot fit), double valvesprings etc. I did clay test to prove valve to piston clearance and it was only maybe 1.2 mm. How tight it is actually, if i will drive mostly under 7000 rpm (bcf2 range is 2500-6500rpm)? Is it good idea to put all things together with only around 1.2mm valve to piston clearance? Sorry my english, no Google translator. Greetings from Finland Quote Share this post Link to post Share on other sites
STEVE440 12 Posted October 20, 2025 Generally 2 mm is considered the minimum on most engines, I have never rebuilt a X Flow but seeing the amount of damage that can be caused with to small clearances on other engines I would suggest you need to increase the clearances. Quote Share this post Link to post Share on other sites
