Reciprocal range of motion for valves 1GR-FE

Just out of curiosity, does anyone know the exact range of motion of valves on 1GR-FE, assuming that the cam-tapet clearance is in the dead center of the recommended range?

My guess is somewhere around 1/4" but I can't be sure.

 

Are you asking how far the valve will stick out of the head when the valve is fully open?

 

Yes, exactly

 

Can find out for you tonight as my heads are off.

 

Mine are too but it's not exactly easy to simulate the motion by the cam unless the camshafts are on and you spin them with a ratchet. even then, how do you measure?

 

considering the aftermarket cams have a lift around 9.5mm Id imagine the stock cams are around the 8-9mm mark of total lift.

 

I got too excited to go through all that. Heads been off since August 1st, so they went on today. I'd measure with a set of calipers.

 

Measure cam lobe height from base circle . Since cam lobe is directly over shim bucket the is no exaggeration of motion that a rocker arm could impart. Measure base circle of cam at 90° from lobe center ( across smallest diameter) then measure bottom base to top of lobe. (Now the largest diameter) The difference would be your valve lift.
(Not 1gr-get spec, just where to measure)

 

@Blkvoodoo -- so take the lobe lift and subtract from it the clearance between the cam and the tapet when it's not opening the valve and that's the opening.

I'm surprised the lobe lift isn't more than 0.22". I would have guess it was.

 

First off that image wasn’t for a Toyota cam, just an image to show where to measure.

second, valve lash clearance isn’t subtracted, that measurement is a minimum spec to allow parts to grow/expand from heat and still allow everything to seat and seal, that’s why the measurement is taken cold.

This is what happens when valve adjustment is to tight and run hard

 

That's true if the running lash closes down to zero in operation, which it typically should not do. Lash is always subtracted from theoretical valve lift in order to arrive at the net valve lift.

 

You could measure with a dial indicator and base. If you dont have one you should, very handy for random stuff like this and not too expensive.

 

Is 0.22" what you got following the method above?