Re: hydralic lifters
Well I've given myself a couple of day to think about this and I think there are a couple of possibilities.
1> The spring in the lifter has failed and the lifter is fully compressed. When I take up the slack and then put on another one and a half turns all I'm doing is compressing the valve springs. This would have to be true for every single lifter.
2> The spring in the lifter is fully extending the lifter and when I take up the slack and then put on another one and a half turns the valve springs are not able to drive the oil out of the lifter so it is locked in the fully extended position. This would also have to be true for every single lifter.
3> The lifters have spent so long in a particular partly compressed position that they have seized up and are just solid - to the extent that even the fully compressed valve springs do not apply enough pressure to move them. This would also have to be true for every single lifter.
4> Some clown in the past life of this engine has replace all the lifters with solids. There is a lot of evidence that it has been run on a tight budget in the past so this is possible.
As an experiment I set the valve clearances as if this was a 2.8 i.e. had solid lifters. It started straight away and ran very smoothly (to my ear). I shut it off very quickly because I still had the rocker covers off so I don't know what it would sound like when it was warm, but it works like that.
It sounds, to me, like I need to buy a whole new set of lifters. What do you think? Can you replace the lifters without replacing the camshaft - I really don't want to go there.
When you replace the lifters do you prime them with oil? If not where does the air go? Is there a bleed system?