hydraulic preload settings 440

[high perf mopar]

new 440 build 9.5 compression,509 cam 108 centerline..mp lifters..all ava lit says to preload the lifters with comp adj rockers 1321-16 with a half turn preload..including comps tech line...have dropped 2 exhaust pushrods and bent 2 intake pushrods so far???

after researching this with another pushrod in the mail from summit,7262 comp pushrod,,i have found in a direct connection engine book that says when converting from stamped steel rocker arms to adj to set preload at 1 1/2 turns!!!

app my preload (hopefully) was not enough to keep the exhaust pushrod in my case in place after bleed down upon cold fire up..no app damage anywhere including cam where down..no debree..runs great when int installed..next day dropped exhaust pushrod,,bent intake,,,#3...am going to try 1+ turns preload next time and monitor...book is dated 1984 direct connection engines..crossing my fingers..i think all those half turn suggestions r chevy based? 

[72cudamaan]

Preload isn't based on a brand. It's a mechanical adjustment. Are you sure you are adjusting after all play is taken up.
 That's usually where the problem lies.   

[Changin Gears]

Anything from 0 to 3 turns would work. 

You usually take out the intake pushrod when the exhaust pushrod on the same cylinder fails because the combustion chamber is still filled with compressed exhaust when the intake is trying to open.  The pushrod just bends under the pressure on the head of the intake valve.

You could have possibly wiped a couple of cam lobes during break causing a lot of free-play and the push rod to come out of the rocker, then bending.

[high perf mopar]

Anything from 0 to 3 turns would work. 

You usually take out the intake pushrod when the exhaust pushrod on the same cylinder fails because the combustion chamber is still filled with compressed exhaust when the intake is trying to open.  The pushrod just bends under the pressure on the head of the intake valve.

You could have possibly wiped a couple of cam lobes during break causing a lot of free-play and the push rod to come out of the rocker, then bending.

thats good info,,backs up what the direct connection book says..and thats also what i thought concerning the bending of the intake pushrod,,i pulled the exhaust lifter where the pushrod was dropping and all looks good,,no where of any kind,or shavings..after i get thru fixing the rear brake problem and install the replacement steering box they will all be 1+ turns this time...thanks