Holden202T wrote:i dont understand how an un-shrouded roll would bleed oil pressure ? unless its the wrong length to suit the lifter bore ?
i would expect that at full lift it shouldn't expose the roller, are you meaning at high lift it is getting into the lifter oil gallery a bit ?
funnily enough i found this on google
https://www.performanceboats.com/gn7-dy ... ost1624833
The oil gallery is low down on the lifter bore, right over where the shroud is so not having one the oil just pisses straight out the galley as it's uncovered.
Problem is you have get hydro roller lifters that suit with full shroud but I have not seen any mechanical ones that do. Looking more and more like I will have to have a custom version made.
I am looking at have these customized as the base forging is fully shrouded but they cut some of it away. Although it looks like it might work I measured from the pic that the cut away area is only a few single mm away from the galley in this case at full lift as well and at no lift the top of the "collar" part is also a bit too high and might not let the oil into the turned down area. I really need it to be based on the dimensions of the OEM lifter to work, but be link bar and mechanical.
https://www.johnsonlifters.com/Products ... 116SB.aspx
I'm thinking about getting one pare of them to be sure if it will work or not and note the changes either way for custom ones. One option is maybe even get the cam deliberately ground with a smaller base circle than it will already would have to drop the lifter down, it will fixed both cut away and raised collar issue but not sure on reducing the base circle by say 6mm diameter is a good idea.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
