Mercruiser 420 - Valve Adjustment
 

Does anyone have the appropriate valve lash/adjustment for the Crane valvetrain on the 420 mercs? I am picking up my cylinder heads from the machine shop tomorrow and was hoping someone has the information handy. I am reusing the stock rockers, lifters, pushrods, etc.

Crane has always stated 3/4 to
one turn therefore half to three quarter is fine too

Thanks SB! I hope your summer is going well buddy.

Adjusting them before you install the intake manifold is easier to see/feel 0 lash. 3/4 turn is about perfect for Crane cams and will give about .040 of preload.

Thanks Griff, great to hear from you!

spin push rod ,,tighten rocker till cant spin push rod..then 1/2 ....3/4 turn...

That would be too tight.

Loosen, then tighten while spinning pushrod between fingers. Stop when you feel the pushrod has begun to feel resistance as it touches lifter and turn to desired lash.

well,,best way run motor motors till hear rockers are loose,,,then tighten,,,but it makes a big mess running motor with out covers..,,but i stand corrected tighten till u feel drag on push rod,,then tighten..

If their Morels almost a full turn down..........:D