[slobrd]

When checking the clearances of my rockers and 9.20 pushrods on an uncut 455 deck and 87cc e-heads I was told to put a couple of lifters in and see how everything looks. My question is that I have heard that I should use solid lifters to check the clearances of the valvetrain and piston to valve clearances. Don't I have to account for an increase in the oil pressure to the hydraulic lifters when the car will be running?

[slobrd]

When checking the clearances of my rockers and 9.20 pushrods on an uncut 455 deck and 87cc e-heads I was told to put a couple of lifters in and see how everything looks. My question is that I have heard that I should use solid lifters to check the clearances of the valvetrain and piston to valve clearances. Don't I have to account for an increase in the oil pressure to the hydraulic lifters when the car will be running?

[Will]

slobrd, when you're checking valvetrain geometry you need to simulate the "pumped up" condition of a hydraulic lifter, or in other words the condition the lifter will be in as you drive the car around. If you just put a regular hydraulic lifter in while checking geometry, the pressure of the valvespring will compress the plunger in the lifter and you'll get inaccurate readings as the lifter plunger will be much further down in the lifter body than it would be with the engine running and oil pressurizing it.

What I did was take an old lifter, pop the retaining ring out of it, pull out the cup and all the guts, then packed aluminum foil into it as tight as I could until I could barely get the cup and retaining ring back in. This worked like a charm. Instead of aluminum foil you can also fill the lifter body with epoxy (but wait for it to dry) or have the pushrod cup tack-welded in place.

Actual solid lifters might have a different cup height than a hydraulic lifter and therefore could give false readings.

-Will

[slobrd]

Thanks for the response.