to shim or not to shim?

bak2burbles · Post by **bak2burbles** » Thu Oct 11, 2007 3:11 pm

replacing old type heads with efi ones that have been skimmed & also
changing cam for a crane 216, Question is will I need to shim rocker shaft pedastals or not? Its a budget rebuild (joke) so I want to save, but obviously not at the expense of loss of power or possible damage.
Thanks for any help.
regards all.

JP. · Post by **JP.** » Thu Oct 11, 2007 3:31 pm

Yess you might have to shim, preload is very importand. For shure you have to measure it.

Post by **katanaman** » Thu Oct 11, 2007 3:52 pm

Post by **Coops** » Thu Oct 11, 2007 5:53 pm

if your going to the bother of changing heads and cam,
why take the risk?
i personally would fit adjustable pushrods, at least then you know each lifter will have the correct preload,
they aint cheap though at around £130 from real steel,
v8 tuner sells them too, and he gives members discount from the forum. (check members discount area of how to apply)

kiwicar · Post by **kiwicar** » Thu Oct 11, 2007 6:05 pm

as Tony says go for ajustable push rods, then you can shim the rocker shaft pedistals to get the rockers to sweep the top of the valve correctly and then use the adjustable pushrod to get the preload correct, then it is as correct as it can be and no compromise (you could buy one adjustable push rod and use it to set the preload one at a time and then buy rods without one end fitted and make them up individually to the right length) bit more work but you would end up with an absolutly correct valve train.
Mike