harald

hi all, i have a theoretical question:

in P 2 V clearance, i caught myself making the mistake of letting my cam selection be overly dependant on not too big a lift to clear the stock pistons in my 87 block (0,030 notched). so i thought that everything over 0,500 lift would be risky and i'd have to send it back or worse...

but actually, after thinking this through, i would never get full lift during the overlap period, would i? i would say that by the time the valve is at full lift, or at the time the ex. valve is still at full lift, the piston is nowhere near TDC, right?

so what should i look at then to be more or less okay in P2V clearance? i would say duration at .050, and less duration would then mean that the valve opens later and closes sooner meaning that by the time the valve is further open, the piston has had more time to move away from TDC, right?

so, two questions i suppose: AM I RIGHT? first of all,

and second, if so, what is a safe margin to go by?

any thoughts or ideas or downright schoolbook theaory is very welcome.

thx,

harald