Buick 3.6 6cyl aka:moo motor rocker arm spacing

[littlefireyone]

Had to pull the heads off my VR cos #6 cylinder was full of coolant. Had them reco'd (not that it could fix the issue if it's something else) and according to my engine builder now I have to space the rocker arms so the valves don't stay open. He wouldn't go into any sort of detail on how the hell I actually measure the correct spacing for this cos he didn't have an original head thickness to work off. This motor has been worked a little or more correctly flogged a lot before I bought it at the wreckers. It's got yella terra 1.7 ratio roller rockers and had extractors, dunno if it had different management if that has any bearing on the condition of it. I should have acsess to some standard rockers but they're not adjustable either.

Can anyone guide me through this? getting the car to a mechanic is not an option.

[Mr Jones]

Being a hydraulic cam you want to preload the lifter enough so they're not noisy but not too much that they hold the valve open. You need to put shims between the rocker and the head where the rocker bolts down. Easiest thing to use is a washer.

Basically you want it so you can screw the rocker bolts in to the point where you have zero clearance at the valve tip, then another 1/4 to 3/4 of a turn before the bolt tightens down.

So just try different thickness washers until you get it right

[Glenno]

On the moo motors you can use washers but you need to grind flats on them so they fit.

[littlefireyone]

I got a mechanic friend over to help me and we have a thickness! .9mm. Thanks guys.