Issues when 'Clay-ing' an Engine with Hydraulic Lifters?
 

Does anyone know of any precautions / adjustments to make when you use clay to check the valve clearance on an engine with hydraulic lifters? Does the lack of hydraulic pressure in the lifters cause the measurement to be inaccurate? Are there any good books/info sources on this topic?

Thanks in advance for your help,
Marc

Marc, you are right about the hydraulic lifters being different with pressure. I don't know the details but there has to be a procedure for doing this. I'll see if I can find anything on this but hopefully one of these hard core engine builders will let us both know.

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69 351W Sportsroof deluxe

When claying heads and you have a hydraulic cam, use solid lifters. A solid lifter doesn't give do your readings will be accurate. Normally you have .080 - .100 of play in a hydraulic lifter so that can be a problem real fast. just cruise to the parts house and get two solid lifters. One for intake, one for exhaust.

Also a little tip...

Clean the piston good before you put the clay down so it will stick. After applying the clay to the piston, spray the clay with WD-40 or coat it with oil or ATF. Then spray the valves and combustion chamber so it won't stick to them either. That way the valves won't stick to the clay when they come down and screw your progress up.

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http://members.aol.com/BOSSC351/index.html

I know this may sound a bit odd, but I seem to remember something about being able to convert your old worn out hydraulic lifters into a solid lifter for just these sort of uses. I think it had something to do with removing the clip, taking the lifter apart, and removing the spring. I know I've done it before, but it's been years ago. I think you flip the plunger part upside down when you put it back in. Makes a handy part for checking cam specs, but I never used it for piston/valve clearance checks. Hope you can understand this, I'm really tired and not sure if I'm making any sense or not.