When you 0 deck a block do you have to change the installed height of the valves to get valve geometry correct? In other words, does pushrod length matter at all in a adjustable valvetrain?I'm just trying to understand relationship of the cam, pushrods, rocker arms & valve spring pressure Via a broken stock rocker arm? Is there more spring pressure on the rocker tip(alum.) with shorter pushrod aposed to a longer pushrod? I'm trying to articulate this correctly so bear with me. Thanks for ideas .
Not the valve height. But you'll need adjustable (or custom length) pushrods to get the lifter preload right. Difference in spring pressure would be negligible.
Valve stems Stock valve stem height is 1.87". What lift cam are you running and what springs do you have. THere has been a few people with the steel tips breaking off. T/A offer a HD stamped steel rocker that works good on a budget. Milling your heads and block have no effect on your geometry since the rocker shaft is fixed. You do need the right length pushrod for the correct lifter preload. If you mill at least .050" off your block/heads then go to a .050" shorter pushrod. Adjustable pushrods is a option for a mild application.
I'm using TA 288-98H W the 1125 springs, I decked the block .040 the new pushrod lenth ended up @ 9.250 BTW I splurged for TA's roller rockers1.6's Thanks for the feed back :TU:
When I cut my block way down I used Chevy lifters which I am told are about.060 shorter than Buick lifters so I could use the good Stock length pushrods I already had. I removed real close to .050 off my block and a little cleanup cut on the heads so the Chevy lifters put things almost back to stock preload. I have old KB rollers so I can adjust them also. Tom
For Buick 455 cast iron heads: 1.87-1.89" is the stock valve spring installed height. (distance between valve spring seat and bottom of retainer) 2.08" is the stock valve stem height. (distance from valve spring seat to tip of valve stem)
